连接画布与线 [英] Connect canvas with lines

问题描述

我需要连接两个画布与一行来创建动态工作流。

我将生成画布矩形动态（我在数据库中的步骤数量）

解决方案

div>

以下是如何使用自动连接两个可拖动的画布矩形

首先，定义一些框和连接符：

 将被绘制的框
 var boxes = []; 
 boxes.push（{x：50，y：25，w：75，h：50}）; // x，y，width，height 
 boxes.push（{x：200，y：100，w：50，h：50}）; 
 
 //在任何框之间定义任何连接器
 var connectors = []; 
 connectors.push（{box1：0，box2：1}）; 
  

绘制框并自动绘制其连接符：

 函数draw（）{
 
 //清除画布
 ctx.clearRect（0,0，canvas.width，canvas.height） ; 
 
 for（var i = 0; i  var box = boxes [i]; 
 ctx.fillRect（box.x，box.y，box.w，box.h）; 
} 
 for（var i = 0; i< connectors.length; i ++）{
 var connector = connectors [i]; 
 var box1 = boxes [connector.box1]; 
 var box2 = boxes [connector.box2]; 
 ctx.beginPath（）; 
 ctx.moveTo（box1.x + box1.w / 2，box1.y + box1.h / 2）; 
 ctx.lineTo（box2.x + box2.w / 2，box2.y + box2.h / 2）; 
 ctx.stroke（）; 
} 
 
} 
  

下面的代码允许任何框

这里是代码和小提琴： http://jsfiddle.net/m1erickson/GX6HS/

 <！doctype html& 
< html> 
< head> 
< link rel =stylesheettype =text / cssmedia =allhref =css / reset.css/> <！ -  reset css  - > 
< script type =text / javascriptsrc =http://code.jquery.com/jquery.min.js>< / script> 
 
< style> 
 body {background-color：ivory; padding：20px;} 
 #canvas {border：1px solid red;} 
< / style> 
 
< script> 
 $（function（）{
 
 var canvas = document.getElementById（canvas）; 
 var ctx = canvas.getContext（2d）; 
 
 var canvasOffset = $（＃canvas）。offset（）; 
 var offsetX = canvasOffset.left; 
 var offsetY = canvasOffset.top; 
 
 var startX; 
 var startY; 
 var isDown = false; 
 var dragTarget; 
 
 var boxes = []; 
 boxes.push（{x： 50，y：25，w：75，h：50}）; // x，y，width，height 
 boxes.push（{x：200，y：100，w：50，h：50} ）; 
 
 
 var connectors = []; 
 connectors.push（{box1：0，box2：1}）; 
 
 draw ; 
 
 function draw（）{
 
 //清除画布
 ctx.clearRect（0,0，canvas.width，canvas.height）; 
 
 for（var i = 0; i  var box = boxes [i]; 
 ctx.fillRect（box.x，box.y， box.w，box.h）; 
} 
 for（var i = 0; i< connectors.length; i ++）{
 var connector = connectors [i]; 
 var box1 = boxes [connector.box1]; 
 var box2 = boxes [connector.box2]; 
 ctx.beginPath（）; 
 ctx.moveTo（box1.x + box1.w / 2，box1.y + box1.h / 2）; 
 ctx.lineTo（box2.x + box2.w / 2，box2.y + box2.h / 2）; 
 ctx.stroke（）; 
} 
 
} 
 
 function hit（x，y）{
 for（var i = 0; i  var box = boxes [i]; 
 if（x> = box.x&& x< = box.x + box.w&& y> = box.y&& y< = box.y + box.h ）{
 dragTarget = box; 
 return（true）; 
} 
} 
 return（false）; 
} 
 
 function handleMouseDown（e）{
 startX = parseInt（e.clientX-offsetX）; 
 startY = parseInt（e.clientY-offsetY）; 
 
 //把你的mousedown东西放在这里
 isDown = hit（startX，startY）; 
} 
 
 function handleMouseUp（e）{
 //将鼠标放在这里
 dragTarget = null; 
 isDown = false; 
} 
 
 function handleMouseOut（e）{
 handleMouseUp（e）; 
} 
 
函数handleMouseMove（e）{
 if（！isDown）{return;} 
 
 mouseX = parseInt（e.clientX-offsetX） ; 
 mouseY = parseInt（e.clientY-offsetY）; 
 
 //把你的mousemove东西放在这里
 var dx = mouseX-startX; 
 var dy = mouseY-startY; 
 startX = mouseX; 
 startY = mouseY; 
 dragTarget.x + = dx; 
 dragTarget.y + = dy; 
 draw（）; 
} 
 
 $（＃canvas）。mousedown（function（e）{handleMouseDown（e）;}）; 
 $（＃canvas）。mousemove（function（e）{handleMouseMove（e）;}）; 
 $（＃canvas）mouseup（function（e）{handleMouseUp（e）;}）; 
 $（＃canvas）mouseout（function（e）{handleMouseOut（e）;}）; 
 
}）; // end $（function（）{}）; 
< / script> 
 
< / head> 
 
< body> 
< p>拖动框 - 它们保持连接状态< / p> 
< canvas id =canvaswidth = 300 height = 300>< / canvas> 
< / body> 
< / html> 
  

I need to connect two canvas with a line to create a dynamic workflow.

