Creaete AnimationDrawable and copy frames from another AnimationDrawable

Modify from ast exercise "Set alpha of AnimationDrawable", we are going to create a new AnimationDrawable, copy frame from the original myAnimationDrawable, and re-arrange frame order in reverse.



Modify main.xml to add a ImageView for the new animation.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:orientation="vertical" >

  <TextView
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:text="@string/hello" />
  <TextView
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:text="Set Alpha" />
  <SeekBar
      android:id="@+id/setalpha"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:progress="255"
      android:max="255" />
  <Button
      android:id="@+id/startanimation"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:text="Start Animation" />
  <Button
      android:id="@+id/stopanimation"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:text="Stop Animation" />
  <ImageView
      android:id="@+id/myanimation"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:src="@anim/anim_android"
      />
  <ImageView
      android:id="@+id/myanimation2"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      />
</LinearLayout>

Modify the Java code, implement a new method copyReversedAnim(). It return the new AnimationDrawable. Then set it the ImageDrawable of the ImageView.

package com.exercise.AndroidAnimation;

import android.app.Activity;
import android.graphics.drawable.AnimationDrawable;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.SeekBar;
import android.widget.Toast;

public class AndroidAnimationActivity extends Activity {
  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
    
      ImageView myAnimation = (ImageView)findViewById(R.id.myanimation);
      ImageView myAnimation2 = (ImageView)findViewById(R.id.myanimation2);
      final AnimationDrawable myAnimationDrawable
       = (AnimationDrawable)myAnimation.getDrawable();
    
      //Copy a new AnimationDrawable in reversed order
      final AnimationDrawable reversedAnimationDrawable = copyReversedAnim(myAnimationDrawable);
      //apply the new AnimationDrawable
      myAnimation2.setImageDrawable(reversedAnimationDrawable);
    
      SeekBar setAnimationAlpha = (SeekBar)findViewById(R.id.setalpha);
      Button startAnimation = (Button)findViewById(R.id.startanimation);
      Button stopAnimation = (Button)findViewById(R.id.stopanimation);
    
      startAnimation.setOnClickListener(new Button.OnClickListener(){

   @Override
   public void onClick(View arg0) {
    // TODO Auto-generated method stub
    if(!reversedAnimationDrawable.isRunning()){
     myAnimationDrawable.start();
     reversedAnimationDrawable.start();
    }
   }});
    
      stopAnimation.setOnClickListener(new Button.OnClickListener(){

   @Override
   public void onClick(View arg0) {
    // TODO Auto-generated method stub
    if(reversedAnimationDrawable.isRunning()){
     myAnimationDrawable.stop();
     reversedAnimationDrawable.stop();
    }
   }});
    
      setAnimationAlpha.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener(){

   @Override
   public void onProgressChanged(SeekBar seekBar, int progress,
     boolean fromUser) {
    myAnimationDrawable.setAlpha(progress);
    reversedAnimationDrawable.setAlpha(progress);
    
   }

   @Override
   public void onStartTrackingTouch(SeekBar seekBar) {
    // TODO Auto-generated method stub
    
   }

   @Override
   public void onStopTrackingTouch(SeekBar seekBar) {
    // TODO Auto-generated method stub
    
   }});

  }

  private AnimationDrawable copyReversedAnim(AnimationDrawable src){
   
   AnimationDrawable newAnim = new AnimationDrawable();
   
   int numberOfFrame = src.getNumberOfFrames();
   
   for(int i = 0; i < numberOfFrame; i++){
    newAnim.addFrame(
      src.getFrame(numberOfFrame - i - 1),
      src.getDuration(numberOfFrame - i - 1));
   }
   newAnim.setOneShot(false);
   
   return newAnim;
  }
}

Download the files.