一个简单的自定义view

参考自http://www.jianshu.com/p/1b2cdba03d23

public class CheckView extends View {
    private Context mContext;
    //圆环画笔
    private Paint mPaintRing;
    //对号画笔
    private Paint mPaintTick;
    //圆的画笔
    private Paint mPaintCircle;

    private int unCheckBaseColor;
    private int checkBaseColor;
    private int checkTickColor;
    private RectF mRectF = new RectF();
    private float centerX, centerY;
    private float[] mPoints = new float[8];
    private boolean mIsChecked;
    private int radius;
    private float tickRadius;
    private float tickRadiusOffset;

    private int ringProgress = 0;
    private int circleProgress = 0;
    private int rightAlpha = 0;
    private boolean IsAnimeRuning;
    private boolean ringAnimeEnd;

    private OnCheckChangeListener mCheckChangeListener;
    public CheckView(Context context) {
        this(context, null);
    }

    public CheckView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public CheckView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        mContext = context;
        init(attrs);
        initPaint();
        setClickEvent();
    }

    private void initPaint() {
        mPaintRing = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaintRing.setStyle(Paint.Style.STROKE);
        mPaintRing.setColor(mIsChecked ? checkBaseColor : unCheckBaseColor);
        mPaintRing.setStrokeWidth(dp2px(mContext, 2.5f));
        mPaintRing.setStrokeCap(Paint.Cap.ROUND);

        mPaintCircle = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaintCircle.setColor(checkTickColor);
        mPaintCircle.setStrokeWidth(dp2px(mContext, 1));

        mPaintTick = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaintTick.setColor(mIsChecked ? checkTickColor : unCheckBaseColor);
        mPaintTick.setStyle(Paint.Style.STROKE);
        mPaintTick.setStrokeCap(Paint.Cap.ROUND);
        mPaintTick.setStrokeWidth(dp2px(mContext, 2.5f));
    }

    private void init(AttributeSet attrs) {
        TypedArray a = mContext.obtainStyledAttributes(attrs, R.styleable.CheckView);
        unCheckBaseColor = a.getColor(R.styleable.CheckView_uncheck_color, getResources().getColor(R.color.tick_gray));
        checkBaseColor = a.getColor(R.styleable.CheckView_check_color, getResources().getColor(R.color.tick_yellow));
        checkTickColor = a.getColor(R.styleable.CheckView_check_right_color, getResources().getColor(R.color.tick_white));

        a.recycle();
        radius = dp2px(mContext, 30);
        tickRadius = dp2px(mContext, 12);
        tickRadiusOffset = dp2px(mContext, 4);
    }

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

        int width = getMySize(radius * 2, widthMeasureSpec);
        int height = getMySize(radius * 2, heightMeasureSpec);

        int res = Math.max(width, height);

        setMeasuredDimension(res, res);

        centerX = getMeasuredWidth() / 2;
        centerY = getMeasuredHeight() / 2;

        mRectF.set(centerX - radius, centerY - radius, centerX + radius, centerY + radius);


        //设置打钩的几个点坐标
        mPoints[0] = centerX - tickRadius + tickRadiusOffset;
        mPoints[1] = (float) centerY;
        mPoints[2] = centerX - tickRadius / 2 + tickRadiusOffset;
        mPoints[3] = centerY + tickRadius / 2;
        mPoints[4] = centerX - tickRadius / 2 + tickRadiusOffset;
        mPoints[5] = centerY + tickRadius / 2;
        mPoints[6] = centerX + tickRadius * 2 / 4 + tickRadiusOffset;
        mPoints[7] = centerY - tickRadius * 2 / 4;
    }


