Gắn hiệu ứng chuyễn động cho pageView

mPager = (ViewPager) findViewById(R.id.pager); //the UI pagermPagerAdapter = new ScreenSlidePagerAdapter(getSupportFragmentManager());
mPager.setAdapter(mPagerAdapter);
mPager.setPageTransformer(true, new RotateDownTransformer()); //set the animation