fix: memory leaks (#615)

example/lib/pages/editor.dart

@@ -5,7 +5,7 @@ import 'package:example/pages/desktop_editor.dart';
 import 'package:example/pages/mobile_editor.dart';
 import 'package:flutter/material.dart';
 
-class Editor extends StatelessWidget {
+class Editor extends StatefulWidget {
   const Editor({
     super.key,
     required this.jsonString,
@@ -20,16 +20,30 @@ class Editor extends StatelessWidget {
 
   final TextDirection textDirection;
 
+  @override
+  State<Editor> createState() => _EditorState();
+}
+
+class _EditorState extends State<Editor> {
+  EditorState? editorState;
+
+  @override
+  void dispose() {
+    editorState?.dispose();
+
+    super.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
     return Container(
       color: Colors.white,
       child: FutureBuilder<String>(
-        future: jsonString,
+        future: widget.jsonString,
         builder: (context, snapshot) {
           if (snapshot.hasData &&
               snapshot.connectionState == ConnectionState.done) {
-            final editorState = EditorState(
+            EditorState editorState = EditorState(
               document: Document.fromJson(
                 Map<String, Object>.from(
                   json.decode(snapshot.data!),
@@ -42,14 +56,16 @@ class Editor extends StatelessWidget {
 
             editorState.transactionStream.listen((event) {
               if (event.$1 == TransactionTime.after) {
-                onEditorStateChange(editorState);
+                widget.onEditorStateChange(editorState);
               }
             });
 
+            this.editorState = editorState;
+
             if (PlatformExtension.isDesktopOrWeb) {
               return DesktopEditor(
                 editorState: editorState,
-                textDirection: textDirection,
+                textDirection: widget.textDirection,
               );
             } else if (PlatformExtension.isMobile) {
               return MobileEditor(

lib/src/core/document/document.dart

@@ -86,6 +86,14 @@ class Document {
     return last;
   }
 
+  /// Must call this method when the [Document] is no longer needed.
+  void dispose() {
+    final nodes = NodeIterator(document: this, startNode: root).toList();
+    for (final node in nodes) {
+      node.dispose();
+    }
+  }
+
   /// Returns the node at the given [path].
   Node? nodeAtPath(Path path) {
     return root.childAtPath(path);

lib/src/editor/editor_component/entry/page_block_component.dart

@@ -83,7 +83,6 @@ class PageBlockComponent extends BlockComponentStatelessWidget {
 
       return ScrollablePositionedList.builder(
         shrinkWrap: scrollController.shrinkWrap,
-        // padding: editorState.editorStyle.padding,
         scrollDirection: Axis.vertical,
         itemCount: items.length + extentCount,
         itemBuilder: (context, index) {

lib/src/editor/editor_component/service/scroll/auto_scrollable_widget.dart

@@ -25,6 +25,12 @@ class _AutoScrollableWidgetState extends State<AutoScrollableWidget> {
   late AutoScroller _autoScroller;
   late ScrollableState _scrollableState;
 
+  @override
+  void dispose() {
+    _scrollableState.dispose();
+    super.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
     Widget builder(context) {

lib/src/editor/editor_component/service/scroll/editor_scroll_controller.dart

@@ -3,6 +3,7 @@ import 'dart:math';
 
 import 'package:appflowy_editor/appflowy_editor.dart';
 import 'package:appflowy_editor/src/flutter/scrollable_positioned_list/scrollable_positioned_list.dart';
+import 'package:appflowy_editor/src/flutter/scrollable_positioned_list/src/item_positions_notifier.dart';
 import 'package:flutter/material.dart';
 
 /// This class controls the scroll behavior of the editor.
@@ -145,7 +146,13 @@ class EditorScrollController {
     if (!shrinkWrap) {
       _scrollOffsetSubscription.cancel();
       _itemPositionsListener.itemPositions.removeListener(_listenItemPositions);
+      (_itemPositionsListener as ItemPositionsNotifier?)
+          ?.itemPositions
+          .dispose();
     }
+
+    offsetNotifier.dispose();
+    visibleRangeNotifier.dispose();
   }
 
   Future<void> animateTo({

lib/src/editor/editor_component/service/scroll_service_widget.dart

@@ -1,6 +1,4 @@
 import 'package:appflowy_editor/appflowy_editor.dart';
-import 'package:appflowy_editor/src/editor/editor_component/service/scroll/auto_scrollable_widget.dart';
-import 'package:appflowy_editor/src/editor/editor_component/service/scroll/auto_scroller.dart';
 import 'package:appflowy_editor/src/editor/editor_component/service/scroll/desktop_scroll_service.dart';
 import 'package:appflowy_editor/src/editor/editor_component/service/scroll/mobile_scroll_service.dart';
 import 'package:flutter/material.dart';
@@ -51,15 +49,13 @@ class _ScrollServiceWidgetState extends State<ScrollServiceWidget>
   Widget build(BuildContext context) {
     return Provider.value(
       value: widget.editorScrollController,
-      child: AutoScrollableWidget(
-        scrollController: scrollController,
-        builder: (context, autoScroller) {
+      child: Builder(
+        builder: (context) {
           if (PlatformExtension.isDesktopOrWeb) {
-            return _buildDesktopScrollService(context, autoScroller);
+            return _buildDesktopScrollService(context);
           } else if (PlatformExtension.isMobile) {
-            return _buildMobileScrollService(context, autoScroller);
+            return _buildMobileScrollService(context);
           }
-
           throw UnimplementedError();
         },
       ),
@@ -68,7 +64,6 @@ class _ScrollServiceWidgetState extends State<ScrollServiceWidget>
 
