Implement undo delete properly

This way the git History is not modified.

lib/main.dart

@@ -4,7 +4,6 @@ import 'package:flutter/material.dart';
 import 'package:flutter_crashlytics/flutter_crashlytics.dart';
 import 'package:journal/apis/git.dart';
 import 'package:journal/app.dart';
-import 'package:journal/gitapp.dart';
 import 'package:journal/settings.dart';
 import 'package:journal/state_container.dart';
 import 'package:shared_preferences/shared_preferences.dart';

lib/note_viewer.dart

@@ -5,6 +5,7 @@ import 'package:journal/widgets/note_header.dart';
 
 import 'note.dart';
 import 'note_editor.dart';
+import 'utils.dart';
 
 class NoteBrowsingScreen extends StatefulWidget {
   final List<Note> notes;
@@ -23,6 +24,7 @@ class NoteBrowsingScreen extends StatefulWidget {
 
 class NoteBrowsingScreenState extends State<NoteBrowsingScreen> {
   PageController pageController;
+  final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();
 
   NoteBrowsingScreenState({@required int noteIndex}) {
     pageController = PageController(initialPage: noteIndex);
@@ -39,6 +41,7 @@ class NoteBrowsingScreenState extends State<NoteBrowsingScreen> {
     );
 
     return Scaffold(
+      key: _scaffoldKey,
       appBar: AppBar(
         title: Text('TIMELINE'),
         actions: <Widget>[
@@ -46,9 +49,16 @@ class NoteBrowsingScreenState extends State<NoteBrowsingScreen> {
             icon: Icon(Icons.delete),
             onPressed: () {
               final stateContainer = StateContainer.of(context);
-              Note note = widget.notes[_currentIndex()];
+              var noteIndex = _currentIndex();
+              Note note = widget.notes[noteIndex];
               stateContainer.removeNote(note);
               Navigator.pop(context);
+
+              print("Shwoing an undo snackbar");
+              var snackbar = buildUndoDeleteSnackbar(context, note, noteIndex);
+              _scaffoldKey.currentState
+                ..removeCurrentSnackBar()
+                ..showSnackBar(snackbar);
             },
           ),
         ],

lib/state_container.dart

@@ -172,6 +172,26 @@ class StateContainerState extends State<StateContainer> {
     });
   }
 
+  /*
+  String _getGitDir(BuildContext context) {
+    var state = StateContainer.of(context).appState;
+    if (state.remoteGitRepoConfigured) {
+      return state.remoteGitRepoFolderName;
+    } else {
+      return state.localGitRepoPath;
+    }
+  }
+  */
+
+  void undoRemoveNote(Note note, int index) {
+    setState(() {
+      appState.notes.insert(index, note);
+      noteRepo.resetLastCommit().then((NoteRepoResult _) {
+        _syncNotes();
+      });
+    });
+  }
+
   void insertNote(int index, Note note) {
     print("State Container insertNote");
     setState(() {

lib/storage/git_storage.dart

@@ -73,6 +73,11 @@ class GitNoteRepository implements NoteRepository {
     return result;
   }
 
+  Future<NoteRepoResult> resetLastCommit() async {
+    await gitResetLast(this.dirName);
+    return NoteRepoResult(error: false);
+  }
+
   @override
   Future<NoteRepoResult> updateNote(Note note) async {
     return _addNote(note, "Edited Journal Entry");

lib/utils.dart

@@ -1,6 +1,10 @@
-import 'package:journal/app.dart';
+import 'package:flutter/material.dart';
 import 'package:package_info/package_info.dart';
 
+import 'app.dart';
+import 'note.dart';
+import 'state_container.dart';
+
 Future<String> getVersionString() async {
   var info = await PackageInfo.fromPlatform();
   var versionText = "";
@@ -14,3 +18,23 @@ Future<String> getVersionString() async {
 
   return versionText;
 }
+
+SnackBar buildUndoDeleteSnackbar(
+  BuildContext context,
+  Note deletedNote,
+  int deletedNoteIndex,
+) {
+  var snackbar = SnackBar(
+    content: Text("Note Deleted"),
+    action: SnackBarAction(
+      label: "Undo",
+      onPressed: () {
+        print("Undoing delete");
+        var stateContainer = StateContainer.of(context);
+        stateContainer.undoRemoveNote(deletedNote, deletedNoteIndex);
+      },
+    ),
+  );
+
+  return snackbar;
+}

lib/widgets/journal_list.dart

@@ -3,6 +3,7 @@ import 'package:flutter/material.dart';
 import 'package:intl/intl.dart';
 import 'package:journal/note.dart';
 import 'package:journal/state_container.dart';
+import 'package:journal/utils.dart';
 
 typedef void NoteSelectedFunction(int noteIndex);
 
@@ -37,13 +38,8 @@ class JournalList extends StatelessWidget {
             final stateContainer = StateContainer.of(context);
             stateContainer.removeNote(note);
 
-            Scaffold.of(context).showSnackBar(SnackBar(
-              content: Text("Note deleted"),
-              action: SnackBarAction(
-                label: 'Undo',
-                onPressed: () => stateContainer.insertNote(i, note),
-              ),
-            ));
+            Scaffold.of(context)
+                .showSnackBar(buildUndoDeleteSnackbar(context, note, i));
           },
         );
       },