fix(icon-button): Remove unused styles and update docs

packages/mdc-icon-button/README.md

@@ -51,6 +51,7 @@ npm install @material/icon-button
 ```scss
 @import "@material/icon-button/mdc-icon-button";
 ```
+
 ### JavaScript Instantiation
 
 The icon button will work without JavaScript, but you can enhance it to have a ripple effect by instantiating `MDCRipple` on the root element.
@@ -81,7 +82,7 @@ The icon button can be used to toggle between an on and off icon. To style an ic
    data-toggle-on-content="favorite"
    data-toggle-on-label="Remove from favorites"
    data-toggle-off-content="favorite_border"
-   data-toggle-off-label="Add to favorites">favorites_border</button>
+   data-toggle-off-label="Add to favorites">favorite_border</button>
 ```
 
 ```js
@@ -101,10 +102,27 @@ Attribute | Description
 `data-toggle-<TOGGLE STATE>-content` | The text content to set on the element. Note that if an inner icon is used, the text content will be set on that element instead.
 `data-toggle-<TOGGLE STATE>-class` | A CSS class to apply to the icon element. The same rules regarding inner icon elements described for `content` apply here as well.
 
+#### Icon Button Toggle with Font Awesome
+
+The icon button toggle can be used with other font libraries such as Font Awesome that use an inner icon element.
+
+```html
+<button id="star-this-item"
+   class="mdc-icon-button"
+   aria-label="Unstar this item"
+   aria-hidden="true"
+   aria-pressed="true"
+   data-toggle-on-class="fa-star"
+   data-toggle-on-label="Unstar this item"
+   data-toggle-off-class="fa-star-o"
+   data-toggle-off-label="Star this item"><i class="fa fa-2x fa-star"></i></button>
+```
+
 ### Icons
 
-The icon button can be used with a standard icon library or an `svg`. The icon button toggle should only be used with
-an standard icon library. We recommend you use [Material Icons](https://material.io/tools/icons) from Google Fonts.
+The icon button can be used with a standard icon library such as Material Icons or Font Awesome, or with an `svg`.
+The icon button toggle should only be used with an standard icon library. We recommend you use 
+[Material Icons](https://material.io/tools/icons) from Google Fonts.
 
 ### Disabled
 

packages/mdc-icon-button/adapter.js

@@ -58,12 +58,6 @@ class MDCIconButtonToggleAdapter {
   /** @param {string} text */
   setText(text) {}
 
-  /** @return {number} */
-  getTabIndex() {}
-
-  /** @param {number} tabIndex */
-  setTabIndex(tabIndex) {}
-
   /**
    * @param {string} name
    * @return {string}
@@ -76,9 +70,6 @@ class MDCIconButtonToggleAdapter {
    */
   setAttr(name, value) {}
 
-  /** @param {string} name */
-  removeAttr(name) {}
-
   /** @param {!IconButtonToggleEvent} evtData */
   notifyChange(evtData) {}
 }

packages/mdc-icon-button/foundation.js

@@ -39,27 +39,23 @@ class MDCIconButtonToggleFoundation extends MDCFoundation {
       registerInteractionHandler: (/* type: string, handler: EventListener */) => {},
       deregisterInteractionHandler: (/* type: string, handler: EventListener */) => {},
       setText: (/* text: string */) => {},
-      getTabIndex: () => /* number */ 0,
-      setTabIndex: (/* tabIndex: number */) => {},
       getAttr: (/* name: string */) => /* string */ '',
       setAttr: (/* name: string, value: string */) => {},
-      removeAttr: (/* name: string */) => {},
       notifyChange: (/* evtData: IconButtonToggleEvent */) => {},
     };
   }
 
   constructor(adapter) {
     super(Object.assign(MDCIconButtonToggleFoundation.defaultAdapter, adapter));
 
+    const {ARIA_PRESSED} = MDCIconButtonToggleFoundation.strings;
+
     /** @private {boolean} */
-    this.on_ = false;
+    this.on_ = this.adapter_.getAttr(ARIA_PRESSED) === 'true';
 
     /** @private {boolean} */
     this.disabled_ = false;
 
-    /** @private {number} */
-    this.savedTabIndex_ = -1;
-
     /** @private {?IconButtonToggleState} */
     this.toggleOnData_ = null;
 
