FolderViews: Hide the AppBar when scrolling

This breaks a number of other things, but this commit was becoming
messy.

lib/folder_views/card_view.dart

@@ -4,6 +4,7 @@ import 'package:flutter_staggered_grid_view/flutter_staggered_grid_view.dart';
 
 import 'package:gitjournal/core/note.dart';
 import 'package:gitjournal/core/notes_folder.dart';
+import 'package:gitjournal/folder_views/empty_text_sliver.dart';
 import 'package:gitjournal/folder_views/note_tile.dart';
 
 class CardView extends StatelessWidget {
@@ -30,17 +31,7 @@ class CardView extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     if (folder.isEmpty) {
-      return Center(
-        child: Text(
-          emptyText,
-          textAlign: TextAlign.center,
-          style: TextStyle(
-            fontSize: 28.0,
-            fontWeight: FontWeight.w300,
-            color: Colors.grey[350],
-          ),
-        ),
-      );
+      return EmptyTextSliver(emptyText: emptyText);
     }
 
     StaggeredTile stagTile;
@@ -50,7 +41,7 @@ class CardView extends StatelessWidget {
       stagTile = const StaggeredTile.fit(1);
     }
 
-    var gridView = StaggeredGridView.extentBuilder(
+    var gridView = SliverStaggeredGrid.extentBuilder(
       itemCount: folder.notes.length,
       itemBuilder: (BuildContext context, int index) {
         var note = folder.notes[index];
@@ -66,9 +57,11 @@ class CardView extends StatelessWidget {
       staggeredTileBuilder: (int i) => stagTile,
       mainAxisSpacing: 8.0,
       crossAxisSpacing: 8.0,
-      padding: const EdgeInsets.fromLTRB(8.0, 16.0, 8.0, 16.0),
     );
 
-    return gridView;
+    return SliverPadding(
+      sliver: gridView,
+      padding: const EdgeInsets.fromLTRB(8.0, 12.0, 8.0, 12.0 + 48.0),
+    );
   }
 }

lib/folder_views/empty_text_sliver.dart

@@ -0,0 +1,30 @@
+import 'package:flutter/material.dart';
+
+// FIXME: Why are you scrollable!!
+class EmptyTextSliver extends StatelessWidget {
+  const EmptyTextSliver({
+    Key? key,
+    required this.emptyText,
+  }) : super(key: key);
+
+  final String emptyText;
+
+  @override
+  Widget build(BuildContext context) {
+    return SliverFillRemaining(
+      child: Center(
+        child: Text(
+          emptyText,
+          textAlign: TextAlign.center,
+          style: TextStyle(
+            fontSize: 28.0,
+            fontWeight: FontWeight.w300,
+            color: Colors.grey[350],
+          ),
+        ),
+      ),
+      hasScrollBody: false,
+      fillOverscroll: false,
+    );
+  }
+}

lib/folder_views/folder_view.dart

@@ -94,40 +94,38 @@ class _FolderViewState extends State<FolderView> {
       title = NumberFormat.compact().format(1);
     }
 
-    Widget folderView = Builder(
-      builder: (BuildContext context) {
-        return buildFolderView(
-          viewType: _viewType,
-          folder: sortedNotesFolder,
-          emptyText: tr('screens.folder_view.empty'),
-          header: _headerType,
-          showSummary: _showSummary,
-          noteTapped: (Note note) {
-            if (!inSelectionMode) {
-              openNoteEditor(context, note, widget.notesFolder);
-            } else {
-              _resetSelection();
-            }
-          },
-          noteLongPressed: (Note note) {
-            setState(() {
-              inSelectionMode = true;
-              selectedNote = note;
-            });
-          },
-          isNoteSelected: (n) => n == selectedNote,
-          searchTerm: "",
-        );
+    // vHanda: Fixme the openNoteEditor will fail! Wrong context!
+    var folderView = buildFolderView(
+      viewType: _viewType,
+      folder: sortedNotesFolder,
+      emptyText: tr('screens.folder_view.empty'),
+      header: _headerType,
+      showSummary: _showSummary,
+      noteTapped: (Note note) {
+        if (!inSelectionMode) {
+          openNoteEditor(context, note, widget.notesFolder);
+        } else {
+          _resetSelection();
+        }
       },
+      noteLongPressed: (Note note) {
+        setState(() {
+          inSelectionMode = true;
+          selectedNote = note;
+        });
+      },
+      isNoteSelected: (n) => n == selectedNote,
+      searchTerm: "",
     );
+    // assert(folderView is SliverWithKeepAliveWidget);
 
