feat(dropdown): focus toggle on close from click

- Focus the toggle element when the click causes the dropdown menu to close

BREAKING CHANGE: This changes the focus behavior of the dropdown slightly, and potentially may break code built around current usage

Closes #5934
Fixes #5782

Author: wesleycho

src/dropdown/dropdown.js

@@ -50,6 +50,7 @@ angular.module('ui.bootstrap.dropdown', ['ui.bootstrap.position'])
     }
 
     openScope.isOpen = false;
+    openScope.focusToggleElement();
 
     if (!$rootScope.$$phase) {
       openScope.$apply();

src/dropdown/test/dropdown.spec.js

@@ -220,12 +220,28 @@ describe('uib-dropdown', function() {
 
     beforeEach(function() {
       element = dropdown();
+      $document.find('body').append(element);
+    });
+
+    afterEach(function() {
+      element.remove();
     });
 
     it('adds the menu to the body', function() {
       expect($document.find('#dropdown-menu').parent()[0]).toBe($document.find('body')[0]);
     });
 
+    it('focuses the dropdown element on close', function() {
+      var toggle = element.find('[uib-dropdown-toggle]');
+      var menu = $document.find('#dropdown-menu a');
+      toggle.trigger('click');
+      menu.focus();
+
+      menu.trigger('click');
+
+      expect(document.activeElement).toBe(toggle[0]);
+    });
+
     it('removes the menu when the dropdown is removed', function() {
       element.remove();
       $rootScope.$digest();
@@ -268,6 +284,17 @@ describe('uib-dropdown', function() {
       expect(container).not.toHaveClass('uib-dropdown-open');
     });
 
+    it('focuses the dropdown element on close', function() {
+      var toggle = element.find('[uib-dropdown-toggle]');
+      var menu = $document.find('#dropdown-menu a');
+      toggle.trigger('click');
+      menu.focus();
+
+      menu.trigger('click');
+
+      expect(document.activeElement).toBe(toggle[0]);
+    });
+
     it('removes the menu when the dropdown is removed', function() {
       element.remove();
       $rootScope.$digest();