@@ -72,7 +68,6 @@ class MDCIconButtonToggleFoundation extends MDCFoundation {
 
   init() {
     this.refreshToggleData();
-    this.savedTabIndex_ = this.adapter_.getTabIndex();
     this.adapter_.registerInteractionHandler('click', this.clickHandler_);
   }
 

packages/mdc-icon-button/index.js

@@ -64,11 +64,8 @@ class MDCIconButtonToggle extends MDCComponent {
       registerInteractionHandler: (type, handler) => this.root_.addEventListener(type, handler),
       deregisterInteractionHandler: (type, handler) => this.root_.removeEventListener(type, handler),
       setText: (text) => this.iconEl_.textContent = text,
-      getTabIndex: () => /* number */ this.root_.tabIndex,
-      setTabIndex: (tabIndex) => this.root_.tabIndex = tabIndex,
-      getAttr: (name, value) => this.root_.getAttribute(name, value),
+      getAttr: (name) => this.root_.getAttribute(name),
       setAttr: (name, value) => this.root_.setAttribute(name, value),
-      removeAttr: (name) => this.root_.removeAttribute(name),
       notifyChange: (evtData) => this.emit(MDCIconButtonToggleFoundation.strings.CHANGE_EVENT, evtData),
     });
   }

packages/mdc-icon-button/mdc-icon-button.scss

@@ -23,10 +23,4 @@
   @include mdc-states;
 }
 
-.mdc-icon-button--disabled {
-  @include mdc-theme-prop(color, text-disabled-on-light);
-
-  pointer-events: none;
-}
-
 // postcss-bem-linter: end

test/unit/mdc-icon-button/foundation.test.js

@@ -36,15 +36,24 @@ test('exports cssClasses', () => {
 test('defaultAdapter returns a complete adapter implementation', () => {
   verifyDefaultAdapter(MDCIconButtonToggleFoundation, [
     'addClass', 'removeClass', 'registerInteractionHandler', 'deregisterInteractionHandler',
-    'setText', 'getTabIndex', 'setTabIndex', 'getAttr', 'setAttr', 'removeAttr', 'notifyChange',
+    'setText', 'getAttr', 'setAttr', 'notifyChange',
   ]);
 });
 
 const setupTest = () => setupFoundationTest(MDCIconButtonToggleFoundation);
 
 test('#constructor sets on to false', () => {
-  const {foundation} = setupTest();
-  assert.isNotOk(foundation.isOn());
+  const {mockAdapter} = setupTest();
+  td.when(mockAdapter.getAttr(strings.ARIA_PRESSED)).thenReturn('false');
+  const foundation = new MDCIconButtonToggleFoundation(mockAdapter);
+  assert.isFalse(foundation.isOn());
+});
+
+test('#constructor sets on to true if the toggle is pressed', () => {
+  const {mockAdapter} = setupTest();
+  td.when(mockAdapter.getAttr(strings.ARIA_PRESSED)).thenReturn('true');
+  const foundation = new MDCIconButtonToggleFoundation(mockAdapter);
+  assert.isTrue(foundation.isOn());
 });
 
 test('#toggle flips on', () => {

test/unit/mdc-icon-button/mdc-icon-button-toggle.test.js

@@ -158,17 +158,6 @@ test('#adapter.setText sets the text content of the inner icon element when used
   assert.equal(root.querySelector('#icon').textContent, 'foo');
 });
 
-test('#adapter.getTabIndex returns the tabIndex of the element', () => {
-  const {component} = setupTest({tabIndex: 4});
-  assert.equal(component.getDefaultFoundation().adapter_.getTabIndex(), 4);
-});
-
-test('#adapter.setTabIndex sets the tabIndex of the element', () => {
-  const {root, component} = setupTest({tabIndex: 4});
-  component.getDefaultFoundation().adapter_.setTabIndex(2);
-  assert.equal(root.tabIndex, 2);
-});
-
 test('#adapter.getAttr retrieves an attribute from the root element', () => {
   const {root, component} = setupTest();
   root.setAttribute('aria-label', 'hello');
@@ -181,13 +170,6 @@ test('#adapter.setAttr sets an attribute on the root element', () => {
   assert.equal(root.getAttribute('aria-label'), 'hello');
 });
 
-test('#adapter.removeAttr removes an attribute from the root element', () => {
-  const {root, component} = setupTest();
-  root.setAttribute('aria-label', 'hello');
-  component.getDefaultFoundation().adapter_.removeAttr('aria-label');
-  assert.isNotOk(root.hasAttribute('aria-label'));
-});
-
 test(`#adapter.notifyChange broadcasts a ${MDCIconButtonToggleFoundation.strings.CHANGE_EVENT} custom event`, () => {
   const {root, component} = setupTest();
   const handler = td.func('custom event handler');