系统流程图javascript代码

flowchart.js

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+/**
+ * 流程图绘制方法集
+ * 作者：刘广文
+ * 邮箱：liugw@imut.edu.cn
+ * 版本：20230813
+ * 功能：基于canvas实现流程图的绘制 
+ */
+var tool = 1;
+var current = -1;
+var flag=false;
+var mouseX= 0;
+var mouseY= 0;
+var mouseX1= 0;
+var mouseY1= 0;
+var aryPoint = [];
+var aryObject = [];
+
+//加载工具
+function loadTools(target){
+    target.innerHTML = "<div id=\"begin\" onclick=\"clickTool(this, 1);\" title=\"绘制开始框\">开始</div>"
+    + "<div id=\"process\" onclick=\"clickTool(this, 2);\" title=\"绘制处理框\">处理</div>" 
+    + "<div id=\"arrow\" onclick=\"clickTool(this, 3);\" title=\"绘制直线连接箭头\"></div>"
+    + "<div id=\"arrow1\" onclick=\"clickTool(this, 4);\" title=\"绘制折线连接箭头\"></div>"
+    + "<div id=\"judge\" onclick=\"clickTool(this, 5);\" title=\"绘制判断框\">条件？</div>"
+    + "<div id=\"end\" onclick=\"clickTool(this, 6);\" title=\"绘制结束框\">结束</div>"
+    + "<div id=\"led\" onclick=\"clickTool(this, 7);\" title=\"绘制显示框\">显示</div>"
+    + "<div id=\"link\" onclick=\"clickTool(this, 8);\" title=\"绘制连接框\">1</div>";
+}
+//鼠标抬起响应动作
+function myMouseUp(e, page){
+    flag=false;
+    pushTool(tool, mouseX, mouseY, mouseX1, mouseY1, text.value, color.value, bcolor.value, size.value);
+    updateTools(cxt);
+}
+//鼠标移动响应动作
+function myMouseMove(e, page){
+    mouseX1= e.pageX-page.offsetLeft;
+    mouseY1= e.pageY-page.offsetTop;
+    if(flag){
+        var aryPoint1 = [];
+        var i = 0;
+        while(i < aryPoint.length){
+            aryPoint1.push(aryPoint[i]);
+            i ++;
+        }
+        updateTools(cxt);
+        aryPoint = [];
+        i = 0;
+        while(i < aryPoint1.length){
+            aryPoint.push(aryPoint1[i]);
+            i ++;
+        }
+        if (tool == 4){
+            var s = aryPoint[aryPoint.length - 1];
+            ary = s.split(",");
+            var x = parseFloat(ary[0]), y = parseFloat(ary[1]);
+            if (Math.abs(x - mouseX1) > 10 || Math.abs(y - mouseY1) > 10)
+                aryPoint.push(mouseX1 + "," + mouseY1);
+        }
+        drawTool(cxt, tool, mouseX, mouseY, mouseX1, mouseY1, color.value, bcolor.value, size.value);
+    }
+}
+
+//鼠标按下响应动作
+function myMouseDown(e, page)
+{
+    mouseX= e.pageX-page.offsetLeft;
+    mouseY= e.pageY-page.offsetTop;
+    aryPoint = [];
+    aryPoint.push(mouseX + "," + mouseY);
+    flag=true;
+}
+//保存
+function save(){
+    var ary = [];
+    var i = 0;
+    while(i <= current){
+        ary.push(aryObject[i]);
+        i ++;
+    }
+    aryObject = ary;
+    updateButton();
+    const fileName = 'flowchart.txt';
+    var str = '';
+    i = 0;
+    while(i < aryObject.length){
+        if (i == 0)
+            str = aryObject[i]
+        else{
+            str += "\r\n"
+            str += aryObject[i]
+        }
+        i ++;
+    }
+    const content = str
+    const blob = new Blob([content], {type: 'application/text'});
+    // 构造一个blob对象来处理数据
+    // 对于<a>标签，只有 Firefox 和 Chrome（内核） 支持 download 属性
+    // IE10以上支持blob但是依然不支持download
+    if ('download' in document.createElement('a')) 
+    { 
+        // 支持a标签download的浏览器
+        const link = document.createElement('a') 
+        // 创建a标签
+        link.download = fileName 
+        // a标签添加属性
+        link.style.display = 'none'
+        link.href = URL.createObjectURL(blob)
+        document.body.appendChild(link)
+        link.click() 
+        // 执行下载
+        URL.revokeObjectURL(link.href) 
+        // 释放url
+        document.body.removeChild(link) 
+        // 释放标签
+    } else { 
+        // 其他浏览器
+        navigator.msSaveBlob(blob, fileName)
+    }
+}
+//撤销
+function undo(){
+    if (current >= 0)
+    {
+        current --;
+        updateTools();
+    }
+    updateButton();
+}
+//刷新按钮状态
