如何停止d3力图布局模拟？

Question

一旦d3.layout.force().... start()在D3中强制布局模拟,它就会继续运行一个活动事件.

我想设置5秒的超时让图形强制布局模拟成形并停止(调用.stop()或alpha(0).这可以停止,但是一旦我拖动一个节点,模拟就会重新开始.

下面的代码,也可以从jsfiddle轻松测试,在最后一行显示stop()将被发出并且模拟立即停止,但是一旦拖动任何节点,模拟将再次开始.我认为这在力量拖拽中是硬编码的.有没有办法禁用/取消注册？

var svgContainer = d3.select("#svgContainer");

var element0a = svgContainer.append("g").attr("class","node").attr("transform","translate(100,100)");
var element0b = element0a.append("rect").attr("x",0).attr("y",0).attr("width",20).attr("height",10).attr("fill","red");

var element1a = svgContainer.append("g").attr("class","node").attr("transform","translate(100,200)");
var element1b = element1a.append("rect").attr("x",0).attr("y",0).attr("width",20).attr("height",10).attr("fill","green");

var element2a = svgContainer.append("g").attr("class","node").attr("transform","translate(100,300)");
var element2b = element2a.append("rect").attr("x",0).attr("y",0).attr("width",20).attr("height",10).attr("fill","blue");

var nodeArray = new Array();
nodeArray[0] = { id : "000", label : "label 000", ui : element0a };
nodeArray[1] = { id : "001", label : "label 001", ui : element1a };
nodeArray[2] = { id : "002", label : "label 002", ui : element2a };

var linkArray = new Array();

var force = self.force = d3.layout.force()
    .nodes(nodeArray)
    .links(linkArray)
    .gravity(.05)
    .distance(80)
    .charge(-100)
    .size([600, 600])
    .start();

var node = svgContainer.selectAll("g.node")
    .data(nodeArray)
    .call(force.drag);


force.on("tick", function() {
      node.attr("transform", function(d) {return "translate(" + d.x + "," + d.y + ")";});
    });

// HERE !!!! Without the stop() the simulation goes fine. With the stop() the simulation will immediately stop, but will continue as soon as you drap something. I want the simulation to never start again. 

force.stop();

这是示例的屏幕截图:

Answer 1

在内部拖动节点时调用的函数中重新启动模拟.但是,您可以覆盖此行为.事件名称为"drag.force",您可以通过它访问它force.drag.您可以直接修改坐标而不是重新启动模拟,而不是通常的行为:

var node...
  .call(force.drag().on("drag.force", function() {
    d3.select(this).attr("transform", "translate(" + d3.event.x + "," + d3.event.y + ")");
  }));

这对应于正常的拖动行为.在执行此操作之前,建议停止模拟以防止拖动事件和强制嘀嗒声干扰.只需force.stop()在修改后的事件处理程序的开头调用即可.

最后,您需要重置拖动事件的原点,否则当您再次拖动时,您会注意到拖动的元素会"跳回"到原始位置.这与修改事件处理程序的方式类似.您只需获取当前转换并以预期格式返回坐标.

var node...
  .call(force.drag().origin(function() {
    var t = d3.transform(d3.select(this).attr("transform")).translate;
    return {x: t[0], y: t[1]};
  }));

完整的代码在这里更新的jsfiddle中.