Define Default Activity (when app starts) programmatically

Question

My application is composed by a few activity.

Activity A is my main menu with some icons. This Activity can launch depending on which icon you press: Activity B,C,D,

Answer 1

Instead of ActivityA, consider using wrapper activity to be called from launcher. You will eliminate a need for checking for ACTION_MAIN. Also you can store target activity name in preferences and use it to directly start your target activity via different intent signature:

public Intent (String action)

---

 <activity class=".StartActivity" android:label="...">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
 </activity>

 <activity class=".ActivityA" android:label="...">
             <intent-filter>
                 <action android:name="mypackage.ActivityA" />                    
             </intent-filter>
 </activity>

And in StartActivity

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    settings = PreferenceManager
            .getDefaultSharedPreferences(getBaseContext());

    String action = settings.getString("Activitypref","mypackage.ActivityA");
    Intent intent = new Intent(action);
    startActivity(intent);
    ....
}

You may need to fiddle around little bit to get it right.