+function updateButton(){
+    var undo = document.getElementById("undo");
+    var redo = document.getElementById("redo");
+    var save = document.getElementById("save");
+    if (current >= 0)
+    {
+        save.disabled = false;
+        undo.disabled = false;
+    }
+    else 
+    {
+        undo.disabled = true;
+        save.disabled = true;
+    }
+    if (current < aryObject.length - 1)
+    {
+        redo.disabled = false;
+    }
+    else {
+        redo.disabled = true;
+    }
+}
+//重做
+function redo(){
+    if (current < aryObject.length - 1)
+    {
+        current ++;
+        updateTools();
+    }
+    updateButton();
+}
+
+//选择工具
+function clickTool(o, tag){
+    tool = tag;
+    for(var i = 0; i < tools.children.length; i ++){
+        tools.children[i].style.border = '1px solid black';
+    }
+    o.style.border = '2px solid red';
+    text.hidden = true;
+    text.value = "";
+    if (tag == 1)
+    {
+        text.hidden = false;
+        text.value = "开始";
+    }
+    if (tag == 2)
+    {
+        text.hidden = false;
+        text.value = "处理";
+    }
+    if (tag == 3 || tag == 4){
+        text.hidden = false;
+        text.value = "";
+    }
+    if (tag == 5)
+    {
+        text.hidden = false;
+        text.value = "条件";
+    }
+    if (tag == 6)
+    {
+        text.hidden = false;
+        text.value = "结束";
+    }
+    if (tag == 7)
+    {
+        text.hidden = false;
+        text.value = "显示信息";
+    }
+    if (tag == 8)
+    {
+        text.hidden = false;
+        text.value = "1";
+    }
+}
+
+//绘制所有工具
+function updateTools(context){
+    canvas.width = canvas.width;
+    var i = 0;
+    while (i <= current){
+        var ary = aryObject[i].split('|');
+        var type = parseInt(ary[0]);
+        var ary1 = ary[1].split(',');
+        var x1 = parseFloat(ary1[0]);
+        var y1 = parseFloat (ary1[1]);
+        var x2 = parseFloat(ary1[2]);
+        var y2 = parseFloat(ary1[3]);
+        var size = parseFloat(ary[5]);
+        var color = ary[3];
+        var bcolor = ary[4];
+        if(type == 4){
+            x2 = parseFloat(ary1[ary1.length - 2]);
+            y2 = parseFloat(ary1[ary1.length - 1]);
+            aryPoint = [];
+            var j = 0;
+            while(j < ary1.length){
+                var x = parseFloat(ary1[j]), y = parseFloat(ary1[j + 1]);
+                aryPoint.push(x + "," + y);
+                j += 2;
+            }
+        }
+        drawTool(cxt, type, x1, y1, x2, y2, color, bcolor, size);
+        drawText(cxt, type, x1, y1, x2, y2, ary[2], color);
+        i ++;
+    }
+}
+//保存当前的绘制
+function pushTool(type, x1, y1, x2, y2, text, color, bcolor, size){
+    var ary = [];
+    var i = 0;
+    while(i <= current){
+        ary.push(aryObject[i]);
+        i ++;
+    }
+    aryObject = ary;
+    var s = type + '|' + x1 + ',' + y1 + ',' + x2 + ',' + y2 + '|' + text + '|' + color + '|' + bcolor + '|' + size;
+    if(type == 4){
+        s = type + '|';
+        i = 0;
+        while(i < aryPoint.length){
+            if (i > 0)
+                s += ","; 
+            s += aryPoint[i];
+            i ++;
+        }
+        s = s + '|' + text + '|' + color + '|' + bcolor + '|' + size;
+    }
+    aryObject.push(s);
+    current ++;
+    updateButton();
+}
+//绘制文本
+function drawText(context, type, x1, y1, x2, y2, text, color){
+    if (text == "" || context == null || type < 1) return;
+    switch(type){
+        case 1:
+        case 2:
+        case 5:
+        case 6:
+        case 7:
+        case 8:{     
+            //绘制开始框
+            //计算宽高
+            var l = x1, t = y1;
+            var w = x2 - x1, h = y2 - y1;
+            if (w < 0)
+            {
+                l = x2;
+                w = x1 - x2;
+            }               
