feat(chips): add keyboard interaction. (#2046)

Add basic focus/keyboard support for chips.

 - Up/down arrows navigate chips.
 - Clicking a chip properly focuses it for subsequent keyboard
   navigation.
 - More demos.

Confirmed AoT compatibility.

References #120.

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

@@ -2,11 +2,67 @@
   <section>
     <h3>Static Chips</h3>
 
+    <h5>Simple</h5>
+
+    <md-chip-list>
+      <md-chip>Chip 1</md-chip>
+      <md-chip>Chip 2</md-chip>
+      <md-chip>Chip 3</md-chip>
+    </md-chip-list>
+
+    <h5>Advanced</h5>
+
+    <md-chip-list>
+      <md-chip class="md-accent selected">Selected/Colored</md-chip>
+      <md-chip class="md-warn" *ngIf="visible"
+               (destroy)="alert('chip destroyed')" (click)="toggleVisible()">
+        With Events
+      </md-chip>
+    </md-chip-list>
+
+    <h5>Unstyled</h5>
+
+    <md-chip-list>
+      <md-basic-chip>Basic Chip 1</md-basic-chip>
+      <md-basic-chip>Basic Chip 2</md-basic-chip>
+      <md-basic-chip>Basic Chip 3</md-basic-chip>
+    </md-chip-list>
+
+    <h3>Material Contributors</h3>
+
     <md-chip-list>
-      <md-chip>Basic Chip</md-chip>
-      <md-chip class="selected md-primary">Primary</md-chip>
-      <md-chip class="selected md-accent">Accent</md-chip>
-      <md-chip class="selected md-warn">Warn</md-chip>
+      <md-chip *ngFor="let person of people; let even = even" [ngClass]="[color, even ? 'selected' : '' ]">
+        {{person.name}}
+      </md-chip>
+    </md-chip-list>
+
+    <br />
+
+    <md-input #input (keyup.enter)="add(input)" (blur)="add(input)" placeholder="New Contributor...">
+    </md-input>
+
+    <h3>Stacked Chips</h3>
+
+    <p>
+      You can also stack the chips if you want them on top of each other.
+    </p>
+
+    <md-chip-list class="md-chip-list-stacked">
+      <md-chip (focus)="color = ''" class="selected">
+        None
+      </md-chip>
+
+      <md-chip (focus)="color = 'md-primary'" class="selected md-primary">
+        Primary
+      </md-chip>
+
+      <md-chip (focus)="color = 'md-accent'" class="selected md-accent">
+        Accent
+      </md-chip>
+
+      <md-chip (focus)="color = 'md-warn'" class="selected md-warn">
+        Warn
+      </md-chip>
     </md-chip-list>
   </section>
 </div>

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

@@ -1,2 +1,10 @@
 .chips-demo {
+  .md-chip-list-stacked {
+    display: block;
+    max-width: 200px;
+  }
+
+  md-basic-chip {
+    margin: auto 10px;
+  }
 }

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

@@ -1,4 +1,9 @@
 import {Component} from '@angular/core';
+import {MdInput} from '@angular/material';
+
+export interface Person {
+  name: string;
+}
 
 @Component({
   moduleId: module.id,
@@ -7,4 +12,30 @@ import {Component} from '@angular/core';
   styleUrls: ['chips-demo.css']
 })
 export class ChipsDemo {
+  visible: boolean = true;
+  color: string = '';
+
+  people: Person[] = [
+    { name: 'Kara' },
+    { name: 'Jeremy' },
+    { name: 'Topher' },
+    { name: 'Elad' },
+    { name: 'Kristiyan' },
+    { name: 'Paul' }
+  ];
+
+  alert(message: string): void {
+    alert(message);
+  }
+
+  add(input: MdInput): void {
+    if (input.value && input.value.trim() != '') {
+      this.people.push({ name: input.value.trim() });
+      input.value = '';
+    }
+  }
+
+  toggleVisible(): void {
+    this.visible = false;
+  }
 }

src/lib/chips/_chips-theme.scss

@@ -13,6 +13,12 @@
   }
 
   .md-chip.selected {
+    // There is no dark theme in the current spec, so this applies to both
+    background-color: #808080;
+
+    // Use a contrast color for a grey very close to the background color
+    color: md-contrast($md-grey, 600);
+
     &.md-primary {
       background-color: md-color($primary, 500);
       color: md-contrast($primary, 500);
@@ -26,4 +32,4 @@
       color: md-contrast($warn, 500);
     }
   }
-}
+}

