feat(tab-nav-bar): support disabling tab links (#5257)

Adds support for disabling tab links inside of the tab-nav-bar
No longer requires having an extra directive for the ripples of tab links (no exposion of attributes like `mdRippleColor` - which could be flexible but should not be public API here)

Closes #5208

src/demo-app/tabs/tabs-demo.html

@@ -13,6 +13,7 @@
        [active]="rla.isActive">
       {{tabLink.label}}
     </a>
+    <a md-tab-link disabled>Disabled Link</a>
   </nav>
   <router-outlet></router-outlet>
 </div>

src/lib/tabs/_tabs-common.scss

@@ -14,10 +14,16 @@ $mat-tab-animation-duration: 500ms !default;
   opacity: 0.6;
   min-width: 160px;
   text-align: center;
+
   &:focus {
     outline: none;
     opacity: 1;
   }
+
+  &.mat-tab-disabled {
+    cursor: default;
+    pointer-events: none;
+  }
 }
 
 // Mixin styles for the top section of the view; contains the tab labels.

src/lib/tabs/index.ts

@@ -15,7 +15,7 @@ import {MdTab} from './tab';
 import {MdTabGroup} from './tab-group';
 import {MdTabLabel} from './tab-label';
 import {MdTabLabelWrapper} from './tab-label-wrapper';
-import {MdTabNav, MdTabLink, MdTabLinkRipple} from './tab-nav-bar/tab-nav-bar';
+import {MdTabNav, MdTabLink} from './tab-nav-bar/tab-nav-bar';
 import {MdInkBar} from './ink-bar';
 import {MdTabBody} from './tab-body';
 import {VIEWPORT_RULER_PROVIDER} from '../core/overlay/position/viewport-ruler';
@@ -38,7 +38,6 @@ import {ScrollDispatchModule} from '../core/overlay/scroll/index';
     MdTab,
     MdTabNav,
     MdTabLink,
-    MdTabLinkRipple
   ],
   declarations: [
     MdTabGroup,
@@ -49,7 +48,6 @@ import {ScrollDispatchModule} from '../core/overlay/scroll/index';
     MdTabNav,
     MdTabLink,
     MdTabBody,
-    MdTabLinkRipple,
     MdTabHeader
   ],
   providers: [VIEWPORT_RULER_PROVIDER],

src/lib/tabs/tab-group.scss

@@ -55,9 +55,3 @@
     overflow-y: hidden;
   }
 }
-
-// Styling for any tab that is marked disabled
-.mat-tab-disabled {
-  cursor: default;
-  pointer-events: none;
-}

src/lib/tabs/tab-nav-bar/tab-nav-bar.spec.ts

@@ -53,6 +53,58 @@ describe('MdTabNavBar', () => {
       expect(fixture.componentInstance.activeIndex).toBe(2);
     });
 
+    it('should add the disabled class if disabled', () => {
+      const tabLinkElements = fixture.debugElement.queryAll(By.css('a'))
+        .map(tabLinkDebugEl => tabLinkDebugEl.nativeElement);
+
+      expect(tabLinkElements.every(tabLinkEl => !tabLinkEl.classList.contains('mat-tab-disabled')))
+        .toBe(true, 'Expected every tab link to not have the disabled class initially');
+
+      fixture.componentInstance.disabled = true;
+      fixture.detectChanges();
+
+      expect(tabLinkElements.every(tabLinkEl => tabLinkEl.classList.contains('mat-tab-disabled')))
+        .toBe(true, 'Expected every tab link to have the disabled class if set through binding');
+    });
+
+    it('should update aria-disabled if disabled', () => {
+      const tabLinkElements = fixture.debugElement.queryAll(By.css('a'))
+        .map(tabLinkDebugEl => tabLinkDebugEl.nativeElement);
+
+      expect(tabLinkElements.every(tabLink => tabLink.getAttribute('aria-disabled') === 'false'))
+        .toBe(true, 'Expected aria-disabled to be set to "false" by default.');
+
+      fixture.componentInstance.disabled = true;
+      fixture.detectChanges();
+
+      expect(tabLinkElements.every(tabLink => tabLink.getAttribute('aria-disabled') === 'true'))
+        .toBe(true, 'Expected aria-disabled to be set to "true" if link is disabled.');
+    });
+
+    it('should update the tabindex if links are disabled', () => {
+      const tabLinkElements = fixture.debugElement.queryAll(By.css('a'))
+        .map(tabLinkDebugEl => tabLinkDebugEl.nativeElement);
+
+      expect(tabLinkElements.every(tabLink => tabLink.tabIndex === 0))
+        .toBe(true, 'Expected element to be keyboard focusable by default');
+
+      fixture.componentInstance.disabled = true;
+      fixture.detectChanges();
+
+      expect(tabLinkElements.every(tabLink => tabLink.tabIndex === -1))
+        .toBe(true, 'Expected element to no longer be keyboard focusable if disabled.');
+    });
+
+    it('should show ripples for tab links', () => {
+      const tabLink = fixture.debugElement.nativeElement.querySelector('.mat-tab-link');
+
+      dispatchMouseEvent(tabLink, 'mousedown');
+      dispatchMouseEvent(tabLink, 'mouseup');
+
+      expect(tabLink.querySelectorAll('.mat-ripple-element').length)
+        .toBe(1, 'Expected one ripple to show up if user clicks on tab link.');
+    });
+
     it('should re-align the ink bar when the direction changes', () => {
       const inkBar = fixture.componentInstance.tabNavBar._inkBar;
 
