问完整的Gmail三片段动画场景的工作示例？

EN

package com.commonsware.android.anim.threepane;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ObjectAnimator;
import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.widget.LinearLayout;

public class ThreePaneLayout extends LinearLayout {
  private static final int ANIM_DURATION=500;
  private View left=null;
  private View middle=null;
  private View right=null;
  private int leftWidth=-1;
  private int middleWidthNormal=-1;

  public ThreePaneLayout(Context context, AttributeSet attrs) {
    super(context, attrs);
    initSelf();
  }

  void initSelf() {
    setOrientation(HORIZONTAL);
  }

  @Override
  public void onFinishInflate() {
    super.onFinishInflate();

    left=getChildAt(0);
    middle=getChildAt(1);
    right=getChildAt(2);
  }

  public View getLeftView() {
    return(left);
  }

  public View getMiddleView() {
    return(middle);
  }

  public View getRightView() {
    return(right);
  }

  public void hideLeft() {
    if (leftWidth == -1) {
      leftWidth=left.getWidth();
      middleWidthNormal=middle.getWidth();
      resetWidget(left, leftWidth);
      resetWidget(middle, middleWidthNormal);
      resetWidget(right, middleWidthNormal);
      requestLayout();
    }

    translateWidgets(-1 * leftWidth, left, middle, right);

    ObjectAnimator.ofInt(this, "middleWidth", middleWidthNormal,
                         leftWidth).setDuration(ANIM_DURATION).start();
  }

  public void showLeft() {
    translateWidgets(leftWidth, left, middle, right);

    ObjectAnimator.ofInt(this, "middleWidth", leftWidth,
                         middleWidthNormal).setDuration(ANIM_DURATION)
                  .start();
  }

  public void setMiddleWidth(int value) {
    middle.getLayoutParams().width=value;
    requestLayout();
  }

  private void translateWidgets(int deltaX, View... views) {
    for (final View v : views) {
      v.setLayerType(View.LAYER_TYPE_HARDWARE, null);

      v.animate().translationXBy(deltaX).setDuration(ANIM_DURATION)
       .setListener(new AnimatorListenerAdapter() {
         @Override
         public void onAnimationEnd(Animator animation) {
           v.setLayerType(View.LAYER_TYPE_NONE, null);
         }
       });
    }
  }

  private void resetWidget(View v, int width) {
    LinearLayout.LayoutParams p=
        (LinearLayout.LayoutParams)v.getLayoutParams();

    p.width=width;
    p.weight=0;
  }
}

layout = new ThreeLayout(this, 3);
layout.setAnimationDuration(1000);
setContentView(layout);
layout.getLeftView();   //<---inflate FragmentA here
layout.getMiddleView(); //<---inflate FragmentB here
layout.getRightView();  //<---inflate FragmentC here

//Left Animation set
layout.startLeftAnimation();

//Right Animation set
layout.startRightAnimation();

//You can even set interpolators

public FrameLayout getLeftLayout() {}

public FrameLayout getMiddleLayout() {}

public FrameLayout getRightLayout() {}