<!--使用默认UI属性-->
 <com.mcxtzhang.lib.AnimShopButton
 android:id="@+id/btn1"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 app:maxCount="3"/>
 <!--设置了两圆间距-->
 <com.mcxtzhang.lib.AnimShopButton
 android:id="@+id/btn2"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 app:count="3"
 app:gapBetweenCircle="90dp"
 app:maxCount="99"/>
 <!--仿饿了么-->
 <com.mcxtzhang.lib.AnimShopButton
 android:id="@+id/btnEle"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 app:addEnableBgColor="#3190E8"
 app:addEnableFgColor="#ffffff"
 app:hintBgColor="#3190E8"
 app:hintBgRoundValue="15dp"
 app:hintFgColor="#ffffff"
 app:maxCount="99"/>

@Override
 protected void onDraw(Canvas canvas) {
 if (isHintMode) {
  //hint 展开
  //背景
  mHintPaint.setColor(mHintBgColor);
  RectF rectF = new RectF(mLeft, mTop
   , mWidth - mCircleWidth, mHeight - mCircleWidth);
  canvas.drawRoundRect(rectF, mHintBgRoundValue, mHintBgRoundValue, mHintPaint);
  //前景文字
  mHintPaint.setColor(mHintFgColor);
  // 计算Baseline绘制的起点X轴坐标
  int baseX = (int) (mWidth / 2 - mHintPaint.measureText(mHintText) / 2);
  // 计算Baseline绘制的Y坐标
  int baseY = (int) ((mHeight / 2) - ((mHintPaint.descent() + mHintPaint.ascent()) / 2));
  canvas.drawText(mHintText, baseX, baseY, mHintPaint);
 } else {
  //左边
  //背景 圆
  if (mCount > 0) {
  mDelPaint.setColor(mDelEnableBgColor);
  } else {
  mDelPaint.setColor(mDelDisableBgColor);
  }
  mDelPaint.setStrokeWidth(mCircleWidth);
  mDelPath.reset();
  mDelPath.addCircle(mLeft + mRadius, mTop + mRadius, mRadius, Path.Direction.CW);
  mDelRegion.setPath(mDelPath, new Region(mLeft, mTop, mWidth - getPaddingRight(), mHeight - getPaddingBottom()));
  canvas.drawPath(mDelPath, mDelPaint);
  //前景 -
  if (mCount > 0) {
  mDelPaint.setColor(mDelEnableFgColor);
  } else {
  mDelPaint.setColor(mDelDisableFgColor);
  }
  mDelPaint.setStrokeWidth(mLineWidth);
  canvas.drawLine(-mRadius / 2, 0,
   +mRadius / 2, 0,
   mDelPaint);
  //数量
  //是没有动画的普通写法,x left, y baseLine
  canvas.drawText(mCount + "", mLeft + mRadius * 2, mTop + mRadius - (mFontMetrics.top + mFontMetrics.bottom) / 2, mTextPaint);
  //右边
  //背景 圆
  if (mCount < mMaxCount) {
  mAddPaint.setColor(mAddEnableBgColor);
  } else {
  mAddPaint.setColor(mAddDisableBgColor);
  }
  mAddPaint.setStrokeWidth(mCircleWidth);
  float left = mLeft + mRadius * 2 + mGapBetweenCircle;
  mAddPath.reset();
  mAddPath.addCircle(left + mRadius, mTop + mRadius, mRadius, Path.Direction.CW);
  mAddRegion.setPath(mAddPath, new Region(mLeft, mTop, mWidth - getPaddingRight(), mHeight - getPaddingBottom()));
  canvas.drawPath(mAddPath, mAddPaint);
  //前景 +
  if (mCount < mMaxCount) {
  mAddPaint.setColor(mAddEnableFgColor);
  } else {
  mAddPaint.setColor(mAddDisableFgColor);
  }
  mAddPaint.setStrokeWidth(mLineWidth);
  canvas.drawLine(left + mRadius / 2, mTop + mRadius, left + mRadius / 2 + mRadius, mTop + mRadius, mAddPaint);
  canvas.drawLine(left + mRadius, mTop + mRadius / 2, left + mRadius, mTop + mRadius / 2 + mRadius, mAddPaint);
 }
 }

 /**
 * Return true if the region contains the specified point
 */
 public native boolean contains(int x, int y);

