feat(slide-toggle): add ripple focus indicator (#3739)

* feat(slide-toggle): add ripple focus indicator

* Introduces a focus indiactor using the persistent ripples.

* Address comments

src/lib/slide-toggle/index.ts

@@ -1,16 +1,19 @@
 import {NgModule, ModuleWithProviders} from '@angular/core';
 import {FormsModule} from '@angular/forms';
 import {HAMMER_GESTURE_CONFIG} from '@angular/platform-browser';
-import {GestureConfig, CompatibilityModule} from '../core';
 import {MdSlideToggle} from './slide-toggle';
-import {MdRippleModule} from '../core/ripple/index';
-
+import {
+  GestureConfig, CompatibilityModule, MdRippleModule, FOCUS_ORIGIN_MONITOR_PROVIDER
+} from '../core';
 
 @NgModule({
   imports: [FormsModule, MdRippleModule, CompatibilityModule],
   exports: [MdSlideToggle, CompatibilityModule],
   declarations: [MdSlideToggle],
-  providers: [{provide: HAMMER_GESTURE_CONFIG, useClass: GestureConfig}],
+  providers: [
+    FOCUS_ORIGIN_MONITOR_PROVIDER,
+    { provide: HAMMER_GESTURE_CONFIG, useClass: GestureConfig }
+  ],
 })
 export class MdSlideToggleModule {
   /** @deprecated */

src/lib/slide-toggle/slide-toggle.html

@@ -11,8 +11,6 @@
            [attr.name]="name"
            [attr.aria-label]="ariaLabel"
            [attr.aria-labelledby]="ariaLabelledby"
-           (blur)="_onInputBlur()"
-           (focus)="_onInputFocus()"
            (change)="_onChangeEvent($event)"
            (click)="_onInputClick($event)">
 

src/lib/slide-toggle/slide-toggle.spec.ts

@@ -5,6 +5,7 @@ import {FormsModule, NgControl, ReactiveFormsModule, FormControl} from '@angular
 import {MdSlideToggle, MdSlideToggleChange, MdSlideToggleModule} from './index';
 import {TestGestureConfig} from '../slider/test-gesture-config';
 import {dispatchFakeEvent} from '../core/testing/dispatch-events';
+import {RIPPLE_FADE_IN_DURATION, RIPPLE_FADE_OUT_DURATION} from '../core/ripple/ripple-renderer';
 
 describe('MdSlideToggle', () => {
 
@@ -268,6 +269,26 @@ describe('MdSlideToggle', () => {
       fixture.detectChanges();
     });
 
+    it('should show a ripple when focused by a keyboard action', fakeAsync(() => {
+      expect(slideToggleElement.querySelectorAll('.mat-ripple-element').length)
+          .toBe(0, 'Expected no ripples to be present.');
+
+      dispatchFakeEvent(inputElement, 'keydown');
+      dispatchFakeEvent(inputElement, 'focus');
+
+      tick(RIPPLE_FADE_IN_DURATION);
+
+      expect(slideToggleElement.querySelectorAll('.mat-ripple-element').length)
+          .toBe(1, 'Expected the focus ripple to be showing up.');
+
+      dispatchFakeEvent(inputElement, 'blur');
+
+      tick(RIPPLE_FADE_OUT_DURATION);
+
+      expect(slideToggleElement.querySelectorAll('.mat-ripple-element').length)
+          .toBe(0, 'Expected focus ripple to be removed.');
+    }));
+
     it('should have the correct control state initially and after interaction', () => {
       // The control should start off valid, pristine, and untouched.
       expect(slideToggleControl.valid).toBe(true);
@@ -327,15 +348,6 @@ describe('MdSlideToggle', () => {
       });
     }));
 
-    it('should correctly set the slide-toggle to checked on focus', () => {
-      expect(slideToggleElement.classList).not.toContain('mat-slide-toggle-focused');
-
-      dispatchFakeEvent(inputElement, 'focus');
-      fixture.detectChanges();
-
-      expect(slideToggleElement.classList).toContain('mat-slide-toggle-focused');
-    });
-
     it('should forward the required attribute', () => {
       testComponent.isRequired = true;
       fixture.detectChanges();
@@ -349,14 +361,12 @@ describe('MdSlideToggle', () => {
     });
 
     it('should focus on underlying input element when focus() is called', () => {
-      expect(slideToggleElement.classList).not.toContain('mat-slide-toggle-focused');
       expect(document.activeElement).not.toBe(inputElement);
 
       slideToggle.focus();
       fixture.detectChanges();
 
       expect(document.activeElement).toBe(inputElement);
-      expect(slideToggleElement.classList).toContain('mat-slide-toggle-focused');
     });
 
     it('should set a element class if labelPosition is set to before', () => {

src/lib/slide-toggle/slide-toggle.ts

@@ -10,11 +10,20 @@ import {
   AfterContentInit,
   ViewChild,
   ViewEncapsulation,
+  OnDestroy,
 } from '@angular/core';
+import {
+  applyCssTransform,
+  coerceBooleanProperty,
+  HammerInput,
+  FocusOriginMonitor,
+  FocusOrigin,
+  MdRipple,
+  RippleRef
+} from '../core';
 import {ControlValueAccessor, NG_VALUE_ACCESSOR} from '@angular/forms';
-import {applyCssTransform, coerceBooleanProperty, HammerInput} from '../core';
 import {Observable} from 'rxjs/Observable';
-
+import {Subscription} from 'rxjs/Subscription';
 
