java-universal-tween-engine，一个动画系统库

http://code.google.com/p/java-universal-tween-engine/

可以用来创建平滑的移动系统，比如循环，移动，旋转等。由于项目使用纯java写成，所以支持swt,swing,android,opengles等。Tween缓冲大家应该都不陌生，说白了就是从一起始位置逐渐移动到目标位置的过程，这个过程可以是加速移动，也可以是减速移动，这些不同的缓动方式就是Tween的各种ease。

源码在最后，将其解压后复制到src就可以了。

用法,先定义一个需要运动的物体：

public class Particule {private float x, y;        public float getX() {            return x;    }        public float getY() {            return y;    }        public void setX(float x) {            this.x = x;    }        public void setY(float y) {            this.y = y;    }}

然后，实现Tweenable接口，用于表明运动的返回值和变化值

import aurelienribon.tweenengine.Tweenable;public class TweenableParticule implements Tweenable {    // The following lines define the different possible tween types.    // It's up to you to define what you need :-)    public static final int X = 1;    public static final int Y = 2;    public static final int XY = 3;    // Composition pattern    private Particule target;    // Constructor    public TweenableParticule(Particule particule) {            this.target = particule;    }    // Tweenable implementation    @Override    public int getTweenValues(int tweenType, float[] returnValues) {            switch (tweenType) {                    case X: returnValues[0] = target.getX(); return 1;                    case Y: returnValues[0] = target.getY(); return 1;                    case XY:                            returnValues[0] = target.getX();                            returnValues[1] = target.getY();                            return 2;                    default: assert false; return 0;            }    }        @Override    public void onTweenUpdated(int tweenType, float[] newValues) {            switch (tweenType) {                    case X: target.setX(newValues[0]); break;                    case Y: target.setY(newValues[1]); break;                    case XY:                            target.setX(newValues[0]);                            target.setY(newValues[1]);                            break;                    default: assert false; break;            }    }}

最后，在Activity中运动：

import android.app.Activity;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.os.Bundle;import android.view.View;import aurelienribon.tweenengine.Tween;import aurelienribon.tweenengine.TweenGroup;import aurelienribon.tweenengine.TweenManager;import aurelienribon.tweenengine.Tweenable;import aurelienribon.tweenengine.equations.*;import com.ql.test.Particule;import com.ql.test.TweenableParticule;/** * http://code.google.com/p/java-universal-tween-engine/ * @author admin * */public class Screen4 extends Activity {Particule particule;TweenManager manager;     @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);//        setContentView(R.layout.screen_4);//Button btn_11=(Button)findViewById(R.id.btn_11);        setContentView(new ScreenView(this));// Let's say we are working with an Android target. We need to pool our objects.Tween.setPoolEnabled(true);// We also need a manager to handle every tween.manager = new TweenManager();// We can now create as many interpolations as we need !particule=new Particule();particule.setX(100);particule.setY(100);Tweenable tweenParticle=new TweenableParticule(particule);Tween tween = Tween.to(tweenParticle, TweenableParticule.XY, 10000, Cubic.OUT).target(400, 500);manager.add(tween.start());tween = Tween.to(tweenParticle, TweenableParticule.XY, 10000, Bounce.OUT).target(100, 500).delay(10000);manager.add(tween.start());//TweenGroup tweenGroup=new TweenGroup().pack(//Tween.set(tweenParticle, TweenableParticule.XY),//Tween.to(tweenParticle, TweenableParticule.XY, 10000, Sine.OUT),//Tween.from(tweenParticle, TweenableParticule.XY, 10000, Sine.OUT),//Tween.to(tweenParticle, TweenableParticule.XY, 10000, Bounce.OUT)//);//manager.add(tweenGroup.sequence().repeat(2,5000).start());//TweenGroup tweenGroup= new TweenGroup().pack(//    Tween.to(tweenParticle, TweenableParticule.XY, 500, Quad.INOUT).target(200),//    Tween.to(tweenParticle, TweenableParticule.XY, 500, Quad.INOUT).target(100),//    Tween.to(tweenParticle, TweenableParticule.XY, 500, Quad.INOUT).target(200).delay(1000)//).sequence().start();    }    @Override    protected void onResume() {        super.onResume();            }    @Override    protected void onPause() {        super.onPause();        manager.clear();    }    class ScreenView extends View{    Paint paint;public ScreenView(Context context) {super(context);// TODO Auto-generated constructor stubpaint=new Paint();paint.setAntiAlias(true);paint.setColor(Color.RED);paint.setStyle(Paint.Style.FILL_AND_STROKE);invalidate();}@Overrideprotected void onDraw(Canvas canvas) {// TODO Auto-generated method stub//super.onDraw(canvas);canvas.drawCircle(particule.getX(), particule.getY(), 20, paint);manager.update();invalidate();}        }}