feat(radio): support for color binding

* Introduces the `color` binding for radio buttons. By default every selection control uses accent as per Material design specifications.

Closes angular#4677

src/demo-app/radio/radio-demo.html

@@ -4,6 +4,15 @@ <h1>Basic Example</h1>
   <md-radio-button name="group1">Option 2</md-radio-button>
   <md-radio-button name="group1" disabled="true">Option 3 (disabled)</md-radio-button>
 </section>
+
+<h1>Color Example</h1>
+<section class="demo-section">
+  <md-radio-button name="group2">Default (accent)</md-radio-button>
+  <md-radio-button name="group2" color="primary">Primary</md-radio-button>
+  <md-radio-button name="group2" color="accent">Accent</md-radio-button>
+  <md-radio-button name="group2" color="warn">Warn</md-radio-button>
+</section>
+
 <h1>Dynamic Example</h1>
 <section class="demo-section">
   <div>

src/lib/radio/_radio-theme.scss

@@ -2,6 +2,19 @@
 @import '../core/theming/theming';
 @import '../core/typography/typography-utils';
 
+@mixin mat-radio-color($palette) {
+  &.mat-radio-checked .mat-radio-outer-circle {
+    border-color: mat-color($palette);
+  }
+
+  .mat-radio-inner-circle {
+    background-color: mat-color($palette);
+  }
+
+  .mat-radio-ripple .mat-ripple-element {
+    background-color: mat-color($palette, 0.26);
+  }
+}
 
 @mixin mat-radio-theme($theme) {
   $primary: map-get($theme, primary);
@@ -14,22 +27,10 @@
     border-color: mat-color($foreground, secondary-text);
   }
 
-  .mat-radio-checked .mat-radio-outer-circle {
-    border-color: mat-color($accent);
-  }
-
   .mat-radio-disabled .mat-radio-outer-circle {
     border-color: mat-color($foreground, disabled);
   }
 
-  .mat-radio-inner-circle {
-    background-color: mat-color($accent);
-  }
-
-  .mat-radio-ripple .mat-ripple-element {
-    background-color: mat-color($accent, 0.26);
-  }
-
   .mat-radio-disabled {
     .mat-radio-ripple .mat-ripple-element, .mat-radio-inner-circle {
       background-color: mat-color($foreground, disabled);
@@ -39,6 +40,20 @@
       color: mat-color($foreground, disabled);
     }
   }
+
+  .mat-radio-button {
+    &.mat-primary {
+      @include mat-radio-color($primary);
+    }
+
+    &.mat-accent {
+      @include mat-radio-color($accent);
+    }
+
+    &.mat-warn {
+      @include mat-radio-color($warn);
+    }
+  }
 }
 
 @mixin mat-radio-typography($config) {

src/lib/radio/radio.spec.ts

@@ -332,6 +332,29 @@ describe('MdRadio', () => {
       expect(radioInstances[1].checked).toBeFalsy('should not select the second button');
       expect(radioInstances[2].checked).toBeFalsy('should not select the third button');
     });
+
+    it('should apply class based on color attribute', () => {
+      expect(radioNativeElements.every(radioEl => radioEl.classList.contains('mat-accent')))
+        .toBe(true, 'Expected every radio element to use the accent color by default.');
+
+      testComponent.color = 'primary';
+      fixture.detectChanges();
+
+      expect(radioNativeElements.every(radioEl => radioEl.classList.contains('mat-primary')))
+        .toBe(true, 'Expected every radio element to use the primary color from the binding.');
+
+      testComponent.color = 'warn';
+      fixture.detectChanges();
+
+      expect(radioNativeElements.every(radioEl => radioEl.classList.contains('mat-warn')))
+        .toBe(true, 'Expected every radio element to use the primary color from the binding.');
+
+      testComponent.color = null;
+      fixture.detectChanges();
+
+      expect(radioNativeElements.every(radioEl => radioEl.classList.contains('mat-accent')))
+        .toBe(true, 'Expected every radio element to fallback to accent color if value is falsy.');
+    });
   });
 
