feat(chips): Add removal functionality/styling. (#4912)

* feat(chips): Add remove functionality/styling.

Add events, styling and keyboard controls to allow removable chips.

 - Add basic styling for a user-provided remove icon.
 - Add keyboard controls for backspace/delete.
 - Add `(remove)` event which is emitted when the remove icon or
   one of the delete keys is pressed.
 - Add `md-chip-remove` directive which can be applied to `<md-icon>`
   (or others) to inform the chip of the remove request.

Add new directive `mdChipInput` for controlling:
 - `(chipAdded)` - Event fired when a chip should be added.
 - `[separatorKeys]` - The list of keycodes that will fire the
   `(chipAdded)` event.
 - `[addOnBlur]` - Whether or not to fire the `(chipAdded)` event
   when the input is blurred.

Additionally, fix some issues with dark theme and add styling/support
for usage inside the `md-input-container` and add styling for focused
chips.

BREAKING CHANGE - The `selectable` property of the `md-chip-list` has
now been moved to `md-chip` to maintain consistency with the new
`removable` option.

If you used the following code,

```html
<md-chip-list [selectable]="selectable">
  <md-chip>My Chip</md-chip>
</md-chip-list>
```

you should switch it to

```html
<md-chip-list>
  <md-chip [selectable]="selectable">My Chip</md-chip>
</md-chip-list>
```

References #120. Closes #3143.

src/demo-app/chips/chips-demo.html

@@ -23,11 +23,14 @@ <h4>Advanced</h4>
 
       <md-chip-list selectable="false">
         <md-chip color="accent" selected="true">Selected/Colored</md-chip>
+
         <md-chip color="warn" selected="true" *ngIf="visible"
-                 (destroy)="alert('chip destroyed')" (click)="toggleVisible()">
+                 (destroy)="displayMessage('chip destroyed')" (remove)="toggleVisible()">
           With Events
+          <md-icon mdChipRemove>cancel</md-icon>
         </md-chip>
       </md-chip-list>
+      <div>{{message}}</div>
     </md-card-content>
   </md-card>
 
@@ -37,16 +40,61 @@ <h4>Advanced</h4>
     <md-card-content>
       <h4>Input Container</h4>
 
-      <md-chip-list>
-        <md-chip *ngFor="let person of people" [color]="color">
+      <p>
+        You can easily put the the <code>&lt;md-chip-list&gt;</code> inside of an
+        <code>&lt;md-input-container&gt;</code>.
+      </p>
+
+
+      <md-input-container>
+        <md-chip-list mdPrefix #chipList1>
+          <md-chip *ngFor="let person of people" [color]="color" [selectable]="selectable"
+                   [removable]="removable" (remove)="remove(person)">
+            {{person.name}}
+            <md-icon mdChipRemove *ngIf="removable">cancel</md-icon>
+          </md-chip>
+        </md-chip-list>
+        <input mdInput placeholder="New Contributor..."
+               [mdChipInputFor]="chipList1"
+               [mdChipInputSeparatorKeyCodes]="separatorKeysCodes"
+               [mdChipInputAddOnBlur]="addOnBlur"
+               (mdChipInputTokenEnd)="add($event)" />
+      </md-input-container>
+
+
+
+      <p>
+        You can also put <code>&lt;md-input-container&gt;</code> outside of an <code>md-chip-list</code>.
+        With <code>mdChipInput</code> the input work with chip-list
+      </p>
+
+      <md-chip-list #chipList2>
+        <md-chip *ngFor="let person of people" [color]="color" [selectable]="selectable"
+                 [removable]="removable" (remove)="remove(person)">
           {{person.name}}
+          <md-icon mdChipRemove *ngIf="removable">cancel</md-icon>
         </md-chip>
       </md-chip-list>
-
       <md-input-container>
-        <input mdInput #input (keyup.enter)="add(input)" placeholder="New Contributor..."/>
+        <input mdInput placeholder="New Contributor..."
+               [mdChipInputFor]="chipList2"
+               [mdChipInputSeparatorKeyCodes]="separatorKeysCodes"
+               [mdChipInputAddOnBlur]="addOnBlur"
+               (mdChipInputTokenEnd)="add($event)" />
       </md-input-container>
 
+      <p>
+        The example above has overridden the <code>[separatorKeys]</code> input to allow for
+        <code>ENTER</code>, <code>COMMA</code> and <code>SEMI COLON</code> keys.
+      </p>
+
+      <h4>Options</h4>
+      <p>
+        <md-checkbox name="selectable" [(ngModel)]="selectable">Selectable</md-checkbox>
+        <md-checkbox name="removable" [(ngModel)]="removable">Removable</md-checkbox>
+        <md-checkbox name="addOnBlur" [(ngModel)]="addOnBlur">Add on Blur</md-checkbox>
+      </p>
+
       <h4>Stacked Chips</h4>
 
