Android圆形饼图绘制（当饼图占比很小时描述文字的分开绘制）

由于项目中需要用到饼图，用MpAndroidChart，当饼图部分占比很小时，描述文字重叠，所以自己重新绘制了饼图，并提供饼图各部分的点击监听，效果图如下：

绘制饼图的类：

package com.karoline.views.bars;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.RectF;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

import com.karoline.utils.SizeUtils;

import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.List;

/**
 * Created by ${Karoline} on 2017/6/14.
 */

public class AssetKcPie extends View {
   
   //继承View类
    private Context mContext;
    private Paint textPaint; 
    private Paint arcPaint;
    private Paint linePaint;

    private WeakReference<Bitmap> bitmapBuffer;
    private Canvas bitmapCanvas;

    private float distance;
    private float radius;
    private int barWidth,barHeight;
    private List<AssetKcData> datas;
    private List<AngleSE> angleSEs;
    private List<RectF> lengedRectes;
    private OnSelectedListener mListener;

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if(event.getAction() == MotionEvent.ACTION_DOWN){
            float actionX = event.getX(); //点击点的坐标
            float actionY = event.getY();
            double distance = Math.sqrt(Math.pow(Math.abs(actionX-barWidth/2),2)+
                                Math.pow(Math.abs(actionY-barHeight/2),2));
            double angle = Math.atan((actionY-barHeight/2) /(actionX-barWidth/2)) /3.14 * 180 - 90;
            float X = barWidth/2,Y=(barHeight-lengedHeight)/2;
            if(actionX > X && actionY<Y){
                angle = 90-angle;
            } else if (actionX > X && actionY>Y) {
                angle = 90+angle;
            }else if (actionX < X && actionY>Y) {
                angle = 270-angle;
            }else if (actionX < X && actionY<Y) {
                angle = 270+angle;
            }

            if(angleSEs == null || angleSEs.size() == 0 || mListener == null) return false;

            for(int i=0;i<angleSEs.size();i++){
                if(distance <= radius){
                    if(angle > angleSEs.get(i).getStartAngle() && angle<angleSEs.get(i).getSweepAngle()){
                        mListener.onSelected(i); //当点击点在圆内且在扇形上时，触发监听事件
                    }
                }else if(lengedRectes.get(i).contains(actionX,actionY)){
                    mListener.onSelected(i); //当点击点在描述文字上时，触发监听事件(此处是当饼图部分太小，无法点击时的补充)
                }
            }
            return false;
        }

        return super.onTouchEvent(event);
    }

    private float totalNum;

    private int lengedHeight = 0;
    private boolean isLengedVisible = false;

    public AssetKcPie(Context context) {
        super(context);
    }

    public AssetKcPie(Context context, AttributeSet attrs) {
        super(context, attrs); 

        mContext = context;

        textPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        textPaint.setColor(Color.BLACK);
        textPaint.setTextSize(SizeUtils.dp2px(context,11));

        arcPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        arcPaint.setTextSize(radius);

        linePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        linePaint.setColor(Color.DKGRAY);
        linePaint .setTextSize(3);

        distance = SizeUtils.dp2px(context,16);

        setRadius(SizeUtils.dp2px(context,80));

    }

    public AssetKcPie(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public void setRadius(float rs){
        this.radius = rs;
    }

    public void setData(List<AssetKcData> dataS,float total){
        this.datas = dataS;
        this.totalNum = total;
        invalidate();
    }

    public void setLenged(){ //设置是否绘制控件下方的描述
        isLengedVisible = true;
        lengedHeight = (int) SizeUtils.dp2px(mContext,32);
                setMeasuredDimension(onWidthMeasure(getMeasuredWidth()),onHeightMeasure(getMeasuredHeight()));
    }

    private void drawLenged(){ //绘制控件下面的描述
        lengedRectes = new ArrayList<>();
        Rect rect = new Rect();
        float lengedX = distance;
        float lengedY = barHeight - lengedHeight + distance;
        float totalWidth;
        for(int i = 0;i<datas.size();i++){
            RectF rectF = new RectF();
            textPaint.setTextSize(SizeUtils.dp2px(mContext,13));
            textPaint.setFakeBoldText(true);
            textPaint.setShadowLayer(5,4,4,Color.GRAY);
            textPaint.getTextBounds(datas.get(i).getDesc(),0,datas.get(i).getDesc().length(),rect);