+            if (h < 0){
+                t = y2;
+                h = y1 - y2;
+            }
+            context.font = "10pt SimSun";
+            //updateFont(context, w, h, text, 100);
+            var w1 = getFontWidth(context, text);
+            var h1 = getFontHeight(context, text);
+            context.fillStyle = color;
+            context.fillText(text, l + (w - w1) / 2, t + h1 / 4 + h / 2);
+            break;
+        }  
+        case 3:{     
+            //绘制箭头
+            //计算文字大小                
+            context.font = "10pt SimSun";
+            var w = getFontWidth(context, text);
+            var h = getFontHeight(context, text);
+            //获得输出坐标
+            var x = (x2 + x1) / 2;
+            var y = (y2 + y1) / 2;                
+            context.fillStyle = color;
+            context.fillText(text, x, y);
+            break;
+        } 
+        case 4:{     
+            //绘制箭头
+            //计算文字大小                
+            context.font = "10pt SimSun";
+            var w = getFontWidth(context, text);
+            var h = getFontHeight(context, text);
+            //获得输出坐标
+            var px1 = x1, py1 = y1;
+            var i = 1;
+            var pp = 0;
+            while(i < aryPoint.length)
+            {
+                var ary = aryPoint[i].split(',');
+                var px = parseFloat(ary[0]), py = parseFloat(ary[1]);
+                var pp1 = 2;
+                if (Math.abs(px - px1) > Math.abs(py - py1)) pp1 = 1;
+                if (pp != 0 && pp1 != pp) break;
+                pp = pp1;
+                px1 = px;
+                py1 = py;
+                i ++;
+            }
+            var x = (px1 + x1) / 2;
+            var y = (py1 + y1) / 2;                
+            context.fillStyle = color;
+            context.fillText(text, x, y);
+            break;
+        } 
+    }
+    
+}
+//绘制当前工具
+function drawTool(context, type, x1, y1, x2, y2, color, bcolor, size){
+    if (context == null || type < 1) return;
+    switch(type){
+        case 1:{     
+            //绘制开始框
+            //计算宽高
+            var l = x1, t = y1;
+            var w = x2 - x1, h = y2 - y1;
+            if (w < 0)
+            {
+                l = x2;
+                w = x1 - x2;
+            }               
+            if (h < 0){
+                t = y2;
+                h = y1 - y2;
+            }
+            context.strokeStyle = color;
+            context.lineWidth = size;
+            context.beginPath();
+            context.moveTo(l, t + h / 2);
+            context.lineTo(l + w * 0.15, t);
+            context.lineTo(l + w - w * 0.15, t);
+            context.lineTo(l + w, t + h / 2);
+            context.lineTo(l + w - w * 0.15, t + h);
+            context.lineTo(l + w * 0.15, t + h);
+            context.lineTo(l, t + h / 2);
+            context.closePath();
+            context.fillStyle = bcolor;
+            context.fill();
+            context.stroke();
+            break;
+        }  
+        case 2:{     
+            //绘制处理框
+            //计算宽高
+            var l = x1, t = y1;
+            var w = x2 - x1, h = y2 - y1;
+            if (w < 0)
+            {
+                l = x2;
+                w = x1 - x2;
+            }               
+            if (h < 0){
+                t = y2;
+                h = y1 - y2;
+            }
+            context.strokeStyle = color;
+            context.lineWidth = size;
+            context.beginPath();
+            context.moveTo(l, t);
+            context.lineTo(l + w, t);
+            context.lineTo(l + w, t + h);
+            context.lineTo(l, t + h);
+            context.lineTo(l, t);
+            context.closePath();
+            context.fillStyle = bcolor;
