feat(cdk-experimental/menu): add ability to close menus when clicking outside the menu tree

src/cdk-experimental/menu/menu-bar.spec.ts

@@ -34,6 +34,8 @@ import {CdkMenuItemRadio} from './menu-item-radio';
 import {CdkMenu} from './menu';
 import {CdkMenuItem} from './menu-item';
 import {CdkMenuItemCheckbox} from './menu-item-checkbox';
+import {CdkMenuItemTrigger} from './menu-item-trigger';
+import {CdkMenuGroup} from './menu-group';
 
 describe('MenuBar', () => {
   describe('as radio group', () => {
@@ -735,6 +737,106 @@ describe('MenuBar', () => {
       );
     });
   });
+
+  describe('background click closeout', () => {
+    let fixture: ComponentFixture<MenuBarWithMenus>;
+
+    let menus: CdkMenu[];
+    let triggers: CdkMenuItemTrigger[];
+
+    /** open the attached menu. */
+    function openMenu() {
+      triggers[0].toggle();
+      detectChanges();
+    }
+
+    /** set the menus and triggers arrays. */
+    function grabElementsForTesting() {
+      menus = fixture.componentInstance.menus.toArray();
+      triggers = fixture.componentInstance.triggers.toArray();
+    }
+
+    /** run change detection and, extract and set the rendered elements. */
+    function detectChanges() {
+      fixture.detectChanges();
+      grabElementsForTesting();
+    }
+
+    beforeEach(async(() => {
+      TestBed.configureTestingModule({
+        imports: [CdkMenuModule],
+        declarations: [MenuBarWithMenus],
+      }).compileComponents();
+    }));
+
+    beforeEach(() => {
+      fixture = TestBed.createComponent(MenuBarWithMenus);
+      detectChanges();
+    });
+
+    it('should close out all open menus when clicked outside the menu tree', () => {
+      openMenu();
+      expect(menus.length).toBe(1);
+
+      fixture.debugElement.query(By.css('#container')).nativeElement.click();
+      detectChanges();
+
+      expect(menus.length).toBe(0);
+    });
+
+    it('should not close open menus when clicking on a menu group', () => {
+      openMenu();
+      expect(menus.length).toBe(1);
+
+      const menuGroups = fixture.debugElement.queryAll(By.directive(CdkMenuGroup));
+      menuGroups[2].nativeElement.click();
+      detectChanges();
+
+      expect(menus.length).toBe(1);
+    });
+
+    it('should not close open menus when clicking on a menu', () => {
+      openMenu();
+      expect(menus.length).toBe(1);
+
+      fixture.debugElement.query(By.directive(CdkMenu)).nativeElement.click();
+      detectChanges();
+
+      expect(menus.length).toBe(1);
+    });
+
+    it('should not close open menus when clicking on a menu bar', () => {
+      openMenu();
+      expect(menus.length).toBe(1);
+
+      fixture.debugElement.query(By.directive(CdkMenuBar)).nativeElement.click();
+      detectChanges();
+
+      expect(menus.length).toBe(1);
+    });
+
+    it('should not close when clicking on a CdkMenuItemCheckbox element', () => {
+      openMenu();
+      expect(menus.length).toBe(1);
+
+      fixture.debugElement.query(By.directive(CdkMenuItemCheckbox)).nativeElement.click();
+      fixture.detectChanges();
+
+      expect(menus.length).toBe(1);
+    });
+
+    it('should not close when clicking on a non-menu element inside menu', () => {
+      openMenu();
+      expect(menus.length).toBe(1);
+
+      fixture.debugElement.query(By.css('#inner-element')).nativeElement.click();
+      detectChanges();
+
+      expect(menus.length)
+        .withContext('menu should stay open if clicking on an inner span element')
+        .toBe(1);
+    });
+  });
 });
 
