fix(material/menu): position classes not updated when window is resized

src/material-experimental/mdc-menu/menu.spec.ts

@@ -1331,6 +1331,29 @@ describe('MDC-based MatMenu', () => {
       expect(panel.classList).not.toContain('mat-menu-above');
     }));
 
+    it('should update the position classes if the window is resized', fakeAsync(() => {
+      trigger.style.position = 'fixed';
+      trigger.style.top = '300px';
+      fixture.componentInstance.yPosition = 'above';
+      fixture.componentInstance.trigger.openMenu();
+      fixture.detectChanges();
+      tick(500);
+
+      const panel = overlayContainerElement.querySelector('.mat-mdc-menu-panel') as HTMLElement;
+
+      expect(panel.classList).toContain('mat-menu-above');
+      expect(panel.classList).not.toContain('mat-menu-below');
+
+      trigger.style.top = '0';
+      dispatchFakeEvent(window, 'resize');
+      fixture.detectChanges();
+      tick(500);
+      fixture.detectChanges();
+
+      expect(panel.classList).not.toContain('mat-menu-above');
+      expect(panel.classList).toContain('mat-menu-below');
+    }));
+
     it('should be able to update the position after the first open', fakeAsync(() => {
       trigger.style.position = 'fixed';
       trigger.style.top = '200px';

src/material-experimental/mdc-menu/menu.ts

@@ -9,6 +9,7 @@
 import {Overlay, ScrollStrategy} from '@angular/cdk/overlay';
 import {
   ChangeDetectionStrategy,
+  ChangeDetectorRef,
   Component,
   ElementRef,
   Inject,
@@ -56,11 +57,22 @@ export class MatMenu extends _MatMenuBase {
   protected override _elevationPrefix = 'mat-mdc-elevation-z';
   protected override _baseElevation = 8;
 
+  /*
+   * @deprecated `changeDetectorRef` parameter will become a required parameter.
+   * @breaking-change 15.0.0
+   */
+  constructor(
+    elementRef: ElementRef<HTMLElement>,
+    ngZone: NgZone,
+    defaultOptions: MatMenuDefaultOptions,
+  );
+
   constructor(
     _elementRef: ElementRef<HTMLElement>,
     _ngZone: NgZone,
     @Inject(MAT_MENU_DEFAULT_OPTIONS) _defaultOptions: MatMenuDefaultOptions,
+    changeDetectorRef?: ChangeDetectorRef,
   ) {
-    super(_elementRef, _ngZone, _defaultOptions);
+    super(_elementRef, _ngZone, _defaultOptions, changeDetectorRef);
   }
 }

src/material/menu/menu-trigger.ts

@@ -32,6 +32,7 @@ import {
   Inject,
   InjectionToken,
   Input,
+  NgZone,
   OnDestroy,
   Optional,
   Output,
@@ -200,6 +201,21 @@ export abstract class _MatMenuTriggerBase implements AfterContentInit, OnDestroy
     focusMonitor?: FocusMonitor | null,
   );
 
+  /**
+   * @deprecated `ngZone` will become a required parameter.
+   * @breaking-change 15.0.0
+   */
+  constructor(
+    overlay: Overlay,
+    element: ElementRef<HTMLElement>,
+    viewContainerRef: ViewContainerRef,
+    scrollStrategy: any,
+    parentMenu: MatMenuPanel,
+    menuItemInstance: MatMenuItem,
+    dir: Directionality,
+    focusMonitor: FocusMonitor,
+  );
+
   constructor(
     private _overlay: Overlay,
     private _element: ElementRef<HTMLElement>,
@@ -211,6 +227,7 @@ export abstract class _MatMenuTriggerBase implements AfterContentInit, OnDestroy
     @Optional() @Self() private _menuItemInstance: MatMenuItem,
     @Optional() private _dir: Directionality,
     private _focusMonitor: FocusMonitor | null,
+    private _ngZone?: NgZone,
   ) {
     this._scrollStrategy = scrollStrategy;
     this._parentMaterialMenu = parentMenu instanceof _MatMenuBase ? parentMenu : undefined;
@@ -472,7 +489,14 @@ export abstract class _MatMenuTriggerBase implements AfterContentInit, OnDestroy
         const posX: MenuPositionX = change.connectionPair.overlayX === 'start' ? 'after' : 'before';
         const posY: MenuPositionY = change.connectionPair.overlayY === 'top' ? 'below' : 'above';
 
