Android自定义View实现弹性小球效果

public class BezierView extends View { Paint paint;//画笔 Path path;//路径 int radius = 50;//圆的半径 int time = 100;//计数时长 int index; int offsetIndex; float viewX, viewY;//图形中心点坐标 float width;//屏幕宽度 float partWidth;//屏幕宽度的1/4 int paddingLeft, paddingRight;//图形内边距 float x1, y1, x2, y2, x3, y3, x4, y4;//圆形左上右下四个点 float x12, y12, x23, y23, x34, y34, x41, y41;//圆形左上右下四个点之间的渐变点 public BezierView(Context context) {  this(context, null); } public BezierView(Context context, AttributeSet attrs) {  this(context, attrs, 0); } public BezierView(Context context, AttributeSet attrs, int defStyleAttr) {  super(context, attrs, defStyleAttr);  paint = new Paint();  paint.setColor(ResourcesCompat.getColor(getResources(), R.color.colorPrimary, null));  paint.setAntiAlias(true); } @Override protected void onDraw(Canvas canvas) {  paddingLeft = getPaddingLeft();  paddingRight = getPaddingRight();  width = getWidth() - paddingLeft - paddingRight;  partWidth = width / 4;  path = new Path();  path.moveTo(x1, y1);  path.cubicTo(x1, y1, x12, y12, x2, y2);  path.cubicTo(x2, y2, x23, y23, x3, y3);  path.cubicTo(x3, y3, x34, y34, x4, y4);  path.cubicTo(x4, y4, x41, y41, x1, y1);  canvas.drawPath(path, paint);  move(); } public void move() {  new Timer().schedule(new TimerTask() {   @Override   public void run() {    if (index < time - 1) {     index++;     viewX = width / time * index + paddingLeft;     viewY = 400;     x1 = viewX - radius;     x2 = viewX;     x3 = viewX + radius;     x4 = viewX;     y1 = viewY;     y2 = viewY - radius;     y3 = viewY;     y4 = viewY + radius;     offsetIndex = index % (time / 4) + 1;     //根据图形移动到的区域进行曲线变化     float position = (viewX - paddingLeft) / partWidth;     //右边半圆     if (position >= 0 && position < 1) {      x3 = viewX + radius + radius / (time / 4) * offsetIndex;     } else if (position >= 1 && position < 2) {      x3 = viewX + radius + radius;     } else if (position >= 2 && position < 3) {      x3 = viewX + radius + radius - radius / (time / 4) * offsetIndex;     } else {      x3 = viewX + radius;     }     x23 = x34 = x3;     y12 = y23 = y2;     //左边半圆     if (position >= 1 && position < 2) {      x1 = viewX - radius - radius / (time / 4) * offsetIndex;     } else if (position >= 2 && position < 3) {      x1 = viewX - radius - radius;     } else if (position >= 3) {      x1 = viewX - radius - radius + radius / (time / 4) * offsetIndex;     } else {      x1 = viewX - radius;     }     x12 = x41 = x1;     y34 = y41 = y4;     postInvalidate();    } else {     cancel();    }   }  }, 0, 5000); }}