 @Component({
@@ -847,3 +949,27 @@ class MenuWithRadioButtons {
 
   @ViewChildren(CdkMenuItemRadio) radioItems: QueryList<CdkMenuItemRadio>;
 }
+
+@Component({
+  template: `
+    <div id="container">
+      <div cdkMenuBar>
+        <button cdkMenuItem [cdkMenuTriggerFor]="sub1">Trigger</button>
+      </div>
+
+      <ng-template cdkMenuPanel #sub1="cdkMenuPanel">
+        <div cdkMenu [cdkMenuPanel]="sub1">
+          <div cdkMenuGroup>
+            <button cdkMenuItemCheckbox>Trigger</button>
+            <span id="inner-element">A nested non-menuitem element</span>
+          </div>
+        </div>
+      </ng-template>
+    </div>
+  `,
+})
+class MenuBarWithMenus {
+  @ViewChildren(CdkMenu) menus: QueryList<CdkMenu>;
+
+  @ViewChildren(CdkMenuItemTrigger) triggers: QueryList<CdkMenuItemTrigger>;
+}

src/cdk-experimental/menu/menu-bar.ts

@@ -25,6 +25,15 @@ import {CDK_MENU, Menu} from './menu-interface';
 import {CdkMenuItem} from './menu-item';
 import {MenuStack, MenuStackItem, FocusNext} from './menu-stack';
 
+/**
+ * Check if the given element is part of the cdk menu module.
+ * @param target the element to check.
+ * @return true if the given element is part of the menu module.
+ */
+function isMenuElement(target: Element) {
+  return target.className.indexOf('cdk-menu') !== -1;
+}
+
 /**
  * Directive applied to an element which configures it as a MenuBar by setting the appropriate
  * role, aria attributes, and accessible keyboard and mouse handling logic. The component that
@@ -36,8 +45,10 @@ import {MenuStack, MenuStackItem, FocusNext} from './menu-stack';
   exportAs: 'cdkMenuBar',
   host: {
     '(keydown)': '_handleKeyEvent($event)',
+    '(document:click)': '_closeOnBackgroundClick($event)',
     '(focus)': 'focusFirstItem()',
     'role': 'menubar',
+    'class': 'cdk-menu-bar',
     'tabindex': '0',
     '[attr.aria-orientation]': 'orientation',
   },
@@ -212,6 +223,22 @@ export class CdkMenuBar extends CdkMenuGroup implements Menu, AfterContentInit,
     return this.orientation === 'horizontal';
   }
 
+  /** Close any open submenu if there was a click event which occurred outside the menu stack. */
+  _closeOnBackgroundClick(event: MouseEvent) {
+    if (this._hasOpenSubmenu()) {
+      // get target from composed path to account for shadow dom
+      let target = event.composedPath ? event.composedPath()[0] : event.target;
+      while (target instanceof Element) {
+        if (isMenuElement(target)) {
+          return;
+        }
+        target = target.parentElement;
+      }
+
+      this._openItem?.getMenuTrigger()?.toggle();
+    }
+  }
+
   /**
    * Subscribe to the menu trigger's open events in order to track the trigger which opened the menu
    * and stop tracking it when the menu is closed.
@@ -236,6 +263,11 @@ export class CdkMenuBar extends CdkMenuGroup implements Menu, AfterContentInit,
       .subscribe(() => (this._openItem = undefined));
   }
 
+  /** Return true if the MenuBar has an open submenu. */
+  private _hasOpenSubmenu() {
+    return !!this._openItem;
+  }
+
   ngOnDestroy() {
     super.ngOnDestroy();
     this._destroyed.next();

src/cdk-experimental/menu/menu-group.ts

@@ -29,6 +29,7 @@ import {CdkMenuItem} from './menu-item';
   exportAs: 'cdkMenuGroup',
   host: {
     'role': 'group',
+    'class': 'cdk-menu-group',
   },
   providers: [{provide: UniqueSelectionDispatcher, useClass: UniqueSelectionDispatcher}],
 })

src/cdk-experimental/menu/menu-item.ts

@@ -45,6 +45,7 @@ function removeIcons(element: Element) {
     'tabindex': '-1',
     'type': 'button',
     'role': 'menuitem',
+    'class': 'cdk-menu-item',
     '[attr.aria-disabled]': 'disabled || null',
   },
 })

src/cdk-experimental/menu/menu.ts

@@ -51,6 +51,7 @@ import {MenuStack, MenuStackItem, FocusNext} from './menu-stack';
   host: {
     '(keydown)': '_handleKeyEvent($event)',
     'role': 'menu',
+    'class': 'cdk-menu',
     '[attr.aria-orientation]': 'orientation',
   },
   providers: [