feat(dialog): disable scrolling on parent while showing dialog

closes #987

src/components/dialog/dialog.js

@@ -203,6 +203,8 @@ function MdDialogDirective($$rAF, $mdTheming) {
  *   - `targetEvent` - `{DOMClickEvent=}`: A click's event object. When passed in as an option,
  *     the location of the click will be used as the starting point for the opening animation
  *     of the the dialog.
+ *   - `disableParentScroll` - `{boolean=}`: Whether to disable scrolling while the dialog is open.
+ *     Default true.
  *   - `hasBackdrop` - `{boolean=}`: Whether there should be an opaque backdrop behind the dialog.
  *     Default true.
  *   - `clickOutsideToClose` - `{boolean=}`: Whether the user can click outside the dialog to
@@ -254,7 +256,7 @@ function MdDialogProvider($$interimElementProvider) {
 
   return $$interimElementProvider('$mdDialog')
     .setDefaults({
-      methods: ['hasBackdrop', 'clickOutsideToClose', 'escapeToClose', 'targetEvent'],
+      methods: ['disableParentScroll', 'hasBackdrop', 'clickOutsideToClose', 'escapeToClose', 'targetEvent'],
       options: dialogDefaultOptions
     })
     .addPreset('alert', {
@@ -309,11 +311,13 @@ function MdDialogProvider($$interimElementProvider) {
       clickOutsideToClose: true,
       escapeToClose: true,
       targetEvent: null,
+      disableParentScroll: true,
       transformTemplate: function(template) {
         return '<div class="md-dialog-container">' + template + '</div>';
       }
     };
 
+
     // On show method for dialogs
     function onShow(scope, element, options) {
       // Incase the user provides a raw dom element, always wrap it in jqLite
@@ -330,6 +334,11 @@ function MdDialogProvider($$interimElementProvider) {
         $animate.enter(options.backdrop, options.parent);
       }
 
+      if (options.disableParentScroll) {
+        options.oldOverflowStyle = options.parent.css('overflow');
+        options.parent.css('overflow', 'hidden');
+      }
+
       return dialogPopIn(
         element,
         options.parent,
@@ -377,6 +386,10 @@ function MdDialogProvider($$interimElementProvider) {
       if (options.backdrop) {
         $animate.leave(options.backdrop);
       }
+      if (options.disableParentScroll) {
+        options.parent.css('overflow', options.oldOverflowStyle);
+        $document[0].removeEventListener('scroll', options.captureScroll, true);
+      }
       if (options.escapeToClose) {
         $rootElement.off('keyup', options.rootElementKeyupCallback);
       }

src/components/dialog/dialog.spec.js

@@ -237,6 +237,19 @@ describe('$mdDialog', function() {
       expect(parent[0].querySelectorAll('md-dialog').length).toBe(1);
     }));
 
+    it('should disableParentScroll == true', inject(function($mdDialog, $animate, $rootScope) {
+      var parent = angular.element('<div>');
+      $mdDialog.show({
+        template: '<md-dialog>',
+        parent: parent,
+        disableParentScroll: true
+      });
+      $rootScope.$apply();
+      $animate.triggerCallbacks();
+      $rootScope.$apply();
+      expect(parent.css('overflow')).toBe('hidden');
+    }));
+
     it('should hasBackdrop == true', inject(function($mdDialog, $animate, $rootScope) {
       var parent = angular.element('<div>');
       $mdDialog.show({