Check if phone orientation changed without changing layout

Question

I would like to accomplish the following:

1. When I turn my phone into landscape mode, I want an activity to be started.
2. When I turn it back again into portrait mode, I want that activity to be closed again.

In essence I'd like to know when my orientation changed, but without changing the layout. Is that possible?

Answer 1

I am not 100% sure what you are asking, because 1 and 2 do not equate to your final question. Either way, the answer you are looking for is onConfigurationChanged.

If you already have an activity running you can tell Android in the AndroidManfest that you want to handle rotation. Then override onConfigurationChange to launch a new activity. In that activity also tell android you want to handle configuration changes and in the ondonfigurationchange it can call finish() to go back to the previous activity.

See: Android Activity onConfigurationCjhanged

Put this code in your android manifest for the activities:

<activity android:name=".MyActivity" android:label="@string/appName"
                android:configChanges="orientation|keyboard|keyboardHidden">

Answer 2

Android Developer Guide here

the following manifest code declares an activity that handles both the screen orientation change and keyboard availability change:

<activity android:name=".MyActivity"
          android:configChanges="orientation|keyboardHidden|screenSize"
          android:label="@string/app_name">

Now, when one of these configurations change, your Activity does not restart. Instead, your Activity receives a call to onConfigurationChanged().

The following onConfigurationChanged() implementation checks the current device orientation:

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);

    // Checks the orientation of the screen
    if (newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE) {
        Toast.makeText(this, "landscape", Toast.LENGTH_SHORT).show();
        //call new Activity here  
    } else if (newConfig.orientation == Configuration.ORIENTATION_PORTRAIT){
        Toast.makeText(this, "portrait", Toast.LENGTH_SHORT).show();
    }
}