canvas绘制树形结构可视图形的实现

<canvas id="canvas" width="750" height="800"></canvas>

const canvas_options={    canvasWidth: 750,    canvasHeight: 800,    chartZone: [70,70,750,570], //坐标绘制区域    yAxisLabel: ['0%','10%','20%','30%','40%','50%','60%','70%','80%','90%','100%'],//y轴坐标text    yAxisLabelWidth: 70,//y轴最大宽度    yAxisLabelMax: 100,//y轴最大值    middleLine: 410, //中间线    pillarWidth: 10,//柱子宽度    distanceBetween: 50,//柱状图绘制区域距离两边间隙    pillar: [120,70,700,750],//柱状图绘制区域    mainTrunkHeight: 90,//底部开始主干高度    dialogWidth: 300,//弹窗宽度    dialogLineHeight: 30,//弹窗高度    dialogDrawLineMax: 4,}const nodeClick = [];var chooseNode = null;const datalist={    showDataInfo: {        city:[            {                 name: '项目1',                 status: 1, //状态：0已完成 1进行中                node: [                    { value: 10, date: '2020-03-12 15:50:02', content: '用于组织信息和操作，通常也作为详细信息的入口。' },                    { value: 20, date: '2020-03-12 15:50:02', content: '用于组织信息和操作，通常也作为详细信息的入口。' },                ]             },            {                 name: '项目2',                 status: 0, //状态：0已完成 1进行中                node: [                    { value: 10, date: '2020-03-12 15:50:02', content: '用于组织信息和操作，通常也作为详细信息的入口。' },                    { value: 50, date: '2020-03-12 15:50:02', content: '用于组织信息和操作，通常也作为详细信息的入口。' },                    { value: 100, date: '2020-03-12 15:50:02', content: '用于组织信息和操作，通常也作为详细信息的入口。' },                ]             },            {                 name: '项目3',                 status: 1, //状态：0已完成 1进行中                node: [                    { value: 20, date: '2020-03-12 15:50:02', content: '用于组织信息和操作，通常也作为详细信息的入口。' },                    { value: 30, date: '2020-03-12 15:50:02', content: '用于组织信息和操作，通常也作为详细信息的入口。' },                    { value: 40, date: '2020-03-12 15:50:02', content: '用于组织信息和操作，通常也作为详细信息的入口。' },                ]             },            {                 name: '项目4',                 status: 1, //状态：0已完成 1进行中                node: [                    { value: 20, date: '2020-03-12 15:50:02', content: '用于组织信息和操作，通常也作为详细信息的入口。' },                    { value: 30, date: '2020-03-12 15:50:02', content: '用于组织信息和操作，通常也作为详细信息的入口。' },                ]             },        ]    }}const canvas = document.getElementById("canvas");const ctx = canvas.getContext('2d');ctx.save();drawYLabel(canvas_options,ctx); //绘制y轴坐标drawStartButton(ctx,canvas_options);drawData(ctx,datalist.showDataInfo,canvas_options);canvas.addEventListener("click",event=>{    //清除之前的弹窗    if(chooseNode!=null){        ctx.clearRect(0, 0, canvas.width, canvas.height);        ctx.save();         drawYLabel(canvas_options,ctx); //绘制y轴坐标         drawStartButton(ctx,canvas_options);         drawData(ctx,datalist.showDataInfo,canvas_options);        chooseNode = null    }    //判断点击节点    let rect = canvas.getBoundingClientRect();    let zoom = rect.width/canvas_options.canvasWidth;    let x = (event.clientX/zoom - rect.left/zoom).toFixed(2);    let y = (event.clientY/zoom - rect.top/zoom).toFixed(2);    for(var t=0;t<nodeClick.length;t++){        ctx.beginPath();        ctx.arc(nodeClick[t].x,nodeClick[t].y,15,0,Math.PI*2,true);        if(ctx.isPointInPath(x, y)){            textPrewrap(ctx,`备注描述：${nodeClick[t].date}`,nodeClick[t].x+20,nodeClick[t].y+20,canvas_options.dialogWidth-40);            ctx.restore();            chooseNode=t            break;        }else{            chooseNode=null        }    }});//content：需要绘制的文本内容; drawX：绘制文本的x坐标; drawY：绘制文本的y坐标;//lineMaxWidth：每行文本的最大宽度function textPrewrap(ctx,content,drawX, drawY, lineMaxWidth){    var drawTxt=''; //当前绘制的内容    var drawLine  = 1;//第几行开始绘制    var drawIndex=0;//当前绘制内容的索引    //判断内容是够可以一行绘制完毕    if(ctx.measureText(content).width<=lineMaxWidth){        drawDialog(ctx,canvas_options.dialogWidth,canvas_options.dialogLineHeight,drawX,drawY);        ctx.fillText(content.substring(drawIndex,i),drawX.drawY);    }else{        for(var i=0;i<content.length;i++){            drawTxt += content[i];            if(ctx.measureText(drawTxt).width>=lineMaxWidth){                drawDialog(ctx,canvas_options.dialogWidth,canvas_options.dialogLineHeight,drawX,drawY);                ctx.fillText(content.substring(drawIndex,i+1),drawX,drawY);                drawIndex = i+1;                drawLine+=1;                //drawY+=lineHeight;                drawTxt='';            }else{                //内容绘制完毕，但是剩下的内容宽度不到lineMaxWidth                if(i===content.length-1){                    drawDialog(ctx,canvas_options.dialogWidth,canvas_options.dialogLineHeight,drawX,drawY);                    ctx.fillText(content.substring(drawIndex,i+1),drawX,drawY)                }            }        }    }}function drawDialog(ctx,width,height,x,y){    