I'll generate the canvas rectangle dynamic (amount of steps I have at DB) but I need to connect the steps with lines.

Anybody have some ideas?

解决方案

Here’s how to automatically connect 2 draggable canvas rectangles with a line

First, define some boxes and connectors:

    // define any boxes that will be drawn
    var boxes=[];
    boxes.push({x:50,y:25,w:75,h:50});    // x,y,width,height
    boxes.push({x:200,y:100,w:50,h:50});

    // define any connectors between any boxes
    var connectors=[];
    connectors.push({box1:0,box2:1});

Draw the boxes and automatically draw their connectors:

    function draw(){

        // clear the canvas
        ctx.clearRect(0,0,canvas.width,canvas.height);

        for(var i=0;i<boxes.length;i++){
            var box=boxes[i];
            ctx.fillRect(box.x,box.y,box.w,box.h);
        }
        for(var i=0;i<connectors.length;i++){
            var connector=connectors[i];
            var box1=boxes[connector.box1];
            var box2=boxes[connector.box2];
            ctx.beginPath();
            ctx.moveTo(box1.x+box1.w/2,box1.y+box1.h/2);
            ctx.lineTo(box2.x+box2.w/2,box2.y+box2.h/2);
            ctx.stroke();
        }

    }

The code below allows any box to be dragged and remain connected.

Here is code and a Fiddle: http://jsfiddle.net/m1erickson/GX6HS/

<!doctype html>
<html>
<head>
<link rel="stylesheet" type="text/css" media="all" href="css/reset.css" /> <!-- reset css -->
<script type="text/javascript" src="http://code.jquery.com/jquery.min.js"></script>

<style>
    body{ background-color: ivory; padding:20px;}
    #canvas{border:1px solid red;}
</style>

<script>
$(function(){

    var canvas=document.getElementById("canvas");
    var ctx=canvas.getContext("2d");

    var canvasOffset=$("#canvas").offset();
    var offsetX=canvasOffset.left;
    var offsetY=canvasOffset.top;

    var startX;
    var startY;
    var isDown=false;
    var dragTarget;

    var boxes=[];
    boxes.push({x:50,y:25,w:75,h:50});    // x,y,width,height
    boxes.push({x:200,y:100,w:50,h:50});


    var connectors=[];
    connectors.push({box1:0,box2:1});

    draw();

    function draw(){

        // clear the canvas
        ctx.clearRect(0,0,canvas.width,canvas.height);

        for(var i=0;i<boxes.length;i++){
            var box=boxes[i];
            ctx.fillRect(box.x,box.y,box.w,box.h);
        }
        for(var i=0;i<connectors.length;i++){
            var connector=connectors[i];
            var box1=boxes[connector.box1];
            var box2=boxes[connector.box2];
            ctx.beginPath();
            ctx.moveTo(box1.x+box1.w/2,box1.y+box1.h/2);
            ctx.lineTo(box2.x+box2.w/2,box2.y+box2.h/2);
            ctx.stroke();
        }

    }

    function hit(x,y){
        for(var i=0;i<boxes.length;i++){
            var box=boxes[i];
            if(x>=box.x && x<=box.x+box.w && y>=box.y && y<=box.y+box.h){
                dragTarget=box;
                return(true);
            }
        }
        return(false);
    }

    function handleMouseDown(e){
      startX=parseInt(e.clientX-offsetX);
      startY=parseInt(e.clientY-offsetY);

      // Put your mousedown stuff here
      isDown=hit(startX,startY);
    }

    function handleMouseUp(e){
      // Put your mouseup stuff here
      dragTarget=null;
      isDown=false;
    }

    function handleMouseOut(e){
        handleMouseUp(e);
    }

    function handleMouseMove(e){
      if(!isDown){return;}

      mouseX=parseInt(e.clientX-offsetX);
      mouseY=parseInt(e.clientY-offsetY);

      // Put your mousemove stuff here
      var dx=mouseX-startX;
      var dy=mouseY-startY;
      startX=mouseX;
      startY=mouseY;
      dragTarget.x+=dx;
      dragTarget.y+=dy;
      draw();
    }

    $("#canvas").mousedown(function(e){handleMouseDown(e);});
    $("#canvas").mousemove(function(e){handleMouseMove(e);});
    $("#canvas").mouseup(function(e){handleMouseUp(e);});
    $("#canvas").mouseout(function(e){handleMouseOut(e);});

}); // end $(function(){});
</script>

</head>

<body>
    <p>Drag boxes--they remain connected</p>
    <canvas id="canvas" width=300 height=300></canvas>
</body>
</html>

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