Twitter的like动画安卓版 - 备选方案

英文： Twitter’s like animation in Android - alternative

相关动画网址：http://frogermcs.github.io/twitters-like-animation-in-android-alternative/，

更多动画网址：http://frogermcs.github.io/

作者来源：Miroslaw Stanek

小编自己遇到的问题：最近在研究一个Twitter的like动画安卓版，在任何手机上面都可以正常播放动画，只有在一个htc的手机上面，没有任何错误日志，动画播放不出来

操作：设置–》开发者选择–》高级选项–》动画，把动画的选项打开就好了。

不久前Twitter展示了具有现代感的心形动画－作为star图标的替代。





虽然实现这个动画最简单的方法是使用 Frame Animation ，但是我们尝试用更灵活的方法来实现－手动绘制并用属性动画。这篇文章只是概要，没有深入的技术细节

一：实现

我们将创建一个名叫LikeButtonView的view，它是一个由三个子view构成的FrameLayout－ CircleView 显示星星图标下面的圆，ImageView （星星）以及代表按钮周围浮点的DotsView 。

CircleView

这个视图负责绘制星星图标下面的大圆。它本可以实现得更简单（通过xml ），但是这里我们应该考虑按钮下面的背景颜色。

我们在canvas上绘制圆的实现：

Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
tempCanvas.drawColor(0xffffff, PorterDuff.Mode.CLEAR);
tempCanvas.drawCircle(getWidth() / 2, getHeight() / 2, outerCircleRadiusProgress * maxCircleSize, circlePaint);
tempCanvas.drawCircle(getWidth() / 2, getHeight() / 2, innerCircleRadiusProgress * maxCircleSize, maskPaint);
canvas.drawBitmap(tempBitmap, 0, 0, null);
}

先使用CLEAR 模式绘制颜色以清除canvas。然后根据给定的进度（各自的进度是独立的）绘制内外圆。

内圆使用这样定义的mask paint ：

Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
maxCircleSize = w / 2;
tempBitmap = Bitmap.createBitmap(getWidth(), getWidth(), Bitmap.Config.ARGB_8888);
tempCanvas = new Canvas(tempBitmap);
}

我们需要完全透明，不然的话内圆就会显示窗口颜色。

对于那些眼睛机灵的人应该还注意到了另外一件事－我们的外圆颜色是基于当前进度而变化的。这是通过 ArgbEvaluator 类来完成，该类可以基于一个给定的因子在两个颜色之间变换：

private void updateCircleColor() {
float colorProgress = (float) Utils.clamp(outerCircleRadiusProgress, 0.5, 1);
colorProgress = (float) Utils.mapValueFromRangeToRange(colorProgress, 0.5f, 1f, 0f, 1f);
this.circlePaint.setColor((Integer) argbEvaluator.evaluate(colorProgress, START_COLOR, END_COLOR));
}

三：DotsView

这个view将绘制浮动在星星图标周围的圆点。跟CircleView一样，它是使用onDraw()来做这件事的：

protected void onDraw(Canvas canvas) {
drawOuterDotsFrame(canvas);
drawInnerDotsFrame(canvas);
}

private void drawOuterDotsFrame(Canvas canvas) {
for (int i = 0; i < DOTS_COUNT; i++) {
int cX = (int) (centerX + currentRadius1 * Math.cos(i * OUTER_DOTS_POSITION_ANGLE * Math.PI / 180));
int cY = (int) (centerY + currentRadius1 * Math.sin(i * OUTER_DOTS_POSITION_ANGLE * Math.PI / 180));
canvas.drawCircle(cX, cY, currentDotSize1, circlePaints[i % circlePaints.length]);
}
}

private void drawInnerDotsFrame(Canvas canvas) {
for (int i = 0; i < DOTS_COUNT; i++) {
int cX = (int) (centerX + currentRadius2 * Math.cos((i * OUTER_DOTS_POSITION_ANGLE - 10) * Math.PI / 180));
int cY = (int) (centerY + currentRadius2 * Math.sin((i * OUTER_DOTS_POSITION_ANGLE - 10) * Math.PI / 180));
canvas.drawCircle(cX, cY, currentDotSize2, circlePaints[(i + 1) % circlePaints.length]);
}
}

圆点是基于currentProgress绘制的，背后是数学逻辑，老实说从安卓sdk的角度来看这里没有什么有趣的地方，倒是有两个跟数学相关的东西：

圆点分布在一个圆上－它们的位置决定于:

int cX = (int) (centerX + currentRadius1 * Math.cos(i * OUTER_DOTS_POSITION_ANGLE * Math.PI / 180));

int cY = (int) (centerY + currentRadius1 * Math.sin(i * OUTER_DOTS_POSITION_ANGLE * Math.PI / 180));

意味着：在每个 OUTER_DOTS_POSITION_ANGLE 上设置圆点 (51 度).

