在arbor.js中为边添加标签(查询插件)

Question

如何在arbor.js中为边添加标签这是一个图形可视化库.

假设A和B是节点而E是边缘.一种粗略的方式是插入"文本节点"T并加入AT和TB

但我不想这样,还有其他方法吗？

这是示例代码

var theUI = {
  nodes:{A:{color:"red", shape:"dot", alpha:1}, 
      B:{color:"#b2b19d", shape:"dot", alpha:1}, 
      C:{color:"#b2b19d", shape:"dot", alpha:1}, 
      D:{color:"#b2b19d", shape:"dot", alpha:1},
  },
  edges:{
      A:{
          B:{length:.8},
          C:{length:.8},
          D:{length:.8}
           }
  }
}

var sys = arbor.ParticleSystem()
sys.parameters({stiffness:900, repulsion:2000, gravity:true, dt:0.015})
sys.renderer = Renderer("#sitemap")
sys.graft(theUI) 

在此,A连接到B,C和D.如何为边缘提供标签？

Answer 1

arbor.js允许您编写代码来呈现整个图形.您可以在渲染方法中执行任何操作,包括绘制可以存储在单独地图中的边标题.

只需在Renderer中以这种方式覆盖方法:

redraw:function()
{
    ctx.fillStyle = "white";
    ctx.fillRect (0,0, canvas.width, canvas.height);

    particleSystem.eachEdge (function (edge, pt1, pt2)
    {
        ctx.strokeStyle = "rgba(0,0,0, .333)";
        ctx.lineWidth = 1;
        ctx.beginPath ();
        ctx.moveTo (pt1.x, pt1.y);
        ctx.lineTo (pt2.x, pt2.y);
        ctx.stroke ();

        ctx.fillStyle = "black";
        ctx.font = 'italic 13px sans-serif';
        ctx.fillText (edge.data.name, (pt1.x + pt2.x) / 2, (pt1.y + pt2.y) / 2);

    });

    particleSystem.eachNode (function (node, pt)
    {
        var w = 10;
        ctx.fillStyle = "orange";
        ctx.fillRect (pt.x-w/2, pt.y-w/2, w,w);
        ctx.fillStyle = "black";
        ctx.font = 'italic 13px sans-serif';
        ctx.fillText (node.name, pt.x+8, pt.y+8);
    });       
   };

此代码期望在初始化时填充每个边的数据属性.

我使用自定义地图和方法addNode/addEdge手动创建所有节点和边缘,我想你可以改变一点代码来用这种方式用自定义数据初始化边:

var theUI = {
  nodes:{A:{color:"red", shape:"dot", alpha:1}, 
      B:{color:"#b2b19d", shape:"dot", alpha:1}, 
      C:{color:"#b2b19d", shape:"dot", alpha:1}, 
      D:{color:"#b2b19d", shape:"dot", alpha:1},
  },
  edges:{
      A:{
          B:{length:.8, data:{name:"A->B"}},
          C:{length:.8, data:{name:"A->C"}},
          D:{length:.8, data:{name:"A->D"}}
           }
  }
}

PS:看看这个例子,我从中学到了很多东西.