D3.js - 在 TreeLayout 中单击连接节点的链接时添加一个按钮答案

【问题标题】：D3.js - add a button on click of a link connecting nodes in a TreeLayoutD3.js - 在 TreeLayout 中单击连接节点的链接时添加一个按钮
【发布时间】：2020-09-04 09:37:57
【问题描述】：

我正在寻找一种将按钮添加到 D3 中 TreeLayout 中连接节点的链接的方法。单击此按钮时，我必须在其下方添加另一个菱形/矩形节点。下图只是一个 UX 可视化。该示例可以是 D3 中的简单树形布局。

示例 D3 树布局：

var jsonData = getData();

var margin = {
    top: 20,
    right: 120,
    bottom: 20,
    left: 120
  },
  width = 960 - margin.right - margin.left,
  height = 500 - 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 + ")");

root = jsonData;
root.x0 = height / 2;
root.y0 = 0;

update(root);

//svg.style("height", "500px");

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)
    .attr('stroke', function(d) {
      return d.color ? d.color : 'blue';
    })
    .style("fill", function(d) {
      return d._children ? "#ccc" : "#fff";
    });

  nodeEnter.append("text")
    .attr("x", function(d) {
      return d.children || d._children ? -13 : 13;
    })
    .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", 10)
    .style("fill", function(d) {
      var collapseColor = d.color ? d.color : '#ccc';
      return d._children ? collapseColor : "#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);
}


function getData() {
  return {
    "name": "js",
    "parent": "null",
    "color": "green",
    "children": [{
        "name": "frameworks",
        "parent": "js",
        "color": "red",
        "children": [{
            "name": "Angular",
            "parent": "frameworks",
            "color": "red",
            "size": 75
          },
          {
            "name": "Backbone",
            "parent": "frameworks",
            "color": "red",
            "size": 15
          },
          {
            "name": "Ember",
            "parent": "frameworks",
            "color": "red",
            "size": 5
          },
          {
            "name": "Aurelia",
            "parent": "frameworks",
            "color": "red",
            "size": 5
          }
        ]
      },
      {
        "name": "libraries",
        "parent": "js",
        "color": "blue",
        "children": [{
            "name": "jQuery",
            "parent": "libraries",
            "size": 70
          },
          {
            "name": "YUI",
            "parent": "libraries",
            "size": 30
          },
          {
            "name": "Dojo",
            "parent": "libraries",
            "size": 10
          },
          {
            "name": "Prototype",
            "parent": "libraries",
            "size": 15
          },
          {
            "name": "MooTools",
            "parent": "libraries",
            "size": 5
          },
          {
            "name": "ExtJS",
            "parent": "libraries",
            "size": 5
          }
        ]
      }
    ]
  };
};

.node {
  cursor: pointer;
}

.node circle {
  fill: #fff;
  stroke-width: 3px;
}

.node text {
  font: 12px sans-serif;
}

.link {
  fill: none;
  stroke: #ccc;
  stroke-width: 2px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.17/d3.min.js"></script>
<div class="tree-diagram"></div>

当用户单击（或悬停？）任何链接时，应显示“+”按钮。我想出了绘制 + 的 SVG 路径。

<svg height="400" width="450">
  <path d= "M0 6 H12 M6 0 V12" stroke="blue" stroke-width="1.5" />
</svg>

但我不知道需要做什么才能将其转换为按钮并将其附加到链接并使其可点击。

【问题讨论】：

标签： javascript flowchart d3.js

【解决方案1】：

我将按钮添加到您的示例中，但尚未使其执行任何操作。只是，只要将鼠标悬停在链接上，该按钮就会显示在该链接的中间，当您单击它时，它会记录到控制台。

现在，您将来可能会想要一些东西：

Increase the hitbox的链接，方便使用；
通过写入全局变量clickedLink 或通过在链接的on('mouseenter') 内重新分配on('click', ...) 了解单击了哪个链接；
通过添加新节点并在整个数据集（简单，但计算量大）或源节点及其子节点上调用 update 来更改数据对象。

var jsonData = getData();

var margin = {
    top: 20,
    right: 120,
    bottom: 20,
    left: 120
  },
  width = 960 - margin.right - margin.left,
  height = 500 - 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 + ")");

// New part
var plusButton = svg
  .append('g')
  .classed('button', true)
  .classed('hide', true)
  .on('click', function() {
    console.log("CLICKED");
  });

plusButton
  .append('rect')
  .attr('transform', 'translate(-8, -8)') // center the button inside the `g`
  .attr('width', 16)
  .attr('height', 16)
  .attr('rx', 2);

plusButton
  .append('path')
  .attr('d', 'M-6 0 H6 M0 -6 V6');

root = jsonData;
root.x0 = height / 2;
root.y0 = 0;

update(root);

//svg.style("height", "500px");

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)
    .attr('stroke', function(d) {
      return d.color ? d.color : 'blue';
    })
    .style("fill", function(d) {
      return d._children ? "#ccc" : "#fff";
    });

  nodeEnter.append("text")
    .attr("x", function(d) {
      return d.children || d._children ? -13 : 13;
    })
    .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", 10)
    .style("fill", function(d) {
      var collapseColor = d.color ? d.color : '#ccc';
      return d._children ? collapseColor : "#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
      });
    })
    // New part
    .on('mouseenter', function(d, i) {
      // Use the native SVG interface to get the bounding box to
      // calculate the center of the path
      var bbox = this.getBBox();
      var x = bbox.x + bbox.width/2,
        y = bbox.y + bbox.height/2;
      plusButton
        .attr('transform', 'translate(' + x + ', ' + y + ')')
        .classed('hide', false);
    })
    .on('mouseleave', function(d, i) {
      plusButton
        .classed('hide', true);
    });

  // 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);
}


function getData() {
  return {
    "name": "js",
    "parent": "null",
    "color": "green",
    "children": [{
        "name": "frameworks",
        "parent": "js",
        "color": "red",
        "children": [{
            "name": "Angular",
            "parent": "frameworks",
            "color": "red",
            "size": 75
          },
          {
            "name": "Backbone",
            "parent": "frameworks",
            "color": "red",
            "size": 15
          },
          {
            "name": "Ember",
            "parent": "frameworks",
            "color": "red",
            "size": 5
          },
          {
            "name": "Aurelia",
            "parent": "frameworks",
            "color": "red",
            "size": 5
          }
        ]
      },
      {
        "name": "libraries",
        "parent": "js",
        "color": "blue",
        "children": [{
            "name": "jQuery",
            "parent": "libraries",
            "size": 70
          },
          {
            "name": "YUI",
            "parent": "libraries",
            "size": 30
          },
          {
            "name": "Dojo",
            "parent": "libraries",
            "size": 10
          },
          {
            "name": "Prototype",
            "parent": "libraries",
            "size": 15
          },
          {
            "name": "MooTools",
            "parent": "libraries",
            "size": 5
          },
          {
            "name": "ExtJS",
            "parent": "libraries",
            "size": 5
          }
        ]
      }
    ]
  };
};

.node {
  cursor: pointer;
}

.node circle {
  fill: #fff;
  stroke-width: 3px;
}

.node text {
  font: 12px sans-serif;
}

.link {
  fill: none;
  stroke: #ccc;
  stroke-width: 2px;
}


/* New part */
.button > path {
  stroke: blue;
  stroke-width: 1.5;
}

.button > rect {
  fill: #ddd;
  stroke: grey;
  stroke-width: 1px;
}


.hide {
  opacity: 0 !important;
  pointer-events: none;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.17/d3.min.js"></script>
<div class="tree-diagram"></div>

【讨论】：