每个圆点都有它自己的颜色动画：

private void updateDotsPaints() {
if (currentProgress < 0.5f) {
float progress = (float) Utils.mapValueFromRangeToRange(currentProgress, 0f, 0.5f, 0, 1f);
circlePaints[0].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_1, COLOR_2));
circlePaints[1].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_2, COLOR_3));
circlePaints[2].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_3, COLOR_4));
circlePaints[3].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_4, COLOR_1));
} else {
float progress = (float) Utils.mapValueFromRangeToRange(currentProgress, 0.5f, 1f, 0, 1f);
circlePaints[0].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_2, COLOR_3));
circlePaints[1].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_3, COLOR_4));
circlePaints[2].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_4, COLOR_1));
circlePaints[3].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_1, COLOR_2));
}
}

这意味着圆点颜色在3个区间形式的值之间动画。我们再一次使用ArgbEvaluator 让它平滑。其余就很简单了

CircleView完整代码

package com.loveta.umengexample;

import android.animation.ArgbEvaluator;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.util.AttributeSet;
import android.util.Log;
import android.util.Property;
import android.view.View;

/**
* Created by Miroslaw Stanek on 21.12.2015.
*/
public class CircleView extends View {
private static final int START_COLOR = 0xFFFF5722;
private static final int END_COLOR = 0xFFFFC107;

private ArgbEvaluator argbEvaluator = new ArgbEvaluator();

private Paint circlePaint = new Paint();
private Paint maskPaint = new Paint();

private Bitmap tempBitmap;
private Canvas tempCanvas;

private float outerCircleRadiusProgress = 0f;
private float innerCircleRadiusProgress = 0f;

private int maxCircleSize;

public CircleView(Context context) {
super(context);
init();
}

public CircleView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}

public CircleView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}

public CircleView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
init();
}

private void init() {
//        Log.e("==tjj", "============");
circlePaint.setStyle(Paint.Style.FILL);//实心园
maskPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
//PorterDuff.Mode.CLEAR---所绘制不会提交到画布上。http://blog.csdn.net/edisonlg/article/details/7084977
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
maxCircleSize = w / 2;
tempBitmap = Bitmap.createBitmap(getWidth(), getWidth(), Bitmap.Config.ARGB_8888);
tempCanvas = new Canvas(tempBitmap);
}

@Override
protected void onDraw(Canvas canvas) {//视图负责绘制星星图标下面的大圆
super.onDraw(canvas);
Log.e("==========tan111===", "tan111");
tempCanvas.drawColor(0xffffff, PorterDuff.Mode.CLEAR);//设置画布的背景颜色
tempCanvas.drawCircle(getWidth() / 2, getHeight() / 2, outerCircleRadiusProgress * maxCircleSize, circlePaint);
tempCanvas.drawCircle(getWidth() / 2, getHeight() / 2, innerCircleRadiusProgress * maxCircleSize, maskPaint);
canvas.drawBitmap(tempBitmap, 0, 0, null);
}

public void setInnerCircleRadiusProgress(float innerCircleRadiusProgress) {
this.innerCircleRadiusProgress = innerCircleRadiusProgress;
//        Log.e("==========tan===", "tan");
postInvalidate();
//        invalidate();
}

public float getInnerCircleRadiusProgress() {
return innerCircleRadiusProgress;
}

public void setOuterCircleRadiusProgress(float outerCircleRadiusProgress) {
this.outerCircleRadiusProgress = outerCircleRadiusProgress;
updateCircleColor();
postInvalidate();
//        invalidate();
}

private void updateCircleColor() {
float colorProgress = (float) Utils.clamp(outerCircleRadiusProgress, 0.5, 1);
colorProgress = (float) Utils.mapValueFromRangeToRange(colorProgress, 0.5f, 1f, 0f, 1f);
this.circlePaint.setColor((Integer) argbEvaluator.evaluate(colorProgress, START_COLOR, END_COLOR));
}

public float getOuterCircleRadiusProgress() {
return outerCircleRadiusProgress;
}

public static final Property<CircleView, Float> INNER_CIRCLE_RADIUS_PROGRESS =
new Property<CircleView, Float>(Float.class, "innerCircleRadiusProgress") {
@Override
public Float get(CircleView object) {
return object.getInnerCircleRadiusProgress();
}

