AnimatedListView Android

AnimatedListView.java

package com.leonziyo.imagegallery;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewTreeObserver;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.view.animation.AnimationSet;
import android.view.animation.ScaleAnimation;
import android.view.animation.TranslateAnimation;
import android.widget.ListView;

/**
 * Created by leonziyo on 3/26/16.
 */
public class AnimatedListView extends ListView {

    private boolean alreadySetup = false;

    public AnimatedListView(Context context) {
        this(context, null);
    }

    public AnimatedListView(Context context, AttributeSet attrs) {
        this(context, attrs, android.R.attr.listViewStyle);
    }

    public AnimatedListView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        
        setDivider(null);
        getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                if (alreadySetup)
                    return;
                alreadySetup = true;

                setUpAnimations();
            }
        });
    }

    private void setUpAnimations() {
        final int childCount = getChildCount();

        for(int i = 0; i < childCount; i++)
            getChildAt(i).setVisibility(View.INVISIBLE);

        final View lastChild = getChildAt(childCount - 1);
        lastChild.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
            @Override
            public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {

                lastChild.removeOnLayoutChangeListener(this);
                for (int i = 0; i < childCount; i++)
                    postAnimation(getChildAt(i), (i+1) * 150);

            }
        });

    }

    private void postAnimation(final View element, int delay) {
        element.postDelayed(new Runnable() {
            @Override
            public void run() {
                animate(element);
            }
        }, delay);
    }

    private void animate(final View element) {
        AnimationSet set = new AnimationSet(false);

        TranslateAnimation translateAnimation = new TranslateAnimation(0f, 0f, 600f, 0f);
        //animation.setInterpolator();
        translateAnimation.setInterpolator(getContext(), android.R.anim.accelerate_decelerate_interpolator);
        translateAnimation.setDuration(400);
        translateAnimation.setAnimationListener(new Animation.AnimationListener() {
            @Override
            public void onAnimationStart(Animation animation) {
                element.setVisibility(View.VISIBLE);
            }

            @Override
            public void onAnimationEnd(Animation animation) {
                final ScaleAnimation scaleAnimation = new ScaleAnimation(
                        1f, 1.1f,
                        1f, 1.1f,
                        Animation.RELATIVE_TO_SELF, .5f,
                        Animation.RELATIVE_TO_SELF, .5f
                );
                scaleAnimation.setRepeatCount(1);
                scaleAnimation.setDuration(80);
                scaleAnimation.setRepeatMode(Animation.REVERSE);

                element.startAnimation(scaleAnimation);
            }

            @Override
            public void onAnimationRepeat(Animation animation) {

            }
        });

        AlphaAnimation alphaAnimation = new AlphaAnimation(0f, 1f);
        alphaAnimation.setDuration(400);

        set.addAnimation(translateAnimation);
        set.addAnimation(alphaAnimation);
        element.startAnimation(set);
    }
}