fix text edit: copy/paste/select keyboard shortcut

Runtime/rendering/editable.cs

             bool vKey = pressedKeyCode == KeyCode.V;
             bool cKey = pressedKeyCode == KeyCode.C;
             bool del = pressedKeyCode == KeyCode.Delete;
-            bool backDel = pressedKeyCode == KeyCode.Backspace;
+
+            if (keyEvent is RawKeyCommandEvent) { // editor case
+                this._handleShortcuts(((RawKeyCommandEvent)keyEvent).command);
+                return;
+            }
+            if ((ctrl || (isMac && cmd)) && (xKey || vKey || cKey || aKey)) { // runtime case
+                if (xKey) {
+                    this._handleShortcuts(KeyCommand.Cut);
+                } else if (aKey) {
+                    this._handleShortcuts(KeyCommand.SelectAll);
+                } else if (vKey) {
+                    this._handleShortcuts(KeyCommand.Paste);
+                } else if (cKey) {
+                    this._handleShortcuts(KeyCommand.Copy);
+                }
+                return;
+            }
             
             if (arrow) {
                 int newOffset = this._extentOffset;
                 newOffset = this._handleShift(rightArrow, leftArrow, shift, newOffset);
 
                 this._extentOffset = newOffset;
-            } else if ((ctrl || (isMac && cmd)) && (xKey || vKey || cKey || aKey)) {
-                this._handleShortcuts(pressedKeyCode);
-            if (del || backDel) {
-                this._handleDelete(backDel);
+            if (del) {
+                this._handleDelete();
             }
         }
 
             return newOffset;
         }
 
-        void _handleShortcuts(KeyCode pressedKeyCode) {
-            switch (pressedKeyCode) {
-                case KeyCode.C:
+        void _handleShortcuts(KeyCommand cmd) {
+            switch (cmd) {
+                case KeyCommand.Copy:
-                case KeyCode.X:
+                case KeyCommand.Cut:
                     if (!this.selection.isCollapsed) {
                         Clipboard.setData(
                             new ClipboardData(text: this.selection.textInside(this.text.text)));
                         );
                     }
                     break;
-                case KeyCode.V:
+                case KeyCommand.Paste:
                     TextEditingValue value = this.textSelectionDelegate.textEditingValue;
                     Clipboard.getData(Clipboard.kTextPlain).Then(data => {
                         if (data != null) {
                     });
                     
                     break;
-                case KeyCode.A:
+                case KeyCommand.SelectAll:
                     this._baseOffset = 0;
                     this._extentOffset = this.textSelectionDelegate.textEditingValue.text.Length;
                     this.onSelectionChanged(
             }
         }
 
-        void _handleDelete(bool backDel) {
+        void _handleDelete() {
-            if (backDel && selection.isCollapsed) {
-                if (selection.start <= 0) {
-                    return;
-                }
-                selection = TextSelection.collapsed(selection.start - 1, selection.affinity);
-            }
             if (selection.textAfter(this.text.text).isNotEmpty()) {
                 this.textSelectionDelegate.textEditingValue = new TextEditingValue(
                     text: selection.textBefore(this.text.text)

Runtime/service/keyboard.cs

 
 namespace Unity.UIWidgets.service {
 
-    
     interface KeyboardDelegate: IDisposable {
         void show();
         void hide();
     class DefaultKeyboardDelegate : KeyboardDelegate, TextInputOnGUIListener {
 
         int _client;
-        string _lastCompositionString;
+        
         TextEditingValue _value;
 
