feat(interaction): added service to detect last interaction

src/components/sidenav/sidenav.js

@@ -243,8 +243,8 @@ function SidenavFocusDirective() {
  *   - `<md-sidenav md-is-locked-open="$mdMedia('min-width: 1000px')"></md-sidenav>`
  *   - `<md-sidenav md-is-locked-open="$mdMedia('sm')"></md-sidenav>` (locks open on small screens)
  */
-function SidenavDirective($mdMedia, $mdUtil, $mdConstant, $mdTheming,
-  $animate, $compile, $parse, $log, $q, $document, $window) {
+function SidenavDirective($mdMedia, $mdUtil, $mdConstant, $mdTheming, $mdInteraction, $animate, $compile,
+                          $parse, $log, $q, $document, $window) {
   return {
     restrict: 'E',
     scope: {
@@ -265,6 +265,7 @@ function SidenavDirective($mdMedia, $mdUtil, $mdConstant, $mdTheming,
     var lastParentOverFlow;
     var backdrop;
     var disableScrollTarget = null;
+    var triggeringInteractionType;
     var triggeringElement = null;
     var previousContainerStyles;
     var promise = $q.when(true);
@@ -356,6 +357,7 @@ function SidenavDirective($mdMedia, $mdUtil, $mdConstant, $mdTheming,
       if ( isOpen ) {
         // Capture upon opening..
         triggeringElement = $document[0].activeElement;
+        triggeringInteractionType = $mdInteraction.getLastInteractionType();
       }
 
       disableParentScroll(isOpen);
@@ -455,9 +457,9 @@ function SidenavDirective($mdMedia, $mdUtil, $mdConstant, $mdTheming,
             // When the current `updateIsOpen()` animation finishes
             promise.then(function(result) {
 
-              if ( !scope.isOpen ) {
+              if ( !scope.isOpen && triggeringElement && triggeringInteractionType === 'keyboard') {
                 // reset focus to originating element (if available) upon close
-                triggeringElement && triggeringElement.focus();
+                triggeringElement.focus();
                 triggeringElement = null;
               }
 

src/components/sidenav/sidenav.spec.js

@@ -256,6 +256,82 @@ describe('mdSidenav', function() {
 
   });
 
+  describe("focus", function() {
+
+    var $material, $mdInteraction, $mdConstant;
+    var triggerElement;
+
+    beforeEach(inject(function($injector) {
+      $material = $injector.get('$material');
+      $mdInteraction = $injector.get('$mdInteraction');
+      $mdConstant = $injector.get('$mdInteraction');
+
+      triggerElement = angular.element('<button>Trigger Element</button>');
+      document.body.appendChild(triggerElement[0]);
+    }));
+
+    afterEach(function() {
+      triggerElement.remove();
+    });
+
+    function dispatchEvent(eventName) {
+      angular.element(document.body).triggerHandler(eventName);
+    }
+
+    function flush() {
+      $material.flushInterimElement();
+    }
+
+    function blur() {
+      if ('documentMode' in document) {
+        document.body.focus();
+      } else {
+        triggerElement.blur();
+      }
+    }
+
+    it("should restore after sidenav triggered by keyboard", function() {
+      var sidenavEl = setup('');
+      var controller = sidenavEl.controller('mdSidenav');
+
+      triggerElement.focus();
+
+      dispatchEvent('keydown');
+
+      controller.$toggleOpen(true);
+      flush();
+
+      blur();
+
+      controller.$toggleOpen(false);
+      flush();
+
+      expect($mdInteraction.getLastInteractionType()).toBe("keyboard");
+      expect(document.activeElement).toBe(triggerElement[0]);
+    });
+
+    it("should not restore after sidenav triggered by mouse", function() {
+      var sidenavEl = setup('');
+      var controller = sidenavEl.controller('mdSidenav');
+
+      triggerElement.focus();
+
+      dispatchEvent('mousedown');
+
+      controller.$toggleOpen(true);
+      flush();
+
+      blur();
+
+      controller.$toggleOpen(false);
+      flush();
+
+      expect($mdInteraction.getLastInteractionType()).toBe("mouse");
+      expect(document.activeElement).not.toBe(triggerElement[0]);
+    });
+
+  });
+
   describe("controller Promise API", function() {
     var $material, $rootScope, $timeout;
 

src/core/core.js

@@ -7,6 +7,7 @@ angular
     'ngAnimate',
     'material.core.animate',
     'material.core.layout',
+    'material.core.interaction',
     'material.core.gestures',
     'material.core.theming'
   ])

