Implement cursorRedo

src/vs/editor/contrib/cursorUndo/cursorUndo.ts

@@ -26,81 +26,83 @@ class CursorState {
 	}
 }
 
-export class CursorUndoController extends Disposable implements IEditorContribution {
+export class CursorUndoRedoController extends Disposable implements IEditorContribution {
 
-	public static readonly ID = 'editor.contrib.cursorUndoController';
+	public static readonly ID = 'editor.contrib.cursorUndoRedoController';
 
-	public static get(editor: ICodeEditor): CursorUndoController {
-		return editor.getContribution<CursorUndoController>(CursorUndoController.ID);
+	public static get(editor: ICodeEditor): CursorUndoRedoController {
+		return editor.getContribution<CursorUndoRedoController>(CursorUndoRedoController.ID);
 	}
 
 	private readonly _editor: ICodeEditor;
-	private _isCursorUndo: boolean;
+	private _isCursorUndoRedo: boolean;
 
 	private _undoStack: CursorState[];
+	private _redoStack: CursorState[];
 	private _prevState: CursorState | null;
 
 	constructor(editor: ICodeEditor) {
 		super();
 		this._editor = editor;
-		this._isCursorUndo = false;
+		this._isCursorUndoRedo = false;
 
 		this._undoStack = [];
-		this._prevState = this._readState();
+		this._redoStack = [];
+		this._prevState = null;
 
 		this._register(editor.onDidChangeModel((e) => {
 			this._undoStack = [];
+			this._redoStack = [];
 			this._prevState = null;
 		}));
 		this._register(editor.onDidChangeModelContent((e) => {
 			this._undoStack = [];
+			this._redoStack = [];
 			this._prevState = null;
 		}));
 		this._register(editor.onDidChangeCursorSelection((e) => {
 
-			if (!this._isCursorUndo && this._prevState) {
-				this._undoStack.push(this._prevState);
-				if (this._undoStack.length > 50) {
-					// keep the cursor undo stack bounded
-					this._undoStack.shift();
+			const newState = new CursorState(this._editor.getSelections()!);
+
+			if (!this._isCursorUndoRedo && this._prevState) {
+				const isEqualToLastUndoStack = (this._undoStack.length > 0 && this._undoStack[this._undoStack.length - 1].equals(this._prevState));
+				if (!isEqualToLastUndoStack) {
+					this._undoStack.push(this._prevState);
+					this._redoStack = [];
+					if (this._undoStack.length > 50) {
+						// keep the cursor undo stack bounded
+						this._undoStack.shift();
+					}
 				}
 			}
 
-			this._prevState = this._readState();
+			this._prevState = newState;
 		}));
 	}
 
-	private _readState(): CursorState | null {
-		if (!this._editor.hasModel()) {
-			// no model => no state
-			return null;
+	public cursorUndo(): void {
+		if (!this._editor.hasModel() || this._undoStack.length === 0) {
+			return;
 		}
 
-		return new CursorState(this._editor.getSelections());
+		this._redoStack.push(new CursorState(this._editor.getSelections()));
+		this._applyState(this._undoStack.pop()!);
 	}
 
-	public cursorUndo(): void {
-		if (!this._editor.hasModel()) {
+	public cursorRedo(): void {
+		if (!this._editor.hasModel() || this._redoStack.length === 0) {
 			return;
 		}
 
-		const currState = new CursorState(this._editor.getSelections());
-
-		while (this._undoStack.length > 0) {
-			const prevState = this._undoStack.pop()!;
-
-			if (!prevState.equals(currState)) {
-				this._isCursorUndo = true;
-				this._editor.setSelections(prevState.selections);
-				this._editor.revealRangeInCenterIfOutsideViewport(prevState.selections[0], ScrollType.Smooth);
-				this._isCursorUndo = false;
-				return;
-			}
-		}
+		this._undoStack.push(new CursorState(this._editor.getSelections()));
+		this._applyState(this._redoStack.pop()!);
 	}
 
-	public cursorRedo(): void {
-		throw new Error('Not implemented!');
+	private _applyState(state: CursorState): void {
+		this._isCursorUndoRedo = true;
+		this._editor.setSelections(state.selections);
+		this._editor.revealRangeInCenterIfOutsideViewport(state.selections[0], ScrollType.Smooth);
+		this._isCursorUndoRedo = false;
 	}
 }
 
@@ -120,7 +122,7 @@ export class CursorUndo extends EditorAction {
 	}
 
 	public run(accessor: ServicesAccessor, editor: ICodeEditor, args: any): void {
-		CursorUndoController.get(editor).cursorUndo();
+		CursorUndoRedoController.get(editor).cursorUndo();
 	}
 }
 
@@ -135,10 +137,10 @@ export class CursorRedo extends EditorAction {
 	}
 
 	public run(accessor: ServicesAccessor, editor: ICodeEditor, args: any): void {
-		CursorUndoController.get(editor).cursorRedo();
+		CursorUndoRedoController.get(editor).cursorRedo();
 	}
 }
 
-registerEditorContribution(CursorUndoController.ID, CursorUndoController);
+registerEditorContribution(CursorUndoRedoController.ID, CursorUndoRedoController);
 registerEditorAction(CursorUndo);
 registerEditorAction(CursorRedo);