tep

lib/api/api.dart

@@ -23,11 +23,14 @@ class Api{
 
   static const String ADD_COLLECTION = BASE_URL+'auth/addCollection';//添加收藏
   
-  static const String CHECK_COLLECTED = BASE_URL+'auth/checkCollected';//校验收藏
+  static const String CHECK_COLLECTED = BASE_URL+'checkCollected';//校验收藏
 
   static const String SET_THEMECOLOR = BASE_URL+'auth/setThemeColor';//设置主题颜色
 
   static const String GET_THEMECOLOR = BASE_URL +'/getThemeColor';//获取主题颜色
+
   static const String GET_WIDGET_TREE = 'http://flutter-go.alibaba.net/' + 'getCateList';//获取widget列表树
+
+  static const String SEARCH_WIDGET = BASE_URL+'searchWidget';//搜索组件
 }
 

lib/components/widget_demo.dart

@@ -4,6 +4,7 @@
 import 'dart:core';
 
 import 'package:flutter/material.dart';
+import 'package:flutter_go/utils/data_utils.dart';
 
 import '../routers/application.dart';
 import '../routers/routers.dart';
@@ -37,7 +38,7 @@ class _WidgetDemoState extends State<WidgetDemo> {
   CollectionControlModel _collectionControl = new CollectionControlModel();
   var _collectionIcons;
   List widgetDemosList = new WidgetDemoList().getDemos();
-  String _router = '';
+  String widgetType = 'old';
   final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();
 
   List<Widget> _buildContent() {
@@ -65,60 +66,66 @@ class _WidgetDemoState extends State<WidgetDemo> {
   void initState() {
     super.initState();
     // 这里不能直接 使用 ` ModalRoute.of(context)` 会产生报错
-    Future.delayed(Duration.zero,() {
+    Future.delayed(Duration.zero, () {
       String currentPath = ModalRoute.of(context).settings.name;
-      _collectionControl.getRouterByUrl(currentPath).then((list) {
+      if (currentPath.indexOf('/standard-page') == 0) {
+        widgetType = 'standard';
+      }
+      Map<String, String> params = {
+        'type': widgetType,
+        "url": currentPath,
+        "name": widget.title
+      };
+      DataUtils.checkCollected(params).then((result) {
         if (this.mounted) {
           setState(() {
-            _hasCollected = list.length > 0;
+            _hasCollected = result;
           });
         }
       });
     });
-
   }
 
-
 // 点击收藏按钮
   _getCollection() {
-
     String currentRouterPath = ModalRoute.of(context).settings.name;
-
+    Map<String, String> params = {
+      "type": widgetType,
+      "url": currentRouterPath,
+      "name": widget.title
+    };
     if (_hasCollected) {
       // 删除操作
-      _collectionControl.deleteByPath(currentRouterPath).then((result) {
-        if (result > 0 && this.mounted) {
-          setState(() {
-            _hasCollected = false;
-          });
+      DataUtils.removeCollected(params, context).then((result) {
+        if (result) {
           _scaffoldKey.currentState
               .showSnackBar(SnackBar(content: Text('已取消收藏')));
           if (ApplicationEvent.event != null) {
             ApplicationEvent.event
                 .fire(CollectionEvent(widget.title, currentRouterPath, true));
           }
-          
-          return;
+          if (this.mounted) {
+            setState(() {
+              _hasCollected = false;
+            });
+          }
         }
-        print('删除错误');
       });
     } else {
       // 插入操作
-      _collectionControl
-          .insert(Collection(name: widget.title, router: currentRouterPath))
-          .then((result) {  
-        if (this.mounted) {
-          setState(() {
-            _hasCollected = true;
-          });
-
+      DataUtils.addCollected(params, context).then((result) {
+        if (result) {
+          if (this.mounted) {
+            setState(() {
+              _hasCollected = true;
+            });
+          }
+          _scaffoldKey.currentState
+              .showSnackBar(SnackBar(content: Text('收藏成功')));
           if (ApplicationEvent.event != null) {
             ApplicationEvent.event
                 .fire(CollectionEvent(widget.title, currentRouterPath, false));
           }
-
-          _scaffoldKey.currentState
-              .showSnackBar(SnackBar(content: Text('收藏成功')));
         }
       });
     }

lib/routers/router_handler.dart

@@ -11,6 +11,7 @@ import 'package:flutter_go/model/user_info.dart';
 import 'package:flutter_go/views/collection_page/collection_page.dart';
 import 'package:flutter_go/views/collection_page/collection_full_page.dart';
 import 'package:flutter_go/views/standard_demo_page/index.dart';
+import 'package:flutter_go/views/issuse_message_page/issuse_message_page.dart';
 
 // app的首页
 var homeHandler = new Handler(
@@ -72,3 +73,9 @@ var standardPageHandler = new Handler(
     return StandardView(id: id);
   }
 );
+
+
+var issuesMessageHandler = new Handler(
+    handlerFunc: (BuildContext context, Map<String, List<String>> params) {
+      return IssuesMessagePage();
+    });

lib/routers/routers.dart

@@ -30,7 +30,7 @@ class Routes {
     router.define(loginPage, handler: loginPageHandler);
     router.define(codeView,handler:fullScreenCodeDialog);
     router.define(webViewPage,handler:webViewPageHand);
-    // router.define(issuesMessage, handler: issuesMessageHandler);
+     router.define(issuesMessage, handler: issuesMessageHandler);
       widgetDemosList.forEach((demo) {
         Handler handler = new Handler(
             handlerFunc: (BuildContext context, Map<String, List<String>> params) {

lib/utils/data_utils.dart

@@ -1,7 +1,9 @@
 import 'dart:async' show Future;
 
 import 'package:fluro/fluro.dart';
+import 'package:flutter_go/model/collection.dart';
 import 'package:flutter_go/model/version.dart';
+import 'package:flutter_go/model/widget.dart';
 import 'package:package_info/package_info.dart';
 import 'package:flutter_go/model/responseData.dart';
 
@@ -39,7 +41,6 @@ class DataUtils {
     var response = await NetUtils.get(Api.CHECK_LOGIN);
     print('response: $response');
     try {
-      print('1111');
       if (response['success']) {
         print('${response['success']}   ${response['data']}  response[succes]');
         UserInformation userInfo = UserInformation.fromJson(response['data']);
@@ -56,12 +57,11 @@ class DataUtils {
   // 一键反馈
   static Future feedback(Map<String, String> params, context) async {
     var response = await NetUtils.post(Api.FEEDBACK, params);
-    // print(response);
     if (response['status'] == 401 && response['message'] == '请先登录') {
       Application.router.navigateTo(context, '${Routes.loginPage}',
           transition: TransitionType.nativeModal);
     }
-    return response;
+    return response['success'];
   }
 
   //设置主题颜色
@@ -104,15 +104,97 @@ class DataUtils {
       return false;
     }
   }
+
   /// 获取widget列表处的树型数据
   static Future<List> getWidgetTreeList() async {
-    var response = await NetUtils.get(Api.GET_WIDGET_TREE);
+    try {
+      var response = await NetUtils.get(Api.GET_WIDGET_TREE);
+      print('组件树：$response');
+      if (response != null && response['success']) {
+        return response['data'];
+      } else {
+        return [];
+      }
+    } catch (error) {
+      print('获取组件树 error $error');
+    }
+  }
 
-    if (response['success']) {
-      return response['data'];
+  // 校验是否收藏
+  static Future<bool> checkCollected(Map<String, String> params) async {
+    print('url 地址：${Api.CHECK_COLLECTED} $params');
+    try {
+      var response = await NetUtils.post(Api.CHECK_COLLECTED, params);
+      return response != null && response['hasCollected'];
+    } catch (error) {
+      print('校验收藏 error $error');
+    }
+  }
+
+  // 添加收藏
+  static Future addCollected(Map<String, String> params, context) async {
+    var response = await NetUtils.post(Api.ADD_COLLECTION, params);
+    if (response['status'] == 401 && response['message'] == '请先登录') {
+      Application.router.navigateTo(context, '${Routes.loginPage}',
+          transition: TransitionType.nativeModal);
+    }
+    return response != null && response['success'];
+  }
+
+  // 移出收藏
+  static Future removeCollected(Map<String, String> params, context) async {
+    var response = await NetUtils.post(Api.REMOVE_COLLECTION, params);
+    if (response['status'] == 401 && response['message'] == '请先登录') {
+      Application.router.navigateTo(context, '${Routes.loginPage}',
+          transition: TransitionType.nativeModal);
+    }
+    return response != null && response['success'];
+  }
+
+  // 获取全部收藏
+  static Future getAllCollections(context) async {
+    var response = await NetUtils.get(Api.GET_ALL_COLLECTION);
+    List<Collection> responseList = [];
+    if (response['status'] == 401 && response['message'] == '请先登录') {
+      Application.router.navigateTo(context, '${Routes.loginPage}',
+          transition: TransitionType.nativeModal);
+    }
+    if (response != null && response['success'] == true) {
+      for (int i = 0; i < response['data'].length; i++) {
+        Map<String, dynamic> tempCo = response['data'][i];
+        responseList.add(Collection.fromJSON(
+            {"name": tempCo['name'], "router": tempCo['url']}));
+      }
+      return responseList;
     } else {
       return [];
     }
+  }
 
+  // 搜索组件
+  static Future searchWidget(String name) async {
+    var response = await NetUtils.get(Api.SEARCH_WIDGET, {"name": name});
+    List<WidgetPoint> list = [];
+    if (response != null && response['success'] == true) {
+      for (int i = 0; i < response['data'].length; i++) {
+        var json = response['data'][i];
+        String routerName;
+        if (json['display'] == 'old') {
+          routerName = json['path'];
+        } else {
+          routerName = json['pageId'];
+        }
+        Map<String, dynamic> tempMap = {
+          "name": json['name'],
+          "cnName": json['name'],
+          "routerName": routerName,
+          "catId": int.parse(json['parentId'])
+        };
+        list.add(WidgetPoint.fromJSON(tempMap));
+      }
+      return list;
+    } else {
+      return [];
+    }
   }
 }

lib/views/collection_page/collection_full_page.dart

@@ -4,12 +4,13 @@
 /// @Last Modified time: 2019-06-05 14:01:03
 import 'package:flutter/material.dart';
 import 'package:event_bus/event_bus.dart';
+import 'package:fluro/fluro.dart';
 
 import 'package:flutter_go/model/collection.dart';
 import 'package:flutter_go/routers/application.dart';
-import 'package:flutter_go/routers/routers.dart';
 import 'package:flutter_go/event/event_bus.dart';
 import 'package:flutter_go/event/event_model.dart';
+import 'package:flutter_go/utils/data_utils.dart';
 
 class CollectionFullPage extends StatefulWidget {
   final bool hasLogined;
@@ -41,13 +42,10 @@ class _CollectionFullPageState extends State<CollectionFullPage> {
 
   void _getList() {
     _collectionList.clear();
-    _collectionControl.getAllCollection().then((resultList) {
-      resultList.forEach((item) {
-        _collectionList.add(item);
-      });
+    DataUtils.getAllCollections(context).then((collectionList) {
       if (this.mounted) {
         setState(() {
-          _collectionList = _collectionList;
+          _collectionList = collectionList;
         });
       }
     });
@@ -73,7 +71,7 @@ class _CollectionFullPageState extends State<CollectionFullPage> {
             SizedBox(
               width: 5.0,
             ),
-            Text('模拟器重新运行会丢失收藏'),
+            Text('常用的组件都可以收藏在这里哦'),
           ],
         ),
       );
@@ -115,21 +113,24 @@ class _CollectionFullPageState extends State<CollectionFullPage> {
         trailing:
             Icon(Icons.keyboard_arrow_right, color: Colors.grey, size: 30.0),
         onTap: () {
-          if (_collectionList[index - 1].router.contains('http')) {
-            // 注意这里title已经转义过了
-            Application.router.navigateTo(context,
-                '${Routes.webViewPage}?title=${_collectionList[index - 1].name}&url=${Uri.encodeComponent(_collectionList[index - 1].router)}');
-          } else {
-            Application.router
-                .navigateTo(context, "${_collectionList[index - 1].router}");
-          }
+          Application.router.navigateTo(
+              context, _collectionList[index - 1].router,
+              transition: TransitionType.inFromRight);
+
+          // if (_collectionList[index - 1].router.contains('http')) {
+          //   // 注意这里title已经转义过了
+          //   Application.router.navigateTo(context,
+          //       '${Routes.webViewPage}?title=${_collectionList[index - 1].name}&url=${Uri.encodeComponent(_collectionList[index - 1].router)}');
+          // } else {
+          //   Application.router
+          //       .navigateTo(context, "${_collectionList[index - 1].router}");
+          // }
         },
       ),
     );
   }
 
-
-  ListView buildContent(){
+  ListView buildContent() {
     if (_collectionList.length == 0) {
       return ListView(
         children: <Widget>[

lib/views/collection_page/collection_page.dart

@@ -11,6 +11,7 @@ import 'package:flutter_go/routers/application.dart';
 import 'package:flutter_go/routers/routers.dart';
 import 'package:flutter_go/event/event_bus.dart';
 import 'package:flutter_go/event/event_model.dart';
+import 'package:flutter_go/utils/data_utils.dart';
 
 class CollectionPage extends StatefulWidget {
   final bool hasLogined;
@@ -47,14 +48,10 @@ class _CollectionPageState extends State<CollectionPage> {
 
   void _getList() {
     _collectionList.clear();
-    _collectionControl.getAllCollection().then((resultList) {
-      resultList.forEach((item) {
-        _collectionList.add(item);
-      });
-      print("_collectionList ${_collectionList}");
+    DataUtils.getAllCollections(context).then((collectionList) {
       if (this.mounted) {
         setState(() {
-          _collectionList = _collectionList;
+          _collectionList = collectionList;
         });
       }
     });

lib/views/first_page/drawer_page.dart

@@ -205,28 +205,14 @@ class _DrawerPageState extends State<DrawerPage> {
           onTap: () {
             if (hasLogin) {
               //issue 未登陆状态 返回登陆页面
-              DataUtils.logout().then((result) {
-                Application.router
-                    .navigateTo(context, '${Routes.issuesMessage}');
-              });
+              Application.router.navigateTo(context, '${Routes.issuesMessage}');
             } else {
               //No description provided.
               Application.router.navigateTo(context, '${Routes.loginPage}');
-              //  Application.router.navigateTo(context, '${Routes.issuesMessage}');
+
             }
           },
         ),
-        // ListTile(
-        //   leading: Icon(
-        //     Icons.info,
-        //     size: 27.0,
-        //   ),
-        //   title: Text(
-        //     '关于 App',
-        //     style: textStyle,
-        //   ),
-        //   onTap: () {},
-        // ),
         ListTile(
           leading: Icon(
             Icons.share,

lib/views/home.dart

@@ -7,9 +7,11 @@
 
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
+import 'package:flutter_go/utils/data_utils.dart';
 import 'package:flutter_go/utils/shared_preferences.dart';
 import 'package:flutter_go/views/first_page/first_page.dart';
 import 'package:flutter_go/views/first_page/main_page.dart';
+import 'package:fluro/fluro.dart';
 import 'package:flutter_go/views/widget_page/widget_page.dart';
 import 'package:flutter_go/views/welcome_page/fourth_page.dart';
 import 'package:flutter_go/views/collection_page/collection_page.dart';
@@ -87,26 +89,21 @@ class _MyHomePageState extends State<AppPage>
   }
 
   void onWidgetTap(WidgetPoint widgetPoint, BuildContext context) {
-    List widgetDemosList = new WidgetDemoList().getDemos();
     String targetName = widgetPoint.name;
-    String targetRouter = '/category/error/404';
-    widgetDemosList.forEach((item) {
-      if (item.name == targetName) {
-        targetRouter = item.routerName;
-      }
-    });
     searchHistoryList
-        .add(SearchHistory(name: targetName, targetRouter: targetRouter));
+        .add(SearchHistory(name: targetName, targetRouter: widgetPoint.routerName));
     print("searchHistoryList1 ${searchHistoryList.toString()}");
-    print("searchHistoryList2 ${targetRouter}");
-    print("searchHistoryList3 ${widgetPoint.name}");
-    Application.router.navigateTo(context, "$targetRouter");
+    Application.router.navigateTo(
+              context, widgetPoint.routerName,
+              transition: TransitionType.inFromRight);
   }
 
   Widget buildSearchInput(BuildContext context) {
     return new SearchInput((value) async {
       if (value != '') {
-        List<WidgetPoint> list = await widgetControl.search(value);
+        print('value ::: $value');
+        // List<WidgetPoint> list = await widgetControl.search(value);
+        List<WidgetPoint> list = await DataUtils.searchWidget(value);
         return list
             .map((item) => new MaterialSearchResult<String>(
                   value: item.name,

lib/views/issuse_message_page/issuse_message_page.dart

@@ -0,0 +1,152 @@
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_spinkit/flutter_spinkit.dart';
+import 'package:zefyr/zefyr.dart';
+import 'package:flutter_go/utils/data_utils.dart';
+import 'package:notus/convert.dart';
+import 'package:fluttertoast/fluttertoast.dart';
+
+
+
+class IssuesMessagePage extends StatefulWidget {
+  @override
+  _IssuesMessagePageState createState() => _IssuesMessagePageState();
+}
+
+class _IssuesMessagePageState extends State<IssuesMessagePage> {
+  final TextEditingController _controller = new TextEditingController();
+  final ZefyrController _zefyrController = new ZefyrController(NotusDocument());
+  final FocusNode _focusNode = new FocusNode();
+  String _title = "";
+  var _delta;
+
+  @override
+  void initState() {
+    _controller.addListener(() {
+      print("_controller.text:${_controller.text}");
+      setState(() {
+        _title = _controller.text;
+      });
+    });
+
+    _zefyrController.document.changes.listen((change) {
+      setState(() {
+        _delta = _zefyrController.document.toDelta();
+      });
+    });
+
+    super.initState();
+  }
+
+  void dispose() {
+    _controller.dispose();
+    _zefyrController.dispose();
+    super.dispose();
+  }
+
+  _submit() {
+    String mk = notusMarkdown.encode(_delta);
+    if (_title.trim().isEmpty) {
+      _show('标题不能为空');
+    } else {
+      DataUtils.feedback({'title': _title, "body": mk},context).then((result) {
+        _show('提交成功');
+        Navigator.maybePop(context);
+      });
+    }
+  }
+
+  _show(String msgs){
+    Fluttertoast.showToast(
+        msg: msgs,
+        toastLength: Toast.LENGTH_SHORT,
+        gravity: ToastGravity.CENTER,
+        timeInSecForIos: 1,
+        backgroundColor: Theme.of(context).primaryColor,
+        textColor: Colors.white,
+        fontSize: 16.0);
+  }
+
+  Widget buildLoading() {
+      return Opacity(
+        opacity: .5,
+        child: Container(
+          width: MediaQuery.of(context).size.width * 0.85,
+          decoration: BoxDecoration(
+            borderRadius: BorderRadius.all(Radius.circular(8.0)),
+            color: Colors.black,
+          ),
+          child: SpinKitPouringHourglass(color: Colors.white),
+        ),
+      );
+  }
+
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+        appBar: AppBar(
+          title: Text('反馈/意见'),
+          actions: <Widget>[
+            FlatButton.icon(
+              onPressed: () {
+                _submit();
+              },
+              icon: Icon(
+                Icons.near_me,
+                color: Colors.white,
+                size: 12,
+              ),
+              label: Text(
+                '发送',
+                style: TextStyle(color: Colors.white),
+              ),
+            )
+          ],
+          elevation: 1.0,
+        ),
+        body: ZefyrScaffold(
+          child: Padding(
+            padding: EdgeInsets.all(8),
+            child: ListView(
+              children: <Widget>[
+                Text('输入标题：'),
+                new TextFormField(
+                  maxLength: 50,
+                  controller: _controller,
+                  decoration: new InputDecoration(
+                    hintText: 'Title',
+                  ),
+                ),
+                Text('内容：'),
+                _descriptionEditor(),
+              ],
+            ),
+          ),
+        ));
+  }
+
+  Widget _descriptionEditor() {
+    final theme = new ZefyrThemeData(
+      toolbarTheme: ZefyrToolbarTheme.fallback(context).copyWith(
+        color: Colors.grey.shade800,
+        toggleColor: Colors.grey.shade900,
+        iconColor: Colors.white,
+        disabledIconColor: Colors.grey.shade500,
+      ),
+    );
+
+    return ZefyrTheme(
+      data: theme,
+      child: ZefyrField(
+        height: 400.0,
+        decoration: InputDecoration(labelText: 'Description'),
+        controller: _zefyrController,
+        focusNode: _focusNode,
+        autofocus: true,
+        physics: ClampingScrollPhysics(),
+      ),
+    );
+  }
+}

lib/views/standard_demo_page/index.dart

@@ -34,7 +34,6 @@ class StandardView extends StatefulWidget {
   _StandardView createState() => _StandardView();
 }
 
-
 class _StandardView extends State<StandardView> {
   String markdownDesc = '';
   String pageTitle = '';
@@ -44,7 +43,6 @@ class _StandardView extends State<StandardView> {
   StandardPages standardPage = new StandardPages();
   @override
   void initState() {
-
     super.initState();
     this.getPageInfo();
   }
@@ -62,7 +60,6 @@ class _StandardView extends State<StandardView> {
         email = pageDetail['email'];
       });
     }
-
   }
 
   /// 从本地获取基本文章信息
@@ -73,6 +70,7 @@ class _StandardView extends State<StandardView> {
     return pagesList[pageId];
   }
   Future<String> getContentOnline() async {
+
     String content = 'online content';
     this.setState(() {
       isLoading = true;
@@ -115,9 +113,11 @@ class _StandardView extends State<StandardView> {
       conent = localGetPagesMarkdown();
       localGetPagesAttrsInfo();
     }
-    setState(() {
-      markdownDesc = conent;
-    });
+    if (this.mounted) {
+      setState(() {
+        markdownDesc = conent;
+      });
+    }
     return Future(() => conent);
   }
   Widget buildFootInfo() {
@@ -135,6 +135,7 @@ class _StandardView extends State<StandardView> {
     }
     return Container();
   }
+
   Widget buildMarkdown() {
 
 
@@ -150,20 +151,14 @@ class _StandardView extends State<StandardView> {
           if (demo == null) {
             String errString = "not found ${attrs['id']} in demo packages";
             debugPrint(errString);
-            demo = [
-              Text(errString)
-            ];
+            demo = [Text(errString)];
           }
 
-          return Column(
-            children: demo
-          );
-        }
-    );
+          return Column(children: demo);
+        });
   }
 