+            context.fill();
+            context.stroke();
+            break;
+        } 
+        case 3:{     
+            //绘制连接箭头
+            //计算箭头方向                
+            var ll = 10, ss = 30; 
+            var a = Math.atan2((y2 - y1), (x2 - x1));
+            var x3 = x2 - ll * Math.cos(a + ss * Math.PI/180); 
+            var y3 = y2 - ll * Math.sin(a + ss * Math.PI/180);
+            var x4 = x2 - ll * Math.cos(a - ss * Math.PI/180);
+            var y4 = y2 - ll * Math.sin(a - ss * Math.PI/180);
+            context.strokeStyle = color;
+            context.lineWidth = size;
+            context.beginPath();
+            context.moveTo(x1, y1);
+            context.lineTo(x2, y2);
+            context.lineTo(x3, y3);
+            context.moveTo(x2, y2);
+            context.lineTo(x4, y4)
+            context.closePath();
+            context.stroke();
+            break;
+        }             
+        case 4:{     
+            //绘制折线连接箭头
+            if (aryPoint.length < 3)
+                break;
+            var ary = aryPoint[aryPoint.length - 2].split(',');
+            var px1 = parseFloat(ary[0]), py1 = parseFloat(ary[1]);
+            ary = aryPoint[aryPoint.length - 1].split(',');
+            var px2 = parseFloat(ary[0]), py2 = parseFloat(ary[1]);
+            if (Math.abs(px2 - px1) > Math.abs(py2 - py1))
+                py1 = py2;
+            else px1 = px2;
+            //计算箭头方向                
+            var ll = 10, ss = 30; 
+            var a = Math.atan2((py2 - py1), (px2 - px1));
+            var x3 = px2 - ll * Math.cos(a + ss * Math.PI/180); 
+            var y3 = py2 - ll * Math.sin(a + ss * Math.PI/180);
+            var x4 = px2 - ll * Math.cos(a - ss * Math.PI/180);
+            var y4 = py2 - ll * Math.sin(a - ss * Math.PI/180);
+            context.strokeStyle = color;
+            context.lineWidth = size;
+            context.beginPath();
+            context.lineTo(px2, py2);
+            context.lineTo(x3, y3);
+            context.moveTo(px2, py2);
+            context.lineTo(x4, y4)
+            context.moveTo(px2, py2);
+            context.lineTo(px1, py1);
+            var i = aryPoint.length - 3;
+            while(i >= 0){
+                ary = aryPoint[i].split(',');
+                px2 = parseFloat(ary[0]), py2 = parseFloat(ary[1]);
+                if (Math.abs(px2 - px1) > Math.abs(py2 - py1))
+                    py2 = py1;
+                else px2 = px1;
+                context.moveTo(px1, py1);
+                context.lineTo(px2, py2);
+                px1 = px2;
+                py1 = py2;
+                i --;
+            }
+            context.closePath();
+            context.stroke();
+            break;
+        } 
+        case 5:{     
+            //绘制判断框
+            //计算宽高
+            var l = x1, t = y1;
+            var w = x2 - x1, h = y2 - y1;
+            if (w < 0)
+            {
+                l = x2;
+                w = x1 - x2;
+            }               
+            if (h < 0){
+                t = y2;
+                h = y1 - y2;
+            }
+            context.strokeStyle = color;
+            context.lineWidth = size;
+            context.beginPath();
+            context.moveTo(l, t + h / 2);
+            context.lineTo(l + w / 2, t);
+            context.lineTo(l + w, t + h / 2);
+            context.lineTo(l + w / 2, t + h);
+            context.lineTo(l, t + h / 2);
+            context.closePath();
+            context.fillStyle = bcolor;
+            context.fill();
+            context.stroke();
+            break;
+        } 
+        case 6:{     
+            //绘制结束框
+            //计算宽高
+            var l = x1, t = y1;
+            var w = x2 - x1, h = y2 - y1;
+            if (w < 0)