ctx.beginPath();    ctx.fillStyle="rgba(0,0,0,0.8)";    ctx.fillRect(x,y,width,height);    ctx.font="22px ''";    ctx.fillStyle="#fff";    ctx.textAlign = 'left';    ctx.textBaseline="top";}//绘制y轴坐标function drawYLabel(options,ctx){    let labels = options.yAxisLabel;    let yLength = (options.chartZone[3]-options.chartZone[1])*0.98;    let gap = yLength/(labels.length-1);    labels.forEach((item,index)=>{        //绘制圆角背景        //this.radiusButton(ctx,0,options.chartZone[3]-index*gap-13,50,24,8,"#313947");        //绘制坐标文字        ctx.beginPath();        ctx.fillStyle="#878787";        ctx.font="18px ''";        ctx.textAlign="center";        ctx.fillText(item,25,options.chartZone[3]-index*gap+5);        //绘制辅助线        ctx.beginPath();        ctx.strokeStyle="#eaeaea";        ctx.strokeWidth=2;        ctx.moveTo(options.chartZone[0],options.chartZone[3]-index*gap);        ctx.lineTo(options.chartZone[2],options.chartZone[3]-index*gap);        ctx.stroke();    })}//绘制开始按钮function drawStartButton(ctx,options){    //绘制按钮图形    this.radiusButton(ctx,options.middleLine-(160/2),options.canvasHeight-50,160,50,8,'#F4C63D');    ctx.fillStyle="#fff";    ctx.font="24px ''";    ctx.textAlign="center";    ctx.fillText('开始',options.middleLine,options.canvasHeight-15);    //绘制状态    ctx.beginPath();    ctx.fillStyle="#333";    ctx.font="24px ''";    ctx.textAlign = "left";    ctx.fillText("已完成",0,options.canvasHeight-100);    ctx.fillText("进行中",0,options.canvasHeight-50);    //绘制红色按钮    ctx.beginPath();    ctx.fillStyle="#d35453";    ctx.arc(options.chartZone[0]+30,options.canvasHeight-100-7,8,0,2 * Math.PI,true);    ctx.fill();    ctx.beginPath();    ctx.strokeStyle="#d35453";    ctx.arc(options.chartZone[0]+30,options.canvasHeight-100-7,14,0,2 * Math.PI,true);    ctx.stroke();    //绘制蓝色按钮    ctx.beginPath();    ctx.fillStyle="#24b99a";    ctx.arc(options.chartZone[0]+30,options.canvasHeight-50-8,8,0,2 * Math.PI,true);    ctx.fill();    ctx.beginPath();    ctx.strokeStyle="#24b99a";    ctx.arc(options.chartZone[0]+30,options.canvasHeight-50-8,14,0,2 * Math.PI,true);    ctx.stroke();}//封装绘制圆角矩形函数function radiusButton(ctx,x,y,width,height,radius,color_back){    ctx.beginPath();    ctx.fillStyle= color_back    ctx.moveTo(x,y+radius);    ctx.lineTo(x,y+height-radius);    ctx.quadraticCurveTo(x,y+height,x+radius,y+height);    ctx.lineTo(x+width-radius,y+height);    ctx.quadraticCurveTo(x+width,y+height,x+width,y+height-radius);    ctx.lineTo(x+width,y+radius);    ctx.quadraticCurveTo(x+width,y,x+width-radius,y);    ctx.lineTo(x+radius,y);    ctx.quadraticCurveTo(x,y,x,y+radius);    ctx.fill()}//绘制数据function drawData(ctx,data,options){    //const paths=[];    let number = data.city.length;    //绘制矩形    data.city.forEach((item,index)=>{        let indexVal = number==1?1:index;        let numberVal = number==1?2:number-1        let x0 = options.chartZone[0]+options.distanceBetween+(options.chartZone[2]-options.chartZone[0]-options.distanceBetween*2)/numberVal*indexVal;        let value = item.node[item.node.length-1].value;        let height = (value/options.yAxisLabelMax*(options.chartZone[3]-options.chartZone[0])*0.98).toFixed(2);        let y0=options.chartZone[3] - height;        //柱状图底部        ctx.beginPath();        ctx.fillStyle= '#eee';        ctx.fillRect(x0-5,80,options.pillarWidth,options.chartZone[3]-80);        //贝塞尔曲线        ctx.beginPath();        ctx.strokeStyle = item.status==0?"#d35453":'#24b99a';        ctx.lineWidth=options.pillarWidth;        ctx.moveTo(options.middleLine,options.pillar[3]); //贝塞尔曲线起始点        ctx.lineTo(options.middleLine,options.canvasHeight-50-options.mainTrunkHeight); //贝塞尔曲线中间竖线        ctx.quadraticCurveTo(x0,options.canvasHeight-50-options.mainTrunkHeight,x0,options.chartZone[3]);        //绘制柱状图进度        ctx.lineTo(x0,y0);        ctx.stroke();        //绘制文字        ctx.font="28px ''";        ctx.textAlign='center';        ctx.fillStyle="#333";        ctx.fillText(item.name,x0,options.chartZone[1]-20);        //绘制节点        item.node.forEach((node_item,node_index)=>{            let y1= options.chartZone[3] - (node_item.value/options.yAxisLabelMax*(options.chartZone[3]-options.chartZone[0])*0.98).toFixed(2);            ctx.beginPath();            ctx.arc(x0,y1,15,0,Math.PI*2,true);            ctx.fillStyle="rgba(108,212,148,1)";            ctx.fill();            ctx.beginPath();            ctx.arc(x0,y1,9,0,Math.PI*2,true);            ctx.fillStyle="rgba(255,255,255,0.8)";            ctx.fill();            const pointInfo={                x:x0,                y:y1,                date: node_item.data,                content: node_item.content,                value: node_item.value            };            nodeClick.push(pointInfo);        })    })}