@Override
public void set(CircleView object, Float value) {
//                    Log.e("==================tjj===","INNER_CIRCLE_RADIUS_PROGRESS");
object.setInnerCircleRadiusProgress(value);
}
};

public static final Property<CircleView, Float> OUTER_CIRCLE_RADIUS_PROGRESS =
new Property<CircleView, Float>(Float.class, "outerCircleRadiusProgress") {
@Override
public Float get(CircleView object) {
return object.getOuterCircleRadiusProgress();
}

@Override
public void set(CircleView object, Float value) {
object.setOuterCircleRadiusProgress(value);
}
};
}

DotsView完整代码

package com.loveta.umengexample;

import android.animation.ArgbEvaluator;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.util.Log;
import android.util.Property;
import android.view.View;

/**
* Created by Miroslaw Stanek on 20.12.2015.
*/
public class DotsView extends View {
private static final int DOTS_COUNT = 7;
private static final int OUTER_DOTS_POSITION_ANGLE = 360 / DOTS_COUNT;

private static final int COLOR_1 = 0xFFFFC107;
private static final int COLOR_2 = 0xFFFF9800;
private static final int COLOR_3 = 0xFFFF5722;
private static final int COLOR_4 = 0xFFF44336;

private final Paint[] circlePaints = new Paint[4];

private int centerX;
private int centerY;

private float maxOuterDotsRadius;
private float maxInnerDotsRadius;
private float maxDotSize;

private float currentProgress = 0;

private float currentRadius1 = 0;
private float currentDotSize1 = 0;

private float currentDotSize2 = 0;
private float currentRadius2 = 0;

private ArgbEvaluator argbEvaluator = new ArgbEvaluator();

public DotsView(Context context) {
super(context);
init();
}

public DotsView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}

public DotsView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}

public DotsView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
init();
}

private void init() {
for (int i = 0; i < circlePaints.length; i++) {
circlePaints[i] = new Paint();
circlePaints[i].setStyle(Paint.Style.FILL);
}
}

@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
centerX = w / 2;
centerY = h / 2;
maxDotSize = 20;
maxOuterDotsRadius = w / 2 - maxDotSize * 2;
maxInnerDotsRadius = 0.8f * maxOuterDotsRadius;
}

@Override
protected void onDraw(Canvas canvas) {//绘制浮动在星星图标周围的圆点
drawOuterDotsFrame(canvas);
drawInnerDotsFrame(canvas);
}

private void drawOuterDotsFrame(Canvas canvas) {
for (int i = 0; i < DOTS_COUNT; i++) {
int cX = (int) (centerX + currentRadius1 * Math.cos(i * OUTER_DOTS_POSITION_ANGLE * Math.PI / 180));
int cY = (int) (centerY + currentRadius1 * Math.sin(i * OUTER_DOTS_POSITION_ANGLE * Math.PI / 180));
canvas.drawCircle(cX, cY, currentDotSize1, circlePaints[i % circlePaints.length]);
}
}

private void drawInnerDotsFrame(Canvas canvas) {
for (int i = 0; i < DOTS_COUNT; i++) {
int cX = (int) (centerX + currentRadius2 * Math.cos((i * OUTER_DOTS_POSITION_ANGLE - 10) * Math.PI / 180));
int cY = (int) (centerY + currentRadius2 * Math.sin((i * OUTER_DOTS_POSITION_ANGLE - 10) * Math.PI / 180));
canvas.drawCircle(cX, cY, currentDotSize2, circlePaints[(i + 1) % circlePaints.length]);
}
}

public void setCurrentProgress(float currentProgress) {
this.currentProgress = currentProgress;
updateInnerDotsPosition();//1
updateOuterDotsPosition();//2
updateDotsPaints();//3
updateDotsAlpha();//4

postInvalidate();//1
}

public float getCurrentProgress() {
return currentProgress;
}

private void updateInnerDotsPosition() {
if (currentProgress < 0.3f) {
this.currentRadius2 = (float) Utils.mapValueFromRangeToRange(currentProgress, 0, 0.3f, 0.f, maxInnerDotsRadius);
} else {
this.currentRadius2 = maxInnerDotsRadius;
}

if (currentProgress < 0.2) {
this.currentDotSize2 = maxDotSize;
} else if (currentProgress < 0.5) {
this.currentDotSize2 = (float) Utils.mapValueFromRangeToRange(currentProgress, 0.2f, 0.5f, maxDotSize, 0.3 * maxDotSize);
} else {
this.currentDotSize2 = (float) Utils.mapValueFromRangeToRange(currentProgress, 0.5f, 1f, maxDotSize * 0.3f, 0);
}

