android小球弹跳程序,使用android animator 实现 弹跳的篮球效果

public class MainActivity extends Activity {

private ShapeHolder mShapeHolder;

private final float BALLHEIGH = 100f;

@SuppressWarnings("deprecation")

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.bouncing_balls);

int screenWidth = getWindowManager().getDefaultDisplay().getWidth();

LinearLayout container = (LinearLayout) findViewById(R.id.container);

mShapeHolder = addBall(screenWidth/2, 100);

final MyAnimationView myAnimationView = new MyAnimationView(this);

container.addView(myAnimationView);

myAnimationView.post(new Runnable() {

@Override

public void run() {

myAnimationView.showBall();

}

});

}

public class MyAnimationView extends View implements AnimatorUpdateListener {

public final ArrayList balls = new ArrayList();

AnimatorSet animation = null;

public MyAnimationView(Context context) {

super(context);

}

public void showBall() {

float startY = mShapeHolder.getY();

float endY = getHeight() - BALLHEIGH;

long duration = 1000;

//小球落下

ValueAnimator downAnimator = ObjectAnimator.ofFloat(mShapeHolder, "y", startY , endY);

downAnimator.setDuration(duration);

downAnimator.setInterpolator(new AccelerateInterpolator());

//每次都需要添加这个监听刷新UI 否则不能看到动画

downAnimator.addUpdateListener(this);

// 1.设置小球的宽度变大

ValueAnimator makeBallWide = ObjectAnimator.ofFloat(mShapeHolder, "width", mShapeHolder.getWidth(),

mShapeHolder.getWidth() + BALLHEIGH/2);

makeBallWide.setDuration(duration/4);

//重复一次

makeBallWide.setRepeatCount(1);

//在重复另一次的时候回到原来的状态

makeBallWide.setRepeatMode(ValueAnimator.REVERSE);

makeBallWide.setInterpolator(new DecelerateInterpolator());

// 2.在小球变扁的时候 需要让他居中

ValueAnimator centerAnimator = ObjectAnimator.ofFloat(mShapeHolder, "x", mShapeHolder.getX(),

mShapeHolder.getX() - BALLHEIGH/4);

centerAnimator.setDuration(duration/4);

centerAnimator.setRepeatCount(1);

centerAnimator.setRepeatMode(ValueAnimator.REVERSE);

centerAnimator.setInterpolator(new DecelerateInterpolator());

centerAnimator.addUpdateListener(this);

//3. 小球高度的变小

ValueAnimator makeBallLow = ObjectAnimator.ofFloat(mShapeHolder, "height",

mShapeHolder.getHeight(), mShapeHolder.getHeight() - BALLHEIGH/4);

makeBallLow.setDuration(duration/4);

makeBallLow.setRepeatCount(1);

makeBallLow.setInterpolator(new DecelerateInterpolator());

makeBallLow.setRepeatMode(ValueAnimator.REVERSE);

//4.小球高度变化时y的居中

ValueAnimator yWhenBallisPlan = ObjectAnimator.ofFloat(mShapeHolder, "y", endY, endY + BALLHEIGH/3);

yWhenBallisPlan.setDuration(duration/4);

yWhenBallisPlan.setRepeatCount(1);

yWhenBallisPlan.setInterpolator(new DecelerateInterpolator());

yWhenBallisPlan.setRepeatMode(ValueAnimator.REVERSE);

//小球上升

ValueAnimator upAnimator = ObjectAnimator.ofFloat(mShapeHolder, "y", endY, startY);

upAnimator.setDuration(duration);

upAnimator.setInterpolator(new DecelerateInterpolator());

upAnimator.addUpdateListener(this);

final AnimatorSet animatorSet = new AnimatorSet();

animatorSet.play(downAnimator).before(centerAnimator);

animatorSet.playTogether(centerAnimator , makeBallWide ,makeBallLow, yWhenBallisPlan);

animatorSet.play(upAnimator).after(centerAnimator);

animatorSet.addListener(new AnimatorListenerAdapter() {

@Override

public void onAnimationEnd(Animator animation) {

animatorSet.start();

super.onAnimationEnd(animation);

}

});

animatorSet.start();

}

@Override

protected void onDraw(Canvas canvas) {

canvas.save();

canvas.translate(mShapeHolder.getX(), mShapeHolder.getY());

mShapeHolder.getShape().draw(canvas);

canvas.restore();

}

@Override

public void onAnimationUpdate(ValueAnimator arg0) {

invalidate();

}

}

private ShapeHolder addBall(float x, float y) {

OvalShape circle = new OvalShape();

circle.resize(BALLHEIGH, BALLHEIGH);

ShapeDrawable drawable = new ShapeDrawable(circle);

ShapeHolder shapeHolder = new ShapeHolder(drawable);

shapeHolder.setX(x - BALLHEIGH/2);

shapeHolder.setY(y - BALLHEIGH/2);

int red = (int)(Math.random() * 255);

int green = (int)(Math.random() * 255);

int blue = (int)(Math.random() * 255);

int color = 0xff000000 | red << 16 | green << 8 | blue;

Paint paint = drawable.getPaint(); //new Paint(Paint.ANTI_ALIAS_FLAG);

int darkColor = 0xff000000 | red/4 << 16 | green/4 << 8 | blue/4;

RadialGradient gradient = new RadialGradient(37.5f, 12.5f,

50f, color, darkColor, Shader.TileMode.CLAMP);

paint.setShader(gradient);

shapeHolder.setPaint(paint);

return shapeHolder;

}

}