Fixes #66944: Tokenize viewport with debouncing after scrolling and when the...

Fixes #66944: Tokenize viewport with debouncing after scrolling and when the tokenization support has changed

src/vs/editor/common/model/textModel.ts

@@ -315,6 +315,7 @@ export class TextModel extends Disposable implements model.ITextModel {
 
 			this._resetTokenizationState();
 			this.emitModelTokensChangedEvent({
+				tokenizationSupportChanged: true,
 				ranges: [{
 					fromLineNumber: 1,
 					toLineNumber: this.getLineCount()
@@ -1841,6 +1842,7 @@ export class TextModel extends Disposable implements model.ITextModel {
 	public flushTokens(): void {
 		this._resetTokenizationState();
 		this.emitModelTokensChangedEvent({
+			tokenizationSupportChanged: false,
 			ranges: [{
 				fromLineNumber: 1,
 				toLineNumber: this.getLineCount()
@@ -1923,6 +1925,7 @@ export class TextModel extends Disposable implements model.ITextModel {
 		this._resetTokenizationState();
 
 		this.emitModelTokensChangedEvent({
+			tokenizationSupportChanged: true,
 			ranges: [{
 				fromLineNumber: 1,
 				toLineNumber: this.getLineCount()

src/vs/editor/common/model/textModelEvents.ts

@@ -82,6 +82,7 @@ export interface IModelDecorationsChangedEvent {
  * An event describing that some ranges of lines have been tokenized (their tokens have changed).
  */
 export interface IModelTokensChangedEvent {
+	readonly tokenizationSupportChanged: boolean;
 	readonly ranges: {
 		/**
 		 * The start of the range (inclusive)

src/vs/editor/common/model/textModelTokens.ts

@@ -500,6 +500,7 @@ export class ModelTokensChangedEventBuilder {
 			return null;
 		}
 		return {
+			tokenizationSupportChanged: false,
 			ranges: this._ranges
 		};
 	}

src/vs/editor/common/viewModel/viewModelImpl.ts

@@ -23,6 +23,7 @@ import { IViewModelLinesCollection, IdentityLinesCollection, SplitLinesCollectio
 import { ICoordinatesConverter, IOverviewRulerDecorations, IViewModel, MinimapLinesRenderingData, ViewLineData, ViewLineRenderingData, ViewModelDecoration } from 'vs/editor/common/viewModel/viewModel';
 import { ViewModelDecorations } from 'vs/editor/common/viewModel/viewModelDecorations';
 import { ITheme } from 'vs/platform/theme/common/themeService';
+import { RunOnceScheduler } from 'vs/base/common/async';
 
 const USE_IDENTITY_LINES_COLLECTION = true;
 
@@ -31,6 +32,7 @@ export class ViewModel extends viewEvents.ViewEventEmitter implements IViewModel
 	private readonly editorId: number;
 	private readonly configuration: editorCommon.IConfiguration;
 	private readonly model: ITextModel;
+	private readonly _tokenizeViewportSoon: RunOnceScheduler;
 	private hasFocus: boolean;
 	private viewportStartLine: number;
 	private viewportStartLineTrackedRange: string | null;
@@ -38,7 +40,6 @@ export class ViewModel extends viewEvents.ViewEventEmitter implements IViewModel
 	private readonly lines: IViewModelLinesCollection;
 	public readonly coordinatesConverter: ICoordinatesConverter;
 	public readonly viewLayout: ViewLayout;
-
 	private readonly decorations: ViewModelDecorations;
 
 	constructor(editorId: number, configuration: editorCommon.IConfiguration, model: ITextModel, scheduleAtNextAnimationFrame: (callback: () => void) => IDisposable) {
@@ -47,6 +48,7 @@ export class ViewModel extends viewEvents.ViewEventEmitter implements IViewModel
 		this.editorId = editorId;
 		this.configuration = configuration;
 		this.model = model;
+		this._tokenizeViewportSoon = this._register(new RunOnceScheduler(() => this.tokenizeViewport(), 50));
 		this.hasFocus = false;
 		this.viewportStartLine = -1;
 		this.viewportStartLineTrackedRange = null;
@@ -80,6 +82,9 @@ export class ViewModel extends viewEvents.ViewEventEmitter implements IViewModel
 		this.viewLayout = this._register(new ViewLayout(this.configuration, this.getLineCount(), scheduleAtNextAnimationFrame));
 
 		this._register(this.viewLayout.onDidScroll((e) => {
+			if (e.scrollTopChanged) {
+				this._tokenizeViewportSoon.schedule();
+			}
 			try {
 				const eventsCollector = this._beginEmit();
 				eventsCollector.emit(new viewEvents.ViewScrollChangedEvent(e));
@@ -280,6 +285,10 @@ export class ViewModel extends viewEvents.ViewEventEmitter implements IViewModel
 			} finally {
 				this._endEmit();
 			}
+
+			if (e.tokenizationSupportChanged) {
+				this._tokenizeViewportSoon.schedule();
+			}
 		}));
 
 		this._register(this.model.onDidChangeLanguageConfiguration((e) => {

src/vs/monaco.d.ts

@@ -2263,6 +2263,7 @@ declare namespace monaco.editor {
 	 * An event describing that some ranges of lines have been tokenized (their tokens have changed).
 	 */
 	export interface IModelTokensChangedEvent {
+		readonly tokenizationSupportChanged: boolean;
 		readonly ranges: {
 			/**
 			 * The start of the range (inclusive)