 
-
   @override
   Widget build(BuildContext context) {
     return new WidgetDemo(
@@ -181,4 +176,4 @@ class _StandardView extends State<StandardView> {
       ],
     );
   }
-}
+}

lib/views/web_page/web_view_page.dart

@@ -23,10 +23,6 @@ class WebViewPage extends StatefulWidget {
 
 class _WebViewPageState extends State<WebViewPage> {
   final flutterWebviewPlugin = new FlutterWebviewPlugin();
-  bool _hasCollected = false;
-  String _router = '';
-  var _collectionIcons;
-  CollectionControlModel _collectionControl = new CollectionControlModel();
 
   final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();
   @override
@@ -65,87 +61,14 @@ class _WebViewPageState extends State<WebViewPage> {
         flutterWebviewPlugin.close();
       }
     });
-// 这里 存放不使用 name 改成 url. 确定唯一性
-//    _collectionControl
-//        .getRouterByName(Uri.encodeComponent(widget.title.trim()))
-//        .then((list) {
-//      list.forEach((item) {
-//        if (widget.title.trim() == item['name']) {
-//          _router = item['router'];
-//        }
-//      });
-//      if (mounted) {
-//        setState(() {
-//          _hasCollected = list.length > 0;
-//        });
-//      }
-//    });
-  }
-
-  // 点击收藏按钮
-  _getCollection() {
-    if (_hasCollected) {
-      // 删除操作
-      _collectionControl
-          .deleteByName(Uri.encodeComponent(widget.title.trim()))
-          .then((result) {
-        if (result > 0 && this.mounted) {
-          setState(() {
-            _hasCollected = false;
-          });
-          _scaffoldKey.currentState
-              .showSnackBar(SnackBar(content: Text('已取消收藏')));
-          if (ApplicationEvent.event != null) {
-            ApplicationEvent.event
-                .fire(CollectionEvent(widget.title, _router, true));
-          }
-          return;
-        }
-        print('删除错误');
-      });
-    } else {
-      // 插入操作
-      _collectionControl
-          .insert(Collection(
-              name: Uri.encodeComponent(widget.title.trim()),
-              router: widget.url))
-          .then((result) {
-        if (this.mounted) {
-          setState(() {
-            _hasCollected = true;
-          });
-
-          if (ApplicationEvent.event != null) {
-            ApplicationEvent.event
-                .fire(CollectionEvent(widget.title, _router, false));
-          }
-          _scaffoldKey.currentState
-              .showSnackBar(SnackBar(content: Text('收藏成功')));
-        }
-      });
-    }
   }
 
   @override
   Widget build(BuildContext context) {
-    if (_hasCollected) {
-      _collectionIcons = Icons.favorite;
-    } else {
-      _collectionIcons = Icons.favorite_border;
-    }
     return Scaffold(
       key: _scaffoldKey,
       appBar: AppBar(
         title: Text(widget.title),
-        actions: <Widget>[
-          new IconButton(
-            tooltip: 'goBack home',
-            onPressed: _getCollection,
-            icon: Icon(
-              _collectionIcons,
-            ),
-          ),
-        ],
       ),
       body: WebviewScaffold(
         url: widget.url,

pubspec.lock

@@ -1,364 +0,0 @@
-# Generated by pub
-# See https://dart.dev/tools/pub/glossary#lockfile
-packages:
-  args:
-    dependency: transitive
-    description:
-      name: args
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.5.2"
-  async:
-    dependency: transitive
-    description:
-      name: async
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.2.0"
-  bloc:
-    dependency: "direct main"
-    description:
-      name: bloc
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.12.0"
-  boolean_selector:
-    dependency: transitive
-    description:
-      name: boolean_selector
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.4"
-  charcode:
-    dependency: transitive
-    description:
-      name: charcode
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.2"
-  city_pickers:
-    dependency: "direct main"
-    description:
-      name: city_pickers
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.0.4"
-  collection:
-    dependency: transitive
-    description:
-      name: collection
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.14.11"
-  cookie_jar:
-    dependency: "direct main"
-    description:
-      name: cookie_jar
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.1"
-  csslib:
-    dependency: transitive
-    description:
-      name: csslib
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.16.1"
-  cupertino_icons:
-    dependency: "direct main"
-    description:
-      name: cupertino_icons
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.1.2"
-  dio:
-    dependency: "direct main"
-    description:
-      name: dio
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.13"
-  event_bus:
-    dependency: "direct main"
-    description:
-      name: event_bus
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.0"
-  firebase_analytics:
-    dependency: "direct main"
-    description:
-      name: firebase_analytics
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.2.0+1"
-  firebase_core:
-    dependency: "direct main"
-    description:
-      name: firebase_core
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.3.4"
-  fluro:
-    dependency: "direct main"
-    description:
-      name: fluro
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.5.1"
-  flutter:
-    dependency: "direct main"
-    description: flutter
-    source: sdk
-    version: "0.0.0"
-  flutter_bloc:
-    dependency: "direct main"
-    description:
-      name: flutter_bloc
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.11.1"
-  flutter_downloader:
-    dependency: "direct main"
-    description:
-      name: flutter_downloader
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.9"
-  flutter_jpush:
-    dependency: "direct main"
-    description:
-      name: flutter_jpush
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.0.4"
-  flutter_spinkit:
-    dependency: "direct main"
-    description:
-      name: flutter_spinkit
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "3.1.0"
-  flutter_test:
-    dependency: "direct dev"
-    description: flutter
-    source: sdk
-    version: "0.0.0"
-  flutter_webview_plugin:
-    dependency: "direct main"
-    description:
-      name: flutter_webview_plugin
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.3.5"
-  fluttertoast:
-    dependency: "direct main"
-    description:
-      name: fluttertoast
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "3.1.0"
-  html:
-    dependency: "direct main"
-    description:
-      name: html
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.14.0+2"
-  image_picker:
-    dependency: "direct main"
-    description:
-      name: image_picker
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.5.4+3"
-  intl:
-    dependency: "direct main"
-    description:
-      name: intl
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.15.7"
-  lpinyin:
-    dependency: transitive
-    description:
-      name: lpinyin
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.7"
-  markdown:
-    dependency: "direct main"
-    description:
-      name: markdown
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.3"
-  matcher:
-    dependency: transitive
-    description:
-      name: matcher
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.12.5"
-  meta:
-    dependency: "direct main"
-    description:
-      name: meta
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.6"
-  open_file:
-    dependency: "direct main"
-    description:
-      name: open_file
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.3"
-  package_info:
-    dependency: "direct main"
-    description:
-      name: package_info
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.4.0+3"
-  path:
-    dependency: "direct main"
-    description:
-      name: path
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.6.2"
-  path_provider:
-    dependency: "direct main"
-    description:
-      name: path_provider
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.2.0"
-  pedantic:
-    dependency: transitive
-    description:
-      name: pedantic
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.7.0"
-  permission_handler:
-    dependency: "direct main"
-    description:
-      name: permission_handler
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "3.2.1+1"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.3"
-  rxdart:
-    dependency: transitive
-    description:
-      name: rxdart
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.21.0"
-  share:
-    dependency: "direct main"
-    description:
-      name: share
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.6.2"
-  shared_preferences:
-    dependency: "direct main"
-    description:
-      name: shared_preferences
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.4.3"
-  sky_engine:
-    dependency: transitive
-    description: flutter
-    source: sdk
-    version: "0.0.99"
-  source_span:
-    dependency: transitive
-    description:
-      name: source_span
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.5.5"
-  sqflite:
-    dependency: "direct main"
-    description:
-      name: sqflite
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.6+2"
-  stack_trace:
-    dependency: transitive
-    description:
-      name: stack_trace
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.9.3"
-  stream_channel:
-    dependency: transitive
-    description:
-      name: stream_channel
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.0"
-  string_scanner:
-    dependency: "direct main"
-    description:
-      name: string_scanner
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.4"
-  synchronized:
-    dependency: transitive
-    description:
-      name: synchronized
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.0+1"
-  term_glyph:
-    dependency: transitive
-    description:
-      name: term_glyph
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.0"
-  test_api:
-    dependency: transitive
-    description:
-      name: test_api
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.2.5"
-  typed_data:
-    dependency: transitive
-    description:
-      name: typed_data
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.6"
-  url_launcher:
-    dependency: "direct main"
-    description:
-      name: url_launcher
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "5.0.2"
-  vector_math:
-    dependency: transitive
-    description:
-      name: vector_math
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.8"
-sdks:
-  dart: ">=2.2.2 <3.0.0"
-  flutter: ">=1.2.1 <2.0.0"

pubspec.yaml

@@ -21,7 +21,7 @@ dependencies:
   cupertino_icons: ^0.1.2
   event_bus: ^1.0.1
   fluro: ^1.3.4
-  image_picker: ^0.6.0
+  image_picker: ^0.5.0
   sqflite: ^1.1.5
   url_launcher: ^5.0.2
   # 本地存储、收藏功能
@@ -51,6 +51,9 @@ dependencies:
   open_file: ^2.0.1+2
   package_info: ^0.4.0+3
   flutter_jpush: ^0.0.4
+  zefyr:
+    path: ./zefyr
+
 
 dev_dependencies:
   flutter_test:

zefyr/.gitignore

@@ -0,0 +1,72 @@
+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
+.DS_Store
+.atom/
+.buildlog/
+.history
+.svn/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# The .vscode folder contains launch configuration and tasks you configure in
+# VS Code which you may wish to be included in version control, so this line
+# is commented out by default.
+#.vscode/
+
+# Flutter/Dart/Pub related
+**/doc/api/
+.dart_tool/
+.flutter-plugins
+.packages
+.pub-cache/
+.pub/
+build/
+
+# Android related
+**/android/**/gradle-wrapper.jar
+**/android/.gradle
+**/android/captures/
+**/android/gradlew
+**/android/gradlew.bat
+**/android/local.properties
+**/android/**/GeneratedPluginRegistrant.java
+
+# iOS/XCode related
+**/ios/**/*.mode1v3
+**/ios/**/*.mode2v3
+**/ios/**/*.moved-aside
+**/ios/**/*.pbxuser
+**/ios/**/*.perspectivev3
+**/ios/**/*sync/
+**/ios/**/.sconsign.dblite
+**/ios/**/.tags*
+**/ios/**/.vagrant/
+**/ios/**/DerivedData/
+**/ios/**/Icon?
+**/ios/**/Pods/
+**/ios/**/.symlinks/
+**/ios/**/profile
+**/ios/**/xcuserdata
+**/ios/.generated/
+**/ios/Flutter/App.framework
+**/ios/Flutter/Flutter.framework
+**/ios/Flutter/Generated.xcconfig
+**/ios/Flutter/app.flx
+**/ios/Flutter/app.zip
+**/ios/Flutter/flutter_assets/
+**/ios/ServiceDefinitions.json
+**/ios/Runner/GeneratedPluginRegistrant.*
+
+# Exceptions to above rules.
+!**/ios/**/default.mode1v3
+!**/ios/**/default.mode2v3
+!**/ios/**/default.pbxuser
+!**/ios/**/default.perspectivev3
+!/packages/flutter_tools/test/data/dart_dependencies_test/**/.packages

zefyr/CHANGELOG.md

@@ -0,0 +1,3 @@
+## [0.0.1] - TODO: Add release date.
+
+* TODO: Describe initial release.

zefyr/LICENSE

@@ -0,0 +1 @@
+TODO: Add your license here.

zefyr/README.md

@@ -0,0 +1,14 @@
+# zefyr
+
+A new Flutter package project.
+
+## Getting Started
+
+This project is a starting point for a Dart
+[package](https://flutter.dev/developing-packages/),
+a library module containing code that can be shared easily across
+multiple Flutter or Dart projects.
+
+For help getting started with Flutter, view our 
+[online documentation](https://flutter.dev/docs), which offers tutorials, 
+samples, guidance on mobile development, and a full API reference.

zefyr/lib/src/fast_diff.dart

@@ -0,0 +1,40 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'dart:math' as math;
+
+/// Performs a fast diff operation on two input strings based on provided
+/// [cursorPosition].
+DiffResult fastDiff(String oldText, String newText, int cursorPosition) {
+  var delta = newText.length - oldText.length;
+  var limit = math.max(0, cursorPosition - delta);
+  var end = oldText.length;
+  while (end > limit && oldText[end - 1] == newText[end + delta - 1]) {
+    end -= 1;
+  }
+  var start = 0;
+  var startLimit = cursorPosition - math.max(0, delta);
+  while (start < startLimit && oldText[start] == newText[start]) {
+    start += 1;
+  }
+  final String deleted = (start < end) ? oldText.substring(start, end) : '';
+  final inserted = newText.substring(start, end + delta);
+  return new DiffResult(start, deleted, inserted);
+}
+
+/// A diff between two strings of text.
+class DiffResult {
+  /// Start index in old text at which changes begin.
+  final int start;
+
+  /// Deleted text in old text.
+  final String deleted;
+
+  /// Inserted text.
+  final String inserted;
+
+  DiffResult(this.start, this.deleted, this.inserted);
+
+  @override
+  String toString() => 'DiffResult[$start, "$deleted", "$inserted"]';
+}

zefyr/lib/src/widgets/buttons.dart

@@ -0,0 +1,583 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:image_picker/image_picker.dart';
+import 'package:notus/notus.dart';
+import 'package:url_launcher/url_launcher.dart';
+
+import 'scope.dart';
+import 'theme.dart';
+import 'toolbar.dart';
+
+/// A button used in [ZefyrToolbar].
+///
+/// Create an instance of this widget with [ZefyrButton.icon] or
+/// [ZefyrButton.text] constructors.
+///
+/// Toolbar buttons are normally created by a [ZefyrToolbarDelegate].
+class ZefyrButton extends StatelessWidget {
+  /// Creates a toolbar button with an icon.
+  ZefyrButton.icon({
+    @required this.action,
+    @required IconData icon,
+    double iconSize,
+    this.onPressed,
+  })  : assert(action != null),
+        assert(icon != null),
+        _icon = icon,
+        _iconSize = iconSize,
+        _text = null,
+        _textStyle = null,
+        super();
+
+  /// Creates a toolbar button containing text.
+  ///
+  /// Note that [ZefyrButton] has fixed width and does not expand to accommodate
+  /// long texts.
+  ZefyrButton.text({
+    @required this.action,
+    @required String text,
+    TextStyle style,
+    this.onPressed,
+  })  : assert(action != null),
+        assert(text != null),
+        _icon = null,
+        _iconSize = null,
+        _text = text,
+        _textStyle = style,
+        super();
+
+  /// Toolbar action associated with this button.
+  final ZefyrToolbarAction action;
+  final IconData _icon;
+  final double _iconSize;
+  final String _text;
+  final TextStyle _textStyle;
+
+  /// Callback to trigger when this button is tapped.
+  final VoidCallback onPressed;
+
+  bool get isAttributeAction {
+    return kZefyrToolbarAttributeActions.keys.contains(action);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final toolbar = ZefyrToolbar.of(context);
+    final editor = toolbar.editor;
+    final toolbarTheme = ZefyrTheme.of(context).toolbarTheme;
+    final pressedHandler = _getPressedHandler(editor, toolbar);
+    final iconColor = (pressedHandler == null)
+        ? toolbarTheme.disabledIconColor
+        : toolbarTheme.iconColor;
+    if (_icon != null) {
+      return RawZefyrButton.icon(
+        action: action,
+        icon: _icon,
+        size: _iconSize,
+        iconColor: iconColor,
+        color: _getColor(editor, toolbarTheme),
+        onPressed: _getPressedHandler(editor, toolbar),
+      );
+    } else {
+      assert(_text != null);
+      var style = _textStyle ?? new TextStyle();
+      style = style.copyWith(color: iconColor);
+      return RawZefyrButton(
+        action: action,
+        child: new Text(_text, style: style),
+        color: _getColor(editor, toolbarTheme),
+        onPressed: _getPressedHandler(editor, toolbar),
+      );
+    }
+  }
+
+  Color _getColor(ZefyrScope editor, ZefyrToolbarTheme theme) {
+    if (isAttributeAction) {
+      final attribute = kZefyrToolbarAttributeActions[action];
+      final isToggled = (attribute is NotusAttribute)
+          ? editor.selectionStyle.containsSame(attribute)
+          : editor.selectionStyle.contains(attribute);
+      return isToggled ? theme.toggleColor : null;
+    }
+    return null;
+  }
+
+  VoidCallback _getPressedHandler(
+      ZefyrScope editor, ZefyrToolbarState toolbar) {
+    if (onPressed != null) {
+      return onPressed;
+    } else if (isAttributeAction) {
+      final attribute = kZefyrToolbarAttributeActions[action];
+      if (attribute is NotusAttribute) {
+        return () => _toggleAttribute(attribute, editor);
+      }
+    } else if (action == ZefyrToolbarAction.close) {
+      return () => toolbar.closeOverlay();
+    } else if (action == ZefyrToolbarAction.hideKeyboard) {
+      return () => editor.hideKeyboard();
+    }
+
+    return null;
+  }
+
+  void _toggleAttribute(NotusAttribute attribute, ZefyrScope editor) {
+    final isToggled = editor.selectionStyle.containsSame(attribute);
+    if (isToggled) {
+      editor.formatSelection(attribute.unset);
+    } else {
+      editor.formatSelection(attribute);
+    }
+  }
+}
+
+/// Raw button widget used by [ZefyrToolbar].
+///
+/// See also:
+///
+///   * [ZefyrButton], which wraps this widget and implements most of the
+///     action-specific logic.
+class RawZefyrButton extends StatelessWidget {
+  const RawZefyrButton({
+    Key key,
+    @required this.action,
+    @required this.child,
+    @required this.color,
+    @required this.onPressed,
+  }) : super(key: key);
+
+  /// Creates a [RawZefyrButton] containing an icon.
+  RawZefyrButton.icon({
+    @required this.action,
+    @required IconData icon,
+    double size,
+    Color iconColor,
+    @required this.color,
+    @required this.onPressed,
+  })  : child = new Icon(icon, size: size, color: iconColor),
+        super();
+
+  /// Toolbar action associated with this button.
+  final ZefyrToolbarAction action;
+
+  /// Child widget to show inside this button. Usually an icon.
+  final Widget child;
+
+  /// Background color of this button.
+  final Color color;
+
+  /// Callback to trigger when this button is pressed.
+  final VoidCallback onPressed;
+
+  /// Returns `true` if this button is currently toggled on.
+  bool get isToggled => color != null;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    final width = theme.buttonTheme.constraints.minHeight + 4.0;
+    final constraints = theme.buttonTheme.constraints.copyWith(
+        minWidth: width, maxHeight: theme.buttonTheme.constraints.minHeight);
+    final radius = BorderRadius.all(Radius.circular(3.0));
+    return Padding(
+      padding: const EdgeInsets.symmetric(horizontal: 1.0, vertical: 6.0),
+      child: RawMaterialButton(
+        shape: RoundedRectangleBorder(borderRadius: radius),
+        elevation: 0.0,
+        fillColor: color,
+        constraints: constraints,
+        onPressed: onPressed,
+        child: child,
+      ),
+    );
+  }
+}
+
+/// Controls heading styles.
+///
+/// When pressed, this button displays overlay toolbar with three
+/// buttons for each heading level.
+class HeadingButton extends StatefulWidget {
+  const HeadingButton({Key key}) : super(key: key);
+
+  @override
+  _HeadingButtonState createState() => _HeadingButtonState();
+}
+
+class _HeadingButtonState extends State<HeadingButton> {
+  @override
+  Widget build(BuildContext context) {
+    final toolbar = ZefyrToolbar.of(context);
+    return toolbar.buildButton(
+      context,
+      ZefyrToolbarAction.heading,
+      onPressed: showOverlay,
+    );
+  }
+
+  void showOverlay() {
+    final toolbar = ZefyrToolbar.of(context);
+    toolbar.showOverlay(buildOverlay);
+  }
+
+  Widget buildOverlay(BuildContext context) {
+    final toolbar = ZefyrToolbar.of(context);
+    final buttons = Row(
+      children: <Widget>[
+        SizedBox(width: 8.0),
+        toolbar.buildButton(context, ZefyrToolbarAction.headingLevel1),
+        toolbar.buildButton(context, ZefyrToolbarAction.headingLevel2),
+        toolbar.buildButton(context, ZefyrToolbarAction.headingLevel3),
+      ],
+    );
+    return ZefyrToolbarScaffold(body: buttons);
+  }
+}
+
+/// Controls image attribute.
+///
+/// When pressed, this button displays overlay toolbar with three
+/// buttons for each heading level.
+class ImageButton extends StatefulWidget {
+  const ImageButton({Key key}) : super(key: key);
+
+  @override
+  _ImageButtonState createState() => _ImageButtonState();
+}
+
+class _ImageButtonState extends State<ImageButton> {
+  @override
+  Widget build(BuildContext context) {
+    final toolbar = ZefyrToolbar.of(context);
+    return toolbar.buildButton(
+      context,
+      ZefyrToolbarAction.image,
+      onPressed: showOverlay,
+    );
+  }
+
+  void showOverlay() {
+    final toolbar = ZefyrToolbar.of(context);
+    toolbar.showOverlay(buildOverlay);
+  }
+
+  Widget buildOverlay(BuildContext context) {
+    final toolbar = ZefyrToolbar.of(context);
+    final buttons = Row(
+      children: <Widget>[
+        SizedBox(width: 8.0),
+        toolbar.buildButton(context, ZefyrToolbarAction.cameraImage,
+            onPressed: _pickFromCamera),
+        toolbar.buildButton(context, ZefyrToolbarAction.galleryImage,
+            onPressed: _pickFromGallery),
+      ],
+    );
+    return ZefyrToolbarScaffold(body: buttons);
+  }
+
+  void _pickFromCamera() async {
+    final editor = ZefyrToolbar.of(context).editor;
+    final image = await editor.imageDelegate.pickImage(ImageSource.camera);
+    if (image != null)
+      editor.formatSelection(NotusAttribute.embed.image(image));
+  }
+
+  void _pickFromGallery() async {
+    final editor = ZefyrToolbar.of(context).editor;
+    final image = await editor.imageDelegate.pickImage(ImageSource.gallery);
+    if (image != null)
+      editor.formatSelection(NotusAttribute.embed.image(image));
+  }
+}
+
+class LinkButton extends StatefulWidget {
+  const LinkButton({Key key}) : super(key: key);
+
+  @override
+  _LinkButtonState createState() => _LinkButtonState();
+}
+
+class _LinkButtonState extends State<LinkButton> {
+  final TextEditingController _inputController = TextEditingController();
+  Key _inputKey;
+  bool _formatError = false;
+  ZefyrScope _editor;
+
+  bool get isEditing => _inputKey != null;
+
+  @override
+  Widget build(BuildContext context) {
+    final toolbar = ZefyrToolbar.of(context);
+    final editor = toolbar.editor;
+    final enabled =
+        hasLink(editor.selectionStyle) || !editor.selection.isCollapsed;
+
+    return toolbar.buildButton(
+      context,
+      ZefyrToolbarAction.link,
+      onPressed: enabled ? showOverlay : null,
+    );
+  }
+
+  bool hasLink(NotusStyle style) => style.contains(NotusAttribute.link);
+
+  String getLink([String defaultValue]) {
+    final editor = ZefyrToolbar.of(context).editor;
+    final attrs = editor.selectionStyle;
+    if (hasLink(attrs)) {
+      return attrs.value(NotusAttribute.link);
+    }
+    return defaultValue;
+  }
+
+  void showOverlay() {
+    final toolbar = ZefyrToolbar.of(context);
+    toolbar.showOverlay(buildOverlay).whenComplete(cancelEdit);
+  }
+
+  void closeOverlay() {
+    final toolbar = ZefyrToolbar.of(context);
+    toolbar.closeOverlay();
+  }
+
+  void edit() {
+    final toolbar = ZefyrToolbar.of(context);
+    setState(() {
+      _inputKey = new UniqueKey();
+      _inputController.text = getLink('https://');
+      _inputController.addListener(_handleInputChange);
+      toolbar.markNeedsRebuild();
+    });
+  }
+
+  void doneEdit() {
+    final toolbar = ZefyrToolbar.of(context);
+    setState(() {
+      var error = false;
+      if (_inputController.text.isNotEmpty) {
+        try {
+          var uri = Uri.parse(_inputController.text);
+          if ((uri.isScheme('https') || uri.isScheme('http')) &&
+              uri.host.isNotEmpty) {
+            toolbar.editor.formatSelection(
+                NotusAttribute.link.fromString(_inputController.text));
+          } else {
+            error = true;
+          }
+        } on FormatException {
+          error = true;
+        }
+      }
+      if (error) {
+        _formatError = error;
+        toolbar.markNeedsRebuild();
+      } else {
+        _inputKey = null;
+        _inputController.text = '';
+        _inputController.removeListener(_handleInputChange);
+        toolbar.markNeedsRebuild();
+        toolbar.editor.focus();
+      }
+    });
+  }
+
+  void cancelEdit() {
+    if (mounted) {
+      final editor = ZefyrToolbar.of(context).editor;
+      setState(() {
+        _inputKey = null;
+        _inputController.text = '';
+        _inputController.removeListener(_handleInputChange);
+        editor.focus();
+      });
+    }
+  }
+
+  void unlink() {
+    final editor = ZefyrToolbar.of(context).editor;
+    editor.formatSelection(NotusAttribute.link.unset);
+    closeOverlay();
+  }
+
+  void copyToClipboard() {
+    var link = getLink();
+    assert(link != null);
+    Clipboard.setData(new ClipboardData(text: link));
+  }
+
+  void openInBrowser() async {
+    final editor = ZefyrToolbar.of(context).editor;
+    var link = getLink();
+    assert(link != null);
+    if (await canLaunch(link)) {
+      editor.hideKeyboard();
+      await launch(link, forceWebView: true);
+    }
+  }
+
+  void _handleInputChange() {
+    final toolbar = ZefyrToolbar.of(context);
+    setState(() {
+      _formatError = false;
+      toolbar.markNeedsRebuild();
+    });
+  }
+
+  Widget buildOverlay(BuildContext context) {
+    final toolbar = ZefyrToolbar.of(context);
+    final style = toolbar.editor.selectionStyle;
+
+    String value = 'Tap to edit link';
+    if (style.contains(NotusAttribute.link)) {
+      value = style.value(NotusAttribute.link);
+    }
+    final clipboardEnabled = value != 'Tap to edit link';
+    final body = !isEditing
+        ? _LinkView(value: value, onTap: edit)
+        : _LinkInput(
+            key: _inputKey,
+            controller: _inputController,
+            formatError: _formatError,
+          );
+    final items = <Widget>[Expanded(child: body)];
+    if (!isEditing) {
+      final unlinkHandler = hasLink(style) ? unlink : null;
+      final copyHandler = clipboardEnabled ? copyToClipboard : null;
+      final openHandler = hasLink(style) ? openInBrowser : null;
+      final buttons = <Widget>[
+        toolbar.buildButton(context, ZefyrToolbarAction.unlink,
+            onPressed: unlinkHandler),
+        toolbar.buildButton(context, ZefyrToolbarAction.clipboardCopy,
+            onPressed: copyHandler),
+        toolbar.buildButton(
+          context,
+          ZefyrToolbarAction.openInBrowser,
+          onPressed: openHandler,
+        ),
+      ];
+      items.addAll(buttons);
+    }
+    final trailingPressed = isEditing ? doneEdit : closeOverlay;
+    final trailingAction =
+        isEditing ? ZefyrToolbarAction.confirm : ZefyrToolbarAction.close;
+
+    return ZefyrToolbarScaffold(
+      body: Row(children: items),
+      trailing: toolbar.buildButton(
+        context,
+        trailingAction,
+        onPressed: trailingPressed,
+      ),
+    );
+  }
+}
+
+class _LinkInput extends StatefulWidget {
+  final TextEditingController controller;
+  final bool formatError;
+
+  const _LinkInput(
+      {Key key, @required this.controller, this.formatError: false})
+      : super(key: key);
+
+  @override
+  _LinkInputState createState() {
+    return new _LinkInputState();
+  }
+}
+
+class _LinkInputState extends State<_LinkInput> {
+  final FocusNode _focusNode = FocusNode();
+
+  ZefyrScope _editor;
+  bool _didAutoFocus = false;
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    if (!_didAutoFocus) {
+      FocusScope.of(context).requestFocus(_focusNode);
+      _didAutoFocus = true;
+    }
+
+    final toolbar = ZefyrToolbar.of(context);
+
+    if (_editor != toolbar.editor) {
+      _editor?.toolbarFocusNode = null;
+      _editor = toolbar.editor;
+      _editor.toolbarFocusNode = _focusNode;
+    }
+  }
+
+  @override
+  void dispose() {
+    _editor?.toolbarFocusNode = null;
+    _focusNode.dispose();
+    _editor = null;
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    final toolbarTheme = ZefyrTheme.of(context).toolbarTheme;
+    final color =
+        widget.formatError ? Colors.redAccent : toolbarTheme.iconColor;
+    final style = theme.textTheme.subhead.copyWith(color: color);
+    return TextField(
+      style: style,
+      keyboardType: TextInputType.url,
+      focusNode: _focusNode,
+      controller: widget.controller,
+      autofocus: true,
+      decoration: new InputDecoration(
+        hintText: 'https://',
+        filled: true,
+        fillColor: toolbarTheme.color,
+        border: InputBorder.none,
+        contentPadding: const EdgeInsets.all(10.0),
+      ),
+    );
+  }
+}
+
+class _LinkView extends StatelessWidget {
+  const _LinkView({Key key, @required this.value, this.onTap})
+      : super(key: key);
+  final String value;
+  final VoidCallback onTap;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    final toolbarTheme = ZefyrTheme.of(context).toolbarTheme;
+    Widget widget = new ClipRect(
+      child: ListView(
+        scrollDirection: Axis.horizontal,
+        children: <Widget>[
+          Container(
+            alignment: AlignmentDirectional.centerStart,
+            constraints: BoxConstraints(minHeight: ZefyrToolbar.kToolbarHeight),
+            padding: const EdgeInsets.all(10.0),
+            child: Text(
+              value,
+              maxLines: 1,
+              overflow: TextOverflow.ellipsis,
+              style: theme.textTheme.subhead
+                  .copyWith(color: toolbarTheme.disabledIconColor),
+            ),
+          )
+        ],
+      ),
+    );
+    if (onTap != null) {
+      widget = GestureDetector(
+        child: widget,
+        onTap: onTap,
+      );
+    }
+    return widget;
+  }
+}

