public class GenericApp extends Application {
// hold the reference to some global object here
private CustomObj myObjRef;
public void onCreate() {
...
// initialize it only once!
myObjRef = new CustomObj();
...
}
public CustomObj getMyObjReference() {
return myObjRef;
}
}
Then in each Activity:
public class ActivityXXX extends Activity {
private CustomObj savedObjRef;
public void onCreate() {
...
savedObjRef = ((GenericApp) getApplication()).getMyObjReference();
...
}
}
The reason why I need this is I want to create custom object only once and hold somewhere its reference so that it won't be destroyed when I switch between activities. Each activity runs in its own process (to prevent specific memory leaks; do not suggest me to use the same process instead).
But, as explained there, due to process dependence, each Activity starts in different Application. My custom object is too heavy to be Serializable.
Can I declare to use one Application instance for all processes? I think it's impossible. If so, how can I be sure to create only one instance of my custom object to be synchronized by it later among all activities?
Use case: opening Camera each time onResume() is called and closing it in Activity's onPause(). Since opening and closing Camera performs in separate Thread and takes ~300 ms, sometimes Camera doesn't manage to release itself properly in previous Activity before it begins opening via another AsyncTask in another Activity.
Note. I've already tried:
- Fragments
- common process
- Serializable / Parcelable
I think background Service with its own process (android:process=":detector") can handle my task. But since each process spawns new Application, should I consider my Service to be local or remote? Should I use ResultReceiver or BroadcastReceiver?
Update. Simple approach, described above doesn't work. My AndroidManifest.xml (shortened):
<application android:name=".GenericApp">
<activity android:name=".ActivityOne"
android:process="process1" />
<activity android:name=".ActivityTwo"
android:process="process2" />
</application>
