feat(menu): add setSelectedIndex to set selected item in menu selection group

packages/mdc-menu/README.md

@@ -226,6 +226,7 @@ Method Signature | Description
 `setAnchorMargin(Partial<MDCMenuDistance>) => void` | Proxies to the menu surface's `setAnchorMargin(Partial<MDCMenuDistance>)` method.
 `setAbsolutePosition(x: number, y: number) => void` | Proxies to the menu surface's `setAbsolutePosition(x: number, y: number)` method.
 `setFixedPosition(isFixed: boolean) => void` | Proxies to the menu surface's `setFixedPosition(isFixed: boolean)` method.
+`setSelectedIndex(index: number) => void | Sets the list item to the selected state at the specified index.
 `hoistMenuToBody() => void` | Proxies to the menu surface's `hoistMenuToBody()` method.
 `setIsHoisted(isHoisted: boolean) => void` | Proxies to the menu surface's `setIsHoisted(isHoisted: boolean)` method.
 `setAnchorElement(element: Element) => void` | Proxies to the menu surface's `setAnchorElement(element)` method.
@@ -250,12 +251,12 @@ Method Signature | Description
 `elementContainsClass(element: Element, className: string) => boolean` | Returns true if the `element` contains the `className` class.
 `closeSurface() => void` | Closes the menu surface.
 `getElementIndex(element: Element) => number` | Returns the `index` value of the `element`.
-`getParentElement(element: Element) => Element \| null` | Returns the `.parentElement` element of the `element` provided.
-`getSelectedElementIndex(element: Element) => number` | Returns the `index` value of the element within the selection group provided, `element` that contains the `mdc-menu-item--selected` class.
 `notifySelected(index: number) => void` | Emits a `MDCMenu:selected` event for the element at the `index` specified.
 `getMenuItemCount() => number` | Returns the menu item count.
 `focusItemAtIndex(index: number)` | Focuses the menu item at given index.
 `focusListRoot() => void` | Focuses the list root element.
+`getSelectedSiblingOfItemAtIndex(index: number) => number` | Returns selected list item index within the same selection group which is a sibling of item at given `index`.
+`isSelectableItemAtIndex(index: number) => boolean` | Returns true if menu item at specified index is contained within an `.mdc-menu__selection-group` element.
 
 ### `MDCMenuFoundation`
 
@@ -265,6 +266,7 @@ Method Signature | Description
 `handleItemAction(listItem: Element) => void` | Event handler for list's action event.
 `handleMenuSurfaceOpened() => void` | Event handler for menu surface's opened event.
 `setDefaultFocusState(focusState: DefaultFocusState) => void` | Sets default focus state where the menu should focus every time when menu is opened. Focuses the list root (`DefaultFocusState.LIST_ROOT`) element by default.
+`setSelectedIndex(index: number) => void` | Selects the list item at given `index`.
 
 ### Events
 

packages/mdc-menu/adapter.ts

@@ -65,16 +65,6 @@ export interface MDCMenuAdapter {
    */
   getElementIndex(element: Element): number;
 
-  /**
-   * @return The parentElement of the provided element.
-   */
-  getParentElement(element: Element): Element | null;
-
-  /**
-   * @return The element within the selectionGroup containing the selected element class.
-   */
-  getSelectedElementIndex(selectionGroup: Element): number;
-
   /**
    * Emit an event when a menu item is selected.
    */
@@ -91,4 +81,17 @@ export interface MDCMenuAdapter {
 
   /** Focuses the list root element. */
   focusListRoot(): void;
+
+  /**
+   * @return Returns selected list item index within the same selection group which is
+   * a sibling of item at given `index`.
+   * @param index Index of the menu item with possible selected sibling.
+   */
+  getSelectedSiblingOfItemAtIndex(index: number): number;
+
+  /**
+   * @return Returns true if item at specified index is contained within an `.mdc-menu__selection-group` element.
+   * @param index Index of the selectable menu item.
+   */
+  isSelectableItemAtIndex(index: number): boolean;
 }

packages/mdc-menu/component.ts

@@ -23,6 +23,7 @@
 
 import {MDCComponent} from '@material/base/component';
 import {CustomEventListener, SpecificEventListener} from '@material/base/types';
+import {closest} from '@material/dom/ponyfill';
 import {MDCList, MDCListFactory} from '@material/list/component';
 import {MDCListFoundation} from '@material/list/foundation';
 import {MDCListActionEvent} from '@material/list/types';
@@ -143,6 +144,14 @@ export class MDCMenu extends MDCComponent<MDCMenuFoundation> {
     this.menuSurface_.setAnchorMargin(margin);
   }
 