zefyr/lib/src/widgets/caret.dart

@@ -0,0 +1,42 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'dart:ui';
+
+import 'package:flutter/material.dart';
+
+/// Helper class responsible for cursor layout and painting.
+class CursorPainter {
+  static const double _kCaretHeightOffset = 2.0; // pixels
+  static const double _kCaretWidth = 1.0; // pixels
+
+  static Rect buildPrototype(double lineHeight) {
+    return new Rect.fromLTWH(
+        0.0, 0.0, _kCaretWidth, lineHeight - _kCaretHeightOffset);
+  }
+
+  CursorPainter(Color color)
+      : assert(color != null),
+        _color = color;
+
+  Rect _prototype;
+
+  Rect get prototype => _prototype;
+
+  Color _color;
+  Color get color => _color;
+  set color(Color value) {
+    assert(value != null);
+    _color = value;
+  }
+
+  void layout(double lineHeight) {
+    _prototype = buildPrototype(lineHeight);
+  }
+
+  void paint(Canvas canvas, Offset offset) {
+    final Paint paint = new Paint()..color = _color;
+    final Rect caretRect = _prototype.shift(offset);
+    canvas.drawRect(caretRect, paint);
+  }
+}

zefyr/lib/src/widgets/code.dart

@@ -0,0 +1,47 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'package:flutter/material.dart';
+import 'package:notus/notus.dart';
+
+import 'common.dart';
+import 'theme.dart';
+
+/// Represents a code snippet in Zefyr editor.
+class ZefyrCode extends StatelessWidget {
+  const ZefyrCode({Key key, @required this.node}) : super(key: key);
+
+  /// Document node represented by this widget.
+  final BlockNode node;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = ZefyrTheme.of(context);
+
+    List<Widget> items = [];
+    for (var line in node.children) {
+      items.add(_buildLine(line, theme.blockTheme.code.textStyle));
+    }
+
+    return new Padding(
+      padding: theme.blockTheme.code.padding,
+      child: new Container(
+        // TODO: make decorations configurable
+        decoration: BoxDecoration(
+          color: Colors.blueGrey.shade50,
+          borderRadius: BorderRadius.circular(3.0),
+        ),
+        padding: const EdgeInsets.all(16.0),
+        child: new Column(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: items,
+        ),
+      ),
+    );
+  }
+
+  Widget _buildLine(Node node, TextStyle style) {
+    LineNode line = node;
+    return new RawZefyrLine(node: line, style: style);
+  }
+}

zefyr/lib/src/widgets/common.dart

@@ -0,0 +1,155 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'package:flutter/rendering.dart';
+import 'package:flutter/widgets.dart';
+import 'package:notus/notus.dart';
+
+import 'editable_box.dart';
+import 'horizontal_rule.dart';
+import 'image.dart';
+import 'rich_text.dart';
+import 'scope.dart';
+import 'theme.dart';
+
+/// Raw widget representing a single line of rich text document in Zefyr editor.
+///
+/// See [ZefyrParagraph] and [ZefyrHeading] which wrap this widget and
+/// integrate it with current [ZefyrTheme].
+class RawZefyrLine extends StatefulWidget {
+  const RawZefyrLine({
+    Key key,
+    @required this.node,
+    this.style,
+    this.padding,
+  }) : super(key: key);
+
+  /// Line in the document represented by this widget.
+  final LineNode node;
+
+  /// Style to apply to this line. Required for lines with text contents,
+  /// ignored for lines containing embeds.
+  final TextStyle style;
+
+  /// Padding to add around this paragraph.
+  final EdgeInsets padding;
+
+  @override
+  _RawZefyrLineState createState() => new _RawZefyrLineState();
+}
+
+class _RawZefyrLineState extends State<RawZefyrLine> {
+  final LayerLink _link = new LayerLink();
+
+  @override
+  Widget build(BuildContext context) {
+    final scope = ZefyrScope.of(context);
+    if (scope.isEditable) {
+      ensureVisible(context, scope);
+    }
+    final theme = ZefyrTheme.of(context);
+
+    Widget content;
+    if (widget.node.hasEmbed) {
+      content = buildEmbed(context, scope);
+    } else {
+      assert(widget.style != null);
+      content = ZefyrRichText(
+        node: widget.node,
+        text: buildText(context),
+      );
+    }
+
+    if (scope.isEditable) {
+      content = EditableBox(
+        child: content,
+        node: widget.node,
+        layerLink: _link,
+        renderContext: scope.renderContext,
+        showCursor: scope.showCursor,
+        selection: scope.selection,
+        selectionColor: theme.selectionColor,
+        cursorColor: theme.cursorColor,
+      );
+      content = CompositedTransformTarget(link: _link, child: content);
+    }
+
+    if (widget.padding != null) {
+      return Padding(padding: widget.padding, child: content);
+    }
+    return content;
+  }
+
+  void ensureVisible(BuildContext context, ZefyrScope scope) {
+    if (scope.selection.isCollapsed &&
+        widget.node.containsOffset(scope.selection.extentOffset)) {
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        bringIntoView(context);
+      });
+    }
+  }
+
+  void bringIntoView(BuildContext context) {
+    ScrollableState scrollable = Scrollable.of(context);
+    final object = context.findRenderObject();
+    assert(object.attached);
+    final RenderAbstractViewport viewport = RenderAbstractViewport.of(object);
+    assert(viewport != null);
+
+    final double offset = scrollable.position.pixels;
+    double target = viewport.getOffsetToReveal(object, 0.0).offset;
+    if (target - offset < 0.0) {
+      scrollable.position.jumpTo(target);
+      return;
+    }
+    target = viewport.getOffsetToReveal(object, 1.0).offset;
+    if (target - offset > 0.0) {
+      scrollable.position.jumpTo(target);
+    }
+  }
+
+  TextSpan buildText(BuildContext context) {
+    final theme = ZefyrTheme.of(context);
+    final List<TextSpan> children = widget.node.children
+        .map((node) => _segmentToTextSpan(node, theme))
+        .toList(growable: false);
+    return new TextSpan(style: widget.style, children: children);
+  }
+
+  TextSpan _segmentToTextSpan(Node node, ZefyrThemeData theme) {
+    final TextNode segment = node;
+    final attrs = segment.style;
+
+    return new TextSpan(
+      text: segment.value,
+      style: _getTextStyle(attrs, theme),
+    );
+  }
+
+  TextStyle _getTextStyle(NotusStyle style, ZefyrThemeData theme) {
+    TextStyle result = new TextStyle();
+    if (style.containsSame(NotusAttribute.bold)) {
+      result = result.merge(theme.boldStyle);
+    }
+    if (style.containsSame(NotusAttribute.italic)) {
+      result = result.merge(theme.italicStyle);
+    }
+    if (style.contains(NotusAttribute.link)) {
+      result = result.merge(theme.linkStyle);
+    }
+    return result;
+  }
+
+  Widget buildEmbed(BuildContext context, ZefyrScope scope) {
+    EmbedNode node = widget.node.children.single;
+    EmbedAttribute embed = node.style.get(NotusAttribute.embed);
+
+    if (embed.type == EmbedType.horizontalRule) {
+      return ZefyrHorizontalRule(node: node);
+    } else if (embed.type == EmbedType.image) {
+      return ZefyrImage(node: node, delegate: scope.imageDelegate);
+    } else {
+      throw new UnimplementedError('Unimplemented embed type ${embed.type}');
+    }
+  }
+}

zefyr/lib/src/widgets/controller.dart

@@ -0,0 +1,177 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'dart:math' as math;
+
+import 'package:flutter/widgets.dart';
+import 'package:notus/notus.dart';
+import 'package:quill_delta/quill_delta.dart';
+import 'package:zefyr/util.dart';
+
+const TextSelection _kZeroSelection = const TextSelection.collapsed(
+  offset: 0,
+  affinity: TextAffinity.upstream,
+);
+
+/// Owner of focus.
+enum FocusOwner {
+  /// Current owner is the editor.
+  editor,
+
+  /// Current owner is the toolbar.
+  toolbar,
+
+  /// No focus owner.
+  none,
+}
+
+/// Controls instance of [ZefyrEditor].
+class ZefyrController extends ChangeNotifier {
+  ZefyrController(NotusDocument document)
+      : assert(document != null),
+        _document = document;
+
+  /// Zefyr document managed by this controller.
+  NotusDocument get document => _document;
+  NotusDocument _document;
+
+  /// Currently selected text within the [document].
+  TextSelection get selection => _selection;
+  TextSelection _selection = _kZeroSelection;
+
+  ChangeSource _lastChangeSource;
+
+  /// Source of the last text or selection change.
+  ChangeSource get lastChangeSource => _lastChangeSource;
+
+  /// Updates selection with specified [value].
+  ///
+  /// [value] and [source] cannot be `null`.
+  void updateSelection(TextSelection value,
+      {ChangeSource source: ChangeSource.remote}) {
+    _updateSelectionSilent(value, source: source);
+    notifyListeners();
+  }
+
+  // Updates selection without triggering notifications to listeners.
+  void _updateSelectionSilent(TextSelection value,
+      {ChangeSource source: ChangeSource.remote}) {
+    assert(value != null && source != null);
+    _selection = value;
+    _lastChangeSource = source;
+    _ensureSelectionBeforeLastBreak();
+  }
+
+  @override
+  void dispose() {
+    _document.close();
+    super.dispose();
+  }
+
+  /// Composes [change] into document managed by this controller.
+  ///
+  /// This method does not apply any adjustments or heuristic rules to
+  /// provided [change] and it is caller's responsibility to ensure this change
+  /// can be composed without errors.
+  ///
+  /// If composing this change fails then this method throws [ComposeError].
+  void compose(Delta change,
+      {TextSelection selection, ChangeSource source: ChangeSource.remote}) {
+    if (change.isNotEmpty) {
+      _document.compose(change, source);
+    }
+    if (selection != null) {
+      _updateSelectionSilent(selection, source: source);
+    } else {
+      // Transform selection against the composed change and give priority to
+      // current position (force: false).
+      final base =
+          change.transformPosition(_selection.baseOffset, force: false);
+      final extent =
+          change.transformPosition(_selection.extentOffset, force: false);
+      selection = _selection.copyWith(baseOffset: base, extentOffset: extent);
+      if (_selection != selection) {
+        _updateSelectionSilent(selection, source: source);
+      }
+    }
+    _lastChangeSource = source;
+    notifyListeners();
+  }
+
+  void replaceText(int index, int length, String text,
+      {TextSelection selection}) {
+    Delta delta;
+
+    if (length > 0 || text.isNotEmpty) {
+      delta = document.replace(index, length, text);
+    }
+
+    if (selection != null) {
+      if (delta == null) {
+        _updateSelectionSilent(selection, source: ChangeSource.local);
+      } else {
+        // need to transform selection position in case actual delta
+        // is different from user's version (in deletes and inserts).
+        Delta user = new Delta()
+          ..retain(index)
+          ..insert(text)
+          ..delete(length);
+        int positionDelta = getPositionDelta(user, delta);
+        _updateSelectionSilent(
+          selection.copyWith(
+            baseOffset: selection.baseOffset + positionDelta,
+            extentOffset: selection.extentOffset + positionDelta,
+          ),
+          source: ChangeSource.local,
+        );
+      }
+    }
+    _lastChangeSource = ChangeSource.local;
+    notifyListeners();
+  }
+
+  void formatText(int index, int length, NotusAttribute attribute) {
+    final change = document.format(index, length, attribute);
+    _lastChangeSource = ChangeSource.local;
+    // Transform selection against the composed change and give priority to
+    // the change. This is needed in cases when format operation actually
+    // inserts data into the document (e.g. embeds).
+    final base = change.transformPosition(_selection.baseOffset);
+    final extent =
+        change.transformPosition(_selection.extentOffset);
+    final adjustedSelection =
+        _selection.copyWith(baseOffset: base, extentOffset: extent);
+    if (_selection != adjustedSelection) {
+      _updateSelectionSilent(adjustedSelection, source: _lastChangeSource);
+    }
+    notifyListeners();
+  }
+
+  /// Formats current selection with [attribute].
+  void formatSelection(NotusAttribute attribute) {
+    int index = _selection.start;
+    int length = _selection.end - index;
+    formatText(index, length, attribute);
+  }
+
+  NotusStyle getSelectionStyle() {
+    int start = _selection.start;
+    int length = _selection.end - start;
+    return _document.collectStyle(start, length);
+  }
+
+  TextEditingValue get plainTextEditingValue {
+    return new TextEditingValue(
+      text: document.toPlainText(),
+      selection: selection,
+      composing: new TextRange.collapsed(0),
+    );
+  }
+
+  void _ensureSelectionBeforeLastBreak() {
+    final end = _document.length - 1;
+    final base = math.min(_selection.baseOffset, end);
+    final extent = math.min(_selection.extentOffset, end);
+    _selection = _selection.copyWith(baseOffset: base, extentOffset: extent);
+  }
+}

zefyr/lib/src/widgets/cursor_timer.dart

@@ -0,0 +1,42 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+
+/// Helper class that keeps state relevant to the editing cursor.
+class CursorTimer {
+  static const _kCursorBlinkHalfPeriod = const Duration(milliseconds: 500);
+
+  Timer _timer;
+  final ValueNotifier<bool> _showCursor = new ValueNotifier<bool>(false);
+
+  ValueNotifier<bool> get value => _showCursor;
+
+  void _cursorTick(Timer timer) {
+    _showCursor.value = !_showCursor.value;
+  }
+
+  /// Starts cursor timer.
+  void start() {
+    _showCursor.value = true;
+    _timer = new Timer.periodic(_kCursorBlinkHalfPeriod, _cursorTick);
+  }
+
+  /// Stops cursor timer.
+  void stop() {
+    _timer?.cancel();
+    _timer = null;
+    _showCursor.value = false;
+  }
+
+  /// Starts or stops cursor timer based on current state of [focusNode]
+  /// and [selection].
+  void startOrStop(FocusNode focusNode, TextSelection selection) {
+    final hasFocus = focusNode.hasFocus;
+    final selectionCollapsed = selection.isCollapsed;
+    if (_timer == null && hasFocus && selectionCollapsed) {
+      start();
+    } else if (_timer != null && (!hasFocus || !selectionCollapsed)) {
+      stop();
+    }
+  }
+}

