How To Creating Dynamic Menu to show on Fragment

Question

I have a class BaseFragment i was create a private menu and set that menu from

@Override 
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    inflater.inflate(R.menu.main, menu);
    this.menu = menu;
}

in main.xml i have :

<menu xmlns:android="http://schemas.android.com/apk/res/android" >
<!-- Search / will display always -->
<item android:id="@+id/action_search"
      android:icon="@drawable/ic_action_search"
      android:title="@string/action_search"
      android:showAsAction="ifRoom"/>

<!-- Refresh -->
<item android:id="@+id/action_refresh"
      android:icon="@drawable/ic_action_refresh"
      android:title="@string/action_refresh"
      android:showAsAction="ifRoom" />

<!-- Download -->
<item android:id="@+id/action_download"
      android:icon="@drawable/ic_action_download"
      android:title="@string/action_download"
      android:showAsAction="never"/>

<!-- Favorite -->
<item android:id="@+id/action_favorites"
      android:icon="@drawable/ic_action_favorites"
      android:title="@string/action_favorites"
      android:showAsAction="never" />
</menu>

and i have another fragments FragmentA and FragmentB extends to that BaseFragment. In FragmentA i want to show All menu and all is OK when running the app, but in FragmentB i want to show the download and and favorite whitout search and refresh.

I was try to create a method on base to manipulate the visibility on menuitem and my menu always return null.

protected void setSearchable(boolean isSearchable){
    menu.findItem(R.id.action_search).setVisible(isSearchable);
}
protected void setHasRefreshFuction(boolean isHasRefreshFunction){
    menu.findItem(R.id.action_refresh).setVisible(isHasRefreshFunction);
}
protected void setDownloadable(boolean isDownloadable){
    menu.findItem(R.id.action_download).setVisible(isDownloadable);
}
protected void setFavorite(boolean isFavorite){
    menu.findItem(R.id.action_favorites).setVisible(isFavorite);
}

i call that method on onCreate() in FragmentB like this:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setDownloadable(true);
    setFavorite(true);
    setHasRefreshFuction(false);
    setSearchable(false);
}

Can someone help me please.... i was read many tutorial and doesn't find an answer to make this. note : I was setHasOptionsMenu(true); in oncreate in BaseFragment

Answer 1

The easiest way would be to override onCreateOptionsMenu in FragmentB again.

@Override 
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    inflater.inflate(R.menu.main, menu);
    menu.findItem(R.id.action_search).setVisible(false);
    menu.findItem(R.id.action_refresh).setVisible(false);
    this.menu = menu;
}

Answer 2

You can't access menu outside it's callbacks. For you can implement ActionProvider subclass to handle visibility of needed menu items.

Or you can call invalidateOptionsMenu() method of your activity to request Options Menu recreating, and change visibility of items in onCreateOptionsMenu()

Answer 3

In the menu.xml you should add all the menu items. Then you can hide items that you don't want to see in the initial loading.

<item
    android:id="@+id/action_newItem"
    android:icon="@drawable/action_newItem"
    android:showAsAction="never"
    android:visible="false"
    android:title="@string/action_newItem"/>

Add setHasOptionsMenu(true) in the onCreate() method to invoke the menu items in your Fragment class.

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setHasOptionsMenu(true);
}

You don't need to override onCreateOptionsMenu in your Fragment class again. Menu items can be changed (Add/remoev) by overriding onPrepareOptionsMenumethod available in Fragment.

@Override
public void onPrepareOptionsMenu(Menu menu) {
    menu.findItem(R.id.action_newItem).setVisible(true);
    super.onPrepareOptionsMenu(menu);

}