}

private void updateOuterDotsPosition() {
if (currentProgress < 0.3f) {
this.currentRadius1 = (float) Utils.mapValueFromRangeToRange(currentProgress, 0.0f, 0.3f, 0, maxOuterDotsRadius * 0.8f);
} else {
this.currentRadius1 = (float) Utils.mapValueFromRangeToRange(currentProgress, 0.3f, 1f, 0.8f * maxOuterDotsRadius, maxOuterDotsRadius);
}

if (currentProgress < 0.7) {
this.currentDotSize1 = maxDotSize;
} else {
this.currentDotSize1 = (float) Utils.mapValueFromRangeToRange(currentProgress, 0.7f, 1f, maxDotSize, 0);
}
}

private void updateDotsPaints() {
if (currentProgress < 0.5f) {
float progress = (float) Utils.mapValueFromRangeToRange(currentProgress, 0f, 0.5f, 0, 1f);
circlePaints[0].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_1, COLOR_2));
circlePaints[1].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_2, COLOR_3));
circlePaints[2].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_3, COLOR_4));
circlePaints[3].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_4, COLOR_1));
} else {
float progress = (float) Utils.mapValueFromRangeToRange(currentProgress, 0.5f, 1f, 0, 1f);
circlePaints[0].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_2, COLOR_3));
circlePaints[1].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_3, COLOR_4));
circlePaints[2].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_4, COLOR_1));
circlePaints[3].setColor((Integer) argbEvaluator.evaluate(progress, COLOR_1, COLOR_2));
}
}

private void updateDotsAlpha() {
float progress = (float) Utils.clamp(currentProgress, 0.6f, 1f);
int alpha = (int) Utils.mapValueFromRangeToRange(progress, 0.6f, 1f, 255, 0);
circlePaints[0].setAlpha(alpha);
circlePaints[1].setAlpha(alpha);
circlePaints[2].setAlpha(alpha);
circlePaints[3].setAlpha(alpha);
}

public static final Property<DotsView, Float> DOTS_PROGRESS = new Property<DotsView, Float>(Float.class, "dotsProgress") {
@Override
public Float get(DotsView object) {
return object.getCurrentProgress();
}

@Override
public void set(DotsView object, Float value) {

object.setCurrentProgress(value);
}
};
}

四：LikeButtonView

最终的ViewGroup是由CircleView, ImageView 以及DotsView组成的。

<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">

<frogermcs.io.likeanimation.DotsView
android:id="@+id/vDotsView"
android:layout_width="200dp"
android:layout_height="200dp"
android:layout_gravity="center"/>

<frogermcs.io.likeanimation.CircleView
android:id="@+id/vCircle"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_gravity="center"/>

<ImageView
android:id="@+id/ivStar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:src="@drawable/ic_star_rate_off"/>

</merge>

我们使用 Merge 标签帮助消除多余的ViewGroup。LikeButtonView本身就是一个FrameLayout，因此没有必要出现两次。

我们最终的动画是由更小的动画组成的，通过AnimatorSet一起播放：

LikeButtonView完整代码

package com.loveta.umengexample;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.annotation.TargetApi;
import android.content.Context;
import android.os.Build;
import android.util.AttributeSet;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.view.animation.DecelerateInterpolator;
import android.view.animation.OvershootInterpolator;
import android.widget.FrameLayout;
import android.widget.ImageView;

import butterknife.Bind;
import butterknife.ButterKnife;

/**
* Created by Miroslaw Stanek on 20.12.2015.
*/
public class LikeButtonView extends FrameLayout implements View.OnClickListener {
private static final DecelerateInterpolator DECCELERATE_INTERPOLATOR = new DecelerateInterpolator();
private static final AccelerateDecelerateInterpolator ACCELERATE_DECELERATE_INTERPOLATOR = new AccelerateDecelerateInterpolator();
private static final OvershootInterpolator OVERSHOOT_INTERPOLATOR = new OvershootInterpolator(4);