zefyr/lib/src/widgets/editable_box.dart

@@ -0,0 +1,341 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'dart:math' as math;
+import 'dart:ui' as ui;
+
+import 'package:flutter/rendering.dart';
+import 'package:flutter/widgets.dart';
+import 'package:notus/notus.dart';
+
+import 'caret.dart';
+import 'render_context.dart';
+
+class EditableBox extends SingleChildRenderObjectWidget {
+  EditableBox({
+    @required Widget child,
+    @required this.node,
+    @required this.layerLink,
+    @required this.renderContext,
+    @required this.showCursor,
+    @required this.selection,
+    @required this.selectionColor,
+    @required this.cursorColor,
+  }) : super(child: child);
+
+  final ContainerNode node;
+  final LayerLink layerLink;
+  final ZefyrRenderContext renderContext;
+  final ValueNotifier<bool> showCursor;
+  final TextSelection selection;
+  final Color selectionColor;
+  final Color cursorColor;
+
+  @override
+  RenderEditableProxyBox createRenderObject(BuildContext context) {
+    return new RenderEditableProxyBox(
+      node: node,
+      layerLink: layerLink,
+      renderContext: renderContext,
+      showCursor: showCursor,
+      selection: selection,
+      selectionColor: selectionColor,
+      cursorColor: cursorColor,
+    );
+  }
+
+  @override
+  void updateRenderObject(
+      BuildContext context, RenderEditableProxyBox renderObject) {
+    renderObject
+      ..node = node
+      ..layerLink = layerLink
+      ..renderContext = renderContext
+      ..showCursor = showCursor
+      ..selection = selection
+      ..selectionColor = selectionColor
+      ..cursorColor = cursorColor;
+  }
+}
+
+class RenderEditableProxyBox extends RenderBox
+    with
+        RenderObjectWithChildMixin<RenderEditableBox>,
+        RenderProxyBoxMixin<RenderEditableBox>
+    implements RenderEditableBox {
+  RenderEditableProxyBox({
+    RenderEditableBox child,
+    @required ContainerNode node,
+    @required LayerLink layerLink,
+    @required ZefyrRenderContext renderContext,
+    @required ValueNotifier<bool> showCursor,
+    @required TextSelection selection,
+    @required Color selectionColor,
+    @required Color cursorColor,
+  })  : _node = node,
+        _layerLink = layerLink,
+        _renderContext = renderContext,
+        _showCursor = showCursor,
+        _selection = selection,
+        _selectionColor = selectionColor,
+        super() {
+    this.child = child;
+    _cursorPainter = CursorPainter(cursorColor);
+  }
+
+  CursorPainter _cursorPainter;
+
+  set cursorColor(Color value) {
+    if (_cursorPainter.color != value) {
+      _cursorPainter.color = value;
+      markNeedsPaint();
+    }
+  }
+
+  bool _isDirty = true;
+
+  ContainerNode get node => _node;
+  ContainerNode _node;
+  void set node(ContainerNode value) {
+    _node = value;
+  }
+
+  LayerLink get layerLink => _layerLink;
+  LayerLink _layerLink;
+  void set layerLink(LayerLink value) {
+    if (_layerLink == value) return;
+    _layerLink = value;
+  }
+
+  ZefyrRenderContext _renderContext;
+  void set renderContext(ZefyrRenderContext value) {
+    if (_renderContext == value) return;
+    if (attached) _renderContext.removeBox(this);
+    _renderContext = value;
+    if (attached) _renderContext.addBox(this);
+  }
+
+  ValueNotifier<bool> _showCursor;
+  set showCursor(ValueNotifier<bool> value) {
+    assert(value != null);
+    if (_showCursor == value) return;
+    if (attached) _showCursor.removeListener(markNeedsCursorPaint);
+    _showCursor = value;
+    if (attached) _showCursor.addListener(markNeedsCursorPaint);
+    markNeedsPaint();
+  }
+
+  /// Current document selection.
+  TextSelection get selection => _selection;
+  TextSelection _selection;
+  set selection(TextSelection value) {
+    if (_selection == value) return;
+    // TODO: check if selection affects this block (also check previous value)
+    _selection = value;
+    markNeedsPaint();
+  }
+
+  /// Color of selection.
+  Color get selectionColor => _selectionColor;
+  Color _selectionColor;
+  set selectionColor(Color value) {
+    if (_selectionColor == value) return;
+    _selectionColor = value;
+    markNeedsPaint();
+  }
+
+  /// Returns `true` if current selection is collapsed, located within
+  /// this paragraph and is visible according to tick timer.
+  bool get isCaretVisible {
+    return _showCursor.value && containsCaret;
+  }
+
+  /// Returns `true` if current selection is collapsed and located
+  /// within this paragraph.
+  bool get containsCaret {
+    if (!_selection.isCollapsed) return false;
+
+    final int start = node.documentOffset;
+    final int end = start + node.length;
+    final int caretOffset = _selection.extentOffset;
+    return caretOffset >= start && caretOffset < end;
+  }
+
+  /// Returns `true` if selection is not collapsed and intersects with this
+  /// paragraph.
+  bool get isSelectionVisible {
+    if (_selection.isCollapsed) return false;
+    return intersectsWithSelection(_selection);
+  }
+
+  void markNeedsCursorPaint() {
+    if (containsCaret) {
+      markNeedsPaint();
+    }
+  }
+
+  //
+  // Overridden members of RenderBox
+  //
+
+  @override
+  void attach(PipelineOwner owner) {
+    super.attach(owner);
+    _showCursor.addListener(markNeedsCursorPaint);
+    _renderContext.addBox(this);
+    _renderContext.markDirty(this, _isDirty);
+  }
+
+  @override
+  void detach() {
+    _showCursor.removeListener(markNeedsCursorPaint);
+    _renderContext.removeBox(this);
+    super.detach();
+  }
+
+  @override
+  @mustCallSuper
+  void performLayout() {
+    super.performLayout();
+    _cursorPainter.layout(preferredLineHeight);
+    // Indicate to render context that this object can be used by other
+    // layers (selection overlay, for instance).
+    _isDirty = false;
+    _renderContext.markDirty(this, false);
+  }
+
+  @override
+  void markNeedsLayout() {
+    // Temporarily remove this object from the render context.
+    _isDirty = true;
+    _renderContext.markDirty(this, true);
+    super.markNeedsLayout();
+  }
+
+  @override
+  void paint(PaintingContext context, Offset offset) {
+    if (selectionOrder == SelectionOrder.background && isSelectionVisible) {
+      paintSelection(context, offset, selection, selectionColor);
+    }
+    super.paint(context, offset);
+    if (selectionOrder == SelectionOrder.foreground && isSelectionVisible) {
+      paintSelection(context, offset, selection, selectionColor);
+    }
+    if (isCaretVisible) {
+      _paintCursor(context, offset);
+    }
+  }
+
+  void _paintCursor(PaintingContext context, Offset offset) {
+    Offset caretOffset =
+        getOffsetForCaret(_selection.extent, _cursorPainter.prototype);
+    _cursorPainter.paint(context.canvas, caretOffset + offset);
+  }
+
+  @override
+  bool hitTestSelf(Offset position) => true;
+
+  @override
+  bool hitTest(HitTestResult result, {Offset position}) {
+    if (size.contains(position)) {
+      result.add(new BoxHitTestEntry(this, position));
+      return true;
+    }
+    return false;
+  }
+
+  //
+  // Proxy methods
+  //
+
+  @override
+  double get preferredLineHeight => child.preferredLineHeight;
+
+  @override
+  SelectionOrder get selectionOrder => child.selectionOrder;
+
+  @override
+  void paintSelection(PaintingContext context, Offset offset,
+          TextSelection selection, Color selectionColor) =>
+      child.paintSelection(context, offset, selection, selectionColor);
+
+  @override
+  Offset getOffsetForCaret(TextPosition position, Rect caretPrototype) =>
+      child.getOffsetForCaret(position, caretPrototype);
+
+  @override
+  TextSelection getLocalSelection(TextSelection documentSelection) =>
+      child.getLocalSelection(documentSelection);
+
+  bool intersectsWithSelection(TextSelection selection) =>
+      child.intersectsWithSelection(selection);
+
+  @override
+  List<ui.TextBox> getEndpointsForSelection(TextSelection selection) =>
+      child.getEndpointsForSelection(selection);
+
+  @override
+  ui.TextPosition getPositionForOffset(ui.Offset offset) =>
+      child.getPositionForOffset(offset);
+
+  @override
+  TextRange getWordBoundary(ui.TextPosition position) =>
+      child.getWordBoundary(position);
+}
+
+enum SelectionOrder {
+  /// Background selection is painted before primary content of editable box.
+  background,
+
+  /// Foreground selection is painted after primary content of editable box.
+  foreground,
+}
+
+abstract class RenderEditableBox extends RenderBox {
+  Node get node;
+  double get preferredLineHeight;
+
+  TextPosition getPositionForOffset(Offset offset);
+  List<ui.TextBox> getEndpointsForSelection(TextSelection selection);
+
+  /// Returns the text range of the word at the given offset. Characters not
+  /// part of a word, such as spaces, symbols, and punctuation, have word breaks
+  /// on both sides. In such cases, this method will return a text range that
+  /// contains the given text position.
+  ///
+  /// Word boundaries are defined more precisely in Unicode Standard Annex #29
+  /// <http://www.unicode.org/reports/tr29/#Word_Boundaries>.
+  ///
+  /// Valid only after [layout].
+  TextRange getWordBoundary(TextPosition position);
+
+  /// Paint order of selection in this editable box.
+  SelectionOrder get selectionOrder;
+
+  void paintSelection(PaintingContext context, Offset offset,
+      TextSelection selection, Color selectionColor);
+
+  Offset getOffsetForCaret(TextPosition position, Rect caretPrototype);
+
+  /// Returns part of [documentSelection] local to this box. May return
+  /// `null`.
+  ///
+  /// [documentSelection] must not be collapsed.
+  TextSelection getLocalSelection(TextSelection documentSelection) {
+    if (!intersectsWithSelection(documentSelection)) return null;
+
+    int nodeBase = node.documentOffset;
+    int nodeExtent = nodeBase + node.length;
+    int base = math.max(0, documentSelection.baseOffset - nodeBase);
+    int extent =
+        math.min(documentSelection.extentOffset, nodeExtent) - nodeBase;
+    return documentSelection.copyWith(baseOffset: base, extentOffset: extent);
+  }
+
+  /// Returns `true` if this box intersects with document [selection].
+  bool intersectsWithSelection(TextSelection selection) {
+    final int base = node.documentOffset;
+    final int extent = base + node.length;
+    return base <= selection.extentOffset && selection.baseOffset <= extent;
+  }
+}

zefyr/lib/src/widgets/editable_text.dart

@@ -0,0 +1,283 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/widgets.dart';
+import 'package:notus/notus.dart';
+
+import 'code.dart';
+import 'common.dart';
+import 'controller.dart';
+import 'cursor_timer.dart';
+import 'editor.dart';
+import 'image.dart';
+import 'input.dart';
+import 'list.dart';
+import 'paragraph.dart';
+import 'quote.dart';
+import 'render_context.dart';
+import 'scope.dart';
+import 'selection.dart';
+import 'theme.dart';
+
+/// Core widget responsible for editing Zefyr documents.
+///
+/// Depends on presence of [ZefyrTheme] and [ZefyrScope] somewhere up the
+/// widget tree.
+///
+/// Consider using [ZefyrEditor] which wraps this widget and adds a toolbar to
+/// edit style attributes.
+class ZefyrEditableText extends StatefulWidget {
+  const ZefyrEditableText({
+    Key key,
+    @required this.controller,
+    @required this.focusNode,
+    @required this.imageDelegate,
+    this.autofocus: true,
+    this.enabled: true,
+    this.padding: const EdgeInsets.symmetric(horizontal: 16.0),
+    this.physics,
+  }) : super(key: key);
+
+  final ZefyrController controller;
+  final FocusNode focusNode;
+  final ZefyrImageDelegate imageDelegate;
+  final bool autofocus;
+  final bool enabled;
+  final ScrollPhysics physics;
+
+  /// Padding around editable area.
+  final EdgeInsets padding;
+
+
+
+  @override
+  _ZefyrEditableTextState createState() => new _ZefyrEditableTextState();
+}
+
+class _ZefyrEditableTextState extends State<ZefyrEditableText>
+    with AutomaticKeepAliveClientMixin {
+  //
+  // New public members
+  //
+
+  /// Focus node of this widget.
+  FocusNode get focusNode => widget.focusNode;
+
+  /// Document controlled by this widget.
+  NotusDocument get document => widget.controller.document;
+
+  /// Current text selection.
+  TextSelection get selection => widget.controller.selection;
+
+  /// Express interest in interacting with the keyboard.
+  ///
+  /// If this control is already attached to the keyboard, this function will
+  /// request that the keyboard become visible. Otherwise, this function will
+  /// ask the focus system that it become focused. If successful in acquiring
+  /// focus, the control will then attach to the keyboard and request that the
+  /// keyboard become visible.
+  void requestKeyboard() {
+    if (focusNode.hasFocus)
+      _input.openConnection(widget.controller.plainTextEditingValue);
+    else
+      FocusScope.of(context).requestFocus(focusNode);
+  }
+
+  void focusOrUnfocusIfNeeded() {
+    if (!_didAutoFocus && widget.autofocus && widget.enabled) {
+      FocusScope.of(context).autofocus(focusNode);
+      _didAutoFocus = true;
+    }
+    if (!widget.enabled && focusNode.hasFocus) {
+      _didAutoFocus = false;
+      focusNode.unfocus();
+    }
+  }
+
+  //
+  // Overridden members of State
+  //
+
+
+
+  @override
+  Widget build(BuildContext context) {
+//    var reparentIfNeeded = FocusScope.of(context).reparentIfNeeded(focusNode);
+
+    _nodeAttachment.reparent();
+    super.build(context); // See AutomaticKeepAliveState.
+
+    Widget body = ListBody(children: _buildChildren(context));
+    if (widget.padding != null) {
+      body = new Padding(padding: widget.padding, child: body);
+    }
+    final scrollable = SingleChildScrollView(
+      physics: widget.physics,
+      controller: _scrollController,
+      child: body,
+    );
+
+    final overlay = Overlay.of(context, debugRequiredFor: widget);
+    final layers = <Widget>[scrollable];
+    if (widget.enabled) {
+      layers.add(ZefyrSelectionOverlay(
+        controller: widget.controller,
+        controls: cupertinoTextSelectionControls,
+        overlay: overlay,
+      ));
+    }
+
+    return Stack(fit: StackFit.expand, children: layers);
+  }
+
+  FocusAttachment _nodeAttachment;
+  @override
+  void initState() {
+    super.initState();
+//    FocusScopeNode _node = focusNode;
+    _nodeAttachment = focusNode.attach(context);
+    _input = new InputConnectionController(_handleRemoteValueChange);
+    _updateSubscriptions();
+  }
+
+  @override
+  void didUpdateWidget(ZefyrEditableText oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    _updateSubscriptions(oldWidget);
+    focusOrUnfocusIfNeeded();
+  }
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    final scope = ZefyrScope.of(context);
+    if (_renderContext != scope.renderContext) {
+      _renderContext?.removeListener(_handleRenderContextChange);
+      _renderContext = scope.renderContext;
+      _renderContext.addListener(_handleRenderContextChange);
+    }
+    if (_cursorTimer != scope.cursorTimer) {
+      _cursorTimer?.stop();
+      _cursorTimer = scope.cursorTimer;
+      _cursorTimer.startOrStop(focusNode, selection);
+    }
+    focusOrUnfocusIfNeeded();
+  }
+
+  @override
+  void dispose() {
+    _cancelSubscriptions();
+    super.dispose();
+  }
+
+  //
+  // Overridden members of AutomaticKeepAliveClientMixin
+  //
+
+  @override
+  bool get wantKeepAlive => focusNode.hasFocus;
+
+  //
+  // Private members
+  //
+
+  final ScrollController _scrollController = ScrollController();
+  ZefyrRenderContext _renderContext;
+  CursorTimer _cursorTimer;
+  InputConnectionController _input;
+  bool _didAutoFocus = false;
+
+  List<Widget> _buildChildren(BuildContext context) {
+    final result = <Widget>[];
+    for (var node in document.root.children) {
+      result.add(_defaultChildBuilder(context, node));
+    }
+    return result;
+  }
+
+  Widget _defaultChildBuilder(BuildContext context, Node node) {
+    if (node is LineNode) {
+      if (node.hasEmbed) {
+        return new RawZefyrLine(node: node);
+      } else if (node.style.contains(NotusAttribute.heading)) {
+        return new ZefyrHeading(node: node);
+      }
+      return new ZefyrParagraph(node: node);
+    }
+
+    final BlockNode block = node;
+    final blockStyle = block.style.get(NotusAttribute.block);
+    if (blockStyle == NotusAttribute.block.code) {
+      return new ZefyrCode(node: block);
+    } else if (blockStyle == NotusAttribute.block.bulletList) {
+      return new ZefyrList(node: block);
+    } else if (blockStyle == NotusAttribute.block.numberList) {
+      return new ZefyrList(node: block);
+    } else if (blockStyle == NotusAttribute.block.quote) {
+      return new ZefyrQuote(node: block);
+    }
+
+    throw new UnimplementedError('Block format $blockStyle.');
+  }
+
+  void _updateSubscriptions([ZefyrEditableText oldWidget]) {
+    if (oldWidget == null) {
+      widget.controller.addListener(_handleLocalValueChange);
+      focusNode.addListener(_handleFocusChange);
+      return;
+    }
+
+    if (widget.controller != oldWidget.controller) {
+      oldWidget.controller.removeListener(_handleLocalValueChange);
+      widget.controller.addListener(_handleLocalValueChange);
+      _input.updateRemoteValue(widget.controller.plainTextEditingValue);
+    }
+    if (widget.focusNode != oldWidget.focusNode) {
+      oldWidget.focusNode.removeListener(_handleFocusChange);
+      widget.focusNode.addListener(_handleFocusChange);
+      updateKeepAlive();
+    }
+  }
+
+  void _cancelSubscriptions() {
+    _renderContext.removeListener(_handleRenderContextChange);
+    widget.controller.removeListener(_handleLocalValueChange);
+    focusNode.removeListener(_handleFocusChange);
+    _input.closeConnection();
+    _cursorTimer.stop();
+  }
+
+  // Triggered for both text and selection changes.
+  void _handleLocalValueChange() {
+    if (widget.enabled &&
+        widget.controller.lastChangeSource == ChangeSource.local) {
+      // Only request keyboard for user actions.
+      requestKeyboard();
+    }
+    _input.updateRemoteValue(widget.controller.plainTextEditingValue);
+    _cursorTimer.startOrStop(focusNode, selection);
+    setState(() {
+      // nothing to update internally.
+    });
+  }
+
+  void _handleFocusChange() {
+    _input.openOrCloseConnection(
+        focusNode, widget.controller.plainTextEditingValue);
+    _cursorTimer.startOrStop(focusNode, selection);
+    updateKeepAlive();
+  }
+
+  void _handleRemoteValueChange(
+      int start, String deleted, String inserted, TextSelection selection) {
+    widget.controller
+        .replaceText(start, deleted.length, inserted, selection: selection);
+  }
+
+  void _handleRenderContextChange() {
+    setState(() {
+      // nothing to update internally.
+    });
+  }
+}

zefyr/lib/src/widgets/editor.dart

@@ -0,0 +1,164 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'package:flutter/widgets.dart';
+
+import 'controller.dart';
+import 'editable_text.dart';
+import 'image.dart';
+import 'scaffold.dart';
+import 'scope.dart';
+import 'theme.dart';
+import 'toolbar.dart';
+
+/// Widget for editing Zefyr documents.
+class ZefyrEditor extends StatefulWidget {
+  const ZefyrEditor({
+    Key key,
+    @required this.controller,
+    @required this.focusNode,
+    this.autofocus: true,
+    this.enabled: true,
+    this.padding: const EdgeInsets.symmetric(horizontal: 16.0),
+    this.toolbarDelegate,
+    this.imageDelegate,
+    this.physics,
+  }) : super(key: key);
+
+  final ZefyrController controller;
+  final FocusNode focusNode;
+  final bool autofocus;
+  final bool enabled;
+  final ZefyrToolbarDelegate toolbarDelegate;
+  final ZefyrImageDelegate imageDelegate;
+  final ScrollPhysics physics;
+
+  /// Padding around editable area.
+  final EdgeInsets padding;
+
+  @override
+  _ZefyrEditorState createState() => new _ZefyrEditorState();
+}
+
+class _ZefyrEditorState extends State<ZefyrEditor> {
+  ZefyrImageDelegate _imageDelegate;
+  ZefyrScope _scope;
+  ZefyrThemeData _themeData;
+  GlobalKey<ZefyrToolbarState> _toolbarKey;
+  ZefyrScaffoldState _scaffold;
+
+  bool get hasToolbar => _toolbarKey != null;
+
+  void showToolbar() {
+    assert(_toolbarKey == null);
+    _toolbarKey = GlobalKey();
+    _scaffold.showToolbar(buildToolbar);
+  }
+
+  void hideToolbar() {
+    if (_toolbarKey == null) return;
+    _scaffold.hideToolbar();
+    _toolbarKey = null;
+  }
+
+  Widget buildToolbar(BuildContext context) {
+    return ZefyrTheme(
+      data: _themeData,
+      child: ZefyrToolbar(
+        key: _toolbarKey,
+        editor: _scope,
+        delegate: widget.toolbarDelegate,
+      ),
+    );
+  }
+
+  void _handleChange() {
+    if (_scope.focusOwner == FocusOwner.none) {
+      hideToolbar();
+    } else if (!hasToolbar) {
+      showToolbar();
+    } else {
+      // TODO: is there a nicer way to do this?
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        _toolbarKey?.currentState?.markNeedsRebuild();
+      });
+    }
+  }
+
+  @override
+  void initState() {
+    super.initState();
+    _imageDelegate = widget.imageDelegate ?? new ZefyrDefaultImageDelegate();
+  }
+
+  @override
+  void didUpdateWidget(ZefyrEditor oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    _scope.controller = widget.controller;
+    _scope.focusNode = widget.focusNode;
+    if (widget.imageDelegate != oldWidget.imageDelegate) {
+      _imageDelegate = widget.imageDelegate ?? new ZefyrDefaultImageDelegate();
+      _scope.imageDelegate = _imageDelegate;
+    }
+  }
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    final parentTheme = ZefyrTheme.of(context, nullOk: true);
+    final fallbackTheme = ZefyrThemeData.fallback(context);
+    _themeData = (parentTheme != null)
+        ? fallbackTheme.merge(parentTheme)
+        : fallbackTheme;
+
+    if (_scope == null) {
+      _scope = ZefyrScope.editable(
+        imageDelegate: _imageDelegate,
+        controller: widget.controller,
+        focusNode: widget.focusNode,
+        focusScope: FocusScope.of(context),
+      );
+      _scope.addListener(_handleChange);
+    } else {
+      final focusScope = FocusScope.of(context);
+      _scope.focusScope = focusScope;
+    }
+
+    final scaffold = ZefyrScaffold.of(context);
+    if (_scaffold != scaffold) {
+      bool didHaveToolbar = hasToolbar;
+      hideToolbar();
+      _scaffold = scaffold;
+      if (didHaveToolbar) showToolbar();
+    }
+  }
+
+  @override
+  void dispose() {
+    hideToolbar();
+    _scope.removeListener(_handleChange);
+    _scope.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    Widget editable = new ZefyrEditableText(
+      controller: _scope.controller,
+      focusNode: _scope.focusNode,
+      imageDelegate: _scope.imageDelegate,
+      autofocus: widget.autofocus,
+      enabled: widget.enabled,
+      padding: widget.padding,
+      physics: widget.physics,
+    );
+
+    return ZefyrTheme(
+      data: _themeData,
+      child: ZefyrScopeAccess(
+        scope: _scope,
+        child: editable,
+      ),
+    );
+  }
+}

zefyr/lib/src/widgets/field.dart

@@ -0,0 +1,86 @@
+import 'package:flutter/material.dart';
+
+import 'controller.dart';
+import 'editor.dart';
+import 'image.dart';
+import 'toolbar.dart';
+
+/// Zefyr editor with material design decorations.
+class ZefyrField extends StatefulWidget {
+  /// Decoration to paint around this editor.
+  final InputDecoration decoration;
+
+  /// Height of this editor field.
+  final double height;
+  final ZefyrController controller;
+  final FocusNode focusNode;
+  final bool autofocus;
+  final bool enabled;
+  final ZefyrToolbarDelegate toolbarDelegate;
+  final ZefyrImageDelegate imageDelegate;
+  final ScrollPhysics physics;
+
+  const ZefyrField({
+    Key key,
+    this.decoration,
+    this.height,
+    this.controller,
+    this.focusNode,
+    this.autofocus: false,
+    this.enabled,
+    this.toolbarDelegate,
+    this.imageDelegate,
+    this.physics,
+  }) : super(key: key);
+
+  @override
+  _ZefyrFieldState createState() => _ZefyrFieldState();
+}
+
+class _ZefyrFieldState extends State<ZefyrField> {
+  @override
+  Widget build(BuildContext context) {
+    Widget child = ZefyrEditor(
+      padding: EdgeInsets.symmetric(vertical: 6.0),
+      controller: widget.controller,
+      focusNode: widget.focusNode,
+      autofocus: widget.autofocus,
+      enabled: widget.enabled ?? true,
+      toolbarDelegate: widget.toolbarDelegate,
+      imageDelegate: widget.imageDelegate,
+      physics: widget.physics,
+    );
+
+    if (widget.height != null) {
+      child = ConstrainedBox(
+        constraints: BoxConstraints.tightFor(height: widget.height),
+        child: child,
+      );
+    }
+
+    return AnimatedBuilder(
+      animation:
+          Listenable.merge(<Listenable>[widget.focusNode, widget.controller]),
+      builder: (BuildContext context, Widget child) {
+        return InputDecorator(
+          decoration: _getEffectiveDecoration(),
+          isFocused: widget.focusNode.hasFocus,
+          isEmpty: widget.controller.document.length == 1,
+          child: child,
+        );
+      },
+      child: child,
+    );
+  }
+
+  InputDecoration _getEffectiveDecoration() {
+    final InputDecoration effectiveDecoration =
+        (widget.decoration ?? const InputDecoration())
+            .applyDefaults(Theme.of(context).inputDecorationTheme)
+            .copyWith(
+              enabled: widget.enabled ?? true,
+            );
+
+    return effectiveDecoration;
+  }
+}

