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);
? ?}
? ?}
}