Issue
I have prepared a simple test project at GitHub for my question.
It is based on the well-known Navigation Drawer Example by Google - extended by a right-side Drawer with music-related actions in a ListView:
The actions are all defined in res/values/strings.xml:
<string-array name="music_actions">
<item>Play</item>
<item>Pause</item>
<item>Stop</item>
<item>Shuffle</item>
</string-array>
<integer-array name="music_icons">
<item>@drawable/ic_play_arrow_black_24dp</item>
<item>@drawable/ic_pause_black_24dp</item>
<item>@drawable/ic_stop_black_24dp</item>
<item>@drawable/ic_shuffle_black_24dp</item>
</integer-array>
And here is the code reading them from resources (this works well):
public class MainActivity extends AppCompatActivity {
private String[] mActions;
private int[] mIcons;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mActions = getResources().getStringArray(R.array.music_actions);
TypedArray ta = getResources().obtainTypedArray(R.array.music_icons);
mIcons = new int[ta.length()];
for (int i = 0; i < mIcons.length; i++)
mIcons[i] = ta.getResourceId(i, R.drawable.ic_menu_black_24dp);
ta.recycle();
My problem is:
From the onItemClick
method in the listener for the ListView - how to call the corresponding method in the Fragment?
I only see ugly ways to do it, like here with a hardcoded switch
statement:
mRightDrawer.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, mActions) {
@Override
public View getView(int position, View convertView, ViewGroup parent) {
TextView view = (TextView) super.getView(position, convertView, parent);
view.setCompoundDrawablesWithIntrinsicBounds(mIcons[position], 0, 0, 0);
return view;
}
});
mRightDrawer.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if (mActiveFragment instanceof GameFragment) {
GameFragment fragment = (GameFragment) mActiveFragment;
switch (position) {
case 0:
fragment.playMusic(); // and then this calls myView.playMusic();
break;
case 1:
fragment.pauseMusic(); // calls myView.pauseMusic();
break;
}
}
mDrawerLayout.closeDrawer(mRightDrawer);
}
});
It is ugly, because I have to track my currently active Fragment and then use wrapper methods to finally call the methods on my custom View.
How to improve this situation, should I maybe use BroadcastReceiver in my custom View?
I wish, I could define icon + title + action in my resources and then just use them.
UPDATE:
For now I am using BroadcastReceiver
, but wonder if it's an apropriate solution (or maybe too heavy-weight?).
In my Fragment I call:
@Override
public void onResume() {
super.onResume();
myView.register();
}
@Override
public void onPause() {
super.onPause();
myView.unregister();
}
And in my custom View I have:
public class MyView extends View {
public final static String ACTION_PLAY = "de.afarber.myapp.play";
public final static String ACTION_PAUSE = "de.afarber.myapp.pause";
public final static String ACTION_STOP = "de.afarber.myapp.stop";
public final static String ACTION_SHUFFLE = "de.afarber.myapp.shuffle";
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (ACTION_PLAY.equals(action))
playMusic();
else if (ACTION_PAUSE.equals(action))
pauseMusic();
else if (ACTION_STOP.equals(action))
stopMusic();
else if (ACTION_SHUFFLE.equals(action))
shuffleMusic();
}
};
public void register() {
IntentFilter filter = new IntentFilter();
filter.addAction(ACTION_PLAY);
filter.addAction(ACTION_PAUSE);
filter.addAction(ACTION_STOP);
filter.addAction(ACTION_SHUFFLE);
getContext().registerReceiver(mMessageReceiver, filter);
}
I would prefer to have some kind of "context menu" for Fragments - defining title + icon + action - which then could be used by the actions-ListView in the right Drawer...
public void unregister() {
getContext().unregisterReceiver(mMessageReceiver);
}
Solution
Broadcasts work well for my DrawerLayout based apps, but for better security and efficiency I have switched to LocalBroadcastManager -
MainActivity.java (right action drawer menu sends broadcasts):
mRightDrawer.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String action = mActions[position];
Intent intent = new Intent(action);
//intent.putExtra("message", "data");
LocalBroadcastManager.getInstance(getApplicationContext()).sendBroadcast(intent);
mDrawerLayout.closeDrawer(mRightDrawer);
}
});
PlanetFragment.java (the active fragment receives app-internal broadcasts):
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
...
mManager = LocalBroadcastManager.getInstance(getActivity());
mFilter = new IntentFilter();
mFilter.addAction(ACTION_PLAY);
mFilter.addAction(ACTION_PAUSE);
mFilter.addAction(ACTION_STOP);
mFilter.addAction(ACTION_SHUFFLE);
...
}
@Override
public void onResume() {
super.onResume();
mManager.registerReceiver(mMessageReceiver, mFilter);
}
@Override
public void onPause() {
super.onPause();
mManager.unregisterReceiver(mMessageReceiver);
}
Answered By - Alexander Farber
0 comments:
Post a Comment
Note: Only a member of this blog may post a comment.