zefyr/lib/src/widgets/horizontal_rule.dart

@@ -0,0 +1,121 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'dart:ui' as ui;
+
+import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
+import 'package:flutter/widgets.dart';
+import 'package:notus/notus.dart';
+
+import 'editable_box.dart';
+
+class ZefyrHorizontalRule extends LeafRenderObjectWidget {
+  ZefyrHorizontalRule({@required this.node}) : assert(node != null);
+
+  final EmbedNode node;
+
+  @override
+  RenderHorizontalRule createRenderObject(BuildContext context) {
+    return new RenderHorizontalRule(node: node);
+  }
+
+  @override
+  void updateRenderObject(
+      BuildContext context, RenderHorizontalRule renderObject) {
+    renderObject..node = node;
+  }
+}
+
+class RenderHorizontalRule extends RenderEditableBox {
+  static const _kPaddingBottom = 24.0;
+  static const _kThickness = 3.0;
+  static const _kHeight = _kThickness + _kPaddingBottom;
+
+  RenderHorizontalRule({
+    @required EmbedNode node,
+  }) : _node = node;
+
+  @override
+  EmbedNode get node => _node;
+  EmbedNode _node;
+  set node(EmbedNode value) {
+    if (_node == value) return;
+    _node = value;
+    markNeedsPaint();
+  }
+
+  @override
+  double get preferredLineHeight => size.height;
+
+  @override
+  SelectionOrder get selectionOrder => SelectionOrder.background;
+
+  @override
+  List<ui.TextBox> getEndpointsForSelection(TextSelection selection) {
+    TextSelection local = getLocalSelection(selection);
+    if (local.isCollapsed) {
+      final dx = local.extentOffset == 0 ? 0.0 : size.width;
+      return [
+        new ui.TextBox.fromLTRBD(dx, 0.0, dx, size.height, TextDirection.ltr),
+      ];
+    }
+
+    return [
+      new ui.TextBox.fromLTRBD(0.0, 0.0, 0.0, size.height, TextDirection.ltr),
+      new ui.TextBox.fromLTRBD(
+          size.width, 0.0, size.width, size.height, TextDirection.ltr),
+    ];
+  }
+
+  @override
+  void performLayout() {
+    assert(constraints.hasBoundedWidth);
+    size = new Size(constraints.maxWidth, _kHeight);
+  }
+
+  @override
+  void paint(PaintingContext context, Offset offset) {
+    final rect = new Rect.fromLTWH(0.0, 0.0, size.width, _kThickness);
+    final paint = new ui.Paint()..color = Colors.grey.shade200;
+    context.canvas.drawRect(rect.shift(offset), paint);
+  }
+
+  @override
+  TextPosition getPositionForOffset(Offset offset) {
+    int position = _node.documentOffset;
+
+    if (offset.dx > size.width / 2) {
+      position++;
+    }
+    return new TextPosition(offset: position);
+  }
+
+  @override
+  TextRange getWordBoundary(TextPosition position) {
+    final start = _node.documentOffset;
+    return new TextRange(start: start, end: start + 1);
+  }
+
+  @override
+  void paintSelection(PaintingContext context, Offset offset,
+      TextSelection selection, Color selectionColor) {
+    final localSelection = getLocalSelection(selection);
+    assert(localSelection != null);
+    if (!localSelection.isCollapsed) {
+      final Paint paint = new Paint()..color = selectionColor;
+      final rect = new Rect.fromLTWH(0.0, 0.0, size.width, _kHeight);
+      context.canvas.drawRect(rect.shift(offset), paint);
+    }
+  }
+
+  @override
+  Offset getOffsetForCaret(ui.TextPosition position, ui.Rect caretPrototype) {
+    final pos = position.offset - node.documentOffset;
+    Offset caretOffset = Offset.zero;
+    if (pos == 1) {
+      caretOffset = caretOffset + new Offset(size.width - 1.0, 0.0);
+    }
+    return caretOffset;
+  }
+}

zefyr/lib/src/widgets/image.dart

@@ -0,0 +1,236 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'dart:async';
+import 'dart:io';
+import 'dart:math' as math;
+import 'dart:ui' as ui;
+
+import 'package:flutter/rendering.dart';
+import 'package:flutter/widgets.dart';
+import 'package:notus/notus.dart';
+import 'package:image_picker/image_picker.dart';
+
+import 'editable_box.dart';
+
+abstract class ZefyrImageDelegate<S> {
+  /// Builds image widget for specified [imageSource] and [context].
+  Widget buildImage(BuildContext context, String imageSource);
+
+  /// Picks an image from specified [source].
+  ///
+  /// Returns unique string key for the selected image. Returned key is stored
+  /// in the document.
+  Future<String> pickImage(S source);
+}
+
+class ZefyrDefaultImageDelegate implements ZefyrImageDelegate<ImageSource> {
+  @override
+  Widget buildImage(BuildContext context, String imageSource) {
+    final file = new File.fromUri(Uri.parse(imageSource));
+    final image = new FileImage(file);
+    return new Image(image: image);
+  }
+
+  @override
+  Future<String> pickImage(ImageSource source) async {
+    final file = await ImagePicker.pickImage(source: source);
+    if (file == null) return null;
+    return file.uri.toString();
+  }
+}
+
+class ZefyrImage extends StatefulWidget {
+  const ZefyrImage({Key key, @required this.node, @required this.delegate})
+      : super(key: key);
+
+  final EmbedNode node;
+  final ZefyrImageDelegate delegate;
+
+  @override
+  _ZefyrImageState createState() => _ZefyrImageState();
+}
+
+class _ZefyrImageState extends State<ZefyrImage> {
+  String get imageSource {
+    EmbedAttribute attribute = widget.node.style.get(NotusAttribute.embed);
+    return attribute.value['source'] as String;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final image = widget.delegate.buildImage(context, imageSource);
+    return _EditableImage(
+      child: image,
+      node: widget.node,
+    );
+  }
+}
+
+class _EditableImage extends SingleChildRenderObjectWidget {
+  _EditableImage({@required Widget child, @required this.node})
+      : assert(node != null),
+        super(child: child);
+
+  final EmbedNode node;
+
+  @override
+  RenderEditableImage createRenderObject(BuildContext context) {
+    return new RenderEditableImage(node: node);
+  }
+
+  @override
+  void updateRenderObject(
+      BuildContext context, RenderEditableImage renderObject) {
+    renderObject..node = node;
+  }
+}
+
+class RenderEditableImage extends RenderBox
+    with RenderObjectWithChildMixin<RenderBox>, RenderProxyBoxMixin<RenderBox>
+    implements RenderEditableBox {
+  static const kPaddingBottom = 24.0;
+
+  RenderEditableImage({
+    RenderImage child,
+    @required EmbedNode node,
+  }) : _node = node {
+    this.child = child;
+  }
+
+  @override
+  EmbedNode get node => _node;
+  EmbedNode _node;
+  void set node(EmbedNode value) {
+    _node = value;
+  }
+
+  // TODO: Customize caret height offset instead of adjusting here by 2px.
+  @override
+  double get preferredLineHeight => size.height - kPaddingBottom + 2.0;
+
+  @override
+  SelectionOrder get selectionOrder => SelectionOrder.foreground;
+
+  @override
+  TextSelection getLocalSelection(TextSelection documentSelection) {
+    if (!intersectsWithSelection(documentSelection)) return null;
+
+    int nodeBase = node.documentOffset;
+    int nodeExtent = nodeBase + node.length;
+    int base = math.max(0, documentSelection.baseOffset - nodeBase);
+    int extent =
+        math.min(documentSelection.extentOffset, nodeExtent) - nodeBase;
+    return documentSelection.copyWith(baseOffset: base, extentOffset: extent);
+  }
+
+  @override
+  List<ui.TextBox> getEndpointsForSelection(TextSelection selection) {
+    TextSelection local = getLocalSelection(selection);
+    if (local.isCollapsed) {
+      final dx = local.extentOffset == 0 ? _childOffset.dx : size.width;
+      return [
+        new ui.TextBox.fromLTRBD(
+            dx, 0.0, dx, size.height - kPaddingBottom, TextDirection.ltr),
+      ];
+    }
+
+    final rect = _childRect;
+    return [
+      new ui.TextBox.fromLTRBD(
+          rect.left, rect.top, rect.left, rect.bottom, TextDirection.ltr),
+      new ui.TextBox.fromLTRBD(
+          rect.right, rect.top, rect.right, rect.bottom, TextDirection.ltr),
+    ];
+  }
+
+  @override
+  TextPosition getPositionForOffset(Offset offset) {
+    int position = _node.documentOffset;
+
+    if (offset.dx > size.width / 2) {
+      position++;
+    }
+    return new TextPosition(offset: position);
+  }
+
+  @override
+  TextRange getWordBoundary(TextPosition position) {
+    final start = _node.documentOffset;
+    return new TextRange(start: start, end: start + 1);
+  }
+
+  @override
+  bool intersectsWithSelection(TextSelection selection) {
+    final int base = node.documentOffset;
+    final int extent = base + node.length;
+    return base <= selection.extentOffset && selection.baseOffset <= extent;
+  }
+
+  @override
+  Offset getOffsetForCaret(TextPosition position, Rect caretPrototype) {
+    final pos = position.offset - node.documentOffset;
+    Offset caretOffset = _childOffset - new Offset(kHorizontalPadding, 0.0);
+    if (pos == 1) {
+      caretOffset = caretOffset +
+          new Offset(_lastChildSize.width + kHorizontalPadding, 0.0);
+    }
+    return caretOffset;
+  }
+
+  @override
+  void paintSelection(PaintingContext context, Offset offset,
+      TextSelection selection, Color selectionColor) {
+    final localSelection = getLocalSelection(selection);
+    assert(localSelection != null);
+    if (!localSelection.isCollapsed) {
+      final Paint paint = new Paint()
+        ..color = selectionColor
+        ..style = PaintingStyle.stroke
+        ..strokeWidth = 3.0;
+      final rect = new Rect.fromLTWH(
+          0.0, 0.0, _lastChildSize.width, _lastChildSize.height);
+      context.canvas.drawRect(rect.shift(offset + _childOffset), paint);
+    }
+  }
+
+  void paint(PaintingContext context, Offset offset) {
+    super.paint(context, offset + _childOffset);
+  }
+
+  static const double kHorizontalPadding = 1.0;
+
+  Size _lastChildSize;
+
+  Offset get _childOffset {
+    final dx = (size.width - _lastChildSize.width) / 2 + kHorizontalPadding;
+    final dy = (size.height - _lastChildSize.height - kPaddingBottom) / 2;
+    return new Offset(dx, dy);
+  }
+
+  Rect get _childRect {
+    return new Rect.fromLTWH(_childOffset.dx, _childOffset.dy,
+        _lastChildSize.width, _lastChildSize.height);
+  }
+
+  @override
+  void performLayout() {
+    assert(constraints.hasBoundedWidth);
+    if (child != null) {
+      // Make constraints use 16:9 aspect ratio.
+      final width = constraints.maxWidth - kHorizontalPadding * 2;
+      final childConstraints = constraints.copyWith(
+        minWidth: 0.0,
+        maxWidth: width,
+        minHeight: 0.0,
+        maxHeight: (width * 9 / 16).floorToDouble(),
+      );
+      child.layout(childConstraints, parentUsesSize: true);
+      _lastChildSize = child.size;
+      size = new Size(
+          constraints.maxWidth, _lastChildSize.height + kPaddingBottom);
+    } else {
+      performResize();
+    }
+  }
+}

zefyr/lib/src/widgets/input.dart

@@ -0,0 +1,198 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'package:flutter/services.dart';
+import 'package:flutter/src/foundation/diagnostics.dart';
+import 'package:flutter/widgets.dart';
+import 'package:zefyr/util.dart';
+
+typedef RemoteValueChanged = Function(
+    int start, String deleted, String inserted, TextSelection selection);
+
+class InputConnectionController implements TextInputClient {
+  InputConnectionController(this.onValueChanged)
+      : assert(onValueChanged != null);
+
+  //
+  // New public members
+  //
+
+  final RemoteValueChanged onValueChanged;
+
+  /// Returns `true` if there is open input connection.
+  bool get hasConnection =>
+      _textInputConnection != null && _textInputConnection.attached;
+
+  /// Opens or closes input connection based on the current state of
+  /// [focusNode] and [value].
+  void openOrCloseConnection(FocusNode focusNode, TextEditingValue value) {
+    if (focusNode.hasFocus && focusNode.consumeKeyboardToken()) {
+      openConnection(value);
+    } else if (!focusNode.hasFocus) {
+      closeConnection();
+    }
+  }
+
+  void openConnection(TextEditingValue value) {
+    if (!hasConnection) {
+      _lastKnownRemoteTextEditingValue = value;
+      _textInputConnection = TextInput.attach(
+        this,
+        new TextInputConfiguration(
+          inputType: TextInputType.multiline,
+          obscureText: false,
+          autocorrect: true,
+          inputAction: TextInputAction.newline,
+          textCapitalization: TextCapitalization.sentences,
+        ),
+      )..setEditingState(value);
+      _sentRemoteValues.add(value);
+    }
+    _textInputConnection.show();
+  }
+
+  /// Closes input connection if it's currently open. Otherwise does nothing.
+  void closeConnection() {
+    if (hasConnection) {
+      _textInputConnection.close();
+      _textInputConnection = null;
+      _lastKnownRemoteTextEditingValue = null;
+      _sentRemoteValues.clear();
+    }
+  }
+
+  /// Updates remote value based on current state of [document] and
+  /// [selection].
+  ///
+  /// This method may not actually send an update to native side if it thinks
+  /// remote value is up to date or identical.
+  void updateRemoteValue(TextEditingValue value) {
+    if (!hasConnection) return;
+
+    // Since we don't keep track of composing range in value provided by
+    // ZefyrController we need to add it here manually before comparing
+    // with the last known remote value.
+    // It is important to prevent excessive remote updates as it can cause
+    // race conditions.
+    final actualValue = value.copyWith(
+      composing: _lastKnownRemoteTextEditingValue.composing,
+    );
+
+    if (actualValue == _lastKnownRemoteTextEditingValue) return;
+
+    bool shouldRemember = value.text != _lastKnownRemoteTextEditingValue.text;
+    _lastKnownRemoteTextEditingValue = actualValue;
+    _textInputConnection.setEditingState(actualValue);
+    if (shouldRemember) {
+      // Only keep track if text changed (selection changes are not relevant)
+      _sentRemoteValues.add(actualValue);
+    }
+  }
+
+  //
+  // Overridden members
+  //
+
+  @override
+  void performAction(TextInputAction action) {
+    // no-op
+  }
+
+  @override
+  void updateEditingValue(TextEditingValue value) {
+    if (_sentRemoteValues.contains(value)) {
+      /// There is a race condition in Flutter text input plugin where sending
+      /// updates to native side too often results in broken behavior.
+      /// TextInputConnection.setEditingValue is an async call to native side.
+      /// For each such call native side _always_ sends update which triggers
+      /// this method (updateEditingValue) with the same value we've sent it.
+      /// If multiple calls to setEditingValue happen too fast and we only
+      /// track the last sent value then there is no way for us to filter out
+      /// automatic callbacks from native side.
+      /// Therefore we have to keep track of all values we send to the native
+      /// side and when we see this same value appear here we skip it.
+      /// This is fragile but it's probably the only available option.
+      _sentRemoteValues.remove(value);
+      return;
+    }
+
+    if (_lastKnownRemoteTextEditingValue == value) {
+      // There is no difference between this value and the last known value.
+      return;
+    }
+
+    // Check if only composing range changed.
+    if (_lastKnownRemoteTextEditingValue.text == value.text &&
+        _lastKnownRemoteTextEditingValue.selection == value.selection) {
+      // This update only modifies composing range. Since we don't keep track
+      // of composing range in Zefyr we just need to update last known value
+      // here.
+      // Note: this check fixes an issue on Android when it sends
+      // composing updates separately from regular changes for text and
+      // selection.
+      _lastKnownRemoteTextEditingValue = value;
+      return;
+    }
+
+    // Note Flutter (unintentionally?) silences errors occurred during
+    // text input update, so we have to report it ourselves.
+    // For more details see https://github.com/flutter/flutter/issues/19191
+    // TODO: remove try-catch when/if Flutter stops silencing these errors.
+    try {
+      final effectiveLastKnownValue = _lastKnownRemoteTextEditingValue;
+      _lastKnownRemoteTextEditingValue = value;
+      final oldText = effectiveLastKnownValue.text;
+      final text = value.text;
+      final cursorPosition = value.selection.extentOffset;
+      final diff = fastDiff(oldText, text, cursorPosition);
+      onValueChanged(diff.start, diff.deleted, diff.inserted, value.selection);
+    } catch (e, trace) {
+      FlutterError.reportError(new FlutterErrorDetails(
+        exception: e,
+        stack: trace,
+        library: 'Zefyr',
+//        context: 'while updating editing value',
+      context: new TextNode()
+      ));
+      rethrow;
+    }
+  }
+
+
+  //
+  // Private members
+  //
+
+  final List<TextEditingValue> _sentRemoteValues = [];
+  TextInputConnection _textInputConnection;
+  TextEditingValue _lastKnownRemoteTextEditingValue;
+
+  @override
+  void updateFloatingCursor(RawFloatingCursorPoint point) {
+    // TODO: implement updateFloatingCursor
+  }
+}
+
+class TextNode extends DiagnosticsNode{
+  @override
+  List<DiagnosticsNode> getChildren() {
+    // TODO: implement getChildren
+    return null;
+  }
+
+  @override
+  List<DiagnosticsNode> getProperties() {
+    // TODO: implement getProperties
+    return null;
+  }
+
+  @override
+  String toDescription({TextTreeConfiguration parentConfiguration}) {
+    // TODO: implement toDescription
+    return null;
+  }
+
+  @override
+  Object get value => 'while updating editing value';
+
+}

zefyr/lib/src/widgets/list.dart

@@ -0,0 +1,86 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'package:flutter/material.dart';
+import 'package:notus/notus.dart';
+
+import 'common.dart';
+import 'paragraph.dart';
+import 'theme.dart';
+
+/// Represents number lists and bullet lists in a Zefyr editor.
+class ZefyrList extends StatelessWidget {
+  const ZefyrList({Key key, @required this.node}) : super(key: key);
+
+  final BlockNode node;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = ZefyrTheme.of(context);
+    List<Widget> items = [];
+    int index = 1;
+    for (var line in node.children) {
+      items.add(_buildItem(line, index));
+      index++;
+    }
+
+    final isNumberList =
+        node.style.get(NotusAttribute.block) == NotusAttribute.block.numberList;
+    EdgeInsets padding = isNumberList
+        ? theme.blockTheme.numberList.padding
+        : theme.blockTheme.bulletList.padding;
+    padding = padding.copyWith(left: theme.indentSize);
+
+    return new Padding(
+      padding: padding,
+      child: new Column(children: items),
+    );
+  }
+
+  Widget _buildItem(Node node, int index) {
+    LineNode line = node;
+    return new ZefyrListItem(index: index, node: line);
+  }
+}
+
+/// An item in a [ZefyrList].
+class ZefyrListItem extends StatelessWidget {
+  ZefyrListItem({Key key, this.index, this.node}) : super(key: key);
+
+  final int index;
+  final LineNode node;
+
+  @override
+  Widget build(BuildContext context) {
+    final BlockNode block = node.parent;
+    final style = block.style.get(NotusAttribute.block);
+    final theme = ZefyrTheme.of(context);
+    final bulletText =
+        (style == NotusAttribute.block.bulletList) ? '•' : '$index.';
+
+    TextStyle textStyle;
+    Widget content;
+    EdgeInsets padding;
+
+    if (node.style.contains(NotusAttribute.heading)) {
+      final headingTheme = ZefyrHeading.themeOf(node, context);
+      textStyle = headingTheme.textStyle;
+      padding = headingTheme.padding;
+      content = new ZefyrHeading(node: node);
+    } else {
+      textStyle = theme.paragraphTheme.textStyle;
+      content = new RawZefyrLine(node: node, style: textStyle);
+    }
+
+    Widget bullet =
+        SizedBox(width: 24.0, child: Text(bulletText, style: textStyle));
+    if (padding != null) {
+      bullet = Padding(padding: padding, child: bullet);
+    }
+
+    return Row(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: <Widget>[bullet, Expanded(child: content)],
+    );
+  }
+}

zefyr/lib/src/widgets/paragraph.dart

@@ -0,0 +1,68 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'package:flutter/material.dart';
+import 'package:notus/notus.dart';
+
+import 'common.dart';
+import 'theme.dart';
+
+/// Represents regular paragraph line in a Zefyr editor.
+class ZefyrParagraph extends StatelessWidget {
+  ZefyrParagraph({Key key, @required this.node, this.blockStyle})
+      : super(key: key);
+
+  final LineNode node;
+  final TextStyle blockStyle;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = ZefyrTheme.of(context);
+    TextStyle style = theme.paragraphTheme.textStyle;
+    if (blockStyle != null) {
+      style = style.merge(blockStyle);
+    }
+    return new RawZefyrLine(
+      node: node,
+      style: style,
+      padding: theme.paragraphTheme.padding,
+    );
+  }
+}
+
+/// Represents heading-styled line in [ZefyrEditor].
+class ZefyrHeading extends StatelessWidget {
+  ZefyrHeading({Key key, @required this.node, this.blockStyle})
+      : assert(node.style.contains(NotusAttribute.heading)),
+        super(key: key);
+
+  final LineNode node;
+  final TextStyle blockStyle;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = themeOf(node, context);
+    TextStyle style = theme.textStyle;
+    if (blockStyle != null) {
+      style = style.merge(blockStyle);
+    }
+    return new RawZefyrLine(
+      node: node,
+      style: style,
+      padding: theme.padding,
+    );
+  }
+
+  static StyleTheme themeOf(LineNode node, BuildContext context) {
+    final theme = ZefyrTheme.of(context);
+    final style = node.style.get(NotusAttribute.heading);
+    if (style == NotusAttribute.heading.level1) {
+      return theme.headingTheme.level1;
+    } else if (style == NotusAttribute.heading.level2) {
+      return theme.headingTheme.level2;
+    } else if (style == NotusAttribute.heading.level3) {
+      return theme.headingTheme.level3;
+    }
+    throw new UnimplementedError('Unsupported heading style $style');
+  }
+}