src/core/services/interaction/interaction.js

@@ -0,0 +1,132 @@
+/**
+ * @ngdoc module
+ * @name material.core.interaction
+ * @description
+ * User interaction detection to provide proper accessibility.
+ */
+angular
+  .module('material.core.interaction', [])
+  .service('$mdInteraction', MdInteractionService);
+
+
+/**
+ * @ngdoc service
+ * @name $mdInteraction
+ * @module material.core.interaction
+ *
+ * @description
+ *
+ * Service which keeps track of the last interaction type and validates them for several browsers.
+ * The service hooks into the document's body and listens for touch, mouse and keyboard events.
+ *
+ * The most recent interaction type can be retrieved by calling the `getLastInteractionType` method.
+ *
+ * Here is an example markup for using the interaction service.
+ *
+ * <hljs lang="js">
+ *   var lastType = $mdInteraction.getLastInteractionType();
+ *
+ *   if (lastType === 'keyboard') {
+ *     // We only restore the focus for keyboard users.
+ *     restoreFocus();
+ *   }
+ * </hljs>
+ *
+ */
+function MdInteractionService($timeout) {
+  this.$timeout = $timeout;
+
+  this.bodyElement = angular.element(document.body);
+  this.isBuffering = false;
+  this.bufferTimeout = null;
+  this.lastInteractionType = null;
+
+  // Type Mappings for the different events
+  // There will be three three interaction types
+  // `keyboard`, `mouse` and `touch`
+  // type `pointer` will be evaluated in `pointerMap` for IE Browser events
+  this.inputEventMap = {
+    'keydown': 'keyboard',
+    'mousedown': 'mouse',
+    'mouseenter': 'mouse',
+    'touchstart': 'touch',
+    'pointerdown': 'pointer',
+    'MSPointerDown': 'pointer'
+  };
+
+  // IE PointerDown events will be validated in `touch` or `mouse`
+  // Index numbers referenced here: https://msdn.microsoft.com/library/windows/apps/hh466130.aspx
+  this.iePointerMap = {
+    2: 'touch',
+    3: 'touch',
+    4: 'mouse'
+  };
+
+  this.initializeEvents();
+}
+
+/**
+ * Initializes the interaction service, by registering all interaction events to the
+ * body element.
+ */
+MdInteractionService.prototype.initializeEvents = function() {
+  // IE browsers can also trigger pointer events, which also leads to an interaction.
+  var pointerEvent = 'MSPointerEvent' in window ? 'MSPointerDown' : 'PointerEvent' in window ? 'pointerdown' : null;
+
+  this.bodyElement.on('keydown mousedown', this.onInputEvent.bind(this));
+
+  if ('ontouchstart' in document.documentElement) {
+    this.bodyElement.on('touchstart', this.onBufferInputEvent.bind(this));
+  }
+
+  if (pointerEvent) {
+    this.bodyElement.on(pointerEvent, this.onInputEvent.bind(this));
+  }
+
+};
+
+/**
+ * Event listener for normal interaction events, which should be tracked.
+ * @param event {MouseEvent|KeyboardEvent|PointerEvent}
+ */
+MdInteractionService.prototype.onInputEvent = function(event) {
+  if (this.isBuffering) {
+    return;
+  }
+
+  var type = this.inputEventMap[event.type];
+
+  if (type === 'pointer') {
+    type = this.iePointerMap[event.pointerType] || event.pointerType;
+  }
+
+  this.lastInteractionType = type;
+};
+
+/**
+ * Event listener for interaction events which should be buffered (touch events).
+ * @param event {TouchEvent}
+ */
+MdInteractionService.prototype.onBufferInputEvent = function(event) {
+  this.$timeout.cancel(this.bufferTimeout);
+
+  this.onInputEvent(event);
+  this.isBuffering = true;
+
+  // The timeout of 650ms is needed to delay the touchstart, because otherwise the touch will call
+  // the `onInput` function multiple times.
+  this.bufferTimeout = this.$timeout(function() {
+    this.isBuffering = false;
+  }.bind(this), 650, false);
+
+};
+
+/**
+ * @ngdoc method
+ * @name $mdInteraction#getLastInteractionType
+ * @description Retrieves the last interaction type triggered in body.
+ * @returns {string|null} Last interaction type.
+ */
+MdInteractionService.prototype.getLastInteractionType = function() {
+  return this.lastInteractionType;
+};

src/core/services/interaction/interaction.spec.js

@@ -0,0 +1,33 @@
+describe("$mdInteraction service", function() {
+  var $mdInteraction;
+
+  beforeEach(module('material.core'));
+
+  beforeEach(inject(function($injector) {
+    $mdInteraction = $injector.get('$mdInteraction');
+  }));
+
+  describe("last interaction type", function() {
+
+    var bodyElement = null;
+
+    beforeEach(function() {
+      bodyElement = angular.element(document.body);
+    });
+
+    it("should detect a keyboard interaction", function() {
+
+      bodyElement.triggerHandler('keydown');
+
+      expect($mdInteraction.getLastInteractionType()).toBe('keyboard');
+    });
+
+    it("should detect a mouse interaction", function() {
+
+      bodyElement.triggerHandler('mousedown');
+
+      expect($mdInteraction.getLastInteractionType()).toBe("mouse");
+    });
+
+  });
+});