   describe('group with ngModel', () => {
@@ -595,10 +618,16 @@ describe('MdRadio', () => {
                   [labelPosition]="labelPos"
                   [value]="groupValue"
                   name="test-name">
-    <md-radio-button value="fire" [disableRipple]="disableRipple"
-                     [disabled]="isFirstDisabled">Charmander</md-radio-button>
-    <md-radio-button value="water" [disableRipple]="disableRipple">Squirtle</md-radio-button>
-    <md-radio-button value="leaf" [disableRipple]="disableRipple">Bulbasaur</md-radio-button>
+    <md-radio-button value="fire" [disableRipple]="disableRipple" [disabled]="isFirstDisabled"
+                     [color]="color">
+      Charmander
+    </md-radio-button>
+    <md-radio-button value="water" [disableRipple]="disableRipple" [color]="color">
+      Squirtle
+    </md-radio-button>
+    <md-radio-button value="leaf" [disableRipple]="disableRipple" [color]="color">
+      Bulbasaur
+    </md-radio-button>
   </md-radio-group>
   `
 })
@@ -608,6 +637,7 @@ class RadiosInsideRadioGroup {
   isFirstDisabled: boolean = false;
   groupValue: string = null;
   disableRipple: boolean = false;
+  color: string;
 }
 
 

src/lib/radio/radio.ts

@@ -29,6 +29,7 @@ import {
 } from '../core';
 import {coerceBooleanProperty} from '../core/coercion/boolean-property';
 import {mixinDisabled, CanDisable} from '../core/common-behaviors/disabled';
+import {CanColor, mixinColor} from '../core/common-behaviors/color';
 
 
 /**
@@ -287,6 +288,14 @@ export class MdRadioGroup extends _MdRadioGroupMixinBase
   }
 }
 
+// Boilerplate for applying mixins to MdRadioButton.
+export class MdRadioButtonBase {
+  constructor(public _renderer: Renderer2, public _elementRef: ElementRef) {}
+}
+// As per Material design specifications the selection control radio should use the accent color
+// palette by default. https://material.io/guidelines/components/selection-controls.html
+export const _MdRadioButtonMixinBase = mixinColor(MdRadioButtonBase, 'accent');
+
 /**
  * A radio-button. May be inside of
  */
@@ -295,6 +304,7 @@ export class MdRadioGroup extends _MdRadioGroupMixinBase
   selector: 'md-radio-button, mat-radio-button',
   templateUrl: 'radio.html',
   styleUrls: ['radio.css'],
+  inputs: ['color'],
   encapsulation: ViewEncapsulation.None,
   host: {
     '[class.mat-radio-button]': 'true',
@@ -304,7 +314,8 @@ export class MdRadioGroup extends _MdRadioGroupMixinBase
   },
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class MdRadioButton implements OnInit, AfterViewInit, OnDestroy {
+export class MdRadioButton extends _MdRadioButtonMixinBase
+    implements OnInit, AfterViewInit, OnDestroy, CanColor {
 
   /** The unique ID for the radio button. */
   @Input() id: string = `md-radio-${_uniqueIdCounter++}`;
@@ -443,14 +454,15 @@ export class MdRadioButton implements OnInit, AfterViewInit, OnDestroy {
   @ViewChild('input') _inputElement: ElementRef;
 
   constructor(@Optional() radioGroup: MdRadioGroup,
-              private _elementRef: ElementRef,
-              private _renderer: Renderer2,
+              elementRef: ElementRef,
+              renderer: Renderer2,
               private _changeDetector: ChangeDetectorRef,
               private _focusOriginMonitor: FocusOriginMonitor,
               private _radioDispatcher: UniqueSelectionDispatcher) {
+    super(renderer, elementRef);
+
     // Assertions. Ideally these should be stripped out by the compiler.
     // TODO(jelbourn): Assert that there's no name binding AND a parent radio group.
-
     this.radioGroup = radioGroup;
 
     _radioDispatcher.listen((id: string, name: string) => {