@Override public void onUIPositionChange( PtrFrameLayout frame, boolean isUnderTouch, byte status, PtrIndicator ptrIndicator) { float percent = Math.min(1f, ptrIndicator.getCurrentPercent()); if (status == PtrFrameLayout.PTR_STATUS_PREPARE) { mDrawable.setAlpha((int) (255 * percent)); mDrawable.showArrow(true); float strokeStart = ((percent) * .8f); mDrawable.setStartEndTrim(0f, Math.min(0.8f, strokeStart)); mDrawable.setArrowScale(Math.min(1f, percent)); // magic float rotation = (-0.25f + .4f * percent + percent * 2) * .5f; mDrawable.setProgressRotation(rotation); invalidate(); } }