从BouncingBall.java中学习使用属性动画记录(二)
Animator.ofFloat(newBall, "x", newBall.getX(), newBall.getX() - 25f); squashAnim1.setDuration(duration/4); squashAnim1.setRepeatCount(1);
squashAnim1.setRepeatMode(ValueAnimator.REVERSE); squashAnim1.setInterpolator(new DecelerateInterpolator()); ValueAnimator squashAnim2 = ObjectAnimator.ofFloat(newBall, "width", newBall.getWidth(), newBall.getWidth() + 50); squashAnim2.setDuration(duration/4);
squashAnim2.setRepeatCount(1); squashAnim2.setRepeatMode(ValueAnimator.REVERSE); squashAnim2.setInterpolator(new DecelerateInterpolator()); ValueAnimator stretchAnim1 = ObjectAnimator.ofFloat(newBall, "y", endY, endY + 25f); stretchAnim1.setDuration(duration/4);
stretchAnim1.setRepeatCount(1); stretchAnim1.setInterpolator(new DecelerateInterpolator()); stretchAnim1.setRepeatMode(ValueAnimator.REVERSE); ValueAnimator stretchAnim2 = ObjectAnimator.ofFloat(newBall, "height", newBall.getHeight(), newBall.getHeight() -
25); stretchAnim2.setDuration(duration/4); stretchAnim2.setRepeatCount(1); stretchAnim2.setInterpolator(new DecelerateInterpolator()); stretchAnim2.setRepeatMode(ValueAnimator.REVERSE); ValueAnimator bounceBackAnim = ObjectAnimator.ofFloat(newBall, "y", endY,
startY); bounceBackAnim.setDuration(duration); bounceBackAnim.setInterpolator(new DecelerateInterpolator()); // Sequence the down/squash&stretch/up animations AnimatorSet bouncer = new AnimatorSet();//可以定义一套动画器在一起，并设置他们的播放顺序 bouncer.play(bounceAnim).before(squashAnim1);
bouncer.play(squashAnim1).with(squashAnim2); bouncer.play(squashAnim1).with(stretchAnim1); bouncer.play(squashAnim1).with(stretchAnim2); bouncer.play(bounceBackAnim).after(stretchAnim2); // Fading animation - remove the ball when the animation is done ValueAnimator
fadeAnim = ObjectAnimator.ofFloat(newBall, "alpha", 1f, 0f); fadeAnim.setDuration(250); fadeAnim.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animation) { balls.remove(((ObjectAnimator)animation).getTarget()); }
}); // Sequence the two animations to play one after the other AnimatorSet animatorSet = new AnimatorSet(); animatorSet.play(bouncer).before(fadeAnim); // Start the animation animatorSet.start(); return true; } private ShapeHolder addBall(float x, float y)
{ OvalShape circle = new OvalShape(); circle.resize(50f, 50f); ShapeDrawable drawable = new ShapeDrawable(circle); ShapeHolder shapeHolder = new ShapeHolder(drawable); shapeHolder.setX(x - 25f); shapeHolder.setY(y - 25f); 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;//这四行代码定义了一个随机颜色，这是可以学习的方式 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);//定义着色器，使得画笔颜色是渐变的 paint.setShader(gradient); shapeHolder.setPaint(paint); balls.add(shapeHolder); return shapeHolder;
} @Override protected void onDraw(Canvas canvas) {//这个函数的内容是MyAnimationView所呈现出来的视图的最终样子 for (int i = 0; i < balls.size(); ++i) { ShapeHolder shapeHolder = balls.get(i); canvas.save(); canvas.translate(shapeHolder.getX(), shapeHolder.getY()); shapeHolder.getShape().draw(canvas);//本质上是shapeDrawable的绘制
canvas.restore(); } } }}