feat(menu): add injection token for overriding the default options (#5483)

* feat(menu): add injection token for overriding the default options

Adds a new injection token that allows the consumer to override the default values for the `xPosition`, `yPosition` and `overlapTrigger` options.

Fixes #5479.

* fix: unresolved merge conflict and pr feedback

Author: crisbeto

src/lib/menu/index.ts

@@ -9,7 +9,7 @@
 import {NgModule} from '@angular/core';
 import {CommonModule} from '@angular/common';
 import {OverlayModule, MdCommonModule} from '../core';
-import {MdMenu} from './menu-directive';
+import {MdMenu, MD_MENU_DEFAULT_OPTIONS} from './menu-directive';
 import {MdMenuItem} from './menu-item';
 import {MdMenuTrigger, MD_MENU_SCROLL_STRATEGY_PROVIDER} from './menu-trigger';
 import {MdRippleModule} from '../core/ripple/index';
@@ -24,7 +24,17 @@ import {MdRippleModule} from '../core/ripple/index';
   ],
   exports: [MdMenu, MdMenuItem, MdMenuTrigger, MdCommonModule],
   declarations: [MdMenu, MdMenuItem, MdMenuTrigger],
-  providers: [MD_MENU_SCROLL_STRATEGY_PROVIDER],
+  providers: [
+    MD_MENU_SCROLL_STRATEGY_PROVIDER,
+    {
+      provide: MD_MENU_DEFAULT_OPTIONS,
+      useValue: {
+        overlapTrigger: true,
+        xPosition: 'after',
+        yPosition: 'below',
+      },
+    }
+  ],
 })
 export class MdMenuModule {}
 

src/lib/menu/menu-directive.ts

@@ -20,6 +20,8 @@ import {
   ViewEncapsulation,
   ElementRef,
   ChangeDetectionStrategy,
+  InjectionToken,
+  Inject,
 } from '@angular/core';
 import {AnimationEvent} from '@angular/animations';
 import {MenuPositionX, MenuPositionY} from './menu-positions';
@@ -34,6 +36,16 @@ import {merge} from 'rxjs/observable/merge';
 import {Observable} from 'rxjs/Observable';
 import {Direction} from '../core';
 
+/** Default `md-menu` options that can be overridden. */
+export interface MdMenuDefaultOptions {
+  xPosition: MenuPositionX;
+  yPosition: MenuPositionY;
+  overlapTrigger: boolean;
+}
+
+/** Injection token to be used to override the default options for `md-menu`. */
+export const MD_MENU_DEFAULT_OPTIONS =
+    new InjectionToken<MdMenuDefaultOptions>('md-menu-default-options');
 
 @Component({
   moduleId: module.id,
@@ -50,8 +62,8 @@ import {Direction} from '../core';
 })
 export class MdMenu implements AfterContentInit, MdMenuPanel, OnDestroy {
   private _keyManager: FocusKeyManager;
-  private _xPosition: MenuPositionX = 'after';
-  private _yPosition: MenuPositionY = 'below';
+  private _xPosition: MenuPositionX = this._defaultOptions.xPosition;
+  private _yPosition: MenuPositionY = this._defaultOptions.yPosition;
 
   /** Subscription to tab events on the menu panel */
   private _tabSubscription: Subscription;
@@ -96,7 +108,7 @@ export class MdMenu implements AfterContentInit, MdMenuPanel, OnDestroy {
   @ContentChildren(MdMenuItem) items: QueryList<MdMenuItem>;
 
   /** Whether the menu should overlap its trigger. */
-  @Input() overlapTrigger = true;
+  @Input() overlapTrigger = this._defaultOptions.overlapTrigger;
 
   /**
    * This method takes classes set on the host md-menu element and applies them on the
@@ -120,7 +132,9 @@ export class MdMenu implements AfterContentInit, MdMenuPanel, OnDestroy {
   /** Event emitted when the menu is closed. */
   @Output() close = new EventEmitter<void | 'click' | 'keydown'>();
 
-  constructor(private _elementRef: ElementRef) { }
+  constructor(
+    private _elementRef: ElementRef,
+    @Inject(MD_MENU_DEFAULT_OPTIONS) private _defaultOptions: MdMenuDefaultOptions) { }
 
   ngAfterContentInit() {
     this._keyManager = new FocusKeyManager(this.items).withWrap();

src/lib/menu/menu.spec.ts

@@ -25,6 +25,7 @@ import {
   MenuPositionX,
   MenuPositionY,
   MdMenu,
+  MD_MENU_DEFAULT_OPTIONS,
 } from './index';
 import {MENU_PANEL_TOP_PADDING} from './menu-trigger';
 import {extendObject} from '../core/util/object-extend';
@@ -875,6 +876,29 @@ describe('MdMenu', () => {
 
 });
 
+describe('MdMenu default overrides', () => {
+  beforeEach(async(() => {
+    TestBed.configureTestingModule({
+      imports: [MdMenuModule, NoopAnimationsModule],
+      declarations: [SimpleMenu],
+      providers: [{
+        provide: MD_MENU_DEFAULT_OPTIONS,
+        useValue: {overlapTrigger: false, xPosition: 'before', yPosition: 'above'},
+      }],
+    }).compileComponents();
+  }));
+
+  it('should allow for the default menu options to be overridden', () => {
+    const fixture = TestBed.createComponent(SimpleMenu);
+    fixture.detectChanges();
+    const menu = fixture.componentInstance.menu;
+
+    expect(menu.overlapTrigger).toBe(false);
+    expect(menu.xPosition).toBe('before');
+    expect(menu.yPosition).toBe('above');
+  });
+});
+
 @Component({
   template: `
     <button [mdMenuTriggerFor]="menu" #triggerEl>Toggle menu</button>

src/lib/menu/menu.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-export {MdMenu} from './menu-directive';
+export {MdMenu, MdMenuDefaultOptions, MD_MENU_DEFAULT_OPTIONS} from './menu-directive';
 export {MdMenuItem} from './menu-item';
 export {MdMenuTrigger} from './menu-trigger';
 export {MdMenuPanel} from './menu-panel';