add redo && undo func

packages/notus/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.1.6
+
+* redo && undo func
+
 ## 0.1.5
 
 * Bumped minimum Dart SDK version to 2.2

packages/notus/lib/src/document.dart

@@ -11,6 +11,7 @@ import 'document/leaf.dart';
 import 'document/line.dart';
 import 'document/node.dart';
 import 'heuristics.dart';
+import 'history.dart';
 
 /// Source of a [NotusChange].
 enum ChangeSource {
@@ -40,12 +41,15 @@ class NotusDocument {
   /// Creates new empty Notus document.
   NotusDocument()
       : _heuristics = NotusHeuristics.fallback,
+        // _delta = Delta()..insert('\n') {
+      _history = NotusHistory(),
         _delta = Delta()..insert('\n') {
     _loadDocument(_delta);
   }
 
   NotusDocument.fromJson(List data)
       : _heuristics = NotusHeuristics.fallback,
+      _history = NotusHistory(),
         _delta = Delta.fromJson(data) {
     _loadDocument(_delta);
   }
@@ -59,6 +63,15 @@ class NotusDocument {
 
   final NotusHeuristics _heuristics;
 
+  NotusHistory _history;
+
+  set history(NotusHistory value) {
+    _history?.clear();
+    _history = value;
+  }
+
+  NotusHistory get history => _history;
+
   /// The root node of this document tree.
   RootNode get root => _root;
   final RootNode _root = RootNode();
@@ -216,7 +229,7 @@ class NotusDocument {
   /// of this document.
   ///
   /// In case the [change] is invalid, behavior of this method is unspecified.
-  void compose(Delta change, ChangeSource source) {
+  void compose(Delta change, ChangeSource source, {bool history}) {
     _checkMutable();
     change.trim();
     assert(change.isNotEmpty);
@@ -293,4 +306,14 @@ class NotusDocument {
       _root.remove(node);
     }
   }
+
+  void undo() {
+    assert(_history != null);
+    _history?.undo(this);
+  }
+
+  void redo() {
+    assert(_history != null);
+    _history?.redo(this);
+  }
 }

packages/notus/lib/src/history.dart

@@ -0,0 +1,119 @@
+import 'package:notus/notus.dart';
+import 'package:notus/src/document.dart';
+import 'package:quill_delta/quill_delta.dart';
+
+///
+/// record users operation or api change(Collaborative editing)
+/// used for redo or undo function
+///
+class NotusHistory {
+  final NotusHistoryStack stack = NotusHistoryStack.empty();
+
+  /// used for disable redo or undo function
+  bool ignoreChange;
+
+  int lastRecorded;
+
+  ///Collaborative editing's conditions should be true
+  final bool userOnly;
+
+  ///max operation count for undo
+  final int maxStack;
+
+  ///record delay
+  final int interval;
+
+  NotusHistory(
+      {this.ignoreChange = false,
+      this.interval = 400,
+      this.maxStack = 100,
+      this.userOnly = false,
+      this.lastRecorded = 0});
+
+  void handleDocChange(NotusChange event) {
+    if (ignoreChange) return;
+    if (!userOnly || event.source == ChangeSource.local) {
+      record(event.change, event.before);
+    } else {
+      transform(event.change);
+    }
+  }
+
+  void clear() {
+    stack.clear();
+  }
+
+  void record(Delta change, Delta before) {
+    if (change.isEmpty) return;
+    stack.redo.clear();
+    Delta undoDelta = change.invert(before);
+    final timeStamp = DateTime.now().millisecondsSinceEpoch;
+
+    if (lastRecorded + interval > timeStamp && stack.undo.isNotEmpty) {
+      final lastDelta = stack.undo.removeLast();
+      undoDelta = undoDelta.compose(lastDelta);
+    } else {
+      lastRecorded = timeStamp;
+    }
+
+    if (undoDelta.isEmpty) return;
+    stack.undo.add(undoDelta);
+
+    if (stack.undo.length > maxStack) {
+      stack.undo.removeAt(0);
+    }
+  }
+
+  ///
+  ///It will override pre local undo delta,replaced by remote change
+  ///
+  void transform(Delta delta) {
+    transformStack(this.stack.undo, delta);
+    transformStack(this.stack.redo, delta);
+  }
+
+  void transformStack(List<Delta> stack, Delta delta) {
+    for (int i = stack.length - 1; i >= 0; i -= 1) {
+      final oldDelta = stack[i];
+      stack[i] = delta.transform(oldDelta, true);
+      delta = oldDelta.transform(delta, false);
+      if (stack[i].length == 0) {
+        stack.removeAt(i);
+      }
+    }
+  }
+
+  void _change(NotusDocument doc, List<Delta> source, List<Delta> dest) {
+    if (source.length == 0) return;
+    Delta delta = source.removeLast();
+    Delta base = doc.toDelta();
+    Delta inverseDelta = delta.invert(base);
+    dest.add(inverseDelta);
+    this.lastRecorded = 0;
+    this.ignoreChange = true;
+    doc.compose(delta, ChangeSource.local, history: true);
+    this.ignoreChange = false;
+  }
+
+  void undo(NotusDocument doc) {
+    _change(doc, stack.undo, stack.redo);
+  }
+
+  void redo(NotusDocument doc) {
+    _change(doc, stack.redo, stack.undo);
+  }
+}
+
+class NotusHistoryStack {
+  final List<Delta> undo;
+  final List<Delta> redo;
+
+  NotusHistoryStack.empty()
+      : undo = [],
+        redo = [];
+
+  void clear() {
+    undo.clear();
+    redo.clear();
+  }
+}

