How to get coordinates of an svg element?
I am using d3 to draw a line from a relative svg position and hence want to access the coordinates of the element itself. I tried something like this (where "this" refers to the element)
.attr("x1", this.x)
.attr("y1", this.y)
but the x1 and y1 just defaults to zero. What is the correct way to get the coordinates of the svg element?
EDIT:
Here's my (by request) my whole code. I'm trying to implement this on the collapsible tree, where I draw a line when I hover with the mouse over a circle node. The starting point of the line should be from the circle I click on and the ending point should be a fixed point on the svg plane.
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
<script type="text/javascript" src="d3.v3.js"></script>
<script type="text/javascript" src="d3.layout.js"></script>
<style type="text/css">
.node circle {
cursor: pointer;
fill: #fff;
stroke: steelblue;
stroke-width: 1.5px;
}
.node text {
font: 10px sans-serif;
}
path.link {
fill: none;
stroke: #ccc;
stroke-width: 1.5px;
}
</style>
</head>
<body>
<div id="chart"></div>
<script type="text/javascript">
var m = [20, 120, 20, 120],
w = 2240 - m[1] - m[3],
h = 800 - m[0] - m[2],
i = 0,
duration = 500,
root;
var tree = d3.layout.tree()
.size([h, w]);
var diagonal = d3.svg.diagonal()
.projection(function(d) { return [d.y, d.x]; });
var vis = d3.select("#chart").append("svg")
.attr("width", w + m[1] + m[3])
.attr("height", h + m[0] + m[2])
.append("g")
.attr("transform", "translate(" + m[3] + "," + m[0] + ")");
function loadData(json) {
root = json;
d3.select("#processName").html(root.text);
root.x0 = h / 2;
root.y0 = 0;
root.children.forEach(collapse);
update(root);
}
function collapse(d) {
if (d.children) {
d._children = d.children;
d._children.forEach(collapse);
d.children = null;
}
};
// 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 update(source) {
// Compute the new tree layout.
var nodes = tree.nodes(root).reverse();
// Normalize for fixed-depth.
nodes.forEach(function(d) { d.y = d.depth * 180; });
// Update the nodes…
var node = vis.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"; })
.on('mouseover', function(d, i){
var dataset = [1,2,3,4] // HERE
vis.selectAll("line") // HERE
.data(dataset) // HERE
.enter() // HERE
.append("line") // HERE
.attr("x1", this.x) // HERE'S THE PROBLEM FOR PERRY
.attr("y1", this.y) // HERE'S THE PROBLEM FOR PERRY
.attr("x2", 500) // HERE
.attr("y2", 500) // HERE
.style("stroke", "rgb(6,120,155)");} // HERE
);
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 = vis.selectAll("path.link")
.data(tree.links(nodes), 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()
.duration(duration)
.attr("d", diagonal);
// 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;
});
};
loadData({
"name": "flare",
"children": [
{
"name": "analytics",
"children": [
{
"name": "cluster",
"children": [
{"name": "AgglomerativeCluster", "size": 3938},
{"name": "CommunityStructure", "size": 3812},
{"name": "HierarchicalCluster", "size": 6714},
{"name": "MergeEdge", "size": 743}
]
},
{
"name": "graph",
"children": [
{"name": "BetweennessCentrality", "size": 3534},
{"name": "LinkDistance", "size": 5731},
{"name": "MaxFlowMinCut", "size": 7840},
{"name": "ShortestPaths", "size": 5914},
{"name": "SpanningTree", "size": 3416}
]
},
{
"name": "optimization",
"children": [
{"name": "AspectRatioBanker", "size": 7074}
]
}
]
},
{
"name": "animate",
"children": [
{"name": "Easing", "size": 17010},
{"name": "FunctionSequence", "size": 5842},
{
"name": "interpolate",
"children": [
{"name": "ArrayInterpolator", "size": 1983},
{"name": "ColorInterpolator", "size": 2047},
{"name": "DateInterpolator", "size": 1375},
{"name": "Interpolator", "size": 8746},
{"name": "MatrixInterpolator", "size": 2202},
{"name": "NumberInterpolator", "size": 1382},
{"name": "ObjectInterpolator", "size": 1629},
{"name": "PointInterpolator", "size": 1675},
{"name": "RectangleInterpolator", "size": 2042}
]
},
{"name": "ISchedulable", "size": 1041},
{"name": "Parallel", "size": 5176},
{"name": "Pause", "size": 449},
{"name": "Scheduler", "size": 5593},
{"name": "Sequence", "size": 5534},
{"name": "Transition", "size": 9201},
{"name": "Transitioner", "size": 19975},