@@ -125,6 +177,7 @@ describe('MdTabNavBar', () => {
       <a md-tab-link
          *ngFor="let tab of tabs; let index = index"
          [active]="activeIndex === index"
+         [disabled]="disabled"
          (click)="activeIndex = index">
         Tab link {{label}}
       </a>
@@ -135,6 +188,7 @@ class SimpleTabNavBarTestApp {
   @ViewChild(MdTabNav) tabNavBar: MdTabNav;
 
   label = '';
+  disabled: boolean = false;
   tabs = [0, 1, 2];
 
   activeIndex = 0;

src/lib/tabs/tab-nav-bar/tab-nav-bar.ts

@@ -11,6 +11,7 @@ import {
   Component,
   Directive,
   ElementRef,
+  HostBinding,
   Inject,
   Input,
   NgZone,
@@ -20,15 +21,16 @@ import {
   ViewEncapsulation
 } from '@angular/core';
 import {MdInkBar} from '../ink-bar';
-import {MdRipple} from '../../core/ripple/index';
+import {CanDisable, mixinDisabled} from '../../core/common-behaviors/disabled';
+import {MdRipple} from '../../core';
 import {ViewportRuler} from '../../core/overlay/position/viewport-ruler';
 import {Directionality, MD_RIPPLE_GLOBAL_OPTIONS, Platform, RippleGlobalOptions} from '../../core';
 import {Observable} from 'rxjs/Observable';
+import {Subject} from 'rxjs/Subject';
 import 'rxjs/add/operator/auditTime';
 import 'rxjs/add/operator/takeUntil';
 import 'rxjs/add/observable/of';
 import 'rxjs/add/observable/merge';
-import {Subject} from 'rxjs/Subject';
 
 /**
  * Navigation component matching the styles of the tab group header.
@@ -92,16 +94,30 @@ export class MdTabNav implements AfterContentInit, OnDestroy {
   }
 }
 
+
+// Boilerplate for applying mixins to MdTabLink.
+export class MdTabLinkBase {}
+export const _MdTabLinkMixinBase = mixinDisabled(MdTabLinkBase);
+
 /**
  * Link inside of a `md-tab-nav-bar`.
  */
 @Directive({
   selector: '[md-tab-link], [mat-tab-link], [mdTabLink], [matTabLink]',
-  host: {'class': 'mat-tab-link'}
+  inputs: ['disabled'],
+  host: {
+    'class': 'mat-tab-link',
+    '[attr.aria-disabled]': 'disabled.toString()',
+    '[class.mat-tab-disabled]': 'disabled'
+  }
 })
-export class MdTabLink {
+export class MdTabLink extends _MdTabLinkMixinBase implements OnDestroy, CanDisable {
+  /** Whether the tab link is active or not. */
   private _isActive: boolean = false;
 
+  /** Reference to the instance of the ripple for the tab link. */
+  private _tabLinkRipple: MdRipple;
+
   /** Whether the link is active. */
   @Input()
   get active(): boolean { return this._isActive; }
@@ -112,23 +128,28 @@ export class MdTabLink {
     }
   }
 
-  constructor(private _mdTabNavBar: MdTabNav, private _elementRef: ElementRef) {}
-}
+  /** @docs-private */
+  @HostBinding('tabIndex')
+  get tabIndex(): number {
+    return this.disabled ? -1 : 0;
+  }
 
-/**
- * Simple directive that extends the ripple and matches the selector of the MdTabLink. This
- * adds the ripple behavior to nav bar labels.
- */
-@Directive({
-  selector: '[md-tab-link], [mat-tab-link], [mdTabLink], [matTabLink]',
-})
-export class MdTabLinkRipple extends MdRipple {
-  constructor(
-      elementRef: ElementRef,
-      ngZone: NgZone,
-      ruler: ViewportRuler,
-      platform: Platform,
-      @Optional() @Inject(MD_RIPPLE_GLOBAL_OPTIONS) globalOptions: RippleGlobalOptions) {
-    super(elementRef, ngZone, ruler, platform, globalOptions);
+  constructor(private _mdTabNavBar: MdTabNav,
+              private _elementRef: ElementRef,
+              ngZone: NgZone,
+              ruler: ViewportRuler,
+              platform: Platform,
+              @Optional() @Inject(MD_RIPPLE_GLOBAL_OPTIONS) globalOptions: RippleGlobalOptions) {
+    super();
+
+    // Manually create a ripple instance that uses the tab link element as trigger element.
+    // Notice that the lifecycle hooks for the ripple config won't be called anymore.
+    this._tabLinkRipple = new MdRipple(_elementRef, ngZone, ruler, platform, globalOptions);
+  }
+
+  ngOnDestroy() {
+    // Manually call the ngOnDestroy lifecycle hook of the ripple instance because it won't be
+    // called automatically since its instance is not created by Angular.
+    this._tabLinkRipple.ngOnDestroy();
   }
 }