Android: Rotate whole layout

Not sure why this is useful, but it’s a nice puzzle. Here is something that works for me:

On rotate click, do this:

RelativeLayout mainLayout = (RelativeLayout) findViewById(R.id.main);
int w = mainLayout.getWidth();
int h = mainLayout.getHeight();

mainLayout.setRotation(270.0f);
mainLayout.setTranslationX((w - h) / 2);
mainLayout.setTranslationY((h - w) / 2);

ViewGroup.LayoutParams lp = (ViewGroup.LayoutParams) mainLayout.getLayoutParams();
lp.height = w;
lp.width = h;
mainLayout.requestLayout();

And the layout:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:id="@+id/main"
    android:layout_height="match_parent"
    android:background="#ffcc88"
    tools:context=".TestRotateActivity" >

    <Button 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Test"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        />

    <Button 
        android:id="@+id/rotate"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Rotate"
        android:layout_centerInParent="true"
        />

</RelativeLayout>