feat(slide-toggle): make slide-toggle click and drag actions configurable

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

@@ -8,4 +8,4 @@
 
 export * from './slide-toggle-module';
 export * from './slide-toggle';
-
+export * from './slide-toggle-config';

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

@@ -0,0 +1,24 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import {InjectionToken} from '@angular/core';
+
+
+/** Default `mat-slide-toggle` options that can be overridden. */
+export interface MatSlideToggleDefaultOptions {
+  /** Whether toggle action triggers value changes in slide toggle. */
+  disableToggleValue?: boolean;
+  /** Whether drag action triggers value changes in slide toggle. */
+  disableDragValue?: boolean;
+}
+
+/** Injection token to be used to override the default options for `mat-slide-toggle`. */
+export const MAT_SLIDE_TOGGLE_DEFAULT_OPTIONS =
+  new InjectionToken<MatSlideToggleDefaultOptions>('mat-slide-toggle-default-options', {
+    providedIn: 'root',
+    factory: () => ({disableToggleValue: false, disableDragValue: false})
+  });

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

@@ -6,6 +6,7 @@ import {FormControl, FormsModule, NgModel, ReactiveFormsModule} from '@angular/f
 import {defaultRippleAnimationConfig} from '@angular/material/core';
 import {By, HAMMER_GESTURE_CONFIG} from '@angular/platform-browser';
 import {TestGestureConfig} from '../slider/test-gesture-config';
+import {MAT_SLIDE_TOGGLE_DEFAULT_OPTIONS} from './slide-toggle-config';
 import {MatSlideToggle, MatSlideToggleChange, MatSlideToggleModule} from './index';
 
 describe('MatSlideToggle without forms', () => {
@@ -355,6 +356,96 @@ describe('MatSlideToggle without forms', () => {
     }));
   });
 
+  describe('custom action configuration', () => {
+    it('should not change value on click when click action is noop', fakeAsync(() => {
+      TestBed
+        .resetTestingModule()
+        .configureTestingModule({
+          imports: [MatSlideToggleModule],
+          declarations: [SlideToggleBasic],
+          providers: [
+            {
+              provide: HAMMER_GESTURE_CONFIG,
+              useFactory: () => gestureConfig = new TestGestureConfig()
+            },
+            {provide: MAT_SLIDE_TOGGLE_DEFAULT_OPTIONS, useValue: {disableToggleValue: true}},
+          ]
+        });
+      const fixture = TestBed.createComponent(SlideToggleBasic);
+      const testComponent = fixture.debugElement.componentInstance;
+      const slideToggleDebug = fixture.debugElement.query(By.css('mat-slide-toggle'));
+
+      const slideToggle = slideToggleDebug.componentInstance;
+      const inputElement = fixture.debugElement.query(By.css('input')).nativeElement;
+      const labelElement = fixture.debugElement.query(By.css('label')).nativeElement;
+
+      expect(testComponent.toggleTriggered).toBe(0);
+      expect(testComponent.dragTriggered).toBe(0);
+      expect(slideToggle.checked).toBe(false, 'Expect slide toggle value not changed');
+
+      labelElement.click();
+      fixture.detectChanges();
+
+      expect(slideToggle.checked).toBe(false, 'Expect slide toggle value not changed');
+      expect(testComponent.toggleTriggered).toBe(1, 'Expect toggle once');
+      expect(testComponent.dragTriggered).toBe(0);
+
+      inputElement.click();
+      fixture.detectChanges();
+
+      expect(slideToggle.checked).toBe(false, 'Expect slide toggle value not changed');
+      expect(testComponent.toggleTriggered).toBe(2, 'Expect toggle twice');
+      expect(testComponent.dragTriggered).toBe(0);
+    }));
+
+    it('should not change value on dragging when drag action is noop', fakeAsync(() => {
+      TestBed
+        .resetTestingModule()
+        .configureTestingModule({
+          imports: [MatSlideToggleModule],
+          declarations: [SlideToggleBasic],
+          providers: [
+            {
+              provide: HAMMER_GESTURE_CONFIG,
+              useFactory: () => gestureConfig = new TestGestureConfig()
+            },
+            {provide: MAT_SLIDE_TOGGLE_DEFAULT_OPTIONS, useValue: {disableDragValue: true}},
+          ]
+        });
+      const fixture = TestBed.createComponent(SlideToggleBasic);
+      const testComponent = fixture.debugElement.componentInstance;
+      const slideToggleDebug = fixture.debugElement.query(By.css('mat-slide-toggle'));
+      const thumbContainerDebug = slideToggleDebug
+        .query(By.css('.mat-slide-toggle-thumb-container'));
+
+      const slideThumbContainer = thumbContainerDebug.nativeElement;
+      const slideToggle = slideToggleDebug.componentInstance;
+
+      expect(testComponent.toggleTriggered).toBe(0);
+      expect(testComponent.dragTriggered).toBe(0);
+      expect(slideToggle.checked).toBe(false);
+
+      gestureConfig.emitEventForElement('slidestart', slideThumbContainer);
+
+      expect(slideThumbContainer.classList).toContain('mat-dragging');
+
+      gestureConfig.emitEventForElement('slide', slideThumbContainer, {
+        deltaX: 200 // Arbitrary, large delta that will be clamped to the end of the slide-toggle.
+      });
+
+      gestureConfig.emitEventForElement('slideend', slideThumbContainer);
+
+      // Flush the timeout for the slide ending.
+      tick();
+
+      expect(slideToggle.checked).toBe(false, 'Expect slide toggle value not changed');
+      expect(slideThumbContainer.classList).not.toContain('mat-dragging');
+      expect(testComponent.lastEvent).toBeUndefined();
+      expect(testComponent.toggleTriggered).toBe(0);
+      expect(testComponent.dragTriggered).toBe(1, 'Expect drag once');
+    }));
+  });
+
   describe('with dragging', () => {
     let fixture: ComponentFixture<any>;
 
