CODEWITHSUNDEEP
android
Cheok Yan Cheng
Cheok Yan Cheng

Reputation: 42730

Proper way to restore an activity back to its original orientation

Currently, I have a parent Activity, which its orientation can be either landscape mode or portrait mode, depending on device Accelerometer.

It is going to launch a child Activity, which its orientation is always in landscape mode.

When the user quits from child Activity, I which parent Activity can immediately restore its original orientation.

I try the following mythology. It doesn't work.

public class ParentActivity extends SherlockFragmentActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        ...

        if (savedInstanceState == null) {
        } else {
            int orientation = savedInstanceState.getInt(ORIENTATION_KEY);

            // **Orientation is completely detached from Accelerometer**
            if (orientation == Configuration.ORIENTATION_LANDSCAPE) {
                setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
            } else {
                setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
            }            
        }

        @Override
        protected void onSaveInstanceState (Bundle savedInstanceState) {
            // Calling super.onSaveInstanceState is important.
            super.onSaveInstanceState(savedInstanceState);

            // **Too late**
            int orientation = getResources().getConfiguration().orientation;

            savedInstanceState.putInt(ORIENTATION_KEY, orientation);
        }
    }

There are 2 issues with the code

  1. Too late - When landscape child Activity is launched, and parent Activity's onSaveInstanceState is being called, obtained orientation value is always landscape, although parent Activity is in portrait mode originally.
  2. Orientation is completely detached from Accelerometer - Once setRequestedOrientation is being called, parent Activity orientation will be fixed, and no longer depend on device Accelerometer. My intention is to restore parent Activity initial orientation after child Activity had quit. After that, we are still free to play around with parent Activity orientation, by rotating the device.

Upvotes: 2

Views: 902

Answers (1)

Cheok Yan Cheng
Cheok Yan Cheng

Reputation: 42730

Here's my solution, which will both solve for Too late and Orientation is completely detached from Accelerometer

private int orientationBeforeHistory = Integer.MIN_VALUE;

private void launchChildActivity() {
    this.orientationBeforeHistory = Utils.getScreenOrientation(this.getActivity());
    ...
}

@Override
public void onSaveInstanceState (Bundle savedInstanceState) {
    super.onSaveInstanceState(savedInstanceState);        
    savedInstanceState.putInt(ORIENTATION_BEFORE_HISTORY_KEY, this.orientationBeforeHistory);
}


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

    ...

    if (savedInstanceState != null) {
        final int orientationBeforeHistory = savedInstanceState.getInt(ORIENTATION_BEFORE_HISTORY_KEY);
        if (Integer.MIN_VALUE != orientationBeforeHistory) {
            final Activity activity = getActivity();
            activity.setRequestedOrientation(orientationBeforeHistory);
            // Key step for not locking screen orientation.
            activity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR);
        }
    }      
}

For getting current orientation, please refer to How do I get the CURRENT orientation (ActivityInfo.SCREEN_ORIENTATION_*) of an Android device?

Upvotes: 1

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