悬停时修改行/工具提示

Question

我正在玩D3.js我正在尝试做两件事：

1. 在悬停线条时，我想对线条应用样式(颜色为浅蓝色或其他颜色(。它可以转到父节点或最高级别的父节点，任何一个都会对我有很大帮助。如果您知道如何同时做到这两点，请分享！
2. 在每个节点的文本上悬停时，我想在 JSON 数据中显示"test"属性的工具提示。

我

以前弄乱了工具提示，但在这种情况下，我不确定将,on("mouseover"事件处理程序放在哪里。这也是我第一次测试d3.tree选项。

var margin = {top: 20, right: 120, bottom: 20, left: 120},
    width = 960 - margin.right - margin.left,
    height = 800 - margin.top - margin.bottom;
    
var i = 0,
    duration = 750,
    root;
var tree = d3.layout.tree()
    .size([height, width]);
var diagonal = d3.svg.diagonal()
    .projection(function(d) { return [d.y, d.x]; });
var svg = d3.select("body").append("svg")
    .attr("width", width + margin.right + margin.left)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");
  var root={                      //json var root
        "name": "flare",
          "test": "blue",
            "children": [{
            "name": "analytics",
                "test": "red",
                "children": [{
                "name": "cluster",
                    "test": "green",
                    "children": [{
                    "name": "AgglomerativeCluster",
                        "test": "blue",
                    "size": 3938
                }, {
                    "name": "CommunityStructure",
                    "test": "yellow",
                    "size": 3812
                }, {
                    "name": "HierarchicalCluster",
                    "test": "orange",
                    "size": 6714
                }, {
                    "name": "MergeEdge",
                    "test": "someColor",
                    "size": 743
                }]
            }, {
                "name": "graph",
                "test": "someColor",
                    "children": [{
                    "name": "BetweennessCentrality",
                        "test": "someColor",
                    "size": 3534
                }, {
                    "name": "LinkDistance",
                    "test": "someColor",
                    "size": 5731
                }, {
                    "name": "MaxFlowMinCut",
                    "size": 7840
                }, {
                    "name": "ShortestPaths",
                    "test": "someColor",
                    "size": 5914
                }, {
                    "name": "SpanningTree",
                    "test": "someColor",
                    "size": 3416
                }]
            }, {
                "name": "optimization",
                "test": "someColor",
                    "children": [{
                    "name": "AspectRatioBanker",
                        "test": "someColor",
                    "size": 7074
                }]
            }]
        }, {
            "name": "animate",
            "test": "someColor",
                "children": [{
                "name": "interpolate",
                    "test": "someColor",
                    "children": [{
                    "name": "ArrayInterpolator",
                        "test": "someColor",
                    "size": 1983
                }, {
                    "name": "ColorInterpolator",
                    "test": "someColor",
                    "size": 2047
                }, {
                    "name": "DateInterpolator",
                    "test": "someColor",
                    "size": 1375
                }, {
                    "name": "Interpolator",
                    "test": "someColor",
                    "size": 8746
                }, {
                    "name": "MatrixInterpolator",
                    "test": "someColor",
                    "size": 2202
                }, {
                    "name": "NumberInterpolator",
                    "test": "someColor",
                    "size": 1382
                }, {
                    "name": "ObjectInterpolator",
                    "test": "someColor",
                    "size": 1629
                }, {
                    "name": "PointInterpolator",
                    "test": "someColor",
                    "size": 1675
                }, {
                    "name": "RectangleInterpolator",
                    "test": "someColor",
                    "size": 2042
                }]
            }, {
                "name": "ISchedulable",
                "test": "someColor",
                "size": 1041
            }, {
                "name": "Parallel",
                "test": "someColor",
                "size": 5176
            }, {
                "name": "Pause",
                "test": "someColor",
                "size": 449
            }, {
                "name": "Scheduler",
                "test": "someColor",
                "size": 5593
            }, {
                "name": "Sequence",
                "test": "someColor",
                "size": 5534
            }, {
                "name": "Transition",
                "test": "someColor",
                "size": 9201
            }, {
                "name": "Transitioner",
                "test": "someColor",
                "size": 19975
            }, {
                "name": "TransitionEvent",
                "test": "someColor",
                "size": 1116
            }, {
                "name": "Tween",
                "test": "someColor",
                "size": 6006
            }]
        }, {
            "name": "data",
             "test": "someColor",
            "size": 4322
        }]
    } ;
  root.x0 = height / 2;
  root.y0 = 0;
  function collapse(d) {
    if (d.children) {
      d._children = d.children;
      d._children.forEach(collapse);
      d.children = null;
    }
  }
  root.children.forEach(collapse);
  update(root);
d3.select(self.frameElement).style("height", "800px");
function update(source) {
  // Compute the new tree layout.
  var nodes = tree.nodes(root).reverse(),
      links = tree.links(nodes);
  // Normalize for fixed-depth.
  nodes.forEach(function(d) { d.y = d.depth * 180; });
  // Update the nodes…
  var node = svg.selectAll("g.node")
      .data(nodes, function(d) { return d.id || (d.id = ++i); });
  // Enter any new nodes at the parent's previous position.
  var nodeEnter = node.enter().append("g")
      .attr("class", "node")
      .attr("transform", function(d) { return "translate(" + source.y0 + "," + source.x0 + ")"; })
      .on("click", click);
  nodeEnter.append("circle")
      .attr("r", 1e-6)
      .style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
  nodeEnter.append("text")
      .attr("x", function(d) { return d.children || d._children ? -10 : 10; })
      .attr("dy", ".35em")
      .attr("text-anchor", function(d) { return d.children || d._children ? "end" : "start"; })
      .text(function(d) { return d.name; })
      .style("fill-opacity", 1e-6);
  // Transition nodes to their new position.
  var nodeUpdate = node.transition()
      .duration(duration)
      .attr("transform", function(d) { return "translate(" + d.y + "," + d.x + ")"; });
  nodeUpdate.select("circle")
      .attr("r", 4.5)
      .style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
  nodeUpdate.select("text")
      .style("fill-opacity", 1);
  // Transition exiting nodes to the parent's new position.
  var nodeExit = node.exit().transition()
      .duration(duration)
      .attr("transform", function(d) { return "translate(" + source.y + "," + source.x + ")"; })
      .remove();
  nodeExit.select("circle")
      .attr("r", 1e-6);
  nodeExit.select("text")
      .style("fill-opacity", 1e-6);
  // Update the links…
  var link = svg.selectAll("path.link")
      .data(links, function(d) { return d.target.id; });
  // Enter any new links at the parent's previous position.
  link.enter().insert("path", "g")
      .attr("class", "link")
      .attr("d", function(d) {
        var o = {x: source.x0, y: source.y0};
        return diagonal({source: o, target: o});
      });
  // Transition links to their new position.
  link.transition()
      .duration(duration)
      .attr("d", diagonal);
  // Transition exiting nodes to the parent's new position.
  link.exit().transition()
      .duration(duration)
      .attr("d", function(d) {
        var o = {x: source.x, y: source.y};
        return diagonal({source: o, target: o});
      })
      .remove();
  // Stash the old positions for transition.
  nodes.forEach(function(d) {
    d.x0 = d.x;
    d.y0 = d.y;
  });
}
// Toggle children on click.
function click(d) {
  if (d.children) {
    d._children = d.children;
    d.children = null;
  } else {
    d.children = d._children;
    d._children = null;
  }
  update(d);
}
      