zefyr/lib/src/widgets/quote.dart

@@ -0,0 +1,55 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'package:flutter/material.dart';
+import 'package:notus/notus.dart';
+
+import 'paragraph.dart';
+import 'theme.dart';
+
+/// Represents a quote block in a Zefyr editor.
+class ZefyrQuote extends StatelessWidget {
+  const ZefyrQuote({Key key, @required this.node}) : super(key: key);
+
+  final BlockNode node;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = ZefyrTheme.of(context);
+    final style = theme.blockTheme.quote.textStyle;
+    List<Widget> items = [];
+    for (var line in node.children) {
+      items.add(_buildLine(line, style, theme.indentSize));
+    }
+
+    return Padding(
+      padding: theme.blockTheme.quote.padding,
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.stretch,
+        children: items,
+      ),
+    );
+  }
+
+  Widget _buildLine(Node node, TextStyle blockStyle, double indentSize) {
+    LineNode line = node;
+
+    Widget content;
+    if (line.style.contains(NotusAttribute.heading)) {
+      content = new ZefyrHeading(node: line, blockStyle: blockStyle);
+    } else {
+      content = new ZefyrParagraph(node: line, blockStyle: blockStyle);
+    }
+
+    final row = Row(children: <Widget>[Expanded(child: content)]);
+    return Container(
+      decoration: BoxDecoration(
+        border: Border(
+          left: BorderSide(width: 4.0, color: Colors.grey.shade300),
+        ),
+      ),
+      padding: EdgeInsets.only(left: indentSize),
+      child: row,
+    );
+  }
+}

zefyr/lib/src/widgets/render_context.dart

@@ -0,0 +1,146 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'package:flutter/foundation.dart';
+import 'package:flutter/widgets.dart';
+
+import 'editable_box.dart';
+
+/// Registry of all [RenderEditableProxyBox]es inside a [ZefyrEditableText].
+///
+/// Provides access to all currently active [RenderEditableProxyBox]
+/// instances of a [ZefyrEditableText].
+///
+/// Use [boxForTextOffset] or [boxForGlobalPoint] to retrieve a
+/// specific box.
+///
+/// The [addBox], [removeBox] and [markDirty] are intended to be
+/// only used by [RenderEditableProxyBox] objects to register with a rendering
+/// context.
+///
+/// ### Life cycle details
+///
+/// When a box object is attached to rendering pipeline it registers
+/// itself with a render scope by calling [addBox]. At this point the context
+/// treats this object as "dirty" and query methods like [boxForTextOffset]
+/// still exclude this object from returned results.
+///
+/// When this box considers itself initialized it calls [markDirty] with
+/// `isDirty` set to `false` which activates it. At this point query methods
+/// include this object in results.
+///
+/// When a box is rebuilt it may deactivate itself by calling [markDirty]
+/// again.
+///
+/// When a box is detached from rendering pipeline it unregisters
+/// itself by calling [removeBox].
+class ZefyrRenderContext extends ChangeNotifier {
+  final Set<RenderEditableProxyBox> _dirtyBoxes = new Set();
+  final Set<RenderEditableProxyBox> _activeBoxes = new Set();
+
+  Set<RenderEditableProxyBox> get dirty => _dirtyBoxes;
+  Set<RenderEditableProxyBox> get active => _activeBoxes;
+
+  bool _disposed = false;
+
+  /// Adds [box] to this context. The box is considered "dirty" at
+  /// this point and is not included in query results of `boxFor*`
+  /// methods.
+  void addBox(RenderEditableProxyBox box) {
+    assert(!_disposed);
+    _dirtyBoxes.add(box);
+  }
+
+  /// Removes [box] from this render context.
+  void removeBox(RenderEditableProxyBox box) {
+    assert(!_disposed);
+    _dirtyBoxes.remove(box);
+    _activeBoxes.remove(box);
+    notifyListeners();
+  }
+
+  void markDirty(RenderEditableProxyBox box, bool isDirty) {
+    assert(!_disposed);
+
+    var collection = isDirty ? _dirtyBoxes : _activeBoxes;
+    if (collection.contains(box)) return;
+
+    if (isDirty) {
+      _activeBoxes.remove(box);
+      _dirtyBoxes.add(box);
+    } else {
+      _dirtyBoxes.remove(box);
+      _activeBoxes.add(box);
+    }
+    notifyListeners();
+  }
+
+  /// Returns box containing character at specified document [offset].
+  RenderEditableProxyBox boxForTextOffset(int offset) {
+    assert(!_disposed);
+    return _activeBoxes.firstWhere(
+      (p) => p.node.containsOffset(offset),
+      orElse: _null,
+    );
+  }
+
+  /// Returns box located at specified global [point] on the screen or
+  /// `null`.
+  RenderEditableProxyBox boxForGlobalPoint(Offset point) {
+    assert(!_disposed);
+    return _activeBoxes.firstWhere((p) {
+      final localPoint = p.globalToLocal(point);
+      return p.size.contains(localPoint);
+    }, orElse: _null);
+  }
+
+  /// Returns closest render box to the specified global [point].
+  ///
+  /// If [point] is inside of one of active render boxes that box is returned.
+  /// If no box found this method checks if [point] is to the left or to the right
+  /// side of a box, e.g. if vertical offset of this point is inside of one of
+  /// the active boxes. If it is then that box is returned. If not then this
+  /// method picks a box with shortest vertical distance to this [point].
+  RenderEditableProxyBox closestBoxForGlobalPoint(Offset point) {
+    assert(!_disposed);
+    if (_activeBoxes.isEmpty) return null;
+    RenderEditableProxyBox box = boxForGlobalPoint(point);
+    if (box != null) return box;
+
+    box = _activeBoxes.firstWhere((p) {
+      final localPoint = p.globalToLocal(point);
+      return (localPoint.dy >= 0 && localPoint.dy < p.size.height);
+    }, orElse: _null);
+    if (box != null) return box;
+
+    box = _activeBoxes.map((p) {
+      final localPoint = p.globalToLocal(point);
+      final distance = localPoint.dy - p.size.height;
+      return new MapEntry(distance.abs(), p);
+    }).reduce((a, b) {
+      return (a.key <= b.key) ? a : b;
+    }).value;
+
+    return box;
+  }
+
+  static Null _null() => null;
+
+  @override
+  void dispose() {
+    _disposed = true;
+    _activeBoxes.clear();
+    _dirtyBoxes.clear();
+    super.dispose();
+  }
+
+  @override
+  void notifyListeners() {
+    /// Ensures listeners are not notified during rendering phase where they
+    /// cannot react by updating their state or rebuilding.
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (_disposed) return;
+      super.notifyListeners();
+    });
+  }
+}

zefyr/lib/src/widgets/rich_text.dart

@@ -0,0 +1,223 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'dart:math' as math;
+import 'dart:ui' as ui;
+
+import 'package:flutter/rendering.dart';
+import 'package:flutter/widgets.dart';
+import 'package:notus/notus.dart';
+
+import 'caret.dart';
+import 'editable_box.dart';
+
+/// Represents single paragraph of Zefyr rich-text.
+class ZefyrRichText extends LeafRenderObjectWidget {
+  ZefyrRichText({
+    @required this.node,
+    @required this.text,
+  }) : assert(node != null && text != null);
+
+  final LineNode node;
+  final TextSpan text;
+
+  @override
+  RenderObject createRenderObject(BuildContext context) {
+    return new RenderZefyrParagraph(
+      text,
+      node: node,
+      textDirection: Directionality.of(context),
+    );
+  }
+
+  @override
+  void updateRenderObject(
+      BuildContext context, RenderZefyrParagraph renderObject) {
+    renderObject
+      ..text = text
+      ..node = node;
+  }
+}
+
+class RenderZefyrParagraph extends RenderParagraph
+    implements RenderEditableBox {
+  RenderZefyrParagraph(
+    TextSpan text, {
+    @required LineNode node,
+    TextAlign textAlign: TextAlign.start,
+    @required TextDirection textDirection,
+    bool softWrap: true,
+    TextOverflow overflow: TextOverflow.clip,
+    double textScaleFactor: 1.0,
+    int maxLines,
+  })  : _node = node,
+        _prototypePainter = new TextPainter(
+          text: new TextSpan(text: '.', style: text.style),
+          textAlign: textAlign,
+          textDirection: textDirection,
+          textScaleFactor: textScaleFactor,
+        ),
+        super(
+          text,
+          textAlign: textAlign,
+          textDirection: textDirection,
+          softWrap: softWrap,
+          overflow: overflow,
+          textScaleFactor: textScaleFactor,
+          maxLines: maxLines,
+        );
+
+  LineNode get node => _node;
+  LineNode _node;
+  void set node(LineNode value) {
+    _node = value;
+  }
+
+  @override
+  double get preferredLineHeight => _prototypePainter.height;
+
+  @override
+  SelectionOrder get selectionOrder => SelectionOrder.background;
+
+  @override
+  TextSelection getLocalSelection(TextSelection documentSelection) {
+    if (!intersectsWithSelection(documentSelection)) return null;
+
+    int nodeBase = node.documentOffset;
+    int nodeExtent = nodeBase + node.length;
+    int base = math.max(0, documentSelection.baseOffset - nodeBase);
+    int extent =
+        math.min(documentSelection.extentOffset, nodeExtent) - nodeBase;
+    return documentSelection.copyWith(baseOffset: base, extentOffset: extent);
+  }
+
+  @override
+  TextPosition getPositionForOffset(Offset offset) {
+    final position = super.getPositionForOffset(offset);
+    return new TextPosition(
+      offset: _node.documentOffset + position.offset,
+      affinity: position.affinity,
+    );
+  }
+
+  @override
+  TextRange getWordBoundary(TextPosition position) {
+    final localPosition = new TextPosition(
+      offset: position.offset - _node.documentOffset,
+      affinity: position.affinity,
+    );
+    final localRange = super.getWordBoundary(localPosition);
+    return new TextRange(
+      start: _node.documentOffset + localRange.start,
+      end: _node.documentOffset + localRange.end,
+    );
+  }
+
+  @override
+  Offset getOffsetForCaret(TextPosition position, Rect caretPrototype) {
+    final localPosition = new TextPosition(
+      offset: position.offset - _node.documentOffset,
+      affinity: position.affinity,
+    );
+    return super.getOffsetForCaret(localPosition, caretPrototype);
+  }
+
+  // This method works around some issues in getBoxesForSelection and handles
+  // edge-case with our TextSpan objects not having last line-break character.
+  @override
+  List<ui.TextBox> getEndpointsForSelection(TextSelection selection) {
+    TextSelection local = getLocalSelection(selection);
+    if (local.isCollapsed) {
+      final caret = CursorPainter.buildPrototype(preferredLineHeight);
+      final offset = getOffsetForCaret(local.extent, caret);
+      return [
+        new ui.TextBox.fromLTRBD(
+          offset.dx,
+          offset.dy,
+          offset.dx,
+          offset.dy + caret.height,
+          TextDirection.ltr,
+        )
+      ];
+    }
+
+    int isBaseShifted = 0;
+    bool isExtentShifted = false;
+    if (local.baseOffset == node.length - 1 && local.baseOffset > 0) {
+      // Since we exclude last line-break from rendered TextSpan we have to
+      // handle end-of-line selection explicitly.
+      local = local.copyWith(baseOffset: local.baseOffset - 1);
+      isBaseShifted = -1;
+    } else if (local.baseOffset == 0 && local.isCollapsed) {
+      // This takes care of beginning of line position.
+      local = local.copyWith(baseOffset: local.baseOffset + 1);
+      isBaseShifted = 1;
+    }
+    if (text.codeUnitAt(local.extentOffset - 1) == 0xA) {
+      // This takes care of the rest end-of-line scenarios, where there are
+      // actually line-breaks in the TextSpan (e.g. in code blocks).
+      local = local.copyWith(extentOffset: local.extentOffset + 1);
+      isExtentShifted = true;
+    }
+    final result = getBoxesForSelection(local).toList();
+    if (isBaseShifted != 0) {
+      final box = result.first;
+      final dx = isBaseShifted == -1 ? box.right : box.left;
+      result.removeAt(0);
+      result.insert(0,
+          new ui.TextBox.fromLTRBD(dx, box.top, dx, box.bottom, box.direction));
+    }
+    if (isExtentShifted) {
+      final box = result.last;
+      result.removeLast;
+      result.add(new ui.TextBox.fromLTRBD(
+          box.left, box.top, box.left, box.bottom, box.direction));
+    }
+    return result;
+  }
+
+  @override
+  void set text(InlineSpan value) {
+    _prototypePainter.text = new TextSpan(text: '.', style: value.style);
+    _selectionRects = null;
+    super.text = value;
+  }
+
+  @override
+  void performLayout() {
+    super.performLayout();
+    _prototypePainter.layout(
+        minWidth: constraints.minWidth, maxWidth: constraints.maxWidth);
+  }
+
+  @override
+  void paint(PaintingContext context, Offset offset) {
+    super.paint(context, offset);
+  }
+
+  final TextPainter _prototypePainter;
+  List<ui.TextBox> _selectionRects;
+
+  /// Returns `true` if this paragraph intersects with document [selection].
+  @override
+  bool intersectsWithSelection(TextSelection selection) {
+    final int base = node.documentOffset;
+    final int extent = base + node.length;
+    return base <= selection.extentOffset && selection.baseOffset <= extent;
+  }
+
+  TextSelection _lastPaintedSelection;
+  @override
+  void paintSelection(PaintingContext context, Offset offset,
+      TextSelection selection, Color selectionColor) {
+    if (_lastPaintedSelection != selection) {
+      _selectionRects = null;
+    }
+    _selectionRects ??= getBoxesForSelection(getLocalSelection(selection));
+    final Paint paint = new Paint()..color = selectionColor;
+    for (ui.TextBox box in _selectionRects) {
+      context.canvas.drawRect(box.toRect().shift(offset), paint);
+    }
+    _lastPaintedSelection = selection;
+  }
+}

zefyr/lib/src/widgets/scaffold.dart

@@ -0,0 +1,60 @@
+import 'package:flutter/material.dart';
+
+class ZefyrScaffold extends StatefulWidget {
+  final Widget child;
+
+  const ZefyrScaffold({Key key, this.child}) : super(key: key);
+
+  static ZefyrScaffoldState of(BuildContext context) {
+    final _ZefyrScaffoldAccess widget =
+        context.inheritFromWidgetOfExactType(_ZefyrScaffoldAccess);
+    return widget.scaffold;
+  }
+
+  @override
+  ZefyrScaffoldState createState() => ZefyrScaffoldState();
+}
+
+class ZefyrScaffoldState extends State<ZefyrScaffold> {
+  WidgetBuilder _toolbarBuilder;
+
+  void showToolbar(WidgetBuilder builder) {
+    setState(() {
+      _toolbarBuilder = builder;
+    });
+  }
+
+  void hideToolbar() {
+    if (_toolbarBuilder != null) {
+      setState(() {
+        _toolbarBuilder = null;
+      });
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final toolbar =
+        (_toolbarBuilder == null) ? Container() : _toolbarBuilder(context);
+    return _ZefyrScaffoldAccess(
+      scaffold: this,
+      child: Column(
+        children: <Widget>[
+          Expanded(child: widget.child),
+          toolbar,
+        ],
+      ),
+    );
+  }
+}
+
+class _ZefyrScaffoldAccess extends InheritedWidget {
+  final ZefyrScaffoldState scaffold;
+
+  _ZefyrScaffoldAccess({Widget child, this.scaffold}) : super(child: child);
+
+  @override
+  bool updateShouldNotify(_ZefyrScaffoldAccess oldWidget) {
+    return oldWidget.scaffold != scaffold;
+  }
+}

zefyr/lib/src/widgets/scope.dart

@@ -0,0 +1,232 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:notus/notus.dart';
+
+import 'controller.dart';
+import 'cursor_timer.dart';
+import 'editor.dart';
+import 'image.dart';
+import 'render_context.dart';
+import 'view.dart';
+
+/// Provides access to shared state of [ZefyrEditor] or [ZefyrView].
+///
+/// A scope object can be created by an editable widget like [ZefyrEditor] in
+/// which case it provides access to editing state, including focus nodes,
+/// selection and such. Editable scope can be created using
+/// [ZefyrScope.editable] constructor.
+///
+/// If a scope object is created by a view-only widget like [ZefyrView] then
+/// it only provides access to [imageDelegate].
+///
+/// Can be retrieved using [ZefyrScope.of].
+class ZefyrScope extends ChangeNotifier {
+  /// Creates a view-only scope.
+  ///
+  /// Normally used in [ZefyrView].
+  ZefyrScope.view({@required ZefyrImageDelegate imageDelegate})
+      : assert(imageDelegate != null),
+        isEditable = false,
+        _imageDelegate = imageDelegate;
+
+  /// Creates editable scope.
+  ///
+  /// Normally used in [ZefyrEditor].
+  ZefyrScope.editable({
+    @required ZefyrController controller,
+    @required ZefyrImageDelegate imageDelegate,
+    @required FocusNode focusNode,
+    @required FocusScopeNode focusScope,
+  })  : assert(controller != null),
+        assert(imageDelegate != null),
+        assert(focusNode != null),
+        assert(focusScope != null),
+        isEditable = true,
+        _controller = controller,
+        _imageDelegate = imageDelegate,
+        _focusNode = focusNode,
+        _focusScope = focusScope,
+        _cursorTimer = CursorTimer(),
+        _renderContext = ZefyrRenderContext() {
+    _selectionStyle = _controller.getSelectionStyle();
+    _selection = _controller.selection;
+    _controller.addListener(_handleControllerChange);
+    _focusNode.addListener(_handleFocusChange);
+  }
+
+  static ZefyrScope of(BuildContext context) {
+    final ZefyrScopeAccess widget =
+        context.inheritFromWidgetOfExactType(ZefyrScopeAccess);
+    return widget.scope;
+  }
+
+  ZefyrImageDelegate _imageDelegate;
+  ZefyrImageDelegate get imageDelegate => _imageDelegate;
+  set imageDelegate(ZefyrImageDelegate value) {
+    assert(value != null);
+    if (_imageDelegate != value) {
+      _imageDelegate = value;
+      notifyListeners();
+    }
+  }
+
+  ZefyrController _controller;
+  ZefyrController get controller => _controller;
+  set controller(ZefyrController value) {
+    assert(isEditable && value != null);
+    if (_controller != value) {
+      _controller.removeListener(_handleControllerChange);
+      _controller = value;
+      _selectionStyle = _controller.getSelectionStyle();
+      _selection = _controller.selection;
+      _controller.addListener(_handleControllerChange);
+      notifyListeners();
+    }
+  }
+
+  FocusNode _focusNode;
+  FocusNode get focusNode => _focusNode;
+  set focusNode(FocusNode value) {
+    assert(isEditable && value != null);
+    if (_focusNode != value) {
+      _focusNode.removeListener(_handleFocusChange);
+      _focusNode = value;
+      _focusNode.addListener(_handleFocusChange);
+      notifyListeners();
+    }
+  }
+
+  FocusScopeNode _focusScope;
+  FocusScopeNode get focusScope => _focusScope;
+  set focusScope(FocusScopeNode value) {
+    assert(isEditable && value != null);
+    if (_focusScope != value) {
+      _focusScope = value;
+    }
+  }
+
+  CursorTimer _cursorTimer;
+  CursorTimer get cursorTimer => _cursorTimer;
+  ValueNotifier<bool> get showCursor => cursorTimer.value;
+
+  ZefyrRenderContext _renderContext;
+  ZefyrRenderContext get renderContext => _renderContext;
+
+  NotusStyle get selectionStyle => _selectionStyle;
+  NotusStyle _selectionStyle;
+  TextSelection get selection => _selection;
+  TextSelection _selection;
+
+  bool _disposed = false;
+  FocusNode _toolbarFocusNode;
+
+  /// Whether this scope is backed by editable Zefyr widgets or read-only view.
+  ///
+  /// Returns `true` if this scope provides Zefyr interface that allows editing
+  /// (e.g. created by [ZefyrEditor]). Returns `false` if this scope provides
+  /// read-only view (e.g. created by [ZefyrView]).
+  ///
+  /// Editable scope provides access to corresponding [controller], [focusNode],
+  /// [focusScope], [showCursor], [renderContext] and other shared objects. For
+  /// non-editable scopes these are set to `null`. You can still access
+  /// objects which are not dependent on editing flow, e.g. [imageDelegate].
+  final bool isEditable;
+
+  set toolbarFocusNode(FocusNode node) {
+    assert(isEditable);
+    assert(!_disposed || node == null);
+    if (_toolbarFocusNode != node) {
+      _toolbarFocusNode?.removeListener(_handleFocusChange);
+      _toolbarFocusNode = node;
+      _toolbarFocusNode?.addListener(_handleFocusChange);
+      // We do not notify listeners here because it will happen when
+      // focus state changes, see [_handleFocusChange].
+    }
+  }
+
+  FocusOwner get focusOwner {
+    assert(isEditable);
+    assert(!_disposed);
+    if (_focusNode.hasFocus) {
+      return FocusOwner.editor;
+    } else if (_toolbarFocusNode?.hasFocus == true) {
+      return FocusOwner.toolbar;
+    } else {
+      return FocusOwner.none;
+    }
+  }
+
+  void updateSelection(TextSelection value,
+      {ChangeSource source: ChangeSource.remote}) {
+    assert(isEditable);
+    assert(!_disposed);
+    _controller.updateSelection(value, source: source);
+  }
+
+  void formatSelection(NotusAttribute value) {
+    assert(isEditable);
+    assert(!_disposed);
+    _controller.formatSelection(value);
+  }
+
+  void focus() {
+    assert(isEditable);
+    assert(!_disposed);
+    _focusScope.requestFocus(_focusNode);
+  }
+
+  void hideKeyboard() {
+    assert(isEditable);
+    assert(!_disposed);
+    _focusNode.unfocus();
+  }
+
+  @override
+  void dispose() {
+    assert(!_disposed);
+    _controller?.removeListener(_handleControllerChange);
+    _focusNode?.removeListener(_handleFocusChange);
+    _disposed = true;
+    super.dispose();
+  }
+
+  void _handleControllerChange() {
+    assert(!_disposed);
+    final attrs = _controller.getSelectionStyle();
+    final selection = _controller.selection;
+    if (_selectionStyle != attrs || _selection != selection) {
+      _selectionStyle = attrs;
+      _selection = selection;
+      notifyListeners();
+    }
+  }
+
+  void _handleFocusChange() {
+    assert(!_disposed);
+    if (focusOwner == FocusOwner.none && !_selection.isCollapsed) {
+      // Collapse selection if there is nothing focused.
+      _controller.updateSelection(_selection.copyWith(
+        baseOffset: _selection.extentOffset,
+        extentOffset: _selection.extentOffset,
+      ));
+    }
+    notifyListeners();
+  }
+
+  @override
+  String toString() {
+    return '$ZefyrScope#${shortHash(this)}';
+  }
+}
+
+class ZefyrScopeAccess extends InheritedWidget {
+  final ZefyrScope scope;
+
+  ZefyrScopeAccess({Key key, @required this.scope, @required Widget child})
+      : super(key: key, child: child);
+
+  @override
+  bool updateShouldNotify(ZefyrScopeAccess oldWidget) {
+    return scope != oldWidget.scope;
+  }
+}