{"name": "TransitionEvent", "size": 1116},
{"name": "Tween", "size": 6006}
]
},
{
"name": "data",
"children": [
{
"name": "converters",
"children": [
{"name": "Converters", "size": 721},
{"name": "DelimitedTextConverter", "size": 4294},
{"name": "GraphMLConverter", "size": 9800},
{"name": "IDataConverter", "size": 1314},
{"name": "JSONConverter", "size": 2220}
]
},
{"name": "DataField", "size": 1759},
{"name": "DataSchema", "size": 2165},
{"name": "DataSet", "size": 586},
{"name": "DataSource", "size": 3331},
{"name": "DataTable", "size": 772},
{"name": "DataUtil", "size": 3322}
]
},
{
"name": "display",
"children": [
{"name": "DirtySprite", "size": 8833},
{"name": "LineSprite", "size": 1732},
{"name": "RectSprite", "size": 3623},
{"name": "TextSprite", "size": 10066}
]
},
{
"name": "flex",
"children": [
{"name": "FlareVis", "size": 4116}
]
},
{
"name": "physics",
"children": [
{"name": "DragForce", "size": 1082},
{"name": "GravityForce", "size": 1336},
{"name": "IForce", "size": 319},
{"name": "NBodyForce", "size": 10498},
{"name": "Particle", "size": 2822},
{"name": "Simulation", "size": 9983},
{"name": "Spring", "size": 2213},
{"name": "SpringForce", "size": 1681}
]
},
{
"name": "query",
"children": [
{"name": "AggregateExpression", "size": 1616},
{"name": "And", "size": 1027},
{"name": "Arithmetic", "size": 3891},
{"name": "Average", "size": 891},
{"name": "BinaryExpression", "size": 2893},
{"name": "Comparison", "size": 5103},
{"name": "CompositeExpression", "size": 3677},
{"name": "Count", "size": 781},
{"name": "DateUtil", "size": 4141},
{"name": "Distinct", "size": 933},
{"name": "Expression", "size": 5130},
{"name": "ExpressionIterator", "size": 3617},
{"name": "Fn", "size": 3240},
{"name": "If", "size": 2732},
{"name": "IsA", "size": 2039},
{"name": "Literal", "size": 1214},
{"name": "Match", "size": 3748},
{"name": "Maximum", "size": 843},
{
"name": "methods",
"children": [
{"name": "add", "size": 593},
{"name": "and", "size": 330},
{"name": "average", "size": 287},
{"name": "count", "size": 277},
{"name": "distinct", "size": 292},
{"name": "div", "size": 595},
{"name": "eq", "size": 594},
{"name": "fn", "size": 460},
{"name": "gt", "size": 603},
{"name": "gte", "size": 625},
{"name": "iff", "size": 748},
{"name": "isa", "size": 461},
{"name": "lt", "size": 597},
{"name": "lte", "size": 619},
{"name": "max", "size": 283},
{"name": "min", "size": 283},
{"name": "mod", "size": 591},
{"name": "mul", "size": 603},
{"name": "neq", "size": 599},
{"name": "not", "size": 386},
{"name": "or", "size": 323},
{"name": "orderby", "size": 307},
{"name": "range", "size": 772},
{"name": "select", "size": 296},
{"name": "stddev", "size": 363},
{"name": "sub", "size": 600},
{"name": "sum", "size": 280},
{"name": "update", "size": 307},
{"name": "variance", "size": 335},
{"name": "where", "size": 299},
{"name": "xor", "size": 354},
{"name": "_", "size": 264}
]
},
{"name": "Minimum", "size": 843},
{"name": "Not", "size": 1554},
{"name": "Or", "size": 970},
{"name": "Query", "size": 13896},
{"name": "Range", "size": 1594},
{"name": "StringUtil", "size": 4130},
{"name": "Sum", "size": 791},
{"name": "Variable", "size": 1124},
{"name": "Variance", "size": 1876},
{"name": "Xor", "size": 1101}
]
},
{
"name": "scale",
"children": [
{"name": "IScaleMap", "size": 2105},
{"name": "LinearScale", "size": 1316},
{"name": "LogScale", "size": 3151},
{"name": "OrdinalScale", "size": 3770},
{"name": "QuantileScale", "size": 2435},
{"name": "QuantitativeScale", "size": 4839},
{"name": "RootScale", "size": 1756},
{"name": "Scale", "size": 4268},
{"name": "ScaleType", "size": 1821},
{"name": "TimeScale", "size": 5833}
]
},
{
"name": "util",
"children": [
{"name": "Arrays", "size": 8258},
{"name": "Colors", "size": 10001},
{"name": "Dates", "size": 8217},
{"name": "Displays", "size": 12555},
{"name": "Filter", "size": 2324},
{"name": "Geometry", "size": 10993},
{
"name": "heap",
"children": [
{"name": "FibonacciHeap", "size": 9354},
{"name": "HeapNode", "size": 1233}
]
},
{"name": "IEvaluable", "size": 335},
{"name": "IPredicate", "size": 383},
{"name": "IValueProxy", "size": 874},
{
"name": "math",
"children": [
{"name": "DenseMatrix", "size": 3165},
{"name": "IMatrix", "size": 2815},
