Dispatching drag-end event - javascript

I want to programmatically fire the "end" event of d3-drag.
I have some circles and have the drag-handling of them implemented like so:
...
.call(d3.drag()
.on("drag", function () {...})
.on("end", function () {...})
)
Now, later in my code, I would like to trigger the "end" part of this programmatically.
I have already tried something like this:
d3.select("#myID").dispatch("end");
d3.select("#myID").dispatch("dragend");
d3.select("#myID").call(d3.drag().dispatch("end"));

If you don't need to generate any actual event data, and I understand the question correctly, you can do this relatively easily without d3.dispatch directly. The below will give you this and the node data itself (in d3v5 it will also give you i and nodes).
D3v5 and earlier
In d3v5 and earlier, the signatures for a function passed to selection.each() and drag.on() were the same. In this case you can easily assign the function to a variable and pass it to both. Alternatively, you could access the drag event function with drag.on("typeName").
Here's a quick example:
var svg = d3.select("body")
.append("svg")
.attr("width",500)
.attr("height",300);
var data = [{x:40,y:100},{x:250,y:100}];
var circles = svg.selectAll(null)
.data(data)
.enter()
.append("circle")
.attr("r", 10)
.attr("cx", function(d) { return d.x; })
.attr("cy", function(d) { return d.y; })
.attr("fill", function(d,i) {
return ["steelblue","crimson"][i]
})
var drag = d3.drag()
.on("drag", function(d) {
d.x = d3.event.x; d.y = d3.event.y;
d3.select(this)
.attr("cx", d.x)
.attr("cy", d.y);
})
.on("end", function(d) {
console.log(d.x+","+d.y);
d3.select(this)
.transition()
.attr("r", 30)
.transition()
.attr("r", 10);
})
circles.call(drag);
d3.select("button").on("click", function() {
var circle = d3.select("circle")
.each(drag.on("end"));
})
circle {
cursor: pointer;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/5.7.0/d3.min.js"></script>
<button>Trigger Drag End On Blue Circle</button>
D3v6
In d3v6 the signatures of functions passed to selection.each() and drag.on() are different. The datum is the first parameter of the former and the second parameter of the latter. So we could use Function.apply() within selection.each() to trigger the end function and pass the proper this and d while passing null for the event data.
var svg = d3.select("body")
.append("svg")
.attr("width",500)
.attr("height",300);
var data = [{x:40,y:100},{x:250,y:100}];
var circles = svg.selectAll(null)
.data(data)
.enter()
.append("circle")
.attr("r", 10)
.attr("cx", function(d) { return d.x; })
.attr("cy", function(d) { return d.y; })
.attr("fill", function(d,i) {
return ["steelblue","crimson"][i]
})
var drag = d3.drag()
.on("drag", drag)
.on("end", dragend)
circles.call(drag);
d3.select("button").on("click", function() {
var circle = d3.select("circle")
.each(function(d) {
dragend.apply(this,[null,d])
})
})
function dragend(event,d) {
console.log(d.x+","+d.y);
d3.select(this)
.transition()
.attr("r", 30)
.transition()
.attr("r", 10);
}
function drag(event,d) {
d.x = event.x; d.y = event.y;
d3.select(this)
.attr("cx", d.x)
.attr("cy", d.y);
}
circle {
cursor: pointer;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/6.0.0/d3.min.js"></script>
<button>Trigger Drag End On Blue Circle</button>

