content: package com.cjj.cartoon.viewpageranim;
  
  import android.view.View;
  import android.support.v4.view.ViewPager;
  
  public class DepthPageTransformer implements ViewPager.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);
          }
      }
  }
  