@Bind(R.id.ivStar)
ImageView ivStar;
@Bind(R.id.vDotsView)
DotsView vDotsView;
@Bind(R.id.vCircle)
CircleView vCircle;

private boolean isChecked;
private AnimatorSet animatorSet;

public LikeButtonView(Context context) {
super(context);
init();
}

public LikeButtonView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}

public LikeButtonView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}

@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public LikeButtonView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
init();
}
private void init() {
LayoutInflater.from(getContext()).inflate(R.layout.view_like_button, this, true);
ButterKnife.bind(this);
setOnClickListener(this);
}

@Override
public void onClick(View v) {
//        Log.e("==tjj======",v.getId()+"");
isChecked = !isChecked;
ivStar.setImageResource(isChecked ? R.drawable.smart11 : R.drawable.smart1);

if (animatorSet != null) {
animatorSet.cancel();
}

if (isChecked) {
ivStar.animate().cancel();
ivStar.setScaleX(0);
ivStar.setScaleY(0);
Log.e("====1111=======", "setCurrentProgress");
vCircle.setInnerCircleRadiusProgress(0);
vCircle.setOuterCircleRadiusProgress(0);

vDotsView.setCurrentProgress(0);

animatorSet = new AnimatorSet();

ObjectAnimator outerCircleAnimator = ObjectAnimator.ofFloat(vCircle, CircleView.OUTER_CIRCLE_RADIUS_PROGRESS, 0.1f, 1f);
outerCircleAnimator.setDuration(250);
outerCircleAnimator.setInterpolator(DECCELERATE_INTERPOLATOR);

ObjectAnimator innerCircleAnimator = ObjectAnimator.ofFloat(vCircle, CircleView.INNER_CIRCLE_RADIUS_PROGRESS, 0.1f, 1f);
innerCircleAnimator.setDuration(200);
innerCircleAnimator.setStartDelay(200);
innerCircleAnimator.setInterpolator(DECCELERATE_INTERPOLATOR);

ObjectAnimator starScaleYAnimator = ObjectAnimator.ofFloat(ivStar, ImageView.SCALE_Y, 0.2f, 1f);
starScaleYAnimator.setDuration(350);
starScaleYAnimator.setStartDelay(250);
starScaleYAnimator.setInterpolator(OVERSHOOT_INTERPOLATOR);

ObjectAnimator starScaleXAnimator = ObjectAnimator.ofFloat(ivStar, ImageView.SCALE_X, 0.2f, 1f);
starScaleXAnimator.setDuration(350);
starScaleXAnimator.setStartDelay(250);
starScaleXAnimator.setInterpolator(OVERSHOOT_INTERPOLATOR);

ObjectAnimator dotsAnimator = ObjectAnimator.ofFloat(vDotsView, DotsView.DOTS_PROGRESS, 0, 1f);
dotsAnimator.setDuration(900);
dotsAnimator.setStartDelay(50);
dotsAnimator.setInterpolator(ACCELERATE_DECELERATE_INTERPOLATOR);

animatorSet.playTogether(
outerCircleAnimator,
innerCircleAnimator,
starScaleYAnimator,
starScaleXAnimator,
dotsAnimator
);

animatorSet.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationCancel(Animator animation) {
vCircle.setInnerCircleRadiusProgress(0);
vCircle.setOuterCircleRadiusProgress(0);
//                    Log.e("====2222=======", "setCurrentProgress");
vDotsView.setCurrentProgress(0);
ivStar.setScaleX(1);
ivStar.setScaleY(1);
}
});

animatorSet.start();
}
}

//LikeButtonView还会响应触摸事件（缩放动画）：
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
ivStar.animate().scaleX(0.7f).scaleY(0.7f).setDuration(150).setInterpolator(DECCELERATE_INTERPOLATOR);
setPressed(true);
break;

case MotionEvent.ACTION_MOVE:
float x = event.getX();
float y = event.getY();
boolean isInside = (x > 0 && x < getWidth() && y > 0 && y < getHeight());
if (isPressed() != isInside) {
setPressed(isInside);
}
break;

case MotionEvent.ACTION_UP:
ivStar.animate().scaleX(1).scaleY(1).setInterpolator(DECCELERATE_INTERPOLATOR);
if (isPressed()) {
performClick();
setPressed(false);
}
break;
}
return true;
}

}

源代码可以在github上面得到：https://github.com/frogermcs/LikeAnimation/