-        this.menu.setPositionClasses!(posX, posY);
+        // @breaking-change 15.0.0 Remove null check for `ngZone`.
+        // `positionChanges` fires outside of the `ngZone` and `setPositionClasses` might be
+        // updating something in the view so we need to bring it back in.
+        if (this._ngZone) {
+          this._ngZone.run(() => this.menu.setPositionClasses!(posX, posY));
+        } else {
+          this.menu.setPositionClasses!(posX, posY);
+        }
       });
     }
   }

src/material/menu/menu.spec.ts

@@ -1326,6 +1326,29 @@ describe('MatMenu', () => {
       expect(panel.classList).not.toContain('mat-menu-above');
     }));
 
+    it('should update the position classes if the window is resized', fakeAsync(() => {
+      trigger.style.position = 'fixed';
+      trigger.style.top = '300px';
+      fixture.componentInstance.yPosition = 'above';
+      fixture.componentInstance.trigger.openMenu();
+      fixture.detectChanges();
+      tick(500);
+
+      const panel = overlayContainerElement.querySelector('.mat-menu-panel') as HTMLElement;
+
+      expect(panel.classList).toContain('mat-menu-above');
+      expect(panel.classList).not.toContain('mat-menu-below');
+
+      trigger.style.top = '0';
+      dispatchFakeEvent(window, 'resize');
+      fixture.detectChanges();
+      tick(500);
+      fixture.detectChanges();
+
+      expect(panel.classList).not.toContain('mat-menu-above');
+      expect(panel.classList).toContain('mat-menu-below');
+    }));
+
     it('should be able to update the position after the first open', fakeAsync(() => {
       trigger.style.position = 'fixed';
       trigger.style.top = '200px';

src/material/menu/menu.ts

@@ -37,6 +37,7 @@ import {
   ViewChild,
   ViewEncapsulation,
   OnInit,
+  ChangeDetectorRef,
 } from '@angular/core';
 import {merge, Observable, Subject, Subscription} from 'rxjs';
 import {startWith, switchMap, take} from 'rxjs/operators';
@@ -272,6 +273,8 @@ export class _MatMenuBase
     private _elementRef: ElementRef<HTMLElement>,
     private _ngZone: NgZone,
     @Inject(MAT_MENU_DEFAULT_OPTIONS) private _defaultOptions: MatMenuDefaultOptions,
+    // @breaking-change 15.0.0 `_changeDetectorRef` to become a required parameter.
+    private _changeDetectorRef?: ChangeDetectorRef,
   ) {}
 
   ngOnInit() {
@@ -452,6 +455,9 @@ export class _MatMenuBase
     classes['mat-menu-after'] = posX === 'after';
     classes['mat-menu-above'] = posY === 'above';
     classes['mat-menu-below'] = posY === 'below';
+
+    // @breaking-change 15.0.0 Remove null check for `_changeDetectorRef`.
+    this._changeDetectorRef?.markForCheck();
   }
 
   /** Starts the enter animation. */
@@ -522,11 +528,22 @@ export class MatMenu extends _MatMenuBase {
   protected override _elevationPrefix = 'mat-elevation-z';
   protected override _baseElevation = 4;
 
