Action Widget won't show label for edits in hover when no edits are available (#192238)

* initial working version v1

* cleanup and fixed error in terminal quick fix

* code cleanup, making onFocus optional, removing terminal quickfix edits

* added logic for cancellation v1 and removing extra call to rerender

* registered cancellable tokens and added better checks onFocus

* code cleanup

src/vs/editor/contrib/codeAction/browser/codeActionController.ts

@@ -30,6 +30,7 @@ import { IMarkerService } from 'vs/platform/markers/common/markers';
 import { IEditorProgressService } from 'vs/platform/progress/common/progress';
 import { CodeActionAutoApply, CodeActionFilter, CodeActionItem, CodeActionSet, CodeActionTrigger, CodeActionTriggerSource } from '../common/types';
 import { CodeActionModel, CodeActionsState } from './codeActionModel';
+import { CancellationToken } from 'vs/base/common/cancellation';
 
 
 interface IActionShowOptions {
@@ -251,6 +252,13 @@ export class CodeActionController extends Disposable implements IEditorContribut
 			},
 			onHide: () => {
 				this._editor?.focus();
+			},
+			onFocus: async (action: CodeActionItem, token: CancellationToken) => {
+				await action.resolve(token);
+				if (token.isCancellationRequested) {
+					return;
+				}
+				return { canPreview: !!action.action.edit?.edits.length };
 			}
 		};
 

src/vs/editor/contrib/codeAction/browser/codeActionMenu.ts

@@ -44,7 +44,8 @@ export function toMenuItems(
 				item: action,
 				group: uncategorizedCodeActionGroup,
 				disabled: !!action.action.disabled,
-				label: action.action.disabled || action.action.title
+				label: action.action.disabled || action.action.title,
+				canPreview: !!action.action.edit?.edits.length,
 			};
 		});
 	}

src/vs/platform/actionWidget/browser/actionList.ts

@@ -6,6 +6,7 @@ import * as dom from 'vs/base/browser/dom';
 import { KeybindingLabel } from 'vs/base/browser/ui/keybindingLabel/keybindingLabel';
 import { IListEvent, IListMouseEvent, IListRenderer, IListVirtualDelegate } from 'vs/base/browser/ui/list/list';
 import { List } from 'vs/base/browser/ui/list/listWidget';
+import { CancellationToken, CancellationTokenSource } from 'vs/base/common/cancellation';
 import { Codicon } from 'vs/base/common/codicons';
 import { ResolvedKeybinding } from 'vs/base/common/keybindings';
 import { Disposable } from 'vs/base/common/lifecycle';
@@ -24,6 +25,7 @@ export const previewSelectedActionCommand = 'previewSelectedCodeAction';
 export interface IActionListDelegate<T> {
 	onHide(didCancel?: boolean): void;
 	onSelect(action: T, preview?: boolean): void;
+	onFocus?(action: T, cancellationToken: CancellationToken): Promise<{ canPreview: boolean } | void>;
 }
 
 export interface IActionListItem<T> {
@@ -32,8 +34,8 @@ export interface IActionListItem<T> {
 	readonly group?: { kind?: any; icon?: ThemeIcon; title: string };
 	readonly disabled?: boolean;
 	readonly label?: string;
-
 	readonly keybinding?: ResolvedKeybinding;
+	canPreview?: boolean | undefined;
 }
 
 interface IActionMenuTemplateData {
@@ -126,7 +128,7 @@ class ActionItemRenderer<T> implements IListRenderer<IActionListItem<T>, IAction
 		if (element.disabled) {
 			data.container.title = element.label;
 		} else if (actionTitle && previewTitle) {
-			if (this._supportsPreview) {
+			if (this._supportsPreview && element.canPreview) {
 				data.container.title = localize({ key: 'label-preview', comment: ['placeholders are keybindings, e.g "F2 to apply, Shift+F2 to preview"'] }, "{0} to apply, {1} to preview", actionTitle, previewTitle);
 			} else {
 				data.container.title = localize({ key: 'label', comment: ['placeholder is a keybinding, e.g "F2 to apply"'] }, "{0} to apply", actionTitle);
@@ -168,6 +170,8 @@ export class ActionList<T> extends Disposable {
 
 	private readonly _allMenuItems: readonly IActionListItem<T>[];
 
+	private readonly cts = this._register(new CancellationTokenSource());
+
 	constructor(
 		user: string,
 		preview: boolean,
@@ -230,6 +234,7 @@ export class ActionList<T> extends Disposable {
 
 	hide(didCancel?: boolean): void {
 		this._delegate.onHide(didCancel);
+		this.cts.cancel();
 		this._contextViewService.hideContextView();
 	}
 
@@ -302,7 +307,18 @@ export class ActionList<T> extends Disposable {
 		}
 	}
 
-	private onListHover(e: IListMouseEvent<IActionListItem<T>>): void {
+	private async onListHover(e: IListMouseEvent<IActionListItem<T>>) {
+		const element = e.element;
+		if (element && element.item && this.focusCondition(element)) {
+			if (this._delegate.onFocus && !element.disabled && element.kind === ActionListItemKind.Action) {
+				const result = await this._delegate.onFocus(element.item, this.cts.token);
+				element.canPreview = result ? result.canPreview : undefined;
+			}
+			if (e.index) {
+				this._list.splice(e.index, 1, [element]);
+			}
+		}
+
 		this._list.setFocus(typeof e.index === 'number' ? [e.index] : []);
 	}