Related

Find original color of element before mouseover

I have a bubble chart in which I make bubbles in the following way:
var circles = svg.selectAll(null)
.data(data)
.enter()
.append("circle")
.attr("cx", width / 2)
.attr("cy", height / 2)
.attr("opacity", 0.3)
.attr("r", 20)
.style("fill", function(d){
if(+d.student_percentile <= 40){
return "red";
}
else if(+d.student_percentile > 40 && +d.student_percentile <= 70){
return "yellow";
}
else{
return "green";
}
})
.attr("cx", function(d) {
return xscale(+d.student_percentile);
})
.attr("cy", function(d) {
return yscale(+d.rank);
})
.on('mouseover', function(d, i) {
d3.select(this)
.transition()
.duration(1000)
.ease(d3.easeBounce)
.attr("r", 32)
.style("fill", "orange")
.style("cursor", "pointer")
.attr("text-anchor", "middle");
texts.filter(function(e) {
return +e.rank === +d.rank;
})
.attr("font-size", "20px");
}
)
.on('mouseout', function(d, i) {
d3.select(this).transition()
.style("opacity", 0.3)
.attr("r", 20)
.style("fill", "blue")
.style("cursor", "default");
texts.filter(function(e) {
return e.rank === d.rank;
})
.transition()
.duration(1000)
.ease(d3.easeBounce)
.attr("font-size", "10px")
});
I have given colors red, yellow, green to the bubbles based on the student percentile. On mouseover, I change the color of bubble to 'orange'. Now the issue is, on mouseout, currently I am making colors of bubbles as 'blue' but I want to assign the same color to them as they had before mouseover, i.e., red/green/yellow. How do I find out what color, the bubbles had?
One way is to obviously check the percentile of student and then give color based on that(like I have initially assigned green/yellow/red colors), but is there any direct way of finding the actual color of bubble?
Thanks in advance!
There are several ways for doing this.
Solution 1:
The most obvious one is declaring a variable...
var previous;
... to which you assign to the colour of the element on the mouseover...
previous = d3.select(this).style("fill");
... and reuse in the mouseout:
d3.select(this).style("fill", previous)
Here is a demo:
var svg = d3.select("svg");
var colors = d3.scaleOrdinal(d3.schemeCategory10);
var previous;
var circles = svg.selectAll(null)
.data(d3.range(5))
.enter()
.append("circle")
.attr("cy", 75)
.attr("cx", function(d, i) {
return 50 + 50 * i
})
.attr("r", 20)
.style("fill", function(d, i) {
return colors(i)
})
.on("mouseover", function() {
previous = d3.select(this).style("fill");
d3.select(this).style("fill", "#222");
}).on("mouseout", function() {
d3.select(this).style("fill", previous)
})
<script src="https://d3js.org/d3.v4.min.js"></script>
<svg></svg>
Solution 2:
However, D3 has a nice feature, called local variables. You simply have to define the local...
var local = d3.local();
..., set it on the mouseover:
local.set(this, d3.select(this).style("fill"));
And then, get its value on the mouseout:
d3.select(this).style("fill", local.get(this));
Here is the demo:
var svg = d3.select("svg");
var colors = d3.scaleOrdinal(d3.schemeCategory10);
var local = d3.local();
var circles = svg.selectAll(null)
.data(d3.range(5))
.enter()
.append("circle")
.attr("cy", 75)
.attr("cx", function(d, i) {
return 50 + 50 * i
})
.attr("r", 20)
.style("fill", function(d, i) {
return colors(i)
})
.on("mouseover", function() {
local.set(this, d3.select(this).style("fill"));
d3.select(this).style("fill", "#222");
}).on("mouseout", function() {
d3.select(this).style("fill", local.get(this));
})
<script src="https://d3js.org/d3.v4.min.js"></script>
<svg></svg>
Solution 3:
Since DDD (also known as D3) means data-driven documents, you can use the bound datum to get the previous colour.
First, you set it (in my demo, using the colors scale):
.style("fill", function(d, i) {
return d.fill = colors(i);
})
And then you use it in the mouseout. Check the demo:
var svg = d3.select("svg");
var colors = d3.scaleOrdinal(d3.schemeCategory10);
var circles = svg.selectAll(null)
.data(d3.range(5).map(function(d) {
return {
x: d
}
}))
.enter()
.append("circle")
.attr("cy", 75)
.attr("cx", function(d) {
return 50 + 50 * d.x
})
.attr("r", 20)
.style("fill", function(d, i) {
return d.fill = colors(i);
})
.on("mouseover", function() {
d3.select(this).style("fill", "#222");
}).on("mouseout", function(d) {
d3.select(this).style("fill", d.fill);
})
<script src="https://d3js.org/d3.v4.min.js"></script>
<svg></svg>
For using this solution #3, the element's datum has to be an object.
PS: drop that bunch of if...else for setting the style of the bubbles. Use a scale instead.

