Droid Anim – Android 3.0

When I wanted to try JavaFX 1.x and more particularly the animations, I wrote Duke Anim, and Duke Anim in JavaFX 1.3.
So when I wanted to try the new animation API in Android 3.0, I wrote Droid Anim.

This little application is pretty simple and shows how to use some part of the new animation API in Android 3.0
And how to launch the animation and get the width and the height of the View, just after the View becomes visible, by using the View.post method to add an action in the UI message queue and.

Anim.java

package com.blogspot.paddywebog;

import java.util.Random;

import android.animation.Animator;
import android.animation.ObjectAnimator;
import android.animation.ValueAnimator;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.widget.ImageView;
import android.widget.LinearLayout;

public class Anim extends Activity {

    ObjectAnimator xAnim = null;
    ObjectAnimator yAnim = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        LayoutInflater li = getLayoutInflater();
        View v = li.inflate(R.layout.main, null);
        setContentView(v);

        v.post(new Runnable() {

            public void run() {

                ImageView img = (ImageView) findViewById(R.id.imageView1);

                Bitmap bMap = BitmapFactory.decodeResource(getResources(), R.drawable.android);

                img.setImageBitmap(bMap);

                Point p = generateNextPoint();

                xAnim = ObjectAnimator.ofFloat(img, "translationX", 0.f, p.getX());
                xAnim.setDuration(3000);
                xAnim.setInterpolator(new AccelerateDecelerateInterpolator());
                xAnim.setRepeatCount(ValueAnimator.INFINITE);

                yAnim = ObjectAnimator.ofFloat(img, "translationY", 0.f, p.getY());
                yAnim.setDuration(3000);
                yAnim.setInterpolator(new AccelerateDecelerateInterpolator());
                yAnim.setRepeatCount(ValueAnimator.INFINITE);

                xAnim.addListener(new Animator.AnimatorListener() {

                    public void onAnimationStart(Animator animation) {
                    }

                    public void onAnimationRepeat(Animator animation) {

                        Point p = generateNextPoint();

                        Float x = (Float) xAnim.getAnimatedValue();
                        xAnim.setFloatValues(x, p.getX());

                        Float y = (Float) yAnim.getAnimatedValue();
                        yAnim.setFloatValues(y, p.getY());
                    }

                    public void onAnimationCancel(Animator animation) {
                    }

                    public void onAnimationEnd(Animator animation) {
                    }
                });

                xAnim.start();

                yAnim.start();
            }
        });
    }

    public Point generateNextPoint() {

        Bitmap bMap = BitmapFactory.decodeResource(getResources(), R.drawable.android);

        LinearLayout layout = (LinearLayout) findViewById(R.id.linearLayout1);
        int lWidth = layout.getWidth();
        int lHeight = layout.getHeight();

        int width = lWidth - bMap.getWidth();
        int height = lHeight - bMap.getHeight();

        Random generator = new Random();

        Float xTarget = (generator.nextFloat() * width + 1);
        Float yTarget = (generator.nextFloat() * height + 1);

        return new Point(xTarget, yTarget);
    }
}

class Point {

    private Float x;
    private Float y;

    Point(Float x, Float y) {
        this.x = x;
        this.y = y;
    }

    public Float getX() {
        return x;
    }

    public void setX(Float x) {
        this.x = x;
    }

    public Float getY() {
        return y;
    }

    public void setY(Float y) {
        this.y = y;
    }

    public String toString() {
        StringBuilder sb = new StringBuilder();

        sb.append("x = ");
        sb.append(x);
        sb.append(" ; y = ");
        sb.append(y);

        return sb.toString();
    }
}

The source code, usable with eclipse, is available on github.