+  /**
+   * @deprecated `changeDetectorRef` parameter will become a required parameter.
+   * @breaking-change 15.0.0
+   */
+  constructor(
+    elementRef: ElementRef<HTMLElement>,
+    ngZone: NgZone,
+    defaultOptions: MatMenuDefaultOptions,
+  );
+
   constructor(
     elementRef: ElementRef<HTMLElement>,
     ngZone: NgZone,
     @Inject(MAT_MENU_DEFAULT_OPTIONS) defaultOptions: MatMenuDefaultOptions,
+    changeDetectorRef?: ChangeDetectorRef,
   ) {
-    super(elementRef, ngZone, defaultOptions);
+    super(elementRef, ngZone, defaultOptions, changeDetectorRef);
   }
 }

tools/public_api_guard/material/menu.md

@@ -71,6 +71,7 @@ const MAT_MENU_SCROLL_STRATEGY_FACTORY_PROVIDER: {
 
 // @public
 export class MatMenu extends _MatMenuBase {
+    // @deprecated
     constructor(elementRef: ElementRef<HTMLElement>, ngZone: NgZone, defaultOptions: MatMenuDefaultOptions);
     // (undocumented)
     protected _baseElevation: number;
@@ -90,7 +91,7 @@ export const matMenuAnimations: {
 
 // @public
 export class _MatMenuBase implements AfterContentInit, MatMenuPanel<MatMenuItem>, OnInit, OnDestroy {
-    constructor(_elementRef: ElementRef<HTMLElement>, _ngZone: NgZone, _defaultOptions: MatMenuDefaultOptions);
+    constructor(_elementRef: ElementRef<HTMLElement>, _ngZone: NgZone, _defaultOptions: MatMenuDefaultOptions, _changeDetectorRef?: ChangeDetectorRef | undefined);
     // (undocumented)
     addItem(_item: MatMenuItem): void;
     _allItems: QueryList<MatMenuItem>;
@@ -282,6 +283,8 @@ export class MatMenuTrigger extends _MatMenuTriggerBase {
 export abstract class _MatMenuTriggerBase implements AfterContentInit, OnDestroy {
     // @deprecated
     constructor(overlay: Overlay, element: ElementRef<HTMLElement>, viewContainerRef: ViewContainerRef, scrollStrategy: any, parentMenu: MatMenuPanel, menuItemInstance: MatMenuItem, dir: Directionality, focusMonitor?: FocusMonitor | null);
+    // @deprecated
+    constructor(overlay: Overlay, element: ElementRef<HTMLElement>, viewContainerRef: ViewContainerRef, scrollStrategy: any, parentMenu: MatMenuPanel, menuItemInstance: MatMenuItem, dir: Directionality, focusMonitor: FocusMonitor);
     closeMenu(): void;
     // @deprecated (undocumented)
     get _deprecatedMatMenuTriggerFor(): MatMenuPanel;
@@ -315,7 +318,7 @@ export abstract class _MatMenuTriggerBase implements AfterContentInit, OnDestroy
     // (undocumented)
     static ɵdir: i0.ɵɵDirectiveDeclaration<_MatMenuTriggerBase, never, never, { "_deprecatedMatMenuTriggerFor": "mat-menu-trigger-for"; "menu": "matMenuTriggerFor"; "menuData": "matMenuTriggerData"; "restoreFocus": "matMenuTriggerRestoreFocus"; }, { "menuOpened": "menuOpened"; "onMenuOpen": "onMenuOpen"; "menuClosed": "menuClosed"; "onMenuClose": "onMenuClose"; }, never>;
     // (undocumented)
-    static ɵfac: i0.ɵɵFactoryDeclaration<_MatMenuTriggerBase, [null, null, null, null, { optional: true; }, { optional: true; self: true; }, { optional: true; }, null]>;
+    static ɵfac: i0.ɵɵFactoryDeclaration<_MatMenuTriggerBase, [null, null, null, null, { optional: true; }, { optional: true; self: true; }, { optional: true; }, null, null]>;
 }
 
 // @public