D3: How to validate data during data binding?

I am trying to render a gantt chart, where I am binding my data in d3 and rendering circle in both end. My data is somewhat similar to this structure:
function Event(start, end) {
this.startTime = start;
this.endTime = end;
}
I bind my data as usual:
myplot.selectAll(".EventStart")
.data(EventList).enter()
.append("circle")
.attr("class", "EventStart")
.attr("cx", function (d) { return scaleX(d.startTime)})
.attr("cy", function (d) { return eventRenderingHeight })
.attr("r", 5)
.style("fill", "white");
myplot.selectAll(".EventEnd")
.data(EventList).enter()
.append("circle")
.attr("class", "EventEnd")
.attr("cx", function (d) { return scaleX(d.endTime)})
.attr("cy", function (d) { return eventRenderingHeight })
.attr("r", 5)
.style("fill", "white");
Now, this will render two white circle at teh begining and end of my events.
But I want to omit rendering the 2nd circle if startTime and EndTime is same.
How can I do it?
Thanks.
You can either filter the dataList before binding
myplot.selectAll(".EventEnd")
.data(EventList.filter(function(d){ return d.startTime!=d.endTime }))
.enter()
.append("circle")
.attr("class", "EventEnd")
.attr("cx", function (d) { return scaleX(d.endTime)})
.attr("cy", function (d) { return eventRenderingHeight })
.attr("r", 5)
.style("fill", "white");
OR
Filter as shown below.
myplot.selectAll(".EventEnd")
.data(EventList)
.enter()
.append("circle")
.filter(function(d) { return d.startTime!=d.endTime })
.attr("class", "EventEnd")
.attr("cx", function (d) { return scaleX(d.endTime)})
.attr("cy", function (d) { return eventRenderingHeight })
.attr("r", 5)
.style("fill", "white");

What settings to choose for force directed graph layout in d3

I am visualising a graph of relationships between people with d3. All nodes are connected to a single central node, and then have relationships with other nodes. I've got the basics working, but I'm struggling to work out how to set the parameters like linkDistance, linkStrength, gravity and charge.
Each edge has a rating from 0-5, which I'm then using to compute linkDistance using an inverse linear scale. The main problem is getting the relationships to be represented properly. The central node seems to be much further away than any other node, even though it has the shortest linkDistance with some other nodes. I'm also finding it difficult to find the right settings to get nodes to be an appropriate distance apart.
var h = 500, w = 1000
var color = d3.scale.category20()
var svg = d3.select("body")
.append("svg")
.attr({ height: h, width: w })
queue()
.defer(d3.json, "nodes.json")
.defer(d3.json, "links.json")
.await(makeDiag);
function makeDiag(error, nodes, links, table) {
links = links.filter(function(link) {
if (link.value) return true
})
var scale = d3.scale.linear().domain([0,5]).range([20,0])
var edges = svg.selectAll("line")
.data(links)
.enter()
.append("line")
.style("stroke", "#ccc")
.style("stroke-width", 1)
/* Establish the dynamic force behavor of the nodes */
var force = d3.layout.force()
.nodes(nodes)
.links(links)
.size([w,h])
.linkDistance(function(d) {
if (d.value == 0) return null
console.log('in',d.value,'out',scale(d.value))
return scale(d.value)
})
.charge(-1400)
.start();
/* Draw the edges/links between the nodes */
var texts = svg.selectAll("text")
.data(nodes)
.enter()
.append("text")
.attr("fill", "black")
.attr("font-family", "sans-serif")
.attr("font-size", "10px")
.text(function(d) { return d.name; });
var nodes = svg.selectAll("circle")
.data(nodes)
.enter()
.append("circle")
.attr("r", function(d,i) { return 20 })
.attr("opacity", 0.7)
.style("fill", function(d,i) { return color(i); })
.call(force.drag);
/* Draw the nodes themselves */
/* Run the Force effect */
force.on("tick", function() {
edges.attr("x1", function(d) { return d.source.x; })
.attr("y1", function(d) { return d.source.y; })
.attr("x2", function(d) { return d.target.x; })
.attr("y2", function(d) { return d.target.y; });
nodes.attr("cx", function(d) { return d.x; })
.attr("cy", function(d) { return d.y; })
texts.attr("transform", function(d) {
return "translate(" + (d.x - 12.5) + "," + (d.y + 5) + ")";
});
});
};
jsFiddle
full screen result

