How to add an item to a menu group in NavigationView

Question

In a word game for Android I currently have a hardcoded menu inflated from left_drawer_menu.xml and consisting of 3 groups (my turn, opponent turn and finally other stuff):

mLeftDrawer = (NavigationView) findViewById(R.id.left_drawer); mLeftDrawer.setNavigationItemSelectedListener(         new NavigationView.OnNavigationItemSelectedListener() {             @Override             public boolean onNavigationItemSelected(final MenuItem menuItem) {                 Menu menu = mLeftDrawer.getMenu();                  if (menuItem.getGroupId() == R.id.my_move) {                     menu.setGroupCheckable(R.id.my_move, true, true);                     menu.setGroupCheckable(R.id.his_move, false, false);                     menu.setGroupCheckable(R.id.extras, false, false);                 } else if (menuItem.getGroupId() == R.id.his_move) {                     menu.setGroupCheckable(R.id.my_move, false, false);                     menu.setGroupCheckable(R.id.his_move, true, true);                     menu.setGroupCheckable(R.id.extras, false, false);                 } else if (menuItem.getGroupId() == R.id.extras) {                     menu.setGroupCheckable(R.id.my_move, false, false);                     menu.setGroupCheckable(R.id.his_move, false, false);                     menu.setGroupCheckable(R.id.extras, true, true);                 }                  menuItem.setChecked(true);                 mLeftItem = menuItem.getItemId();                 mDrawerLayout.closeDrawer(mLeftDrawer);                 mHandler.postDelayed(new Runnable() {                     @Override                     public void run() {                         if (mLeftItem == R.id.start) {                             startNewGame();                         }                      }                 },DRAWER_CLOSE_DELAY);                  return true;             }         }); 

Now I am trying to change that menu dynamically.

I have SQLite instance containing all game data and use IntentService to read/write the database - that part works fine.

My current difficulty is: with the following code, the new items are added outside the R.id.my_move group:

if (mLeftItem == R.id.start) {     startNewGame();      Random r = new Random();     int i = r.nextInt(100);     menu.add(R.id.my_move, i, i, "Item " + i);   // why is my_move ignored? }  

UPDATE:

As a further test I have tried assigning even and not even items to 2 separate groups with this code:

Random r = new Random(); int i = r.nextInt(100); int group = 1 + (i % 2); // can be 1 or 2 menu.add(group, i, i, "Item " + i); 

However the result looks chaotic:

Also I have discovered the (probably already fixed?) Issue 176300 and wonder if maybe sub-menus should be better used instead of menu groups?

Answer 1

On checking MenuItemImpl source code

     ...      *    @param group Item ordering grouping control. The item will be added after      *            all other items whose order is <= this number, and before any      *            that are larger than it. This can also be used to define      *            groups of items for batch state changes. Normally use 0.      ...      MenuItemImpl(MenuBuilder menu, int group, int id, int categoryOrder, int ordering,         CharSequence title, int showAsAction) { 

So you should define ordering in your xml (give same order to items in one group and increment in each following group)

<menu xmlns:android="http://schemas.android.com/apk/res/android">      <group android:id="@+id/my_move" android:checkableBehavior="single">         <item             android:orderInCategory="0"             android:id="@+id/game1"             android:icon="@drawable/ic_stars_black_24dp"             android:title="Game #1" />         <item             android:orderInCategory="0"             android:id="@+id/game2"             android:icon="@drawable/ic_stars_black_24dp"             android:title="Game #2" />     </group>     <group android:id="@+id/his_move" android:checkableBehavior="single">         <item             android:orderInCategory="1"             android:id="@+id/game5"             android:icon="@drawable/ic_clock_black_24dp"             android:title="Game #5" />         <item             android:orderInCategory="1"             android:id="@+id/game6"             android:icon="@drawable/ic_clock_black_24dp"             android:title="Game #6" />         <item             android:orderInCategory="1"             android:id="@+id/game7"             android:icon="@drawable/ic_clock_black_24dp"             android:title="Game #7" />     </group>     .....  </menu> 

and give an appropriate order value while adding the item in your code. So if you want to add the item at the end of first group, add it as:

menu.add(R.id.my_move, Menu.NONE, 0, "Item1"); 

and if you want to add to second group, add it as:

menu.add(R.id.his_move, Menu.NONE, 1, "Item2"); 

The problem with your code could be that all items in the xml have default orderInCategory 0 and so the new item gets added after all these items.

UPDATE

To add icon use setIcon method for MenuItem

menu.add(R.id.my_move, Menu.NONE, 0, "Item1").setIcon(R.drawable.ic_stars_black_24dp); 

Answer 2

I've solved it this way:

1. Set up the menu:

   <?xml version="1.0" encoding="utf-8"?> <menu xmlns:android="http://schemas.android.com/apk/res/android">     <item android:title="my moves"           android:id="@+id/submenu_1">         <menu>             <item                 android:id="@+id/my_dummy_item_1"                 android:icon="@drawable/ic_menu_camera"                 android:title="Import" />             <item                 android:id="@+id/my_dummy_item_2"                 android:icon="@drawable/ic_menu_gallery"                 android:title="Gallery" />             <item                 android:id="@+id/add_item"                 android:icon="@drawable/ic_menu_manage"                 android:title="Add Item" />         </menu>     </item>     <item android:title="opponent's moves"           android:id="@+id/submenu_2">         <menu>             <item                 android:id="@+id/opponent_dummy_item_1"                 android:icon="@drawable/ic_menu_camera"                 android:title="Import" />             <item                 android:id="@+id/opponent_dummy_item_2"                 android:icon="@drawable/ic_menu_gallery"                 android:title="Gallery" />             <item                 android:id="@+id/opponent_dummy_item_3"                 android:icon="@drawable/ic_menu_manage"                 android:title="Tools" />         </menu>     </item> </menu> 

2. In onNavigationItemSelected(), get MenuItem you want to expand by order id (or via findItem()), then get SubMenu from it and add new item into it:

   @SuppressWarnings("StatementWithEmptyBody") @Override public boolean onNavigationItemSelected(MenuItem item) {     int id = item.getItemId();      if (id == R.id.add_item) {         Random r = new Random();         int i = r.nextInt(100);         MenuItem myMoveGroupItem = navigationView.getMenu().getItem(0);         // MenuItem myMoveGroupItem = navigationView.getMenu().findItem(R.id.submenu_1);  -- it also works!         SubMenu subMenu = myMoveGroupItem.getSubMenu();         subMenu.add("Item "+i);     }      return true; } 

I hope, it helps