android - MapView in a Fragment (Honeycomb)

Question

now that the final SDK is out with google apis - what is the best way to create a Fragment with a MapView? MapView needs a MapActivity to work right.

Having the Activity managing the Fragments inherit from MapActivity (bad solution because it goes against the idea that Fragments are self contained) and use a regular xml based layout does not work. I get a NullPointerException in MapActivity.setupMapView():

E/AndroidRuntime(  597): Caused by: java.lang.NullPointerException
E/AndroidRuntime(  597):    at com.google.android.maps.MapActivity.setupMapView(MapActivity.java:400)
E/AndroidRuntime(  597):    at com.google.android.maps.MapView.(MapView.java:289)
E/AndroidRuntime(  597):    at com.google.android.maps.MapView.(MapView.java:264)
E/AndroidRuntime(  597):    at com.google.android.maps.MapView.(MapView.java:247)

My second idea was to create the MapView programmatically and pass the associated activity (via getActivity()) as Context to the MapView constructor. Does not work:

E/AndroidRuntime(  834): Caused by: java.lang.IllegalArgumentException: MapViews can only be created inside instances of MapActivity.
E/AndroidRuntime(  834):    at com.google.android.maps.MapView.(MapView.java:291)
E/AndroidRuntime(  834):    at com.google.android.maps.MapView.(MapView.java:235)
E/AndroidRuntime(  834):    at de.foo.FinderMapFragment.onCreateView(FinderMapFragment.java:225)
E/AndroidRuntime(  834):    at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:708)
E/AndroidRuntime(  834):    at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:900)
E/AndroidRuntime(  834):    at android.app.FragmentManagerImpl.addFragment(FragmentManager.java:978)
E/AndroidRuntime(  834):    at android.app.Activity.onCreateView(Activity.java:4090)
E/AndroidRuntime(  834):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:664)

Really there should be something like MapFragment that takes care of the background threads MapView needs I guess... So what is the current best practice to do this?

Thanks and regards from Germany, Valentin

Answer 1

I've managed to resolve this by using TabHost in fragment.

Here is the idea (briefly):

1. MainFragmentActivity extends FragmentActivity (from support library) and has MapFragment.

2. MyMapActivity extends MapActivity and contain MapView.

3. LocalActivityManagerFragment hosts LocalActivityManager

4. MapFragment extends LocalActivityManagerFragment.

5. And LocalActivityManager contains MyMapActivity activity in it.

Example implementation: https://github.com/inazaruk/map-fragment.

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