import android.view.View;
import android.support.v4.view.ViewPager.PageTransformer;



public class DepthPageTransformer implements PageTransformer {
   private static final float MIN_SCALE = 0.75f;

   public void transformPage(View view, float position) {
   int pageWidth = view.getWidth();

   if (position < -1) { // [-Infinity,-1)
       // This page is way off-screen to the left.
       view.setAlpha(0);

   } else if (position <= 0) { // [-1,0]
       // Use the default slide transition when moving to the left page
       view.setAlpha(1);
       view.setTranslationX(0);
       view.setScaleX(1);
       view.setScaleY(1);

   } else if (position <= 1) { // (0,1]
       // Fade the page out.
       view.setAlpha(1 - position);

       // Counteract the default slide transition
       view.setTranslationX(pageWidth * -position);

       // Scale the page down (between MIN_SCALE and 1)
       float scaleFactor = MIN_SCALE
               + (1 - MIN_SCALE) * (1 - Math.abs(position));
       view.setScaleX(scaleFactor);
       view.setScaleY(scaleFactor);

   } else { // (1,+Infinity]
       // This page is way off-screen to the right.
       view.setAlpha(0);
   }
   }
}