+            {
+                l = x2;
+                w = x1 - x2;
+            }               
+            if (h < 0){
+                t = y2;
+                h = y1 - y2;
+            }
+            context.strokeStyle = color;
+            context.lineWidth = size;
+            var r = w * 0.4;
+            if (h < w)
+                r = h * 0.4;
+            context.beginPath();
+            context.moveTo(l + r, t);
+            context.arcTo(l + w, t, l + w, t + h, r);
+            context.arcTo(l + w, t + h, l, t + h, r);
+            context.arcTo(l, t + h, l, t, r);
+            context.arcTo(l, t, l + w, t, r);
+            context.closePath();
+            context.fillStyle = bcolor;
+            context.fill();
+            context.stroke();
+            break;
+        } 
+        case 7:{    
+            //绘制信息显示框
+            //计算宽高
+            var l = x1, t = y1;
+            var w = x2 - x1, h = y2 - y1;
+            if (w < 0)
+            {
+                l = x2;
+                w = x1 - x2;
+            }               
+            if (h < 0){
+                t = y2;
+                h = y1 - y2;
+            }
+            context.strokeStyle = color;
+            context.lineWidth = size;
+            var r = w * 0.4;
+            if (h < w)
+                r = h * 0.4;
+            context.beginPath();
+            context.moveTo(l, t + h / 2);
+            context.lineTo(l + r, t);
+            context.lineTo(l + w - r, t);
+            context.arcTo(l + w, t, l + w, t + h, r);
+            context.arcTo(l + w, t + h, l, t + h, r);
+            context.lineTo(l + w - r, t + h);
+            context.lineTo(l + r, t + h);
+            context.lineTo(l, t + h / 2);
+            //context.arcTo(l, t + h, l, t, r);
+            //context.arcTo(l, t, l + w, t, r);
+            context.closePath();
+            context.fillStyle = bcolor;
+            context.fill();
+            context.stroke();
+            break;
+        }
+        case 8:{    
+            //绘制连接框
+            //计算宽高
+            var l = x1, t = y1;
+            var w = x2 - x1, h = y2 - y1;
+            if (w < 0)
+            {
+                l = x2;
+                w = x1 - x2;
+            }               
+            if (h < 0){
+                t = y2;
+                h = y1 - y2;
+            }
+            context.strokeStyle = color;
+            context.lineWidth = size;
+            context.beginPath();
+            context.arc(l + w / 2, t + h / 2, Math.min(w, h), 0, 360);
+            context.closePath();
+            context.fillStyle = bcolor;
+            context.fill();
+            context.stroke();
+            break;
+        }
+    }
+}
+
+//计算当前字体下的文本宽度
+function getFontWidth(context, txt) {
+    const metrics = context.measureText(txt);
+    const actual = Math.abs(metrics.actualBoundingBoxLeft ?? 0) + Math.abs(metrics.actualBoundingBoxRight ?? 0);
+    const width = Math.max(metrics.width, actual);
+    return width;
+}
+//计算当前字体下的文本高度
+function getFontHeight(context, txt) {
+    const metrics = context.measureText(txt);
+    const fontHeight = metrics.fontBoundingBoxAscent + metrics.fontBoundingBoxDescent;
+    //所有字在这个字体下的高度
+    //const actualHeight = metrics.actualBoundingBoxAscent + metrics.actualBoundingBoxDescent;
+    return fontHeight;
+}
+//自动调整字体大小
+function updateFont(context, w, h, text, size){
+    context.font = size + "pt SimSun";
+    w1 = getFontWidth(context, text) * 2;
+    h1 = getFontHeight(context, text) * 2;
+    var s = size;
+    while (w1 > w || h1 > h){
+        s = s - 1;
+        context.font = s + "pt SimSun";
+        w1 = getFontWidth(context, text) * 2;
+        h1 = getFontHeight(context, text) * 2;
+    }
+    return s;
+}