+  /**
+   * Sets the list item as the selected row at the specified index.
+   * @param index Index of list item within menu.
+   */
+  setSelectedIndex(index: number) {
+    this.foundation_.setSelectedIndex(index);
+  }
+
   /**
    * @return The item within the menu at the index specified.
    */
@@ -203,18 +212,19 @@ export class MDCMenu extends MDCComponent<MDCMenuFoundation> {
       elementContainsClass: (element, className) => element.classList.contains(className),
       closeSurface: () => this.open = false,
       getElementIndex: (element) => this.items.indexOf(element),
-      getParentElement: (element) => element.parentElement,
-      getSelectedElementIndex: (selectionGroup) => {
-        const selectedListItem = selectionGroup.querySelector(`.${cssClasses.MENU_SELECTED_LIST_ITEM}`);
-        return selectedListItem ? this.items.indexOf(selectedListItem) : -1;
-      },
       notifySelected: (evtData) => this.emit<MDCMenuItemComponentEventDetail>(strings.SELECTED_EVENT, {
         index: evtData.index,
         item: this.items[evtData.index],
       }),
       getMenuItemCount: () => this.items.length,
       focusItemAtIndex: (index) => (this.items[index] as HTMLElement).focus(),
       focusListRoot: () => (this.root_.querySelector(strings.LIST_SELECTOR) as HTMLElement).focus(),
+      isSelectableItemAtIndex: (index) => !!closest(this.items[index], `.${cssClasses.MENU_SELECTION_GROUP}`),
+      getSelectedSiblingOfItemAtIndex: (index) => {
+        const selectionGroupEl = closest(this.items[index], `.${cssClasses.MENU_SELECTION_GROUP}`) as HTMLElement;
+        const selectedItemEl = selectionGroupEl.querySelector(`.${cssClasses.MENU_SELECTED_LIST_ITEM}`);
+        return selectedItemEl ? this.items.indexOf(selectedItemEl) : -1;
+      },
     };
     // tslint:enable:object-literal-sort-keys
     return new MDCMenuFoundation(adapter);

packages/mdc-menu/foundation.ts

@@ -22,7 +22,6 @@
  */
 
 import {MDCFoundation} from '@material/base/foundation';
-import {MDCListFoundation} from '@material/list/foundation';
 import {MDCMenuSurfaceFoundation} from '@material/menu-surface/foundation';
 import {MDCMenuAdapter} from './adapter';
 import {cssClasses, DefaultFocusState, numbers, strings} from './constants';
@@ -56,12 +55,12 @@ export class MDCMenuFoundation extends MDCFoundation<MDCMenuAdapter> {
       elementContainsClass: () => false,
       closeSurface: () => undefined,
       getElementIndex: () => -1,
-      getParentElement: () => null,
-      getSelectedElementIndex: () => -1,
       notifySelected: () => undefined,
       getMenuItemCount: () => 0,
       focusItemAtIndex: () => undefined,
       focusListRoot: () => undefined,
+      getSelectedSiblingOfItemAtIndex: () => -1,
+      isSelectableItemAtIndex: () => false,
     };
     // tslint:enable:object-literal-sort-keys
   }
@@ -98,9 +97,8 @@ export class MDCMenuFoundation extends MDCFoundation<MDCMenuAdapter> {
 
     // Wait for the menu to close before adding/removing classes that affect styles.
     this.closeAnimationEndTimerId_ = setTimeout(() => {
-      const selectionGroup = this.getSelectionGroup_(listItem);
-      if (selectionGroup) {
-        this.handleSelectionGroup_(selectionGroup, index);
+      if (this.adapter_.isSelectableItemAtIndex(index)) {
+        this.setSelectedIndex(index);
       }
     }, MDCMenuSurfaceFoundation.numbers.TRANSITION_CLOSE_DURATION);
   }
@@ -132,41 +130,32 @@ export class MDCMenuFoundation extends MDCFoundation<MDCMenuAdapter> {
   }
 
