feat(sideMenu): make android back button close side menu

Closes #1264

js/angular/controller/sideMenuController.js

@@ -3,9 +3,13 @@ IonicModule
   '$scope',
   '$attrs',
   '$ionicSideMenuDelegate',
-function($scope, $attrs, $ionicSideMenuDelegate) {
+  '$ionicPlatform',
+function($scope, $attrs, $ionicSideMenuDelegate, $ionicPlatform) {
+  var self = this;
   angular.extend(this, ionic.controllers.SideMenuController.prototype);
 
+  this.$scope = $scope;
+
   ionic.controllers.SideMenuController.call(this, {
     left: { width: 275 },
     right: { width: 275 }
@@ -28,6 +32,21 @@ function($scope, $attrs, $ionicSideMenuDelegate) {
 
   $scope.sideMenuContentTranslateX = 0;
 
+
+  var deregisterBackButtonAction = angular.noop;
+  var closeSideMenu = angular.bind(this, this.close);
+  $scope.$watch(function() {
+    return self.getOpenAmount() !== 0;
+  }, function(isOpen) {
+    deregisterBackButtonAction();
+    if (isOpen) {
+      deregisterBackButtonAction = $ionicPlatform.registerBackButtonAction(
+        closeSideMenu,
+        PLATFORM_BACK_BUTTON_PRIORITY_SIDE_MENU
+      );
+    }
+  });
+
   var deregisterInstance = $ionicSideMenuDelegate._registerInstance(
     this, $attrs.delegateHandle
   );

js/angular/service/platform.js

@@ -1,4 +1,5 @@
 var PLATFORM_BACK_BUTTON_PRIORITY_VIEW = 100;
+var PLATFORM_BACK_BUTTON_PRIORITY_SIDE_MENU = 150;
 var PLATFORM_BACK_BUTTON_PRIORITY_ACTION_SHEET = 300;
 var PLATFORM_BACK_BUTTON_PRIORITY_POPUP = 400;
 var PLATFORM_BACK_BUTTON_PRIORITY_LOADING = 500;

test/unit/angular/controller/sideMenuController.unit.js

@@ -0,0 +1,37 @@
+describe('$ionicSideMenus controller', function() {
+  beforeEach(module('ionic'));
+
+  function setup(locals, props) {
+    var ctrl;
+    inject(function($controller, $rootScope) {
+      var scope = $rootScope.$new();
+      ctrl = $controller('$ionicSideMenus', angular.extend({
+        $scope: scope,
+        $attrs: {}
+      }, locals || {}));
+      angular.extend(ctrl, props || {});
+    });
+    return ctrl;
+  }
+
+  it('should register with backButton on open and dereg on close', inject(function($ionicPlatform) {
+    var openAmount = 0;
+    var deregSpy = jasmine.createSpy('deregister');
+    spyOn($ionicPlatform, 'registerBackButtonAction').andReturn(deregSpy);
+
+    var ctrl = setup();
+    spyOn(ctrl, 'getOpenAmount').andCallFake(function() { return openAmount; });
+
+    expect($ionicPlatform.registerBackButtonAction).not.toHaveBeenCalled();
+    openAmount = 1;
+    ctrl.$scope.$apply();
+    expect($ionicPlatform.registerBackButtonAction).toHaveBeenCalledWith(
+      jasmine.any(Function),
+      PLATFORM_BACK_BUTTON_PRIORITY_SIDE_MENU
+    );
+    expect(deregSpy).not.toHaveBeenCalled();
+    openAmount = 0;
+    ctrl.$scope.$apply();
+    expect(deregSpy).toHaveBeenCalled();
+  }));
+});