     var settings = Provider.of<Settings>(context);
     final showButtomMenuBar = settings.bottomMenuBar;
 
     // So the FAB doesn't hide parts of the last entry
     if (!showButtomMenuBar) {
-      folderView = Padding(
-        child: folderView,
+      folderView = SliverPadding(
+        sliver: folderView,
         padding: const EdgeInsets.fromLTRB(0.0, 0.0, 0.0, 48.0),
       );
     }
@@ -138,14 +136,22 @@ class _FolderViewState extends State<FolderView> {
     );
 
     return Scaffold(
-      appBar: AppBar(
-        title: Text(title),
-        leading: inSelectionMode ? backButton : GJAppBarMenuButton(),
-        actions: inSelectionMode
-            ? _buildInSelectionNoteActions()
-            : _buildNoteActions(),
+      body: CustomScrollView(
+        slivers: [
+          SliverAppBar(
+            title: Text(title),
+            leading: inSelectionMode ? backButton : GJAppBarMenuButton(),
+            actions: inSelectionMode
+                ? _buildInSelectionNoteActions()
+                : _buildNoteActions(),
+            floating: true,
+            forceElevated: true,
+          ),
+          folderView,
+        ],
       ),
-      body: Center(
+      /*
+      Center(
         child: Builder(
           builder: (context) {
             var child = Scrollbar(child: folderView);
@@ -159,6 +165,7 @@ class _FolderViewState extends State<FolderView> {
           },
         ),
       ),
+      */
       extendBody: true,
       drawer: AppDrawer(),
       floatingActionButton: createButton,

lib/folder_views/list_view.dart

@@ -9,6 +9,7 @@ import 'package:gitjournal/repository.dart';
 import 'package:gitjournal/settings/settings.dart';
 import 'package:gitjournal/utils/utils.dart';
 import 'package:gitjournal/widgets/icon_dismissable.dart';
+import 'empty_text_sliver.dart';
 
 typedef Widget NoteTileBuilder(BuildContext context, Note note);
 
@@ -97,25 +98,14 @@ class _FolderListViewState extends State<FolderListView> {
 
   @override
   Widget build(BuildContext context) {
-    if (widget.folder.notes.isEmpty) {
-      return Center(
-        child: Text(
-          widget.emptyText,
-          textAlign: TextAlign.center,
-          style: TextStyle(
-            fontSize: 28.0,
-            fontWeight: FontWeight.w300,
-            color: Colors.grey[350],
-          ),
-        ),
-      );
+    if (widget.folder.isEmpty) {
+      return EmptyTextSliver(emptyText: widget.emptyText);
     }
 
-    return AnimatedList(
+    return SliverAnimatedList(
       key: _listKey,
       itemBuilder: _buildItem,
       initialItemCount: widget.folder.notes.length,
-      padding: const EdgeInsets.fromLTRB(0, 0, 0, 48),
     );
   }
 

lib/folder_views/note_tile.dart

@@ -81,6 +81,7 @@ class NoteTile extends StatelessWidget {
 
   static const _maxLines = 12;
 
+  // FIXME: vHanda: This doesn't need to be computed again and again!
   String _displayText() {
     var foundSearchTerm = searchTerm.isEmpty ? true : false;
     var buffer = <String>[];