   Widget _buildDesktopScrollService(
     BuildContext context,
-    AutoScroller autoScroller,
   ) {
     return DesktopScrollService(
       key: _forwardKey,
@@ -78,7 +73,6 @@ class _ScrollServiceWidgetState extends State<ScrollServiceWidget>
 
   Widget _buildMobileScrollService(
     BuildContext context,
-    AutoScroller autoScroller,
   ) {
     return MobileScrollService(
       key: _forwardKey,

lib/src/editor/editor_component/service/selection/desktop_selection_service.dart

@@ -82,6 +82,7 @@ class _DesktopSelectionServiceWidgetState
     clearSelection();
     WidgetsBinding.instance.removeObserver(this);
     editorState.selectionNotifier.removeListener(_updateSelection);
+    currentSelection.dispose();
 
     super.dispose();
   }

lib/src/editor_state.dart

@@ -245,6 +245,8 @@ class EditorState {
     _debouncedSealHistoryItemTimer?.cancel();
     onDispose.value += 1;
     onDispose.dispose();
+    document.dispose();
+    selectionNotifier.dispose();
   }
 
   /// Apply the transaction to the state.

lib/src/flutter/scrollable_positioned_list/src/positioned_list.dart

@@ -151,6 +151,8 @@ class _PositionedListState extends State<PositionedList> {
   @override
   void dispose() {
     scrollController.removeListener(_schedulePositionNotificationUpdate);
+    scrollController.dispose();
+    registeredElements.dispose();
     super.dispose();
   }
 

lib/src/flutter/scrollable_positioned_list/src/scrollable_positioned_list.dart

@@ -380,6 +380,9 @@ class _ScrollablePositionedListState extends State<ScrollablePositionedList>
     secondary.itemPositionsNotifier.itemPositions
         .removeListener(_updatePositions);
     _animationController?.dispose();
+    primary.itemPositionsNotifier.itemPositions.dispose();
+    secondary.itemPositionsNotifier.itemPositions.dispose();
+    secondary.scrollController.dispose();
     super.dispose();
   }
 
@@ -695,4 +698,8 @@ class _ListDisplayDetails {
   double alignment = 0;
 
   final Key key;
+
+  void dispose() {
+    itemPositionsNotifier.itemPositions.dispose();
+  }
 }

pubspec.yaml

@@ -49,12 +49,15 @@ dependencies:
   keyboard_height_plugin: ^0.0.4
   numerus: ^2.1.2
 
+
 dev_dependencies:
   flutter_test:
     sdk: flutter
   flutter_lints: ^3.0.1
   network_image_mock: ^2.1.1
   mockito: ^5.4.1
+  leak_tracker_flutter_testing: ^1.0.10
+  leak_tracker: '>=9.0.0 <11.0.0'
 
 # For information on the generic Dart part of this file, see the
 # following page: https://dart.dev/tools/pub/pubspec

test/memory_leak/memory_leak_test.dart

@@ -0,0 +1,76 @@
+import 'package:appflowy_editor/appflowy_editor.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:leak_tracker/leak_tracker.dart';
+import 'package:leak_tracker_flutter_testing/leak_tracker_flutter_testing.dart';
+
+void main() async {
+  testWidgetsWithLeakTracking(
+    'memory leak',
+    (tester) async {
+      await tester.pumpWidget(const _NoMemoryLeaks());
+      await tester.pumpAndSettle();
+    },
+    leakTesting: LeakTesting.settings.copyWith(
+      ignore: false,
+      leakDiagnosticConfig: const LeakDiagnosticConfig(
+        collectStackTraceOnStart: true,
+        collectRetainingPathForNotGCed: true,
+      ),
+      onLeaks: (leaks) {
+        // dump the leaks
+        for (final leak in leaks.all) {
+          final stack =
+              leak.context![ContextKeys.startCallstack]! as StackTrace;
+          final stackInEditor = stack
+              .toString()
+              .split('\n')
+              .where((stack) => stack.contains('package:appflowy_editor'))
+              .join('\n');
+          debugPrint('''
+${leak.type} => ${leak.trackedClass}
+$stackInEditor
+-------------------------------------------------------------------------------
+''');
+        }
+        expect(leaks.all, isEmpty);
+      },
+    ),
+  );
+}
+
+class _NoMemoryLeaks extends StatefulWidget {
+  const _NoMemoryLeaks();
+
+  @override
+  State<_NoMemoryLeaks> createState() => __NoMemoryLeaksState();
+}
+
+class __NoMemoryLeaksState extends State<_NoMemoryLeaks> {
+  final editorState = EditorState.blank();
+
+  @override
+  void dispose() {
+    editorState.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      home: Scaffold(
+        body: SafeArea(
+          child: Container(
+            width: 500,
+            decoration: BoxDecoration(
+              border: Border.all(color: Colors.blue),
+            ),
+            child: AppFlowyEditor(
+              editorState: editorState,
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}