Hover on keyboard modifier should trigger instantly

src/vs/editor/contrib/hover/browser/contentHoverController.ts

@@ -17,7 +17,7 @@ import { IKeybindingService } from '../../../../platform/keybinding/common/keybi
 import { ResultKind } from '../../../../platform/keybinding/common/keybindingResolver.js';
 import { HoverVerbosityAction } from '../../../common/languages.js';
 import { RunOnceScheduler } from '../../../../base/common/async.js';
-import { isMousePositionWithinElement, shouldShowHover } from './hoverUtils.js';
+import { isMousePositionWithinElement, shouldShowHover, isTriggerModifierPressed } from './hoverUtils.js';
 import { ContentHoverWidgetWrapper } from './contentHoverWidgetWrapper.js';
 import './hover.css';
 import { Emitter } from '../../../../base/common/event.js';
@@ -269,6 +269,29 @@ export class ContentHoverController extends Disposable implements IEditorContrib
 		if (this._ignoreMouseEvents) {
 			return;
 		}
+		// New behavior: if hover is configured for keyboard modifier and the user presses the triggering modifier
+		// we should show the hover immediately for the current (last known) mouse location even without moving the mouse again.
+		if (this._hoverSettings.enabled === 'onKeyboardModifier' && this._mouseMoveEvent) {
+			const multiCursorModifier = this._editor.getOption(EditorOption.multiCursorModifier); // 'altKey' | 'ctrlKey' | 'metaKey'
+			const triggerPressed = isTriggerModifierPressed(multiCursorModifier, e);
+			if (triggerPressed) {
+				// Avoid re-trigger if already visible
+				if (!this._contentWidget?.isVisible) {
+					// Get the position/range from the last mouse event and show hover immediately
+					const mouseTarget = this._mouseMoveEvent.target;
+					if (mouseTarget.position) {
+						this.showContentHover(
+							Range.fromPositions(mouseTarget.position),
+							HoverStartMode.Immediate,
+							HoverStartSource.Keyboard,
+							false
+						);
+					}
+				}
+				// Do not hide hover for this key press
+				return;
+			}
+		}
 		if (!this._contentWidget) {
 			return;
 		}

src/vs/editor/contrib/hover/browser/hoverUtils.ts

@@ -26,6 +26,20 @@ export function isMousePositionWithinElement(element: HTMLElement, posx: number,
  * @param mouseEvent - The current mouse event containing modifier key states
  * @returns true if hover should be shown, false otherwise
  */
+/**
+ * Returns true if the trigger modifier (inverse of multi-cursor modifier) is pressed.
+ * This works with both mouse and keyboard events by relying only on the modifier flags.
+ */
+export function isTriggerModifierPressed(
+	multiCursorModifier: 'altKey' | 'ctrlKey' | 'metaKey',
+	event: { ctrlKey: boolean; metaKey: boolean; altKey: boolean }
+): boolean {
+	if (multiCursorModifier === 'altKey') {
+		return event.ctrlKey || event.metaKey;
+	}
+	return event.altKey; // multiCursorModifier is ctrlKey or metaKey
+}
+
 export function shouldShowHover(
 	hoverEnabled: 'on' | 'off' | 'onKeyboardModifier',
 	multiCursorModifier: 'altKey' | 'ctrlKey' | 'metaKey',
@@ -37,9 +51,6 @@ export function shouldShowHover(
 	if (hoverEnabled === 'off') {
 		return false;
 	}
-	if (multiCursorModifier === 'altKey') {
-		return mouseEvent.event.ctrlKey || mouseEvent.event.metaKey;
-	} else {
-		return mouseEvent.event.altKey;
-	}
+	// onKeyboardModifier
+	return isTriggerModifierPressed(multiCursorModifier, mouseEvent.event);
 }