Android实现支付宝蚂蚁森林水滴浮动效果

@Override
  protected void onLayout(boolean changed, int l, int t, int r, int b) {
    final int count = getChildCount();
 
    for (int i = 0; i < count; i++) {
      View child = getChildAt(i);
      int childWidth = child.getMeasuredWidth();
      int childHeight = child.getMeasuredHeight();
      if (child.getVisibility() != GONE) {
        child.layout(listX.get(i), listY.get(i), childWidth + listX.get(i), childHeight + listY.get(i));
      }
    }
  }

List<Integer> listX = new ArrayList<>();
  List<Integer> listY = new ArrayList<>();
 
  public void setChildPosition(int posx, int posy) {
    listX.add(posx);
    listY.add(posy);
  }

@Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    measureChildren(widthMeasureSpec, heightMeasureSpec);
  }

private void doRepeatAnim() {
    ObjectAnimator animator = ObjectAnimator.ofFloat(this, "translationY", -padding, padding, -padding);
    animator.setRepeatMode(ObjectAnimator.REVERSE);
    animator.setRepeatCount(ObjectAnimator.INFINITE);
    animator.setDuration(1500);
    animator.start();
  }

 this.setOnClickListener(new OnClickListener() {
      @Override
      public void onClick(View view) {
        doSetAnim();
      }
    });

private void doSetAnim() {
    if (isCollect) return;
    isCollect = true;
    ObjectAnimator move1 = ObjectAnimator.ofFloat(this, "translationX", startWidth, endWidth);
    ObjectAnimator move2 = ObjectAnimator.ofFloat(this, "translationY", startHeight, endHeight);
    ObjectAnimator move3 = ObjectAnimator.ofFloat(this, "alpha", 1, 0);
 
    AnimatorSet animatorSet = new AnimatorSet();
    animatorSet.playTogether(move1, move2, move3);
    animatorSet.setDuration(1500);
    animatorSet.start();
  }

/**
   * @param context
   */
  public WaterView(Context context) {
    super(context);
    this.context = context;
    endWidth = (int) DeviceUtils.dpToPixel(context, 160);
    endHeight = (int) DeviceUtils.dpToPixel(context, 300);
    padding = (int) DeviceUtils.dpToPixel(context, 10);
    startWidth = 0;
    startHeight = 0;
  }
 
  /**
   * @param index
   * @param startWidth 开始坐标 X
   * @param startHeight 开始坐标 Y
   */
  public void setPosition(int index, int startWidth, int startHeight) {
    this.index = index;
    endWidth = endWidth - startWidth;
    endHeight = endHeight - startHeight;
  }

@Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    mMWidth = getMeasuredWidth();
    mHeight = getMeasuredHeight();
  }
 
  @Override
  protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    mPaint.setColor(getResources().getColor(R.color.color_87d1ab));
    mPaint.setStyle(Paint.Style.FILL);
    canvas.drawCircle(mMWidth / 2, (float) mHeight / 2, DeviceUtils.dpToPixel(context, 30), mPaint);
 
    mTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    mTextPaint.setColor(Color.WHITE);
    mTextPaint.setTextSize(DeviceUtils.dpToPixel(context, 30));
    mTextPaint.setColor(getResources().getColor(R.color.text_color_fc));
    mTextPaint.setStyle(Paint.Style.FILL);
    float width = mTextPaint.measureText(text);
    canvas.drawText(text, mMWidth / 2 - width / 2, (float) mHeight * 0.65f, mTextPaint);
 
    doRepeatAnim();
    this.setOnClickListener(new OnClickListener() {
      @Override
      public void onClick(View view) {
        doSetAnim();
      }
    });
  }

@Override
  protected void onStart() {
    super.onStart();
    int posx = (int) DeviceUtils.dpToPixel(this, 70);
    int posy = (int) DeviceUtils.dpToPixel(this, 70);
    addChildView(this, relative, 1, posx, posy);
    addChildView(this, relative, 2, 2 * posx, 2 * posy);
    addChildView(this, relative, 3, 3 * posx, posy);
  }
 
  /**
   * 添加子水滴
   *
   * @param relative
   * @param index  第几个
   * @param posx   子控件初始位置x
   * @param posy   子控件初始位置y
   */
  private void addChildView(final Context context, final WaterContainer relative, final int index, final int posx, final int posy) {
    relative.postDelayed(new Runnable() {
      @Override
      public void run() {
        int width = (int) DeviceUtils.dpToPixel(context, 60);
        int height = (int) DeviceUtils.dpToPixel(context, 60);
        ViewGroup.LayoutParams layoutParams = new ViewGroup.LayoutParams(width, height);
        WaterView waterView = new WaterView(context);
        waterView.setPosition(index, posx, posy);
        waterView.setLayoutParams(layoutParams);
        relative.setChildPosition(posx, posy);
        relative.addView(waterView);
      }
    }, (index - 1) * 300);
  }