@@ -849,6 +940,8 @@ describe('MatSlideToggle with forms', () => {
                      [tabIndex]="slideTabindex"
                      [labelPosition]="labelPosition"
                      [disableRipple]="disableRipple"
+                     (toggleChange)="onSlideToggleChange()"
+                     (dragChange)="onSlideDragChange()"
                      (change)="onSlideChange($event)"
                      (click)="onSlideClick($event)">
       <span>Test Slide Toggle</span>
@@ -867,9 +960,13 @@ class SlideToggleBasic {
   slideTabindex: number;
   lastEvent: MatSlideToggleChange;
   labelPosition: string;
+  toggleTriggered: number = 0;
+  dragTriggered: number = 0;
 
   onSlideClick: (event?: Event) => void = () => {};
   onSlideChange = (event: MatSlideToggleChange) => this.lastEvent = event;
+  onSlideToggleChange = () => this.toggleTriggered++;
+  onSlideDragChange = () => this.dragTriggered++;
 }
 
 @Component({

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

@@ -42,6 +42,10 @@ import {
   RippleRef,
 } from '@angular/material/core';
 import {ANIMATION_MODULE_TYPE} from '@angular/platform-browser/animations';
+import {
+  MAT_SLIDE_TOGGLE_DEFAULT_OPTIONS,
+  MatSlideToggleDefaultOptions
+} from './slide-toggle-config';
 
 // Increasing integer for generating unique ids for slide-toggle components.
 let nextUniqueId = 0;
@@ -153,6 +157,21 @@ export class MatSlideToggle extends _MatSlideToggleMixinBase implements OnDestro
   @Output() readonly change: EventEmitter<MatSlideToggleChange> =
       new EventEmitter<MatSlideToggleChange>();
 
+  /**
+   * An event will be dispatched each time the slide-toggle input is toggled.
+   * This event always fire when user toggle the slide toggle, but does not mean the slide toggle's
+   * value is changed. The event does not fire when user drag to change the slide toggle value.
+   */
+  @Output() readonly toggleChange: EventEmitter<void> = new EventEmitter<void>();
+
+  /**
+   * An event will be dispatched each time the slide-toggle is dragged.
+   * This event always fire when user drag the slide toggle to make a change that greater than 50%.
+   * It does not mean the slide toggle's value is changed. The event does not fire when user toggle
+   * the slide toggle to change the slide toggle's value.
+   */
+  @Output() readonly dragChange: EventEmitter<void> = new EventEmitter<void>();
+
   /** Returns the unique id for the visual hidden input. */
   get inputId(): string { return `${this.id || this._uniqueId}-input`; }
 
@@ -172,8 +191,9 @@ export class MatSlideToggle extends _MatSlideToggleMixinBase implements OnDestro
               private _changeDetectorRef: ChangeDetectorRef,
               @Attribute('tabindex') tabIndex: string,
               private _ngZone: NgZone,
+              @Inject(MAT_SLIDE_TOGGLE_DEFAULT_OPTIONS)
+                  public defaults: MatSlideToggleDefaultOptions,
               @Optional() @Inject(ANIMATION_MODULE_TYPE) public _animationMode?: string) {
-
     super(elementRef);
     this.tabIndex = parseInt(tabIndex) || 0;
   }
@@ -195,10 +215,15 @@ export class MatSlideToggle extends _MatSlideToggleMixinBase implements OnDestro
     // emit its event object to the component's `change` output.
     event.stopPropagation();
 
+    if (!this._dragging) {
+      this.toggleChange.emit();
+    }
     // Releasing the pointer over the `<label>` element while dragging triggers another
     // click event on the `<label>` element. This means that the checked state of the underlying
-    // input changed unintentionally and needs to be changed back.
-    if (this._dragging) {
+    // input changed unintentionally and needs to be changed back. Or when the slide toggle's config
+    // disabled toggle change event by setting `disableToggleValue: true`, the slide toggle's value
+    // does not change, and the checked state of the underlying input needs to be changed back.
+    if (this._dragging || this.defaults.disableToggleValue) {
       this._inputElement.nativeElement.checked = this.checked;
       return;
     }
@@ -316,8 +341,11 @@ export class MatSlideToggle extends _MatSlideToggleMixinBase implements OnDestro
       const newCheckedValue = this._dragPercentage > 50;
 
       if (newCheckedValue !== this.checked) {
-        this.checked = newCheckedValue;
-        this._emitChangeEvent();
+        this.dragChange.emit();
+        if (!this.defaults.disableDragValue) {
+          this.checked = newCheckedValue;
+          this._emitChangeEvent();
+        }
       }
 
       // The drag should be stopped outside of the current event handler, otherwise the