MapFragment and Camera seem to interfere with each

Question

I'm trying to use a MapFragment from the Google Maps Android API v2 in conjunction with a Camera preview. I need to be able to switch between the camera preview and the MapFragment, but I can’t make it work.

For the Camera preview, I’ve copied the CameraPreview class from the example guide. When I want to see the Camera preview, I add an instance of the CameraPreview class to my activity using

CameraPreview mPreview = new CameraPreview(this); 
addContentView(mPreview, new LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT));

This works fine when when I’m not using the MapFragment.

For the MapFragment, I’ve added it into my activity’s layout via

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >


    <fragment
        android:id="@+id/map"
        android:layout_width="fill_parent"
        android:layout_height="match_parent"
        class="com.google.android.gms.maps.MapFragment" />

</LinearLayout> 

It works fine without the CameraPreview. I can hide and unhide the MapFragment using (e.g. for hide):

FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.hide(map_fragment);
ft.commit();

However, the problem comes when I try and use the two together, i.e. hide the MapFragment and then add a CameraPreview instance into my activity. The hide doesn’t work, and it seems that the MapFragment somehow hijacks the CameraPreview and takes precedence. One strange feature is that if I force the screen to sleep and then wake it up, when it wakes up the CameraPreview is there. If I do it the other way round, i.e. add the CameraPreview first and then hide the MapFragment, the behavior is the same.

FYI: I'm testing the app on a Samsung Galaxy Note 2 LTE running Android Version 4.1.1.

Can anyone tell me what I’m doing wrong?

Answer 1

Use setZOrderOnTop(boolean) on your camerapreview like this mPreview.setZOrderOnTop(true);. It works for me.