@Override
 public boolean onTouchEvent(MotionEvent event) {
 int action = event.getAction();
 switch (action) {
  case MotionEvent.ACTION_DOWN:
  //hint模式
  if (isHintMode) {
   onAddClick();
   return true;
  } else {
   if (mAddRegion.contains((int) event.getX(), (int) event.getY())) {
   onAddClick();
   return true;
   } else if (mDelRegion.contains((int) event.getX(), (int) event.getY())) {
   onDelClick();
   return true;
   }
  }
  break;
  case MotionEvent.ACTION_MOVE:
  break;
  case MotionEvent.ACTION_UP:
  case MotionEvent.ACTION_CANCEL:
  break;
 }
 return super.onTouchEvent(event);
 }

protected void onDelClick() {
 if (mCount > 0) {
  mCount--;
  onCountDelSuccess();
 }
 }
 protected void onAddClick() {
 if (mCount < mMaxCount) {
  mCount++;
  onCountAddSuccess();
 } else {
 }
 }
 /**
 * 数量增加成功后，使用者回调
 */
 public void onCountAddSuccess() {
 if (mCount == 1) {
  cancelAllAnim();
  mAnimReduceHint.start();
 } else {
  mAnimFraction = 0;
  invalidate();
 }
 }
 /**
 * 数量减少成功后，使用者回调
 */
 public void onCountDelSuccess() {
 if (mCount == 0) {
  cancelAllAnim();
  mAniDel.start();
 } else {
  mAnimFraction = 0;
  invalidate();
 }
 }

//动画的基准值 动画：减 0~1, 加 1~0 
 // 普通状态下是0
 protected float mAnimFraction;
 //提示语收缩动画 0-1 展开1-0
 //普通模式时，应该是1， 只在 isHintMode true 才有效
 protected float mAnimExpandHintFraction;

//背景
  mHintPaint.setColor(mHintBgColor);
  RectF rectF = new RectF(mLeft + (mWidth - mRadius * 2) * mAnimExpandHintFraction, mTop
   , mWidth - mCircleWidth, mHeight - mCircleWidth);
  canvas.drawRoundRect(rectF, mHintBgRoundValue, mHintBgRoundValue, mHintPaint);

//动画 mAnimFraction ：减 0~1, 加 1~0 ,
  //动画位移Max,
  float animOffsetMax = (mRadius * 2 +mGapBetweenCircle);
  //透明度动画的基准
  int animAlphaMax = 255;
  int animRotateMax = 360;
  //左边
  //背景 圆
  mDelPaint.setAlpha((int) (animAlphaMax * (1 - mAnimFraction)));
  mDelPath.reset();
  //改变圆心的X坐标，实现位移
  mDelPath.addCircle(animOffsetMax * mAnimFraction + mLeft + mRadius, mTop + mRadius, mRadius, Path.Direction.CW);
  canvas.drawPath(mDelPath, mDelPaint);

//前景 -
  //旋转动画
  canvas.save();
  canvas.translate(animOffsetMax * mAnimFraction + mLeft + mRadius, mTop + mRadius);
  canvas.rotate((int) (animRotateMax * (1 - mAnimFraction)));
  canvas.drawLine(-mRadius / 2, 0,
   +mRadius / 2, 0,
   mDelPaint);
  canvas.restore();

 //数量
  canvas.save();
  //平移动画
  canvas.translate(mAnimFraction * (mGapBetweenCircle / 2 - mTextPaint.measureText(mCount + "") / 2 + mRadius), 0);
  //旋转动画,旋转中心点，x 是绘图中心,y 是控件中心
  canvas.rotate(360 * mAnimFraction,
  mGapBetweenCircle / 2 + mLeft + mRadius * 2 ,
   mTop + mRadius);
  //透明度动画
  mTextPaint.setAlpha((int) (255 * (1 - mAnimFraction)));
  //是没有动画的普通写法,x left, y baseLine
  canvas.drawText(mCount + "", mGapBetweenCircle / 2 - mTextPaint.measureText(mCount + "") / 2 + mLeft + mRadius * 2, mTop + mRadius - (mFontMetrics.top + mFontMetrics.bottom) / 2, mTextPaint);
  canvas.restore();