zefyr/lib/src/widgets/selection.dart

@@ -0,0 +1,512 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'dart:ui' as ui;
+
+import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
+import 'package:notus/notus.dart';
+import 'package:zefyr/util.dart';
+
+import 'controller.dart';
+import 'editable_box.dart';
+import 'scope.dart';
+
+RenderEditableBox _getEditableBox(HitTestResult result) {
+  for (var entry in result.path) {
+    if (entry.target is RenderEditableBox) {
+      return entry.target as RenderEditableBox;
+    }
+  }
+  return null;
+}
+
+/// Selection overlay controls selection handles and other gestures.
+class ZefyrSelectionOverlay extends StatefulWidget {
+  const ZefyrSelectionOverlay({
+    Key key,
+    @required this.controller,
+    @required this.controls,
+    @required this.overlay,
+  }) : super(key: key);
+
+  final ZefyrController controller;
+  final TextSelectionControls controls;
+  final OverlayState overlay;
+
+  @override
+  _ZefyrSelectionOverlayState createState() =>
+      new _ZefyrSelectionOverlayState();
+}
+
+class _ZefyrSelectionOverlayState extends State<ZefyrSelectionOverlay>
+    implements TextSelectionDelegate {
+  @override
+  TextEditingValue get textEditingValue =>
+      widget.controller.plainTextEditingValue;
+
+  set textEditingValue(TextEditingValue value) {
+    final cursorPosition = value.selection.extentOffset;
+    final oldText = widget.controller.document.toPlainText();
+    final newText = value.text;
+    final diff = fastDiff(oldText, newText, cursorPosition);
+    widget.controller.replaceText(
+        diff.start, diff.deleted.length, diff.inserted,
+        selection: value.selection);
+  }
+
+  @override
+  void bringIntoView(ui.TextPosition position) {
+    // TODO: implement bringIntoView
+  }
+
+  bool get isToolbarVisible => _toolbar != null;
+  bool get isToolbarHidden => _toolbar == null;
+
+  @override
+  void hideToolbar() {
+    _didCaretTap = false; // reset double tap.
+    _toolbar?.remove();
+    _toolbar = null;
+    _toolbarController.stop();
+  }
+
+  void showToolbar() {
+    final scope = ZefyrScope.of(context);
+    assert(scope != null);
+    final toolbarOpacity = _toolbarController.view;
+    _toolbar = new OverlayEntry(
+      builder: (context) => new FadeTransition(
+            opacity: toolbarOpacity,
+            child: new _SelectionToolbar(
+              scope: scope,
+              controls: widget.controls,
+              delegate: this,
+            ),
+          ),
+    );
+    widget.overlay.insert(_toolbar);
+    _toolbarController.forward(from: 0.0);
+  }
+
+  //
+  // Overridden members of State
+  //
+
+  @override
+  void initState() {
+    super.initState();
+    _toolbarController = new AnimationController(
+        duration: _kFadeDuration, vsync: widget.overlay);
+  }
+
+  static const Duration _kFadeDuration = const Duration(milliseconds: 150);
+
+  @override
+  void didUpdateWidget(ZefyrSelectionOverlay oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (oldWidget.overlay != widget.overlay) {
+      hideToolbar();
+      _toolbarController.dispose();
+      _toolbarController = new AnimationController(
+          duration: _kFadeDuration, vsync: widget.overlay);
+    }
+  }
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    final editor = ZefyrScope.of(context);
+    if (_editor != editor) {
+      _editor?.removeListener(_handleChange);
+      _editor = editor;
+      _editor.addListener(_handleChange);
+      _selection = _editor.selection;
+      _focusOwner = _editor.focusOwner;
+    }
+  }
+
+  @override
+  void dispose() {
+    _editor.removeListener(_handleChange);
+    hideToolbar();
+    _toolbarController.dispose();
+    _toolbarController = null;
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final overlay = new GestureDetector(
+      behavior: HitTestBehavior.translucent,
+      onTapDown: _handleTapDown,
+      onTap: _handleTap,
+      onTapCancel: _handleTapCancel,
+      onLongPress: _handleLongPress,
+      child: new Stack(
+        fit: StackFit.expand,
+        children: <Widget>[
+          new SelectionHandleDriver(
+            position: _SelectionHandlePosition.base,
+            controls: widget.controls,
+          ),
+          new SelectionHandleDriver(
+            position: _SelectionHandlePosition.extent,
+            controls: widget.controls,
+          ),
+        ],
+      ),
+    );
+    return new Container(child: overlay);
+  }
+
+  //
+  // Private members
+  //
+
+  /// Global position of last TapDown event.
+  Offset _lastTapDownPosition;
+
+  /// Global position of last TapDown which is potentially a long press.
+  Offset _longPressPosition;
+
+  OverlayEntry _toolbar;
+  AnimationController _toolbarController;
+
+  ZefyrScope _editor;
+  TextSelection _selection;
+  FocusOwner _focusOwner;
+
+  bool _didCaretTap = false;
+
+  void _handleChange() {
+    if (_selection != _editor.selection || _focusOwner != _editor.focusOwner) {
+      _updateToolbar();
+    }
+  }
+
+  void _updateToolbar() {
+    if (!mounted) {
+      return;
+    }
+
+    final selection = _editor.selection;
+    final focusOwner = _editor.focusOwner;
+    setState(() {
+      if (focusOwner != FocusOwner.editor) {
+        hideToolbar();
+      } else {
+        if (_selection != selection) {
+          if (selection.isCollapsed && isToolbarVisible) hideToolbar();
+          _toolbar?.markNeedsBuild();
+          if (!selection.isCollapsed && isToolbarHidden) showToolbar();
+        } else {
+          if (!selection.isCollapsed && isToolbarHidden) {
+            showToolbar();
+          } else if (isToolbarVisible) {
+            _toolbar?.markNeedsBuild();
+          }
+        }
+      }
+      _selection = selection;
+      _focusOwner = focusOwner;
+    });
+  }
+
+  void _handleTapDown(TapDownDetails details) {
+    _lastTapDownPosition = details.globalPosition;
+  }
+
+  void _handleTapCancel() {
+    // longPress arrives after tapCancel, so remember the tap position.
+    _longPressPosition = _lastTapDownPosition;
+    _lastTapDownPosition = null;
+  }
+
+  void _handleTap() {
+    assert(_lastTapDownPosition != null);
+    final globalPoint = _lastTapDownPosition;
+    _lastTapDownPosition = null;
+    HitTestResult result = new HitTestResult();
+    WidgetsBinding.instance.hitTest(result, globalPoint);
+
+    RenderEditableProxyBox box = _getEditableBox(result);
+    if (box == null) {
+      box = _editor.renderContext.closestBoxForGlobalPoint(globalPoint);
+    }
+    if (box == null) return null;
+
+    final localPoint = box.globalToLocal(globalPoint);
+    final position = box.getPositionForOffset(localPoint);
+    final selection = new TextSelection.collapsed(
+      offset: position.offset,
+      affinity: position.affinity,
+    );
+    if (_didCaretTap && _selection == selection) {
+      _didCaretTap = false;
+      if (isToolbarVisible) {
+        hideToolbar();
+      } else {
+        showToolbar();
+      }
+    } else {
+      _didCaretTap = true;
+    }
+    widget.controller.updateSelection(selection, source: ChangeSource.local);
+  }
+
+  void _handleLongPress() {
+    final Offset globalPoint = _longPressPosition;
+    _longPressPosition = null;
+    HitTestResult result = new HitTestResult();
+    WidgetsBinding.instance.hitTest(result, globalPoint);
+    final box = _getEditableBox(result);
+    if (box == null) {
+      return;
+    }
+    final localPoint = box.globalToLocal(globalPoint);
+    final position = box.getPositionForOffset(localPoint);
+    final word = box.getWordBoundary(position);
+    final selection = new TextSelection(
+      baseOffset: word.start,
+      extentOffset: word.end,
+    );
+    widget.controller.updateSelection(selection, source: ChangeSource.local);
+  }
+
+  @override
+  bool get copyEnabled => true;
+
+  @override
+  bool get cutEnabled => true;
+
+  @override
+  bool get pasteEnabled => true;
+
+  @override
+  bool get selectAllEnabled => true;
+}
+
+enum _SelectionHandlePosition { base, extent }
+
+class SelectionHandleDriver extends StatefulWidget {
+  const SelectionHandleDriver({
+    Key key,
+    @required this.position,
+    @required this.controls,
+  }) : super(key: key);
+
+  final _SelectionHandlePosition position;
+  final TextSelectionControls controls;
+
+  @override
+  _SelectionHandleDriverState createState() =>
+      new _SelectionHandleDriverState();
+}
+
+class _SelectionHandleDriverState extends State<SelectionHandleDriver> {
+  ZefyrScope _scope;
+
+  /// Current document selection.
+  TextSelection get selection => _selection;
+  TextSelection _selection;
+
+  /// Returns `true` if this handle is located at the baseOffset of selection.
+  bool get isBaseHandle => widget.position == _SelectionHandlePosition.base;
+
+  /// Character offset of this handle in the document.
+  ///
+  /// For base handle this equals to [TextSelection.baseOffset] and for
+  /// extent handle - [TextSelection.extentOffset].
+  int get documentOffset =>
+      isBaseHandle ? selection.baseOffset : selection.extentOffset;
+
+  /// Position in pixels of this selection handle within its paragraph [block].
+  Offset getPosition(RenderEditableBox block) {
+    if (block == null) return null;
+
+    final localSelection = block.getLocalSelection(selection);
+    assert(localSelection != null);
+
+    final boxes = block.getEndpointsForSelection(selection);
+    assert(boxes.isNotEmpty, 'Got empty boxes for selection ${selection}');
+
+    final box = isBaseHandle ? boxes.first : boxes.last;
+    final dx = isBaseHandle ? box.start : box.end;
+    return new Offset(dx, box.bottom);
+  }
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    final scope = ZefyrScope.of(context);
+    if (_scope != scope) {
+      _scope?.removeListener(_handleScopeChange);
+      _scope = scope;
+      _scope.addListener(_handleScopeChange);
+    }
+    _selection = _scope.selection;
+  }
+
+  @override
+  void dispose() {
+    _scope?.removeListener(_handleScopeChange);
+    super.dispose();
+  }
+
+  //
+  // Overridden members
+  //
+
+  @override
+  Widget build(BuildContext context) {
+    if (selection == null ||
+        selection.isCollapsed ||
+        widget.controls == null ||
+        _scope.focusOwner != FocusOwner.editor) {
+      return new Container();
+    }
+    final block = _scope.renderContext.boxForTextOffset(documentOffset);
+    final position = getPosition(block);
+    Widget handle;
+    if (position == null) {
+      handle = new Container();
+    } else {
+      final handleType = isBaseHandle
+          ? TextSelectionHandleType.left
+          : TextSelectionHandleType.right;
+      handle = new Positioned(
+        left: position.dx,
+        top: position.dy,
+        child: widget.controls.buildHandle(
+          context,
+          handleType,
+          block.preferredLineHeight,
+        ),
+      );
+      handle = new CompositedTransformFollower(
+        link: block.layerLink,
+        showWhenUnlinked: false,
+        child: new Stack(
+          overflow: Overflow.visible,
+          children: <Widget>[handle],
+        ),
+      );
+    }
+    // Always return this gesture detector even if handle is an empty container
+    // This way we prevent drag gesture from being canceled in case current
+    // position is somewhere outside of any visible paragraph block.
+    return new GestureDetector(
+      onPanStart: _handleDragStart,
+      onPanUpdate: _handleDragUpdate,
+      child: handle,
+    );
+  }
+
+  //
+  // Private members
+  //
+
+  Offset _dragPosition;
+
+  void _handleScopeChange() {
+    if (_selection != _scope.selection) {
+      setState(() {
+        _selection = _scope.selection;
+      });
+    }
+  }
+
+  void _handleDragStart(DragStartDetails details) {
+    _dragPosition = details.globalPosition;
+  }
+
+  void _handleDragUpdate(DragUpdateDetails details) {
+    _dragPosition += details.delta;
+    final globalPoint = _dragPosition;
+    final paragraph = _scope.renderContext.boxForGlobalPoint(globalPoint);
+    if (paragraph == null) {
+      return;
+    }
+
+    final localPoint = paragraph.globalToLocal(globalPoint);
+    final position = paragraph.getPositionForOffset(localPoint);
+    final newSelection = selection.copyWith(
+      baseOffset: isBaseHandle ? position.offset : selection.baseOffset,
+      extentOffset: isBaseHandle ? selection.extentOffset : position.offset,
+    );
+    if (newSelection.baseOffset >= newSelection.extentOffset) {
+      // Don't allow reversed or collapsed selection.
+      return;
+    }
+
+    if (newSelection != _selection) {
+      _scope.updateSelection(newSelection, source: ChangeSource.local);
+    }
+  }
+}
+
+class _SelectionToolbar extends StatefulWidget {
+  const _SelectionToolbar({
+    Key key,
+    @required this.scope,
+    @required this.controls,
+    @required this.delegate,
+  }) : super(key: key);
+
+  final ZefyrScope scope;
+  final TextSelectionControls controls;
+  final TextSelectionDelegate delegate;
+
+  @override
+  _SelectionToolbarState createState() => new _SelectionToolbarState();
+}
+
+class _SelectionToolbarState extends State<_SelectionToolbar> {
+  ZefyrScope get editable => widget.scope;
+  TextSelection get selection => widget.delegate.textEditingValue.selection;
+
+  @override
+  Widget build(BuildContext context) {
+    return _buildToolbar(context);
+  }
+
+  Widget _buildToolbar(BuildContext context) {
+    final base = selection.baseOffset;
+    // TODO: Editable is not refreshed and may contain stale renderContext instance.
+    final block = editable.renderContext.boxForTextOffset(base);
+    if (block == null) {
+      return Container();
+    }
+    final boxes = block.getEndpointsForSelection(selection);
+    // Find the horizontal midpoint, just above the selected text.
+    final Offset midpoint = new Offset(
+      (boxes.length == 1)
+          ? (boxes[0].start + boxes[0].end) / 2.0
+          : (boxes[0].start + boxes[1].start) / 2.0,
+      boxes[0].bottom - block.preferredLineHeight,
+    );
+
+    final Rect editingRegion = new Rect.fromPoints(
+      block.localToGlobal(Offset.zero),
+      block.localToGlobal(block.size.bottomRight(Offset.zero)),
+    );
+//    final toolbar = widget.controls
+//        .buildToolbar(context, editingRegion, midpoint, widget.delegate);
+    final Offset endpoint = new Offset(
+      (boxes.length == 1)
+          ? (boxes[0].start + boxes[0].end)
+          : (boxes[0].start + boxes[1].start),
+      boxes[0].bottom - block.preferredLineHeight,
+    );
+    final TextSelectionPoint textEndpoint = new TextSelectionPoint(endpoint, TextDirection.ltr);
+    final toolbar = widget.controls
+        .buildToolbar(context, editingRegion,0.0, midpoint, [textEndpoint], widget.delegate);
+    return new CompositedTransformFollower(
+      link: block.layerLink,
+      showWhenUnlinked: false,
+      offset: -editingRegion.topLeft,
+      child: toolbar,
+    );
+  }
+}

zefyr/lib/src/widgets/theme.dart

@@ -0,0 +1,312 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'dart:io';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/widgets.dart';
+import 'package:meta/meta.dart';
+
+/// Applies a Zefyr editor theme to descendant widgets.
+///
+/// Describes colors and typographic styles for an editor.
+///
+/// Descendant widgets obtain the current theme's [ZefyrThemeData] object using
+/// [ZefyrTheme.of].
+///
+/// See also:
+///
+///   * [ZefyrThemeData], which describes actual configuration of a theme.
+class ZefyrTheme extends InheritedWidget {
+  final ZefyrThemeData data;
+
+  /// Applies the given theme [data] to [child].
+  ///
+  /// The [data] and [child] arguments must not be null.
+  ZefyrTheme({
+    Key key,
+    @required this.data,
+    @required Widget child,
+  })  : assert(data != null),
+        assert(child != null),
+        super(key: key, child: child);
+
+  @override
+  bool updateShouldNotify(ZefyrTheme oldWidget) {
+    return data != oldWidget.data;
+  }
+
+  /// The data from the closest [ZefyrTheme] instance that encloses the given
+  /// context.
+  ///
+  /// Returns `null` if there is no [ZefyrTheme] in the given build context
+  /// and [nullOk] is set to `true`. If [nullOk] is set to `false` (default)
+  /// then this method asserts.
+  static ZefyrThemeData of(BuildContext context, {bool nullOk: false}) {
+    final ZefyrTheme widget = context.inheritFromWidgetOfExactType(ZefyrTheme);
+    if (widget == null && nullOk) return null;
+    assert(widget != null,
+        '$ZefyrTheme.of() called with a context that does not contain a ZefyrEditor.');
+    return widget.data;
+  }
+}
+
+/// Holds colors and typography styles for [ZefyrEditor].
+class ZefyrThemeData {
+  final TextStyle boldStyle;
+  final TextStyle italicStyle;
+  final TextStyle linkStyle;
+  final StyleTheme paragraphTheme;
+  final HeadingTheme headingTheme;
+  final BlockTheme blockTheme;
+  final Color selectionColor;
+  final Color cursorColor;
+
+  /// Size of indentation for blocks.
+  final double indentSize;
+  final ZefyrToolbarTheme toolbarTheme;
+
+  factory ZefyrThemeData.fallback(BuildContext context) {
+    final defaultStyle = DefaultTextStyle.of(context);
+    final paragraphStyle = defaultStyle.style.copyWith(
+      fontSize: 16.0,
+      height: 1.25,
+      fontWeight: FontWeight.normal,
+      color: Colors.grey.shade800,
+    );
+    final padding = const EdgeInsets.only(bottom: 16.0);
+    final boldStyle = new TextStyle(fontWeight: FontWeight.bold);
+    final italicStyle = new TextStyle(fontStyle: FontStyle.italic);
+    final linkStyle =
+        TextStyle(color: Colors.blue, decoration: TextDecoration.underline);
+
+    return new ZefyrThemeData(
+      boldStyle: boldStyle,
+      italicStyle: italicStyle,
+      linkStyle: linkStyle,
+      paragraphTheme:
+          new StyleTheme(textStyle: paragraphStyle, padding: padding),
+      headingTheme: new HeadingTheme.fallback(),
+      blockTheme: new BlockTheme.fallback(),
+      selectionColor: Colors.lightBlueAccent.shade100,
+      cursorColor: Colors.black,
+      indentSize: 16.0,
+      toolbarTheme: new ZefyrToolbarTheme.fallback(context),
+    );
+  }
+
+  const ZefyrThemeData({
+    this.boldStyle,
+    this.italicStyle,
+    this.linkStyle,
+    this.paragraphTheme,
+    this.headingTheme,
+    this.blockTheme,
+    this.selectionColor,
+    this.cursorColor,
+    this.indentSize,
+    this.toolbarTheme,
+  });
+
+  ZefyrThemeData copyWith({
+    TextStyle textStyle,
+    TextStyle boldStyle,
+    TextStyle italicStyle,
+    TextStyle linkStyle,
+    StyleTheme paragraphTheme,
+    HeadingTheme headingTheme,
+    BlockTheme blockTheme,
+    Color selectionColor,
+    Color cursorColor,
+    double indentSize,
+    ZefyrToolbarTheme toolbarTheme,
+  }) {
+    return new ZefyrThemeData(
+      boldStyle: boldStyle ?? this.boldStyle,
+      italicStyle: italicStyle ?? this.italicStyle,
+      linkStyle: linkStyle ?? this.linkStyle,
+      paragraphTheme: paragraphTheme ?? this.paragraphTheme,
+      headingTheme: headingTheme ?? this.headingTheme,
+      blockTheme: blockTheme ?? this.blockTheme,
+      selectionColor: selectionColor ?? this.selectionColor,
+      cursorColor: cursorColor ?? this.cursorColor,
+      indentSize: indentSize ?? this.indentSize,
+      toolbarTheme: toolbarTheme ?? this.toolbarTheme,
+    );
+  }
+
+  ZefyrThemeData merge(ZefyrThemeData other) {
+    return copyWith(
+      boldStyle: other.boldStyle,
+      italicStyle: other.italicStyle,
+      linkStyle: other.linkStyle,
+      paragraphTheme: other.paragraphTheme,
+      headingTheme: other.headingTheme,
+      blockTheme: other.blockTheme,
+      selectionColor: other.selectionColor,
+      cursorColor: other.cursorColor,
+      indentSize: other.indentSize,
+      toolbarTheme: other.toolbarTheme,
+    );
+  }
+}
+
+/// Theme for heading-styled lines of text.
+class HeadingTheme {
+  /// Style theme for level 1 headings.
+  final StyleTheme level1;
+
+  /// Style theme for level 2 headings.
+  final StyleTheme level2;
+
+  /// Style theme for level 3 headings.
+  final StyleTheme level3;
+
+  HeadingTheme({
+    @required this.level1,
+    @required this.level2,
+    @required this.level3,
+  });
+
+  /// Creates fallback theme for headings.
+  factory HeadingTheme.fallback() {
+    return HeadingTheme(
+      level1: StyleTheme(
+        textStyle: TextStyle(
+          fontSize: 30.0,
+          color: Colors.grey.shade800,
+          height: 1.25,
+          fontWeight: FontWeight.w600,
+        ),
+        padding: EdgeInsets.only(top: 16.0, bottom: 16.0),
+      ),
+      level2: StyleTheme(
+        textStyle: TextStyle(
+          fontSize: 24.0,
+          color: Colors.grey.shade800,
+          height: 1.25,
+          fontWeight: FontWeight.w600,
+        ),
+        padding: EdgeInsets.only(bottom: 8.0, top: 8.0),
+      ),
+      level3: StyleTheme(
+        textStyle: TextStyle(
+          fontSize: 20.0,
+          color: Colors.grey.shade800,
+          height: 1.25,
+          fontWeight: FontWeight.w600,
+        ),
+        padding: EdgeInsets.only(bottom: 8.0, top: 8.0),
+      ),
+    );
+  }
+}
+
+/// Theme for a block of lines in a document.
+class BlockTheme {
+  /// Style theme for bullet lists.
+  final StyleTheme bulletList;
+
+  /// Style theme for number lists.
+  final StyleTheme numberList;
+
+  /// Style theme for code snippets.
+  final StyleTheme code;
+
+  /// Style theme for quotes.
+  final StyleTheme quote;
+
+  BlockTheme({
+    @required this.bulletList,
+    @required this.numberList,
+    @required this.quote,
+    @required this.code,
+  });
+
+  /// Creates fallback theme for blocks.
+  factory BlockTheme.fallback() {
+    final padding = const EdgeInsets.only(bottom: 8.0);
+    return new BlockTheme(
+      bulletList: new StyleTheme(padding: padding),
+      numberList: new StyleTheme(padding: padding),
+      quote: new StyleTheme(
+        textStyle: new TextStyle(color: Colors.grey.shade700),
+        padding: padding,
+      ),
+      code: new StyleTheme(
+        textStyle: new TextStyle(
+          color: Colors.blueGrey.shade800,
+          fontFamily: Platform.isIOS ? 'Menlo' : 'Roboto Mono',
+          fontSize: 14.0,
+          height: 1.25,
+        ),
+        padding: padding,
+      ),
+    );
+  }
+}
+
+/// Theme for a specific attribute style.
+///
+/// Used in [HeadingTheme] and [BlockTheme], as well as in
+/// [ZefyrThemeData.paragraphTheme].
+class StyleTheme {
+  /// Text style of this theme.
+  final TextStyle textStyle;
+
+  /// Padding to apply around lines of text.
+  final EdgeInsets padding;
+
+  /// Creates a new [StyleTheme].
+  StyleTheme({
+    this.textStyle,
+    this.padding,
+  });
+}
+
+/// Defines styles and colors for [ZefyrToolbar].
+class ZefyrToolbarTheme {
+  /// The background color of toolbar.
+  final Color color;
+
+  /// Color of buttons in toggled state.
+  final Color toggleColor;
+
+  /// Color of button icons.
+  final Color iconColor;
+
+  /// Color of button icons in disabled state.
+  final Color disabledIconColor;
+
+  /// Creates fallback theme for editor toolbars.
+  factory ZefyrToolbarTheme.fallback(BuildContext context) {
+    final theme = Theme.of(context);
+    return ZefyrToolbarTheme._(
+      color: theme.primaryColorLight,
+      toggleColor: theme.primaryColor,
+      iconColor: theme.primaryIconTheme.color,
+      disabledIconColor: theme.primaryColor,
+    );
+  }
+
+  ZefyrToolbarTheme._({
+    @required this.color,
+    @required this.toggleColor,
+    @required this.iconColor,
+    @required this.disabledIconColor,
+  });
+
+  ZefyrToolbarTheme copyWith({
+    Color color,
+    Color toggleColor,
+    Color iconColor,
+    Color disabledIconColor,
+  }) {
+    return ZefyrToolbarTheme._(
+      color: color ?? this.color,
+      toggleColor: toggleColor ?? this.toggleColor,
+      iconColor: iconColor ?? this.iconColor,
+      disabledIconColor: disabledIconColor ?? this.disabledIconColor,
+    );
+  }
+}