   /**
-   * Handles toggling the selected classes in a selection group when a selection is made.
+   * Selects the list item at `index` within the menu.
+   * @param index Index of list item within the menu.
    */
-  private handleSelectionGroup_(selectionGroup: Element, index: number) {
-    // De-select the previous selection in this group.
-    const selectedIndex = this.adapter_.getSelectedElementIndex(selectionGroup);
-    if (selectedIndex >= 0) {
-      this.adapter_.removeAttributeFromElementAtIndex(selectedIndex, strings.ARIA_SELECTED_ATTR);
-      this.adapter_.removeClassFromElementAtIndex(selectedIndex, cssClasses.MENU_SELECTED_LIST_ITEM);
+  setSelectedIndex(index: number) {
+    this.validatedIndex_(index);
+
+    if (!this.adapter_.isSelectableItemAtIndex(index)) {
+      throw new Error('MDCMenuFoundation: No selection group at specified index.');
     }
-    // Select the new list item in this group.
-    this.adapter_.addClassToElementAtIndex(index, cssClasses.MENU_SELECTED_LIST_ITEM);
-    this.adapter_.addAttributeToElementAtIndex(index, strings.ARIA_SELECTED_ATTR, 'true');
-  }
 
-  /**
-   * Returns the parent selection group of an element if one exists.
-   */
-  private getSelectionGroup_(listItem: Element): Element | null {
-    let parent = this.adapter_.getParentElement(listItem);
-    if (!parent) {
-      return null;
+    const prevSelectedIndex = this.adapter_.getSelectedSiblingOfItemAtIndex(index);
+    if (prevSelectedIndex >= 0) {
+      this.adapter_.removeAttributeFromElementAtIndex(prevSelectedIndex, strings.ARIA_SELECTED_ATTR);
+      this.adapter_.removeClassFromElementAtIndex(prevSelectedIndex, cssClasses.MENU_SELECTED_LIST_ITEM);
     }
 
-    let isGroup = this.adapter_.elementContainsClass(parent, cssClasses.MENU_SELECTION_GROUP);
+    this.adapter_.addClassToElementAtIndex(index, cssClasses.MENU_SELECTED_LIST_ITEM);
+    this.adapter_.addAttributeToElementAtIndex(index, strings.ARIA_SELECTED_ATTR, 'true');
+  }
 
-    // Iterate through ancestors until we find the group or get to the list.
-    while (!isGroup && parent && !this.adapter_.elementContainsClass(parent, MDCListFoundation.cssClasses.ROOT)) {
-      parent = this.adapter_.getParentElement(parent);
-      isGroup = parent ? this.adapter_.elementContainsClass(parent, cssClasses.MENU_SELECTION_GROUP) : false;
-    }
+  private validatedIndex_(index: number): void {
+    const menuSize = this.adapter_.getMenuItemCount();
+    const isIndexInRange = index >= 0 && index < menuSize;
 
-    if (isGroup) {
-      return parent;
-    } else {
-      return null;
+    if (!isIndexInRange) {
+      throw new Error('MDCMenuFoundation: No list item at specified index.');
     }
   }
 }

packages/mdc-menu/package.json

@@ -18,6 +18,7 @@
   },
   "dependencies": {
     "@material/base": "^1.0.0",
+    "@material/dom": "^1.1.0",
     "@material/feature-targeting": "^0.44.1",
     "@material/list": "^2.0.0",
     "@material/menu-surface": "^1.1.1",

test/screenshot/golden.json

@@ -807,6 +807,14 @@
       "desktop_windows_ie@11": "https://storage.googleapis.com/mdc-web-screenshot-tests/travis/2019/03/15/18_35_08_782/spec/mdc-menu/classes/menu-selection-group.html.windows_ie_11.png"
     }
   },
+  "spec/mdc-menu/classes/multiple-menu-selection-group.html": {
+    "public_url": "https://storage.googleapis.com/mdc-web-screenshot-tests/travis/2019/04/23/22_44_56_133/spec/mdc-menu/classes/multiple-menu-selection-group.html?utm_source=golden_json",
+    "screenshots": {
+      "desktop_windows_chrome@latest": "https://storage.googleapis.com/mdc-web-screenshot-tests/travis/2019/04/23/22_44_56_133/spec/mdc-menu/classes/multiple-menu-selection-group.html.windows_chrome_73.png",
+      "desktop_windows_firefox@latest": "https://storage.googleapis.com/mdc-web-screenshot-tests/travis/2019/04/23/22_44_56_133/spec/mdc-menu/classes/multiple-menu-selection-group.html.windows_firefox_65.png",
+      "desktop_windows_ie@11": "https://storage.googleapis.com/mdc-web-screenshot-tests/travis/2019/04/23/22_44_56_133/spec/mdc-menu/classes/multiple-menu-selection-group.html.windows_ie_11.png"
+    }
+  },
   "spec/mdc-menu/issues/4025.html": {
     "public_url": "https://storage.googleapis.com/mdc-web-screenshot-tests/travis/2019/01/18/07_50_32_667/spec/mdc-menu/issues/4025.html?utm_source=golden_json",
     "screenshots": {