       <p>

src/demo-app/chips/chips-demo.scss

@@ -20,4 +20,16 @@
   .mat-basic-chip {
     margin: auto 10px;
   }
-}
+
+  md-chip-list input {
+    width: 150px;
+  }
+
+  .mat-chip-remove.mat-icon {
+    font-size: 16px;
+    width: 1em;
+    height: 1em;
+    vertical-align: middle;
+    cursor: pointer;
+  }
+}

src/demo-app/chips/chips-demo.ts

@@ -1,4 +1,7 @@
 import {Component} from '@angular/core';
+import {MdChipInputEvent, ENTER} from '@angular/material';
+
+const COMMA = 188;
 
 export interface Person {
   name: string;
@@ -18,6 +21,13 @@ export interface DemoColor {
 export class ChipsDemo {
   visible: boolean = true;
   color: string = '';
+  selectable: boolean = true;
+  removable: boolean = true;
+  addOnBlur: boolean = true;
+  message: string = '';
+
+  // Enter, comma, semi-colon
+  separatorKeysCodes = [ENTER, COMMA, 186];
 
   people: Person[] = [
     { name: 'Kara' },
@@ -35,17 +45,33 @@ export class ChipsDemo {
     { name: 'Warn', color: 'warn' }
   ];
 
-  alert(message: string): void {
-    alert(message);
+  displayMessage(message: string): void {
+    this.message = message;
   }
 
-  add(input: HTMLInputElement): void {
-    if (input.value && input.value.trim() != '') {
-      this.people.push({ name: input.value.trim() });
+  add(event: MdChipInputEvent): void {
+    let input = event.input;
+    let value = event.value;
+
+    // Add our person
+    if ((value || '').trim()) {
+      this.people.push({ name: value.trim() });
+    }
+
+    // Reset the input value
+    if (input) {
       input.value = '';
     }
   }
 
+  remove(person: Person): void {
+    let index = this.people.indexOf(person);
+
+    if (index >= 0) {
+      this.people.splice(index, 1);
+    }
+  }
+
   toggleVisible(): void {
     this.visible = false;
   }

src/lib/chips/_chips-theme.scss

@@ -6,6 +6,23 @@
 $mat-chip-font-size: 13px;
 $mat-chip-line-height: 16px;
 
+@mixin mat-chips-theme-color($color) {
+  @include mat-chips-color(mat-contrast($color, 500), mat-color($color, 500));
+}
+
+@mixin mat-chips-color($foreground, $background) {
+  background-color: $background;
+  color: $foreground;
+
+  .mat-chip-remove {
+    color: $foreground;
+    opacity: 0.4;
+  }
+
+  .mat-chip-remove:hover {
+    opacity: 0.54;
+  }
+}
 
 @mixin mat-chips-theme($theme) {
   $is-dark-theme: map-get($theme, is-dark);
@@ -28,34 +45,29 @@ $mat-chip-line-height: 16px;
   $selected-background: if($is-dark-theme, mat-color($background, app-bar), #808080);
   $selected-foreground: if($is-dark-theme, mat-color($foreground, text), $light-selected-foreground);
 
-  .mat-chip:not(.mat-basic-chip) {
-    background-color: $unselected-background;
-    color: $unselected-foreground;
+  .mat-chip {
+    @include mat-chips-color($unselected-foreground, $unselected-background);
   }
 
-  .mat-chip.mat-chip-selected:not(.mat-basic-chip) {
-    background-color: $selected-background;
-    color: $selected-foreground;
+  .mat-chip.mat-chip-selected {
+    @include mat-chips-color($selected-foreground, $selected-background);
 
     &.mat-primary {
-      background-color: mat-color($primary);
-      color: mat-color($primary, default-contrast);
+      @include mat-chips-theme-color($primary);
     }
 
-    &.mat-accent {
-      background-color: mat-color($accent);
-      color: mat-color($accent, default-contrast);
+    &.mat-warn {
+      @include mat-chips-theme-color($warn);
     }
 
-    &.mat-warn {
-      background-color: mat-color($warn);
-      color: mat-color($warn, default-contrast);
+    &.mat-accent {
+      @include mat-chips-theme-color($accent);
     }
   }
 }
 
