javascript - 如何获取或设置节点的 x, y 位置

Question

我尝试使用以下代码来获取 Vivagraph.js 中节点的位置。不知道为什么它返回未定义。

当我 console.dir(node) 时，我确实看到正在设置一个位置，但由于某种原因我无法访问它。

var layout = Viva.Graph.Layout.forceDirected(graph, {
   springLength : 20,
   springCoeff : 0.0008,
   dragCoeff : 0.1,
   gravity : -10,
   theta : 0.5
});

var graphics = Viva.Graph.View.webglGraphics();
var nodeSize = 10;

graphics.setNodeProgram(Viva.Graph.View.webglImageNodeProgram());

graphics.node(function(node) {
    //url location on your server
    var ui = Viva.Graph.View.webglImage(nodeSize, 'https://lh4.googleusercontent.com/' + node.data);
    console.dir(ui);
    return ui;
}).link(function(link) {
       return Viva.Graph.View.webglLine(colors[(Math.random() * colors.length) << 0]);
   });

graph.forEachNode(function(node) { 
    console.log('pos ' + node.position); 
});

Answer 1

根据文档HERE ，node.position 不再是有效的属性。请改用 layout.getNodePosition(node.id)。

引用文档(以防链接中断):

position attribute is moved out from the node object into layout provider.

Why? Having shared node position makes impossible rendering of the same graph by two different layouters.

v.0.4.*

// each node object has "position" on it:
graph.forEachNode(function (node) {
  var position = node.position;
  position.x += 1; // move by one pixel
});

v.0.5.*

// "position" is now part of layouter:
graph.forEachNode(function (node) {
  // layout here is instance of Viva.Graph.Layout.forceDirected or Viva.Graph.Layout.constant:
  var position = layout.getNodePosition(node.id);
  position.x += 1; 
});