 export const MD_SLIDE_TOGGLE_VALUE_ACCESSOR: any = {
   provide: NG_VALUE_ACCESSOR,
@@ -41,8 +50,6 @@ let nextId = 0;
     '[class.mat-slide-toggle]': 'true',
     '[class.mat-checked]': 'checked',
     '[class.mat-disabled]': 'disabled',
-    // This mat-slide-toggle prefix will change, once the temporary ripple is removed.
-    '[class.mat-slide-toggle-focused]': '_hasFocus',
     '[class.mat-slide-toggle-label-before]': 'labelPosition == "before"',
     '(mousedown)': '_setMousedown()'
   },
@@ -52,7 +59,7 @@ let nextId = 0;
   encapsulation: ViewEncapsulation.None,
   changeDetection: ChangeDetectionStrategy.OnPush
 })
-export class MdSlideToggle implements AfterContentInit, ControlValueAccessor {
+export class MdSlideToggle implements OnDestroy, AfterContentInit, ControlValueAccessor {
 
   private onChange = (_: any) => {};
   private onTouched = () => {};
@@ -67,8 +74,11 @@ export class MdSlideToggle implements AfterContentInit, ControlValueAccessor {
   private _required: boolean = false;
   private _disableRipple: boolean = false;
 
-  // Needs to be public to support AOT compilation (as host binding).
-  _hasFocus: boolean = false;
+  /** Reference to the focus state ripple. */
+  private _focusRipple: RippleRef;
+
+  /** Subscription to focus-origin changes. */
+  private _focusOriginSubscription: Subscription;
 
   /** Name value will be applied to the input element if present */
   @Input() name: string = null;
@@ -110,12 +120,31 @@ export class MdSlideToggle implements AfterContentInit, ControlValueAccessor {
   /** Returns the unique id for the visual hidden input. */
   get inputId(): string { return `${this.id || this._uniqueId}-input`; }
 
+  /** Reference to the underlying input element. */
   @ViewChild('input') _inputElement: ElementRef;
 
-  constructor(private _elementRef: ElementRef, private _renderer: Renderer) {}
+  /** Reference to the ripple directive on the thumb container. */
+  @ViewChild(MdRipple) _ripple: MdRipple;
+
+  constructor(private _elementRef: ElementRef,
+              private _renderer: Renderer,
+              private _focusOriginMonitor: FocusOriginMonitor) {}
 
   ngAfterContentInit() {
     this._slideRenderer = new SlideToggleRenderer(this._elementRef);
+
+    this._focusOriginSubscription = this._focusOriginMonitor
+      .monitor(this._inputElement.nativeElement, this._renderer, false)
+      .subscribe(focusOrigin => this._onInputFocusChange(focusOrigin));
+  }
+
+  ngOnDestroy() {
+    this._focusOriginMonitor.unmonitor(this._inputElement.nativeElement);
+
+    if (this._focusOriginSubscription) {
+      this._focusOriginSubscription.unsubscribe();
+      this._focusOriginSubscription = null;
+    }
   }
 
   /**
@@ -162,19 +191,6 @@ export class MdSlideToggle implements AfterContentInit, ControlValueAccessor {
     setTimeout(() => this._isMousedown = false, 100);
   }
 
-  _onInputFocus() {
-    // Only show the focus / ripple indicator when the focus was not triggered by a mouse
-    // interaction on the component.
-    if (!this._isMousedown) {
-      this._hasFocus = true;
-    }
-  }
-
-  _onInputBlur() {
-    this._hasFocus = false;
-    this.onTouched();
-  }
-
   /** Implemented as part of ControlValueAccessor. */
   writeValue(value: any): void {
     this.checked = value;
@@ -197,8 +213,7 @@ export class MdSlideToggle implements AfterContentInit, ControlValueAccessor {
 
   /** Focuses the slide-toggle. */
   focus() {
-    this._renderer.invokeElementMethod(this._inputElement.nativeElement, 'focus');
-    this._onInputFocus();
+    this._focusOriginMonitor.focusVia(this._inputElement.nativeElement, this._renderer, 'program');
   }
 
   /** Whether the slide-toggle is checked. */
@@ -223,6 +238,22 @@ export class MdSlideToggle implements AfterContentInit, ControlValueAccessor {
     this.checked = !this.checked;
   }
 
+  /** Function is called whenever the focus changes for the input element. */
+  private _onInputFocusChange(focusOrigin: FocusOrigin) {
+    if (!this._focusRipple && focusOrigin === 'keyboard') {
+      // For keyboard focus show a persistent ripple as focus indicator.
+      this._focusRipple = this._ripple.launch(0, 0, {persistent: true, centered: true});
+    } else if (!focusOrigin) {
+      this.onTouched();
+
+      // Fade out and clear the focus ripple if one is currently present.
+      if (this._focusRipple) {
+        this._focusRipple.fadeOut();
+        this._focusRipple = null;
+      }
+    }
+  }
+
   private _updateColor(newColor: string) {
     this._setElementColor(this._color, false);
     this._setElementColor(newColor, true);