{"name": "SparseMatrix", "size": 3366}
]
},
{"name": "Maths", "size": 17705},
{"name": "Orientation", "size": 1486},
{
"name": "palette",
"children": [
{"name": "ColorPalette", "size": 6367},
{"name": "Palette", "size": 1229},
{"name": "ShapePalette", "size": 2059},
{"name": "SizePalette", "size": 2291}
]
},
{"name": "Property", "size": 5559},
{"name": "Shapes", "size": 19118},
{"name": "Sort", "size": 6887},
{"name": "Stats", "size": 6557},
{"name": "Strings", "size": 22026}
]
},
{
"name": "vis",
"children": [
{
"name": "axis",
"children": [
{"name": "Axes", "size": 1302},
{"name": "Axis", "size": 24593},
{"name": "AxisGridLine", "size": 652},
{"name": "AxisLabel", "size": 636},
{"name": "CartesianAxes", "size": 6703}
]
},
{
"name": "controls",
"children": [
{"name": "AnchorControl", "size": 2138},
{"name": "ClickControl", "size": 3824},
{"name": "Control", "size": 1353},
{"name": "ControlList", "size": 4665},
{"name": "DragControl", "size": 2649},
{"name": "ExpandControl", "size": 2832},
{"name": "HoverControl", "size": 4896},
{"name": "IControl", "size": 763},
{"name": "PanZoomControl", "size": 5222},
{"name": "SelectionControl", "size": 7862},
{"name": "TooltipControl", "size": 8435}
]
},
{
"name": "data",
"children": [
{"name": "Data", "size": 20544},
{"name": "DataList", "size": 19788},
{"name": "DataSprite", "size": 10349},
{"name": "EdgeSprite", "size": 3301},
{"name": "NodeSprite", "size": 19382},
{
"name": "render",
"children": [
{"name": "ArrowType", "size": 698},
{"name": "EdgeRenderer", "size": 5569},
{"name": "IRenderer", "size": 353},
{"name": "ShapeRenderer", "size": 2247}
]
},
{"name": "ScaleBinding", "size": 11275},
{"name": "Tree", "size": 7147},
{"name": "TreeBuilder", "size": 9930}
]
},
{
"name": "events",
"children": [
{"name": "DataEvent", "size": 2313},
{"name": "SelectionEvent", "size": 1880},
{"name": "TooltipEvent", "size": 1701},
{"name": "VisualizationEvent", "size": 1117}
]
},
{
"name": "legend",
"children": [
{"name": "Legend", "size": 20859},
{"name": "LegendItem", "size": 4614},
{"name": "LegendRange", "size": 10530}
]
},
{
"name": "operator",
"children": [
{
"name": "distortion",
"children": [
{"name": "BifocalDistortion", "size": 4461},
{"name": "Distortion", "size": 6314},
{"name": "FisheyeDistortion", "size": 3444}
]
},
{
"name": "encoder",
"children": [
{"name": "ColorEncoder", "size": 3179},
{"name": "Encoder", "size": 4060},
{"name": "PropertyEncoder", "size": 4138},
{"name": "ShapeEncoder", "size": 1690},
{"name": "SizeEncoder", "size": 1830}
]
},
{
"name": "filter",
"children": [
{"name": "FisheyeTreeFilter", "size": 5219},
{"name": "GraphDistanceFilter", "size": 3165},
{"name": "VisibilityFilter", "size": 3509}
]
},
{"name": "IOperator", "size": 1286},
{
"name": "label",
"children": [
{"name": "Labeler", "size": 9956},
{"name": "RadialLabeler", "size": 3899},
{"name": "StackedAreaLabeler", "size": 3202}
]
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{
"name": "layout",
"children": [
{"name": "AxisLayout", "size": 6725},
{"name": "BundledEdgeRouter", "size": 3727},
{"name": "CircleLayout", "size": 9317},
{"name": "CirclePackingLayout", "size": 12003},
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{"name": "PieLayout", "size": 2728},
{"name": "RadialTreeLayout", "size": 12348},
{"name": "RandomLayout", "size": 870},
{"name": "StackedAreaLayout", "size": 9121},
{"name": "TreeMapLayout", "size": 9191}
]
},
{"name": "Operator", "size": 2490},
{"name": "OperatorList", "size": 5248},
{"name": "OperatorSequence", "size": 4190},
{"name": "OperatorSwitch", "size": 2581},
{"name": "SortOperator", "size": 2023}
]
},
{"name": "Visualization", "size": 16540}
]
}
]
});
</script>
</body>
</html>
Answer
The element.getBoundingClientRect() method will return the proper coordinates of an element relative to the viewport regardless of whether the svg has been scaled and/or translated.
While getBBox() works for an untransformed space, if scale and translation have been applied to the layout then it will no longer be accurate. The getBoundingClientRect() function has worked well for me in a force layout project when pan and zoom are in effect, where I wanted to attach HTML Div elements as labels to the nodes instead of using SVG Text elements.