         public void show() {
             if (this._client == 0) {
                 return;
             }
-
+            
+            
-           
+            var oldValue = this._value;
-                if (currentEvent.keyCode == KeyCode.Return) {
-                    Window.instance.run(() => { TextInput._performAction(this._client, TextInputAction.newline); });
-                }
-
-                if (currentEvent.character != '\0') {
+                if (currentEvent.keyCode == KeyCode.Backspace) {
+                    if (this._value.selection.isValid) {
+                        this._value = this._value.deleteSelection(true);
+                    }
+                } else if (currentEvent.character != '\0') {
+                    this._value = this._value.clearCompose();
-                    this._value = this._value.clearCompose();
+
+                    if (ch == '\n') {
+                        Window.instance.run(() => { TextInput._performAction(this._client, TextInputAction.newline); });
+                    }
+                    
-                    } 
-                    Window.instance.run(() => { TextInput._updateEditingState(this._client, this._value); });
+                    }
+                } else if (!string.IsNullOrEmpty(Input.compositionString)) {
+                    this._value = this._value.compose(Input.compositionString);
-
+                
-            if (!string.IsNullOrEmpty(Input.compositionString) &&
-                this._lastCompositionString != Input.compositionString) {
-                this._value = this._value.compose(Input.compositionString);
+           if (this._value != oldValue) {
-            }
-
-            this._lastCompositionString = Input.compositionString;
+           }
         }
 
         public void Dispose() {

Runtime/service/raw_keyboard.cs

                 return;
             }
 
-            var keyboardEvent = RawKeyEvent.fromEvent(evt);
+            var keyboardEvent = RawKeyEvent.processGUIEvent(evt);
-
+            
             foreach (var listener in new List<ValueChanged<RawKeyEvent>>(this._listeners)) {
                 if (this._listeners.Contains(listener)) {
                     listener(keyboardEvent);
             this.data = data;
         }
 
-        public static RawKeyEvent fromEvent(Event evt) {
+        public static RawKeyEvent processGUIEvent(Event evt) {
+            if (evt.type == EventType.ValidateCommand) {
+                var cmd = toKeyCommand(evt.commandName);
+                if (cmd != null) {
+                    evt.Use();
+                    return null;
+                }
+            } else if (evt.type == EventType.ExecuteCommand) { // Validate/ExecuteCommand is editor only
+                var cmd = toKeyCommand(evt.commandName);
+                if (cmd != null) {
+                    return new RawKeyCommandEvent(new RawKeyEventData(evt), cmd.Value);
+                }
+            }
+    
             if (evt.type == EventType.KeyDown) {
                 return new RawKeyDownEvent(new RawKeyEventData(evt));
             } else if (evt.type == EventType.KeyUp) {
         }
         
         public readonly RawKeyEventData data;
+
+        static KeyCommand? toKeyCommand(string commandName) {
+            switch (commandName) {
+                case "Paste":
+                    return KeyCommand.Paste;
+                case "Copy":
+                    return KeyCommand.Copy;
+                case "SelectAll":
+                    return KeyCommand.SelectAll;
+                case "Cut":
+                    return KeyCommand.Cut;
+                    
+            }
+
+            return null;
+        }
     }
     
     public class RawKeyDownEvent: RawKeyEvent {
         }
     }
 
+    public class RawKeyCommandEvent : RawKeyEvent {
+
+        public readonly KeyCommand command;
+        public RawKeyCommandEvent(RawKeyEventData data, KeyCommand command) : base(data) {
+            this.command = command;
+        }
+    }
+
+    public enum KeyCommand {
+        Copy,
+        Cut,
+        Paste,
+        SelectAll,
+    }
+    
     public class RawKeyEventData {
         public readonly Event unityEvent;
 

Runtime/service/text_input.cs

 
                     return this.copyWith(
                         text: this.text.Substring(0, this.selection.start - 1) + this.selection.textAfter(this.text),
-                        selection: TextSelection.collapsed(this.selection.start - 1));
+                        selection: TextSelection.collapsed(this.selection.start - 1),
+                        composing: TextRange.empty);
                 }
 
                 if (this.selection.start >= this.text.Length) {
                 return this.copyWith(text: this.text.Substring(0, this.selection.start) +
-                                           this.text.Substring(this.selection.start + 1));
+                                           this.text.Substring(this.selection.start + 1), 
+                    composing: TextRange.empty);
-                return this.copyWith(text: newText, selection: TextSelection.collapsed(this.selection.start));
+                return this.copyWith(text: newText, selection: TextSelection.collapsed(this.selection.start), 
+                    composing: TextRange.empty);
             }
         }