Programmatically rotate drawable or view

Answer 1

Since you're trying to use Almero's Android Gesture Detectors, I decided to do the same in order to find an appropriate solution:

public class MainActivity extends Activity {

    private RotateGestureDetector mRotateDetector;
    private float mRotationDegrees = 0.f;
    private static final float ROTATION_RATIO = 2;

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mRotateDetector = new RotateGestureDetector(getApplicationContext(), new RotateListener());
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        mRotateDetector.onTouchEvent(event);
        return super.onTouchEvent(event);
    }

    private class RotateListener extends RotateGestureDetector.SimpleOnRotateGestureListener {
        @Override
        public boolean onRotate(RotateGestureDetector detector) {
            mRotationDegrees -= detector.getRotationDegreesDelta();
            ImageView v = (ImageView) findViewById(R.id.imageView);
            // For NineOldAndroids library only!
            ViewHelper.setRotation(v, mRotationDegrees * ROTATION_RATIO);
            // For HONEYCOMB and later only!
            v.setRotation(mRotationDegrees * ROTATION_RATIO);
            return true;
        }
    }
}

It works fine for me (I'm able to rotate the ImageView with two-finger rotation gesture. NOTE: Don't forget to chose appropriate rotation method call. I commented both of them to draw your attention.

ROTATION_RATIO is just a multiplier to speed-up a rotation response on my fingers movement. You can use any rotation axis (setRotation(), setRotationX() and setRotationY()) methods for a View.

To enable support of this code on Android devices with API Level lower than 11 (pre-Honeycomb devices) you may want to engage NineOldAndroid library.