zefyr/lib/src/widgets/toolbar.dart

@@ -0,0 +1,398 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+import 'dart:async';
+import 'dart:ui' as ui;
+
+import 'package:flutter/material.dart';
+import 'package:notus/notus.dart';
+
+import 'buttons.dart';
+import 'scope.dart';
+import 'theme.dart';
+
+/// List of all button actions supported by [ZefyrToolbar] buttons.
+enum ZefyrToolbarAction {
+  bold,
+  italic,
+  link,
+  unlink,
+  clipboardCopy,
+  openInBrowser,
+  heading,
+  headingLevel1,
+  headingLevel2,
+  headingLevel3,
+  bulletList,
+  numberList,
+  code,
+  quote,
+  horizontalRule,
+  image,
+  cameraImage,
+  galleryImage,
+  hideKeyboard,
+  close,
+  confirm,
+}
+
+final kZefyrToolbarAttributeActions = <ZefyrToolbarAction, NotusAttributeKey>{
+  ZefyrToolbarAction.bold: NotusAttribute.bold,
+  ZefyrToolbarAction.italic: NotusAttribute.italic,
+  ZefyrToolbarAction.link: NotusAttribute.link,
+  ZefyrToolbarAction.heading: NotusAttribute.heading,
+  ZefyrToolbarAction.headingLevel1: NotusAttribute.heading.level1,
+  ZefyrToolbarAction.headingLevel2: NotusAttribute.heading.level2,
+  ZefyrToolbarAction.headingLevel3: NotusAttribute.heading.level3,
+  ZefyrToolbarAction.bulletList: NotusAttribute.block.bulletList,
+  ZefyrToolbarAction.numberList: NotusAttribute.block.numberList,
+  ZefyrToolbarAction.code: NotusAttribute.block.code,
+  ZefyrToolbarAction.quote: NotusAttribute.block.quote,
+  ZefyrToolbarAction.horizontalRule: NotusAttribute.embed.horizontalRule,
+};
+
+/// Allows customizing appearance of [ZefyrToolbar].
+abstract class ZefyrToolbarDelegate {
+  /// Builds toolbar button for specified [action].
+  ///
+  /// Returned widget is usually an instance of [ZefyrButton].
+  Widget buildButton(BuildContext context, ZefyrToolbarAction action,
+      {VoidCallback onPressed});
+}
+
+/// Scaffold for [ZefyrToolbar].
+class ZefyrToolbarScaffold extends StatelessWidget {
+  const ZefyrToolbarScaffold({
+    Key key,
+    @required this.body,
+    this.trailing,
+    this.autoImplyTrailing: true,
+  }) : super(key: key);
+
+  final Widget body;
+  final Widget trailing;
+  final bool autoImplyTrailing;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = ZefyrTheme.of(context).toolbarTheme;
+    final toolbar = ZefyrToolbar.of(context);
+    final constraints =
+        BoxConstraints.tightFor(height: ZefyrToolbar.kToolbarHeight);
+    final children = <Widget>[
+      Expanded(child: body),
+    ];
+
+    if (trailing != null) {
+      children.add(trailing);
+    } else if (autoImplyTrailing) {
+      children.add(toolbar.buildButton(context, ZefyrToolbarAction.close));
+    }
+    return new Container(
+      constraints: constraints,
+      child: Material(color: theme.color, child: Row(children: children)),
+    );
+  }
+}
+
+/// Toolbar for [ZefyrEditor].
+class ZefyrToolbar extends StatefulWidget implements PreferredSizeWidget {
+  static const kToolbarHeight = 50.0;
+
+  const ZefyrToolbar({
+    Key key,
+    @required this.editor,
+    this.autoHide: true,
+    this.delegate,
+  }) : super(key: key);
+
+  final ZefyrToolbarDelegate delegate;
+  final ZefyrScope editor;
+
+  /// Whether to automatically hide this toolbar when editor loses focus.
+  final bool autoHide;
+
+  static ZefyrToolbarState of(BuildContext context) {
+    final _ZefyrToolbarScope scope =
+        context.inheritFromWidgetOfExactType(_ZefyrToolbarScope);
+    return scope?.toolbar;
+  }
+
+  @override
+  ZefyrToolbarState createState() => ZefyrToolbarState();
+
+  @override
+  ui.Size get preferredSize => new Size.fromHeight(ZefyrToolbar.kToolbarHeight);
+}
+
+class _ZefyrToolbarScope extends InheritedWidget {
+  _ZefyrToolbarScope({Key key, @required Widget child, @required this.toolbar})
+      : super(key: key, child: child);
+
+  final ZefyrToolbarState toolbar;
+
+  @override
+  bool updateShouldNotify(_ZefyrToolbarScope oldWidget) {
+    return toolbar != oldWidget.toolbar;
+  }
+}
+
+class ZefyrToolbarState extends State<ZefyrToolbar>
+    with SingleTickerProviderStateMixin {
+  final Key _toolbarKey = UniqueKey();
+  final Key _overlayKey = UniqueKey();
+
+  ZefyrToolbarDelegate _delegate;
+  AnimationController _overlayAnimation;
+  WidgetBuilder _overlayBuilder;
+  Completer<void> _overlayCompleter;
+
+  TextSelection _selection;
+
+  void markNeedsRebuild() {
+    setState(() {
+      if (_selection != editor.selection) {
+        _selection = editor.selection;
+        closeOverlay();
+      }
+    });
+  }
+
+  Widget buildButton(BuildContext context, ZefyrToolbarAction action,
+      {VoidCallback onPressed}) {
+    return _delegate.buildButton(context, action, onPressed: onPressed);
+  }
+
+  Future<void> showOverlay(WidgetBuilder builder) async {
+    assert(_overlayBuilder == null);
+    final completer = new Completer<void>();
+    setState(() {
+      _overlayBuilder = builder;
+      _overlayCompleter = completer;
+      _overlayAnimation.forward();
+    });
+    return completer.future;
+  }
+
+  void closeOverlay() {
+    if (!hasOverlay) return;
+    _overlayAnimation.reverse().whenComplete(() {
+      setState(() {
+        _overlayBuilder = null;
+        _overlayCompleter?.complete();
+        _overlayCompleter = null;
+      });
+    });
+  }
+
+  bool get hasOverlay => _overlayBuilder != null;
+
+  ZefyrScope get editor => widget.editor;
+
+  @override
+  void initState() {
+    super.initState();
+    _delegate = widget.delegate ?? new _DefaultZefyrToolbarDelegate();
+    _overlayAnimation = new AnimationController(
+        vsync: this, duration: Duration(milliseconds: 100));
+    _selection = editor.selection;
+  }
+
+  @override
+  void didUpdateWidget(ZefyrToolbar oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (widget.delegate != oldWidget.delegate) {
+      _delegate = widget.delegate ?? new _DefaultZefyrToolbarDelegate();
+    }
+  }
+
+  @override
+  void dispose() {
+    _overlayAnimation.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final layers = <Widget>[];
+
+    // Must set unique key for the toolbar to prevent it from reconstructing
+    // new state each time we toggle overlay.
+    final toolbar = ZefyrToolbarScaffold(
+      key: _toolbarKey,
+      body: ZefyrButtonList(buttons: _buildButtons(context)),
+      trailing: buildButton(context, ZefyrToolbarAction.hideKeyboard),
+    );
+
+    layers.add(toolbar);
+
+    if (hasOverlay) {
+      Widget widget = new Builder(builder: _overlayBuilder);
+      assert(widget != null);
+      final overlay = FadeTransition(
+        key: _overlayKey,
+        opacity: _overlayAnimation,
+        child: widget,
+      );
+      layers.add(overlay);
+    }
+
+    final constraints =
+        BoxConstraints.tightFor(height: ZefyrToolbar.kToolbarHeight);
+    return _ZefyrToolbarScope(
+      toolbar: this,
+      child: Container(
+        constraints: constraints,
+        child: Stack(children: layers),
+      ),
+    );
+  }
+
+  List<Widget> _buildButtons(BuildContext context) {
+    final buttons = <Widget>[
+      buildButton(context, ZefyrToolbarAction.bold),
+      buildButton(context, ZefyrToolbarAction.italic),
+      LinkButton(),
+      HeadingButton(),
+      buildButton(context, ZefyrToolbarAction.bulletList),
+      buildButton(context, ZefyrToolbarAction.numberList),
+      buildButton(context, ZefyrToolbarAction.quote),
+      buildButton(context, ZefyrToolbarAction.code),
+      buildButton(context, ZefyrToolbarAction.horizontalRule),
+      ImageButton(),
+    ];
+    return buttons;
+  }
+}
+
+/// Scrollable list of toolbar buttons.
+class ZefyrButtonList extends StatefulWidget {
+  const ZefyrButtonList({Key key, @required this.buttons}) : super(key: key);
+  final List<Widget> buttons;
+
+  @override
+  _ZefyrButtonListState createState() => _ZefyrButtonListState();
+}
+
+class _ZefyrButtonListState extends State<ZefyrButtonList> {
+  final ScrollController _controller = new ScrollController();
+  bool _showLeftArrow = false;
+  bool _showRightArrow = false;
+
+  @override
+  void initState() {
+    super.initState();
+    _controller.addListener(_handleScroll);
+    // Workaround to allow scroll controller attach to our ListView so that
+    // we can detect if overflow arrows need to be shown on init.
+    // TODO: find a better way to detect overflow
+    Timer.run(_handleScroll);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = ZefyrTheme.of(context).toolbarTheme;
+    final color = theme.iconColor;
+    final list = ListView(
+      scrollDirection: Axis.horizontal,
+      controller: _controller,
+      children: widget.buttons,
+      physics: ClampingScrollPhysics(),
+    );
+
+    final leftArrow = _showLeftArrow
+        ? Icon(Icons.arrow_left, size: 18.0, color: color)
+        : null;
+    final rightArrow = _showRightArrow
+        ? Icon(Icons.arrow_right, size: 18.0, color: color)
+        : null;
+    return Row(
+      children: <Widget>[
+        SizedBox(
+          width: 12.0,
+          height: ZefyrToolbar.kToolbarHeight,
+          child: Container(child: leftArrow, color: theme.color),
+        ),
+        Expanded(child: ClipRect(child: list)),
+        SizedBox(
+          width: 12.0,
+          height: ZefyrToolbar.kToolbarHeight,
+          child: Container(child: rightArrow, color: theme.color),
+        ),
+      ],
+    );
+  }
+
+  void _handleScroll() {
+    setState(() {
+      _showLeftArrow =
+          _controller.position.minScrollExtent != _controller.position.pixels;
+      _showRightArrow =
+          _controller.position.maxScrollExtent != _controller.position.pixels;
+    });
+  }
+}
+
+class _DefaultZefyrToolbarDelegate implements ZefyrToolbarDelegate {
+  static const kDefaultButtonIcons = {
+    ZefyrToolbarAction.bold: Icons.format_bold,
+    ZefyrToolbarAction.italic: Icons.format_italic,
+    ZefyrToolbarAction.link: Icons.link,
+    ZefyrToolbarAction.unlink: Icons.link_off,
+    ZefyrToolbarAction.clipboardCopy: Icons.content_copy,
+    ZefyrToolbarAction.openInBrowser: Icons.open_in_new,
+    ZefyrToolbarAction.heading: Icons.format_size,
+    ZefyrToolbarAction.bulletList: Icons.format_list_bulleted,
+    ZefyrToolbarAction.numberList: Icons.format_list_numbered,
+    ZefyrToolbarAction.code: Icons.code,
+    ZefyrToolbarAction.quote: Icons.format_quote,
+    ZefyrToolbarAction.horizontalRule: Icons.remove,
+    ZefyrToolbarAction.image: Icons.photo,
+    ZefyrToolbarAction.cameraImage: Icons.photo_camera,
+    ZefyrToolbarAction.galleryImage: Icons.photo_library,
+    ZefyrToolbarAction.hideKeyboard: Icons.keyboard_hide,
+    ZefyrToolbarAction.close: Icons.close,
+    ZefyrToolbarAction.confirm: Icons.check,
+  };
+
+  static const kSpecialIconSizes = {
+    ZefyrToolbarAction.unlink: 20.0,
+    ZefyrToolbarAction.clipboardCopy: 20.0,
+    ZefyrToolbarAction.openInBrowser: 20.0,
+    ZefyrToolbarAction.close: 20.0,
+    ZefyrToolbarAction.confirm: 20.0,
+  };
+
+  static const kDefaultButtonTexts = {
+    ZefyrToolbarAction.headingLevel1: 'H1',
+    ZefyrToolbarAction.headingLevel2: 'H2',
+    ZefyrToolbarAction.headingLevel3: 'H3',
+  };
+
+  @override
+  Widget buildButton(BuildContext context, ZefyrToolbarAction action,
+      {VoidCallback onPressed}) {
+    final theme = Theme.of(context);
+    if (kDefaultButtonIcons.containsKey(action)) {
+      final icon = kDefaultButtonIcons[action];
+      final size = kSpecialIconSizes[action];
+      return ZefyrButton.icon(
+        action: action,
+        icon: icon,
+        iconSize: size,
+        onPressed: onPressed,
+      );
+    } else {
+      final text = kDefaultButtonTexts[action];
+      assert(text != null);
+      final style = theme.textTheme.caption
+          .copyWith(fontWeight: FontWeight.bold, fontSize: 14.0);
+      return ZefyrButton.text(
+        action: action,
+        text: text,
+        style: style,
+        onPressed: onPressed,
+      );
+    }
+  }
+}

zefyr/lib/src/widgets/view.dart

@@ -0,0 +1,107 @@
+import 'package:flutter/material.dart';
+import 'package:meta/meta.dart';
+import 'package:notus/notus.dart';
+
+import 'code.dart';
+import 'common.dart';
+import 'image.dart';
+import 'list.dart';
+import 'paragraph.dart';
+import 'quote.dart';
+import 'scope.dart';
+import 'theme.dart';
+
+/// Non-scrollable read-only view of Notus rich text documents.
+@experimental
+class ZefyrView extends StatefulWidget {
+  final NotusDocument document;
+  final ZefyrImageDelegate imageDelegate;
+
+  const ZefyrView({Key key, @required this.document, this.imageDelegate})
+      : super(key: key);
+
+  @override
+  ZefyrViewState createState() => ZefyrViewState();
+}
+
+class ZefyrViewState extends State<ZefyrView> {
+  ZefyrScope _scope;
+  ZefyrThemeData _themeData;
+
+  ZefyrImageDelegate get imageDelegate => widget.imageDelegate;
+
+  @override
+  void initState() {
+    super.initState();
+    _scope = ZefyrScope.view(imageDelegate: widget.imageDelegate);
+  }
+
+  @override
+  void didUpdateWidget(ZefyrView oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    _scope.imageDelegate = widget.imageDelegate;
+  }
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    final parentTheme = ZefyrTheme.of(context, nullOk: true);
+    final fallbackTheme = ZefyrThemeData.fallback(context);
+    _themeData = (parentTheme != null)
+        ? fallbackTheme.merge(parentTheme)
+        : fallbackTheme;
+  }
+
+  @override
+  void dispose() {
+    _scope.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return ZefyrTheme(
+      data: _themeData,
+      child: ZefyrScopeAccess(
+        scope: _scope,
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: _buildChildren(context),
+        ),
+      ),
+    );
+  }
+
+  List<Widget> _buildChildren(BuildContext context) {
+    final result = <Widget>[];
+    for (var node in widget.document.root.children) {
+      result.add(_defaultChildBuilder(context, node));
+    }
+    return result;
+  }
+
+  Widget _defaultChildBuilder(BuildContext context, Node node) {
+    if (node is LineNode) {
+      if (node.hasEmbed) {
+        return new RawZefyrLine(node: node);
+      } else if (node.style.contains(NotusAttribute.heading)) {
+        return new ZefyrHeading(node: node);
+      }
+      return new ZefyrParagraph(node: node);
+    }
+
+    final BlockNode block = node;
+    final blockStyle = block.style.get(NotusAttribute.block);
+    if (blockStyle == NotusAttribute.block.code) {
+      return new ZefyrCode(node: block);
+    } else if (blockStyle == NotusAttribute.block.bulletList) {
+      return new ZefyrList(node: block);
+    } else if (blockStyle == NotusAttribute.block.numberList) {
+      return new ZefyrList(node: block);
+    } else if (blockStyle == NotusAttribute.block.quote) {
+      return new ZefyrQuote(node: block);
+    }
+
+    throw new UnimplementedError('Block format $blockStyle.');
+  }
+}

zefyr/lib/util.dart

@@ -0,0 +1,40 @@
+// Copyright (c) 2018, the Zefyr project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// Utility functions for Zefyr.
+library zefyr.util;
+
+import 'dart:math' as math;
+
+import 'package:quill_delta/quill_delta.dart';
+
+export 'src/fast_diff.dart';
+
+int getPositionDelta(Delta user, Delta actual) {
+  final userIter = new DeltaIterator(user);
+  final actualIter = new DeltaIterator(actual);
+  int diff = 0;
+  while (userIter.hasNext || actualIter.hasNext) {
+    num length = math.min(userIter.peekLength(), actualIter.peekLength());
+    final userOp = userIter.next(length);
+    final actualOp = actualIter.next(length);
+    assert(userOp.length == actualOp.length);
+    if (userOp.key == actualOp.key) continue;
+    if (userOp.isInsert && actualOp.isRetain) {
+      diff -= userOp.length;
+    } else if (userOp.isDelete && actualOp.isRetain) {
+      diff += userOp.length;
+    } else if (userOp.isRetain && actualOp.isInsert) {
+      if (actualOp.data.startsWith('\n') ) {
+        // At this point user input reached its end (retain). If a heuristic
+        // rule inserts a new line we should keep cursor on it's original position.
+        continue;
+      }
+      diff += actualOp.length;
+    } else {
+      // TODO: this likely needs to cover more edge cases.
+    }
+  }
+  return diff;
+}

zefyr/lib/zefyr.dart

@@ -0,0 +1,22 @@
+library zefyr;
+
+export 'package:notus/notus.dart';
+
+export 'src/widgets/buttons.dart' hide HeadingButton, LinkButton;
+export 'src/widgets/code.dart';
+export 'src/widgets/common.dart';
+export 'src/widgets/controller.dart';
+export 'src/widgets/editable_text.dart';
+export 'src/widgets/editor.dart';
+export 'src/widgets/field.dart';
+export 'src/widgets/horizontal_rule.dart';
+export 'src/widgets/image.dart';
+export 'src/widgets/list.dart';
+export 'src/widgets/paragraph.dart';
+export 'src/widgets/quote.dart';
+export 'src/widgets/scaffold.dart';
+export 'src/widgets/scope.dart' hide ZefyrScopeAccess;
+export 'src/widgets/selection.dart' hide SelectionHandleDriver;
+export 'src/widgets/theme.dart';
+export 'src/widgets/toolbar.dart';
+export 'src/widgets/view.dart';

zefyr/pubspec.yaml

@@ -0,0 +1,59 @@
+name: zefyr
+description: A new Flutter package project.
+version: 0.0.1
+author: Anatoly Pulyaevskiy <anatoly.pulyaevskiy@gmail.com>
+homepage:
+
+environment:
+  sdk: ">=2.1.0 <3.0.0"
+
+dependencies:
+  flutter:
+    sdk: flutter
+  collection: ^1.14.6
+  url_launcher: ^5.0.0
+  image_picker: ^0.5.0
+  quill_delta: ^1.0.0-dev.1.0
+  notus: ^0.1.0
+  meta: ^1.1.0
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+
+# For information on the generic Dart part of this file, see the
+# following page: https://dart.dev/tools/pub/pubspec
+
+# The following section is specific to Flutter.
+flutter:
+
+  # To add assets to your package, add an assets section, like this:
+  # assets:
+  #  - images/a_dot_burr.jpeg
+  #  - images/a_dot_ham.jpeg
+  #
+  # For details regarding assets in packages, see
+  # https://flutter.dev/assets-and-images/#from-packages
+  #
+  # An image asset can refer to one or more resolution-specific "variants", see
+  # https://flutter.dev/assets-and-images/#resolution-aware.
+
+  # To add custom fonts to your package, add a fonts section here,
+  # in this "flutter" section. Each entry in this list should have a
+  # "family" key with the font family name, and a "fonts" key with a
+  # list giving the asset and other descriptors for the font. For
+  # example:
+  # fonts:
+  #   - family: Schyler
+  #     fonts:
+  #       - asset: fonts/Schyler-Regular.ttf
+  #       - asset: fonts/Schyler-Italic.ttf
+  #         style: italic
+  #   - family: Trajan Pro
+  #     fonts:
+  #       - asset: fonts/TrajanPro.ttf
+  #       - asset: fonts/TrajanPro_Bold.ttf
+  #         weight: 700
+  #
+  # For details regarding fonts in packages, see
+  # https://flutter.dev/custom-fonts/#from-packages

zefyr/test/zefyr_test.dart

@@ -0,0 +1,13 @@
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:zefyr/zefyr.dart';
+
+void main() {
+//  test('adds one to input values', () {
+//    final calculator = Calculator();
+//    expect(calculator.addOne(2), 3);
+//    expect(calculator.addOne(-7), -6);
+//    expect(calculator.addOne(0), 1);
+//    expect(() => calculator.addOne(null), throwsNoSuchMethodError);
+//  });
+}