 @mixin mat-chips-typography($config) {
-  .mat-chip:not(.mat-basic-chip) {
+  .mat-chip {
     font-size: $mat-chip-font-size;
     line-height: $mat-chip-line-height;
   }

src/lib/chips/chip-input.spec.ts

@@ -0,0 +1,120 @@
+import {async, TestBed, ComponentFixture} from '@angular/core/testing';
+import {MdChipsModule} from './index';
+import {Component, DebugElement} from '@angular/core';
+import {MdChipInput, MdChipInputEvent} from './chip-input';
+import {By} from '@angular/platform-browser';
+import {Directionality} from '../core';
+import {createKeyboardEvent} from '@angular/cdk/testing';
+
+import {ENTER} from '../core/keyboard/keycodes';
+
+const COMMA = 188;
+
+describe('MdChipInput', () => {
+  let fixture: ComponentFixture<any>;
+  let testChipInput: TestChipInput;
+  let inputDebugElement: DebugElement;
+  let inputNativeElement: HTMLElement;
+  let chipInputDirective: MdChipInput;
+
+  let dir = 'ltr';
+
+  beforeEach(async(() => {
+    TestBed.configureTestingModule({
+      imports: [MdChipsModule],
+      declarations: [TestChipInput],
+      providers: [{
+        provide: Directionality, useFactory: () => {
+          return {value: dir.toLowerCase()};
+        }
+      }]
+    });
+
+    TestBed.compileComponents();
+  }));
+
+  beforeEach(async(() => {
+    fixture = TestBed.createComponent(TestChipInput);
+    testChipInput = fixture.debugElement.componentInstance;
+    fixture.detectChanges();
+
+    inputDebugElement = fixture.debugElement.query(By.directive(MdChipInput));
+    chipInputDirective = inputDebugElement.injector.get(MdChipInput) as MdChipInput;
+    inputNativeElement = inputDebugElement.nativeElement;
+  }));
+
+  describe('basic behavior', () => {
+    it('emits the (chipEnd) on enter keyup', () => {
+      let ENTER_EVENT = createKeyboardEvent('keydown', ENTER, inputNativeElement) as any;
+
+      spyOn(testChipInput, 'add');
+
+      chipInputDirective._keydown(ENTER_EVENT);
+      expect(testChipInput.add).toHaveBeenCalled();
+    });
+  });
+
+  describe('[addOnBlur]', () => {
+    it('allows (chipEnd) when true', () => {
+      spyOn(testChipInput, 'add');
+
+      testChipInput.addOnBlur = true;
+      fixture.detectChanges();
+
+      chipInputDirective._blur();
+      expect(testChipInput.add).toHaveBeenCalled();
+    });
+
+    it('disallows (chipEnd) when false', () => {
+      spyOn(testChipInput, 'add');
+
+      testChipInput.addOnBlur = false;
+      fixture.detectChanges();
+
+      chipInputDirective._blur();
+      expect(testChipInput.add).not.toHaveBeenCalled();
+    });
+  });
+
+  describe('[separatorKeysCodes]', () => {
+    it('does not emit (chipEnd) when a non-separator key is pressed', () => {
+      let ENTER_EVENT = createKeyboardEvent('keydown', ENTER, inputNativeElement) as any;
+      spyOn(testChipInput, 'add');
+
+      testChipInput.separatorKeys = [COMMA];
+      fixture.detectChanges();
+
+      chipInputDirective._keydown(ENTER_EVENT);
+      expect(testChipInput.add).not.toHaveBeenCalled();
+    });
+
+    it('emits (chipEnd) when a custom separator keys is pressed', () => {
+      let COMMA_EVENT = createKeyboardEvent('keydown', COMMA, inputNativeElement) as any;
+      spyOn(testChipInput, 'add');
+
+      testChipInput.separatorKeys = [COMMA];
+      fixture.detectChanges();
+
+      chipInputDirective._keydown(COMMA_EVENT);
+      expect(testChipInput.add).toHaveBeenCalled();
+    });
+  });
+});
+
+@Component({
+  template: `
+    <md-chip-list #chipList>
+    </md-chip-list>
+    <input mdInput [mdChipInputFor]="chipList"
+              [mdChipInputAddOnBlur]="addOnBlur"
+              [mdChipInputSeparatorKeyCodes]="separatorKeys"
+              (mdChipInputTokenEnd)="add($event)" />
+  `
+})
+class TestChipInput {
+  addOnBlur: boolean = false;
+  separatorKeys: number[] = [ENTER];
+
+  add(_: MdChipInputEvent) {
+  }
+}