question: private boolean hasFullClippingSupport ( Canvas c ) { if ( Build . VERSION . SDK_INT >= Build . VERSION_CODES . HONEYCOMB && mIsHardwareAccelerated != null ) { try { return ! ( Boolean ) mIsHardwareAccelerated . invoke ( c , ( Object [ ] ) null ) ; } catch ( IllegalArgumentException e ) { } catch ( IllegalAccessException e ) { } catch ( InvocationTargetException e ) { } } return true ; }
target:  As of Android 4.0.4, clipping with Op.DIFFERENCE is not supported if hardware acceleration is used. (see http://android-developers.blogspot.de/2011/03/android-30-hardware-acceleration.html) Op.DIFFERENCE and clipPath supported as of 18 !!! FIXME Disable using HW clipping completely for now, see bug https://github.com/MarcusWolschon/osmeditor4android/issues/307