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

@@ -1,10 +1,17 @@
 import {async, ComponentFixture, TestBed} from '@angular/core/testing';
-import {Component, DebugElement}  from '@angular/core';
+import {Component, DebugElement, QueryList} from '@angular/core';
 import {By} from '@angular/platform-browser';
-import {MdChipList, MdChipsModule} from './index';
+import {MdChip, MdChipList, MdChipsModule} from './index';
+import {ListKeyManager} from '../core/a11y/list-key-manager';
 
-describe('MdChip', () => {
+describe('MdChipList', () => {
   let fixture: ComponentFixture<any>;
+  let chipListDebugElement: DebugElement;
+  let chipListNativeElement: HTMLElement;
+  let chipListInstance: MdChipList;
+  let testComponent: StaticChipList;
+  let items: QueryList<MdChip>;
+  let manager: ListKeyManager;
 
   beforeEach(async(() => {
     TestBed.configureTestingModule({
@@ -15,39 +22,87 @@ describe('MdChip', () => {
     });
 
     TestBed.compileComponents();
+
+    fixture = TestBed.createComponent(StaticChipList);
+    fixture.detectChanges();
+
+    chipListDebugElement = fixture.debugElement.query(By.directive(MdChipList));
+    chipListNativeElement = chipListDebugElement.nativeElement;
+    chipListInstance = chipListDebugElement.componentInstance;
+    testComponent = fixture.debugElement.componentInstance;
   }));
 
   describe('basic behaviors', () => {
-    let chipListDebugElement: DebugElement;
-    let chipListNativeElement: HTMLElement;
-    let chipListInstance: MdChipList;
-    let testComponent: StaticChipList;
+    it('adds the `md-chip-list` class', () => {
+      expect(chipListNativeElement.classList).toContain('md-chip-list');
+    });
+  });
 
+  describe('focus behaviors', () => {
     beforeEach(() => {
-      fixture = TestBed.createComponent(StaticChipList);
+      items = chipListInstance.chips;
+      manager = chipListInstance._keyManager;
+    });
+
+    it('watches for chip focus', () => {
+      let array = items.toArray();
+      let lastIndex = array.length - 1;
+      let lastItem = array[lastIndex];
+
+      lastItem.focus();
       fixture.detectChanges();
 
-      chipListDebugElement = fixture.debugElement.query(By.directive(MdChipList));
-      chipListNativeElement = chipListDebugElement.nativeElement;
-      chipListInstance = chipListDebugElement.componentInstance;
-      testComponent = fixture.debugElement.componentInstance;
+      expect(manager.focusedItemIndex).toBe(lastIndex);
     });
 
-    it('adds the `md-chip-list` class', () => {
-      expect(chipListNativeElement.classList).toContain('md-chip-list');
+    describe('on chip destroy', () => {
+      it('focuses the next item', () => {
+        let array = items.toArray();
+        let midItem = array[2];
+
+        // Focus the middle item
+        midItem.focus();
+
+        // Destroy the middle item
+        testComponent.remove = 2;
+        fixture.detectChanges();
+
+        // It focuses the 4th item (now at index 2)
+        expect(manager.focusedItemIndex).toEqual(2);
+      });
+
+      it('focuses the previous item', () => {
+        let array = items.toArray();
+        let lastIndex = array.length - 1;
+        let lastItem = array[lastIndex];
+
+        // Focus the last item
+        lastItem.focus();
+
+        // Destroy the last item
+        testComponent.remove = lastIndex;
+        fixture.detectChanges();
+
+        // It focuses the next-to-last item
+        expect(manager.focusedItemIndex).toEqual(lastIndex - 1);
+      });
     });
   });
+
 });
 
 @Component({
   template: `
     <md-chip-list>
-      <md-chip>{{name}} 1</md-chip>
-      <md-chip>{{name}} 2</md-chip>
-      <md-chip>{{name}} 3</md-chip>
+      <div *ngIf="remove != 0"><md-chip>{{name}} 1</md-chip></div>
+      <div *ngIf="remove != 1"><md-chip>{{name}} 2</md-chip></div>
+      <div *ngIf="remove != 2"><md-chip>{{name}} 3</md-chip></div>
+      <div *ngIf="remove != 3"><md-chip>{{name}} 4</md-chip></div>
+      <div *ngIf="remove != 4"><md-chip>{{name}} 5</md-chip></div>
     </md-chip-list>
   `
 })
 class StaticChipList {
   name: 'Test';
+  remove: Number;
 }