.node {
  cursor: pointer;
}
.node circle {
  fill: #fff;
  stroke: steelblue;
  stroke-width: 1.5px;
}
.node text {
  font: 10px sans-serif;
}
.link {
  fill: none;
  stroke: #ccc;
  stroke-width: 1.5px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>

Answer 1

首先，您可以使用简单的CSS悬停来更改行(链接(的颜色，如下所示：

.link:hover {
    stroke:blue;
}

这将使鼠标悬停或悬停时链接变为蓝色。

---

其次，添加工具提示稍微复杂一些。一种方法是在页面上设置一个隐藏的<div>，该变得可见并移动到您正在悬停的<text>。然后，当您将鼠标悬停时，它将被隐藏。为此，请添加以下内容：

nodeEnter.on("mouseover", function (d) {
    var r = d3.select(this).node().getBoundingClientRect();
    d3.select("div#tooltip")
        .style("display", "inline")
        .style("top", (r.top-25) + "px")
        .style("left", r.left + "px")
        .style("position", "absolute")
        .text(d.test);
})
.on("mouseout", function(){
    d3.select("div#tooltip").style("display", "none")
});

这要求您将<div id="tooltip" style="display:none"></div>添加到 HTML 页面。为了使工具提示看起来更像工具提示，请使用以下CSS(我相信你可以谷歌搜索并获得更好的样式(：

div#tooltip{
    color:#ffffff;
    background:#000000;
    opacity:1;
    padding:5px;
}

我在这个小提琴中编译了这个例子。