feat(cdk/menu): add output event for contextmenu

this commit exposes an output that emits whenever user triggers `contextmenu` event which contains `clientX` and `clientY` position respectively

fixes #29072

Author: naaajii

src/cdk/menu/context-menu-trigger.spec.ts

@@ -165,6 +165,15 @@ describe('CdkContextMenuTrigger', () => {
       expect(fixture.componentInstance.trigger.outsideClicked.emit).toHaveBeenCalled();
       expect(getContextMenu()).not.toBeDefined();
     });
+
+    it('should emit that menu was triggered', () => {
+      fixture.detectChanges();
+      spyOn(fixture.componentInstance.trigger.triggered, 'emit');
+
+      openContextMenu();
+
+      expect(fixture.componentInstance.trigger.triggered.emit).toHaveBeenCalled();
+    });
   });
 
   describe('nested context menu triggers', () => {

src/cdk/menu/context-menu-trigger.ts

@@ -79,6 +79,7 @@ export type ContextMenuCoordinates = {x: number; y: number};
     'opened: cdkContextMenuOpened',
     'closed: cdkContextMenuClosed',
     'outsideClicked: cdkContextMenuOutsideClicked',
+    'triggered: cdkContextMenuTriggered',
   ],
   providers: [
     {provide: MENU_TRIGGER, useExisting: CdkContextMenuTrigger},
@@ -148,6 +149,9 @@ export class CdkContextMenuTrigger extends CdkMenuTriggerBase implements OnDestr
       } else {
         this.childMenu?.focusFirstItem('program');
       }
+
+      // Emit that the user have triggered contextmenu event.
+      this.triggered.emit({x: event.clientX, y: event.clientY});
     }
   }
 

src/cdk/menu/menu-trigger-base.ts

@@ -76,6 +76,9 @@ export abstract class CdkMenuTriggerBase implements OnDestroy {
   /** Emits when the attached menu has click outside of it in open state */
   readonly outsideClicked: EventEmitter<MouseEvent> = new EventEmitter();
 
+  /** Emits when the user triggers context menu */
+  readonly triggered: EventEmitter<{x: number; y: number}> = new EventEmitter();
+
   /** Template reference variable to the menu this trigger opens */
   menuTemplateRef: TemplateRef<unknown> | null;
 

tools/public_api_guard/cdk/menu.md

@@ -44,7 +44,7 @@ export class CdkContextMenuTrigger extends CdkMenuTriggerBase implements OnDestr
     open(coordinates: ContextMenuCoordinates): void;
     _openOnContextMenu(event: MouseEvent): void;
     // (undocumented)
-    static ɵdir: i0.ɵɵDirectiveDeclaration<CdkContextMenuTrigger, "[cdkContextMenuTriggerFor]", ["cdkContextMenuTriggerFor"], { "menuTemplateRef": { "alias": "cdkContextMenuTriggerFor"; "required": false; }; "menuPosition": { "alias": "cdkContextMenuPosition"; "required": false; }; "menuData": { "alias": "cdkContextMenuTriggerData"; "required": false; }; "disabled": { "alias": "cdkContextMenuDisabled"; "required": false; }; "disableCloseOnOutsideClick": { "alias": "cdkContextMenuDisableCloseOnOutsideClick"; "required": false; }; }, { "opened": "cdkContextMenuOpened"; "closed": "cdkContextMenuClosed"; "outsideClicked": "cdkContextMenuOutsideClicked"; }, never, never, true, never>;
+    static ɵdir: i0.ɵɵDirectiveDeclaration<CdkContextMenuTrigger, "[cdkContextMenuTriggerFor]", ["cdkContextMenuTriggerFor"], { "menuTemplateRef": { "alias": "cdkContextMenuTriggerFor"; "required": false; }; "menuPosition": { "alias": "cdkContextMenuPosition"; "required": false; }; "menuData": { "alias": "cdkContextMenuTriggerData"; "required": false; }; "disabled": { "alias": "cdkContextMenuDisabled"; "required": false; }; "disableCloseOnOutsideClick": { "alias": "cdkContextMenuDisableCloseOnOutsideClick"; "required": false; }; }, { "opened": "cdkContextMenuOpened"; "closed": "cdkContextMenuClosed"; "outsideClicked": "cdkContextMenuOutsideClicked"; "triggered": "cdkContextMenuTriggered"; }, never, never, true, never>;
     // (undocumented)
     static ɵfac: i0.ɵɵFactoryDeclaration<CdkContextMenuTrigger, never>;
 }
@@ -239,6 +239,10 @@ export abstract class CdkMenuTriggerBase implements OnDestroy {
     protected overlayRef: OverlayRef | null;
     registerChildMenu(child: Menu): void;
     protected readonly stopOutsideClicksListener: Observable<void>;
+    readonly triggered: EventEmitter<{
+        x: number;
+        y: number;
+    }>;
     protected readonly viewContainerRef: ViewContainerRef;
     // (undocumented)
     static ɵdir: i0.ɵɵDirectiveDeclaration<CdkMenuTriggerBase, never, never, {}, {}, never, never, true, never>;