 //动画 +
 mAnimAdd = ValueAnimator.ofFloat(1, 0);
 mAnimAdd.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
  @Override
  public void onAnimationUpdate(ValueAnimator animation) {
  mAnimFraction = (float) animation.getAnimatedValue();
  invalidate();
  }
 });
 mAnimAdd.setDuration(350);
 //提示语收缩动画 0-1
 mAnimReduceHint = ValueAnimator.ofFloat(0, 1);
 mAnimReduceHint.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
  @Override
  public void onAnimationUpdate(ValueAnimator animation) {
  mAnimExpandHintFraction = (float) animation.getAnimatedValue();
  invalidate();
  }
 });
 mAnimReduceHint.addListener(new AnimatorListenerAdapter() {
  @Override
  public void onAnimationEnd(Animator animation) {
  if (mCount == 1) {
   //然后底色也不显示了
   isHintMode = false;
  }
  if (mCount == 1) {
   Log.d(TAG, "现在还是1 开始收缩动画");
   if (mAnimAdd != null && !mAnimAdd.isRunning()) {
   mAnimAdd.start();
   }
  }
  }
  @Override
  public void onAnimationStart(Animator animation) {
  if (mCount == 1) {
   //先不显示文字了
   isShowHintText = false;
  }
  }
 });
 mAnimReduceHint.setDuration(350);
 //动画 -
 mAniDel = ValueAnimator.ofFloat(0, 1);
 mAniDel.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
  @Override
  public void onAnimationUpdate(ValueAnimator animation) {
  mAnimFraction = (float) animation.getAnimatedValue();
  invalidate();
  }
 });
 //1-0的动画
 mAniDel.addListener(new AnimatorListenerAdapter() {
  @Override
  public void onAnimationEnd(Animator animation) {
  if (mCount == 0) {
   Log.d(TAG, "现在还是0onAnimationEnd() called with: animation = [" + animation + "]");
   if (mAnimExpandHint != null && !mAnimExpandHint.isRunning()) {
   mAnimExpandHint.start();
   }
  }
  }
 });
 mAniDel.setDuration(350);
 //提示语展开动画
 //分析这个动画，最初是个圆。 就是left 不断减小
 mAnimExpandHint = ValueAnimator.ofFloat(1, 0);
 mAnimExpandHint.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
  @Override
  public void onAnimationUpdate(ValueAnimator animation) {
  mAnimExpandHintFraction = (float) animation.getAnimatedValue();
  invalidate();
  }
 });
 mAnimExpandHint.addListener(new AnimatorListenerAdapter() {
  @Override
  public void onAnimationEnd(Animator animation) {
  if (mCount == 0) {
   isShowHintText = true;
  }
  }
  @Override
  public void onAnimationStart(Animator animation) {
  if (mCount == 0) {
   isHintMode = true;
  }
  }
 });
 mAnimExpandHint.setDuration(350);

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 int wMode = MeasureSpec.getMode(widthMeasureSpec);
 int wSize = MeasureSpec.getSize(widthMeasureSpec);
 int hMode = MeasureSpec.getMode(heightMeasureSpec);
 int hSize = MeasureSpec.getSize(heightMeasureSpec);
 switch (wMode) {
  case MeasureSpec.EXACTLY:
  break;
  case MeasureSpec.AT_MOST:
  //不超过父控件给的范围内，自由发挥
  int computeSize = (int) (getPaddingLeft() + mRadius * 2 +mGapBetweenCircle + mRadius * 2 + getPaddingRight() + mCircleWidth * 2);
  wSize = computeSize < wSize ? computeSize : wSize;
  break;
  case MeasureSpec.UNSPECIFIED:
  //自由发挥
  computeSize = (int) (getPaddingLeft() + mRadius * 2 + mGapBetweenCircle + mRadius * 2 + getPaddingRight() + mCircleWidth * 2);
  wSize = computeSize;
  break;
 }
 switch (hMode) {
  case MeasureSpec.EXACTLY:
  break;
  case MeasureSpec.AT_MOST:
  int computeSize = (int) (getPaddingTop() + mRadius * 2 + getPaddingBottom() + mCircleWidth * 2);
  hSize = computeSize < hSize ? computeSize : hSize;
  break;
  case MeasureSpec.UNSPECIFIED:
  computeSize = (int) (getPaddingTop() + mRadius * 2 + getPaddingBottom() + mCircleWidth * 2);
  hSize = computeSize;
  break;
 }
 setMeasuredDimension(wSize, hSize);
 //复用时会走这里，所以初始化一些UI显示的参数
 mAnimFraction = 0;
 initHintSettings();
 }
 /**
 * 根据当前count数量 初始化 hint提示语相关变量
 */
 private void initHintSettings() {
 if (mCount == 0) {
  isHintMode = true;
  isShowHintText = true;
  mAnimExpandHintFraction = 0;
 } else {
  isHintMode = false;
  isShowHintText = false;
  mAnimExpandHintFraction = 1;
 }
 }

 /**
 * 设置当前数量
 * @param count
 * @return
 */
 public AnimShopButton setCount(int count) {
 mCount = count;
 //先暂停所有动画
 if (mAnimAdd != null && mAnimAdd.isRunning()) {
  mAnimAdd.cancel();
 }
 if (mAniDel != null && mAniDel.isRunning()) {
  mAniDel.cancel();
 }
 //复用机制的处理
 if (mCount == 0) {
  // 0 不显示 数字和-号
  mAnimFraction = 1;
 } else {
  mAnimFraction = 0;
 }
 initHintSettings();
 return this;
 }