Implement Separate Delays for Line Change and Inline Navigation

This update introduces distinct delays for line changes and inline navigation. The update aims to enhance user experience by adjusting the delay based on the user's navigation behavior. When the user navigates within the same line, likely reading content character by character or word by word, longer delays are applied to minimize interference with screen reader output. Conversely, when the user changes lines, possibly skimming through the program, shorter delays are implemented to provide timely feedback. This approach ensures a balance between providing necessary accessibility signals and maintaining a smooth reading experience.

src/vs/workbench/contrib/accessibilitySignals/browser/accessibilitySignalLineFeatureContribution.ts

@@ -150,6 +150,8 @@ export class SignalLineFeatureContribution
 					if (!position) {
 						return false;
 					}
+					feature.trackLineChanged(position);
+
 					return lineFeatureState.read(reader).isPresent(position);
 				}
 			);
@@ -202,13 +204,19 @@ interface LineFeature {
 		editor: ICodeEditor,
 		model: ITextModel
 	): IObservable<LineFeatureState>;
+	trackLineChanged(position: Position): void;
 	getDelay(modality: SignalModality): number;
 }
 
 interface LineFeatureState {
 	isPresent(position: Position): boolean;
 }
 
+type DelayType = {
+	line: number;
+	inline: number;
+};
+
 abstract class BaseLineFeature implements LineFeature {
 	// mandatory properties of the original LineFeature interface
 	abstract signal: AccessibilitySignal;
@@ -218,13 +226,33 @@ abstract class BaseLineFeature implements LineFeature {
 	): IObservable<LineFeatureState>;
 
 	// Holds the current delay values associated with this feature
-	protected _modalityDelays: Map<SignalModality, number> = new Map();
+	protected _modalityDelays: Map<SignalModality, DelayType> = new Map();
+	protected setModalityDelays(modality: SignalModality, lineDelay: number, inlineDelay: number) {
+		this._modalityDelays.set(modality, { line: lineDelay, inline: inlineDelay });
+	}
+
+	protected _previousLine: number = 0;
+	protected _lineChanged: boolean = false;
+	public trackLineChanged(position: Position) {
+		this._lineChanged = position.lineNumber !== this._previousLine;
+		this._previousLine = position.lineNumber;
+	}
+
+	constructor() {
+		// set default delays to "info" feature type (longer delays)
+		// TODO: Retrieve values from user-configurable settings
+		this.setModalityDelays(SignalModality.Sound, 300, 600);
+		this.setModalityDelays(SignalModality.Announcement, 600, 1500);
+	}
 
 	public getDelay(modality: SignalModality): number {
 		let minDelay = Infinity;
-		for (const [key, delay] of this._modalityDelays) {
-			if ((modality & key) !== 0 && delay < minDelay) {
-				minDelay = delay;
+		for (const [key, delayObj] of this._modalityDelays) {
+			if ((modality & key) !== 0) {
+				const delay = this._lineChanged ? delayObj.line : delayObj.inline;
+				if (delay < minDelay) {
+					minDelay = delay;
+				}
 			}
 		}
 		return minDelay === Infinity ? 0 : minDelay;
@@ -234,7 +262,6 @@ abstract class BaseLineFeature implements LineFeature {
 class MarkerLineFeature extends BaseLineFeature implements LineFeature {
 	public readonly debounceWhileTyping = true;
 
-	private _previousLine: number = 0;
 	constructor(
 		public readonly signal: AccessibilitySignal,
 		private readonly severity: MarkerSeverity,
@@ -243,8 +270,8 @@ class MarkerLineFeature extends BaseLineFeature implements LineFeature {
 	) {
 		super();
 		// TODO: Retrieve values from user-configurable settings
-		this._modalityDelays.set(SignalModality.Sound, 50);
-		this._modalityDelays.set(SignalModality.Announcement, 500);
+		this.setModalityDelays(SignalModality.Sound, 0, 300);
+		this.setModalityDelays(SignalModality.Announcement, 300, 600);
 	}
 
 	getObservableState(editor: ICodeEditor, model: ITextModel): IObservable<LineFeatureState> {
@@ -254,14 +281,12 @@ class MarkerLineFeature extends BaseLineFeature implements LineFeature {
 			),
 			() => /** @description this.markerService.onMarkerChanged */({
 				isPresent: (position) => {
-					const lineChanged = position.lineNumber !== this._previousLine;
-					this._previousLine = position.lineNumber;
 					const hasMarker = this.markerService
 						.read({ resource: model.uri })
 						.some(
 							(m) => {
 								const onLine = m.severity === this.severity && m.startLineNumber <= position.lineNumber && position.lineNumber <= m.endLineNumber;
-								return lineChanged ? onLine : onLine && (position.lineNumber <= m.endLineNumber && m.startColumn <= position.column && m.endColumn >= position.column);
+								return this._lineChanged ? onLine : onLine && (position.lineNumber <= m.endLineNumber && m.startColumn <= position.column && m.endColumn >= position.column);
 							});
 					return hasMarker;
 				},
@@ -275,9 +300,6 @@ class FoldedAreaLineFeature extends BaseLineFeature implements LineFeature {
 
 	constructor() {
 		super();
-		// TODO: Retrieve values from user-configurable settings
-		this._modalityDelays.set(SignalModality.Sound, 500);
-		this._modalityDelays.set(SignalModality.Announcement, 1500);
 	}
 
 	getObservableState(editor: ICodeEditor, model: ITextModel): IObservable<LineFeatureState> {
@@ -309,9 +331,6 @@ class BreakpointLineFeature extends BaseLineFeature implements LineFeature {
 
 	constructor(@IDebugService private readonly debugService: IDebugService) {
 		super();
-		// TODO: Retrieve values from user-configurable settings
-		this._modalityDelays.set(SignalModality.Sound, 400);
-		this._modalityDelays.set(SignalModality.Announcement, 1000);
 	}
 
 	getObservableState(editor: ICodeEditor, model: ITextModel): IObservable<LineFeatureState> {