androidcode

package UICtrl;

import android.animation.ObjectAnimator;
import android.content.Context;
import android.graphics.Canvas;
import android.view.animation.Interpolator;
import android.graphics.Paint;
import android.graphics.PointF;
import android.os.Build;
import android.util.AttributeSet;
import android.view.ViewGroup;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.DecelerateInterpolator;
import android.view.animation.LinearInterpolator;
import android.widget.RelativeLayout;

/**
 * Created by wangchaomac on 2017/10/18.
 */
public class AroundCircleBall extends RelativeLayout {

    private  BallView mBall;

    //角度
    private  float mBallRadius;

    //小球的颜色
    private  int mBallColor;

    private int mCircleRadius;

    private int mCircleColor;

    private int mDuration;

    //笔头描宽
    private float mStrokeWidth;

    private int mInterpolator;

    private final int ACCELERATE_DECELERATE_INTERPOLATOR = 1;

    private final int LINEAR_INTERPOLATOR = 2;

    private final int ACCELERATE = 3;

    private final int DECELERATE = 4;

    ObjectAnimator mRotateAnim;

    PointF mCircleCenterPoint = new PointF(mCircleRadius + mBallRadius, mCircleRadius + mBallRadius);
    Paint mPaint = new Paint();

    public AroundCircleBall(Context context, AttributeSet attrs){

        super(context, attrs);
        // TODO Auto-generated constructor stub
        init(context);

    }

    private void init(Context context){
        init();
    }
    private void init() {

        mBall = new BallView(getContext());
        mBall.setRadius(mBallRadius);
        mBall.setBallColor(mBallColor);
        //小球的初始位置在圆环的最底部
        LayoutParams params = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
        params.leftMargin = (int) (mCircleRadius);
        params.topMargin = (int) (mCircleRadius * 2);
        mBall.setLayoutParams(params);
        addView(mBall);

    }
    @Override
    protected void onDraw(Canvas canvas) {
        //绘制圆
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setStrokeWidth(mStrokeWidth);
        mPaint.setColor(mCircleColor);
        canvas.drawCircle(mCircleCenterPoint.x, mCircleCenterPoint.y, mCircleRadius, mPaint);
        super.onDraw(canvas);
    }

    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        //测量控件宽高
        int width = (int) (getPaddingLeft() + mCircleRadius * 2 + mBallRadius * 2 + getPaddingRight());
        int height = (int) (getPaddingTop() + mCircleRadius * 2 + mBallRadius * 2 + getPaddingBottom());
        setMeasuredDimension(width, height);
    }

    private void initRotateAnim(){
        mRotateAnim = ObjectAnimator.ofFloat(mBall, "rotation", 0f, 360f);
        //计算小球旋转的中心点(此点的左边是在小球自身的坐标系中)
        float pivotX = mBall.getRadius();
        float pivotY = mBall.getRadius() - mCircleRadius;
        mBall.setPivotX(pivotX);
        mBall.setPivotY(pivotY);
        mRotateAnim.setDuration(mDuration);
        mRotateAnim.setInterpolator(getInterpolator());
        mRotateAnim.setRepeatCount(-1);
        mRotateAnim.setStartDelay(500);
    }

    private Interpolator getInterpolator(){
        Interpolator interpolator = null;
        switch (mInterpolator){
            case ACCELERATE_DECELERATE_INTERPOLATOR:    //先加上后减速
                interpolator = new AccelerateDecelerateInterpolator();
                break;
            case LINEAR_INTERPOLATOR:   //匀速
                interpolator = new LinearInterpolator();
                break;
            case ACCELERATE:    //加速
                interpolator = new AccelerateInterpolator();
                break;
            case DECELERATE:    //减速
                interpolator = new DecelerateInterpolator();
                break;
        }
        return interpolator;
    }

    /**
     * 启动旋转动画
     */

    public void startRotate(){
        if (mRotateAnim != null){
            mRotateAnim.start();
        }
    }

    /**
     * 暂停旋转动画
     */
    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    public void pauseRotate(){
        if (mRotateAnim != null && mRotateAnim.isRunning()){
            mRotateAnim.pause();
        }
    }

    /**
     * 取消旋转动画
     */
    public void cancelRotate(){
        if (mRotateAnim != null){
            mRotateAnim.cancel();
        }
    }
}

package UICtrl;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PointF;
import android.util.AttributeSet;
import android.view.View;

/**
 * Created by wangchaomac on 2017/10/18.
 */
public class BallView extends View {

    private int mBallColor = Color.BLACK;
    private float mRadius = 10f;
    private PointF mCenterPoint;
    private Paint mPaint;

    public BallView(Context context) {
        this(context, null);
    }

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

    private void init(){
        mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mCenterPoint = new PointF(mRadius, mRadius);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        int width = (int) (getPaddingLeft() + 2*mRadius + getPaddingRight());
        int height = (int) (getPaddingTop() + 2*mRadius + getPaddingBottom());
        setMeasuredDimension(width, height);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        mPaint.setStyle(Paint.Style.FILL);
        mPaint.setColor(mBallColor);
        canvas.drawCircle(mCenterPoint.x, mCenterPoint.y, mRadius, mPaint);
    }

    public void setBallColor(int mBallColor) {
        this.mBallColor = mBallColor;
    }

    public void setRadius(float radius) {
        this.mRadius = radius;
        mCenterPoint.set(radius, radius);
    }

    public float getRadius() {
        return mRadius;
    }
}

<?xml version="1.0" encoding="utf-8"?>
<resources><!--AroundCircleBall自定义属性-->
    <declare-styleable name="AroundCircleBall">
        <!--绘制圆形轨迹的线宽-->
        <attr name="circle_width" format="dimension"></attr>
        <!--绘制圆形轨迹的颜色-->
        <attr name="circle_color" format="color"></attr>
        <!--圆形轨迹的半径-->
        <attr name="circle_radius" format="dimension"></attr>
        <!--小球的颜色-->
        <attr name="ball_color" format="color"></attr>
        <!--小球的半径-->
        <attr name="ball_radius" format="dimension"></attr>
        <!--设置旋转一周需要的时间(单位为秒)-->
        <attr name="rotate_duration" format="integer"></attr>
        <!--设置旋转动画的补间器-->
        <attr name="rotate_interpolator" format="enum">
            <enum name="accelerate_decelerate" value="1"/>
            <enum name="linear" value="2"/>
            <enum name="accelerate" value="3"/>
            <enum name="decelerate" value="4"/>
        </attr>
    </declare-styleable></resources>