    @Override
    protected void onDraw(final Canvas canvas) {
        super.onDraw(canvas);

        if (!mIsChecked) {
            canvas.drawArc(mRectF, 90, 360, false, mPaintRing);
            canvas.drawLines(mPoints, mPaintTick);
            return;
        }
        if (ringAnimeEnd){
            mPaintCircle.setColor(checkBaseColor);
            //画满黄色的圆
            canvas.drawCircle(centerX,centerY,radius,mPaintCircle);
            mPaintCircle.setColor(checkTickColor);
        }
        //画圆环
        canvas.drawArc(mRectF, 90, ringProgress, false, mPaintRing);
        //画逐渐缩小的白圆
        canvas.drawCircle(centerX,centerY,radius-circleProgress,mPaintCircle);
        //画对号
        mPaintTick.setAlpha(rightAlpha);
        canvas.drawLines(mPoints,mPaintTick);
        if (!IsAnimeRuning) {
            IsAnimeRuning = true;
            ObjectAnimator ringAnimator = ObjectAnimator.ofInt(this,"ringProgress",0,360);
            ObjectAnimator circleAnimator = ObjectAnimator.ofInt(this,"circleProgress",0,radius);
            ObjectAnimator rightAnimator = ObjectAnimator.ofInt(this,"rightAlpha",0,255);
            ringAnimator.addListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationEnd(Animator animation) {
                    super.onAnimationEnd(animation);
                    ringAnimeEnd = true;
                }
            });
            PropertyValuesHolder holder1 = PropertyValuesHolder.ofFloat("scaleX", 1f,1.2f,1f);
            PropertyValuesHolder holder2 = PropertyValuesHolder.ofFloat("scaleY", 1f,1.2f,1f);
            ObjectAnimator scaleAnimator = ObjectAnimator.ofPropertyValuesHolder(this, holder1, holder2);
            AnimatorSet animatorSet = new AnimatorSet();
            animatorSet.playSequentially(ringAnimator,circleAnimator,rightAnimator,scaleAnimator);
            animatorSet.start();
        }
    }



    private void reset() {
        initPaint();
        ringProgress = 0;
        circleProgress = 0;
        rightAlpha = 0;
        IsAnimeRuning = false;
        ringAnimeEnd = false;
        mRectF.set(centerX - radius, centerY - radius, centerX + radius, centerY + radius);

        invalidate();
    }

    private void setClickEvent() {
        this.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                mIsChecked = !mIsChecked;
                reset();
                if (mCheckChangeListener!=null){
                    mCheckChangeListener.onCheckChange((TestTickView)v,mIsChecked);
                }
            }
        });
    }

    //用于属性动画的getter和setter
    public int getRingProgress() {
        return ringProgress;
    }
    public void setRingProgress(int ringProgress) {
        this.ringProgress = ringProgress;
        invalidate();
    }
    public int getCircleProgress() {
        return circleProgress;
    }
    public void setCircleProgress(int circleProgress) {
        this.circleProgress = circleProgress;
        invalidate();
    }

    public int getRightAlpha() {
        return rightAlpha;
    }

    public void setRightAlpha(int rightAlpha) {
        this.rightAlpha = rightAlpha;
        invalidate();
    }

    private int getMySize(int defSize, int measureSpec) {
        int result;
        int mode = MeasureSpec.getMode(measureSpec);
        int size = MeasureSpec.getSize(measureSpec);

        if (mode == MeasureSpec.UNSPECIFIED || mode == MeasureSpec.AT_MOST) {
            result = defSize;
        } else {
            result = size;
        }
        return result;
    }

    private static int dp2px(Context context, float dpValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }

    public void setCheckChangeListener(OnCheckChangeListener checkChangeListener) {
        mCheckChangeListener = checkChangeListener;
    }

    public interface OnCheckChangeListener{
        void onCheckChange(TestTickView testTickView,boolean checked);
    }
}

<declare-styleable name="CheckView">
        <attr name="uncheck_color" format="color" />
        <!--选中后的基调颜色-->
        <attr name="check_color" format="color" />
        <!--选中后钩的颜色-->
        <attr name="check_right_color" format="color" />
        <!--圆的半径-->
        <attr name="radius_size" format="dimension" />
</declare-styleable>