Add selection PublicApi method to expose selected count

Author: Robinson7D

src/features/selection/js/selection.js

@@ -292,6 +292,15 @@
                 getSelectedGridRows: function () {
                   return service.getSelectedRows(grid);
                 },
+                /**
+                 * @ngdoc function
+                 * @name getSelectedCount
+                 * @methodOf  ui.grid.selection.api:PublicApi
+                 * @description returns the number of rows selected
+                 */
+                getSelectedCount: function () {
+                  return grid.selection.selectedCount;
+                },
                 /**
                  * @ngdoc function
                  * @name setMultiSelect

src/features/selection/test/uiGridSelectionService.spec.js

@@ -88,6 +88,13 @@ describe('ui.grid.selection uiGridSelectionService', function () {
       expect(uiGridSelectionService.getSelectedRows(grid).length).toBe(0);
     });
 
+    it('should update selectedCount', function () {
+      uiGridSelectionService.toggleRowSelection(grid, grid.rows[0]);
+      expect(grid.api.selection.getSelectedCount()).toBe(1);
+      uiGridSelectionService.clearSelectedRows(grid);
+      expect(grid.api.selection.getSelectedCount()).toBe(0);
+    });
+
     it('should utilize public apis', function () {
       grid.api.selection.toggleRowSelection(grid.rows[0].entity);
       expect(uiGridSelectionService.getSelectedRows(grid).length).toBe(1);