packages/notus/pubspec.yaml

@@ -1,6 +1,6 @@
 name: notus
 description: Platform-agnostic rich text document model based on Delta format and used in Zefyr editor.
-version: 0.1.5
+version: 0.1.6
 author: Anatoly Pulyaevskiy <anatoly.pulyaevskiy@gmail.com>
 homepage: https://github.com/memspace/zefyr
 

packages/zefyr/example/lib/src/images.dart

@@ -53,6 +53,11 @@ class CustomImageDelegate implements ZefyrImageDelegate<ImageSource> {
     }
   }
 
+  @override
+  void onImageTap(BuildContext context, String key) {
+    print(key);
+  }
+
   @override
   Future<String> picked(file, isFullImage) async {
     print(isFullImage);

packages/zefyr/lib/src/widgets/controller.dart

@@ -207,6 +207,16 @@ class ZefyrController extends ChangeNotifier {
     formatText(index, length, attribute);
   }
 
+  void undo() {
+    document.undo();
+    updateSelection(TextSelection.collapsed(offset: document.length));
+  }
+
+  void redo() {
+    document.redo();
+    updateSelection(TextSelection.collapsed(offset: document.length));
+  }
+  
   /// Returns style of specified text range.
   ///
   /// If nothing is selected but we've toggled an attribute,

packages/zefyr/lib/src/widgets/image.dart

@@ -30,6 +30,8 @@ abstract class ZefyrImageDelegate<S> {
   /// [pickImage] method.
   Widget buildImage(BuildContext context, String key);
 
+  void onImageTap(BuildContext context, String key);
+
   /// Picks an image from specified [source].
   ///
   /// Returns unique string key for the selected image. Returned key is stored
@@ -67,7 +69,12 @@ class _ZefyrImageState extends State<ZefyrImage> {
     return _EditableImage(
       child: Padding(
         padding: theme.defaultLineTheme.padding,
-        child: image,
+        child: GestureDetector(
+          onTap: () {
+            widget.delegate.onImageTap(context, imageSource);
+          },
+          child: image,
+        ),
       ),
       node: widget.node,
     );

packages/zefyr/lib/src/widgets/scope.dart

@@ -252,6 +252,18 @@ class ZefyrScope extends ChangeNotifier {
     _controller.formatSelection(value);
   }
 
+  void undo() {
+    assert(isEditable);
+    assert(!_disposed);
+    _controller.undo();
+  }
+
+  void redo() {
+    assert(isEditable);
+    assert(!_disposed);
+    _controller.redo();
+  }
+
   void focus() {
     assert(isEditable);
     assert(!_disposed);

packages/zefyr/test/widgets/buttons_test.dart

@@ -188,6 +188,10 @@ class _TestImageDelegate implements ZefyrImageDelegate<String> {
   Widget buildImage(BuildContext context, String key) {
     return Image.file(File(key));
   }
+  @override
+  void onImageTap(BuildContext context, String key) {
+    print(key);
+  }
 
   @override
   String get cameraSource => "camera";

packages/zefyr/test/widgets/image_test.dart

@@ -92,6 +92,10 @@ class _TestImageDelegate implements ZefyrImageDelegate<String> {
   Widget buildImage(BuildContext context, String key) {
     return Image.file(File(key));
   }
+  @override
+  void onImageTap(BuildContext context, String key) {
+    print(key);
+  }
 
   @override
   String get cameraSource => "camera";

packages/zefyr/test/widgets/scope_test.dart

@@ -79,6 +79,10 @@ class _TestImageDelegate implements ZefyrImageDelegate<String> {
   Widget buildImage(BuildContext context, String key) {
     return null;
   }
+  @override
+  void onImageTap(BuildContext context, String key) {
+    print(key);
+  }
 
   @override
   String get cameraSource => null;