public boolean setMultiTouchEnabled(boolean multiTouchEnabled) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB
        && mMultiTouchEnabled != multiTouchEnabled) {
      mMultiTouchEnabled = multiTouchEnabled;
      if (mMultiTouchEnabled && mScaleDetector == null) {
        mScaleDetector = new ScaleGestureDetector(getContext(), new ScaleListener());
      }
      return true;
    }
    return false;
  }
Set multi touch functionality to enabled/disabled.
core/src/main/java/com/theartofdev/edmodo/cropper/CropOverlayView.java