Don't track selections if tracking is not needed (#42317)

microsoft · Apr 25, 2018 · 9cbc162 · 9cbc162
1 parent 6091135
commit 9cbc162
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Showing 3 changed files with 49 additions and 1 deletion.
diff --git a/src/vs/editor/common/controller/cursor.ts b/src/vs/editor/common/controller/cursor.ts
@@ -476,6 +476,12 @@ export class Cursor extends viewEvents.ViewEventEmitter implements ICursors {
 		const oldState = new CursorModelState(this._model, this);
 		let cursorChangeReason = CursorChangeReason.NotSet;
 
+		if (handlerId !== H.Undo && handlerId !== H.Redo) {
+			// TODO@Alex: if the undo/redo stack contains non-null selections
+			// it would also be OK to stop tracking selections here
+			this._cursors.stopTrackingSelections();
+		}
+
 		// ensure valid state on all cursors
 		this._cursors.ensureValidState();
 
@@ -524,6 +530,10 @@ export class Cursor extends viewEvents.ViewEventEmitter implements ICursors {
 
 		this._isHandling = false;
 
+		if (handlerId !== H.Undo && handlerId !== H.Redo) {
+			this._cursors.startTrackingSelections();
+		}
+
 		if (this._emitStateChangedIfNecessary(source, cursorChangeReason, oldState)) {
 			this._revealRange(RevealTarget.Primary, viewEvents.VerticalRevealType.Simple, true, editorCommon.ScrollType.Smooth);
 		}

diff --git a/src/vs/editor/common/controller/cursorCollection.ts b/src/vs/editor/common/controller/cursorCollection.ts
@@ -31,6 +31,20 @@ export class CursorCollection {
 		this.killSecondaryCursors();
 	}
 
+	public startTrackingSelections(): void {
+		this.primaryCursor.startTrackingSelection(this.context);
+		for (let i = 0, len = this.secondaryCursors.length; i < len; i++) {
+			this.secondaryCursors[i].startTrackingSelection(this.context);
+		}
+	}
+
+	public stopTrackingSelections(): void {
+		this.primaryCursor.stopTrackingSelection(this.context);
+		for (let i = 0, len = this.secondaryCursors.length; i < len; i++) {
+			this.secondaryCursors[i].stopTrackingSelection(this.context);
+		}
+	}
+
 	public updateContext(context: CursorContext): void {
 		this.context = context;
 	}

diff --git a/src/vs/editor/common/controller/oneCursor.ts b/src/vs/editor/common/controller/oneCursor.ts
@@ -16,12 +16,14 @@ export class OneCursor {
 	public viewState: SingleCursorState;
 
 	private _selTrackedRange: string;
+	private _trackSelection: boolean;
 
 	constructor(context: CursorContext) {
 		this.modelState = null;
 		this.viewState = null;
 
 		this._selTrackedRange = null;
+		this._trackSelection = true;
 
 		this._setState(
 			context,
@@ -31,6 +33,28 @@ export class OneCursor {
 	}
 
 	public dispose(context: CursorContext): void {
+		this._removeTrackedRange(context);
+	}
+
+	public startTrackingSelection(context: CursorContext): void {
+		this._trackSelection = true;
+		this._updateTrackedRange(context);
+	}
+
+	public stopTrackingSelection(context: CursorContext): void {
+		this._trackSelection = false;
+		this._removeTrackedRange(context);
+	}
+
+	private _updateTrackedRange(context: CursorContext): void {
+		if (!this._trackSelection) {
+			// don't track the selection
+			return;
+		}
+		this._selTrackedRange = context.model._setTrackedRange(this._selTrackedRange, this.modelState.selection, TrackedRangeStickiness.AlwaysGrowsWhenTypingAtEdges);
+	}
+
+	private _removeTrackedRange(context: CursorContext): void {
 		this._selTrackedRange = context.model._setTrackedRange(this._selTrackedRange, null, TrackedRangeStickiness.AlwaysGrowsWhenTypingAtEdges);
 	}
 
@@ -96,6 +120,6 @@ export class OneCursor {
 		this.modelState = modelState;
 		this.viewState = viewState;
 
-		this._selTrackedRange = context.model._setTrackedRange(this._selTrackedRange, this.modelState.selection, TrackedRangeStickiness.AlwaysGrowsWhenTypingAtEdges);
+		this._updateTrackedRange(context);
 	}
 }