D3js force duplicate nodes on enter()

I am having some issues with d3js and I can't figure out what is going on. The idea is to draw initial graph from some endpoint data (first img), that's fine works well. Each node is clickable, on click ajax call is made for that node and data is returned, based on some criteria at that point nodes.push(xx), links.push(xx) happens to add new nodes and restart() is called to draw new nodes and links. The issue is that the main graph is doing the correct thing (Not showed on screenshots as I had to put fake data on the first graph i.e. calling an endpoint /record/id/first doesn't return a data) but there are bunch of random nodes showing up in the right bottom corner.
You can also see on the example below, even if the data doesn't change after clicking on first/second/third something wrong goes with node.enter() after restart() with the same data passed in...
JS FIDDLE: http://jsfiddle.net/5754j86e/
var w = 1200,
h = 1200;
var nodes = [];
var links = [];
var node;
var link;
var texts;
var ids = [];
var circleWidth = 10;
var initialIdentifier = "marcin";
nodes = initialBuildNodes(initialIdentifier, sparql);
links = initialBuildLinks(sparql);
//Add SVG
var svg = d3.select('#chart').append('svg')
.attr('width', w)
.attr('height', h);
var linkGroup = svg.append("svg:g").attr("id", "link-group");
var nodeGroup = svg.append("svg:g").attr("id", "node-group");
var textGroup = svg.append("svg:g").attr("id", "text-group");
//Add Force Layout
var force = d3.layout.force()
.size([w, h])
.gravity(.05)
.charge(-1040);
force.linkDistance(120);
restart();
function restart() {
force.links(links)
console.log("LINKS ARE: ", links)
link = linkGroup.selectAll(".link").data (links);
link.enter().append('line')
.attr("class", "link");
link.exit().remove();
force.nodes(nodes)
console.log("NODES ARE: ", nodes)
node = nodeGroup.selectAll(".node").data (nodes);
node.enter().append("svg:g")
.attr("class", "node")
.call(force.drag);
node.append('circle')
.attr('cx', function(d) { return d.x; })
.attr('cy', function(d) { return d.y; })
.attr('r', circleWidth )
.attr('fill', function(d, i) {
if (i>0) { return palette.pink }
else { return palette.blue }
})
.on("click", function(d) {
nodeClicked (d);
})
.on('mouseenter', function(d){
nodeMouseEnter(d)
})
.on('mouseout', function(d){
nodeMouseOut(d)
});
node.exit().remove();
var annotation = textGroup.selectAll(".annotation").data (nodes);
annotation.enter().append("svg:g")
.attr("class", "annotation")
.append("text")
.attr("x", function(d) { return d.radius + 4 })
.attr("y", ".31em")
.attr("class", "label")
.text(function(d) { return d.name; });
annotation.exit().remove();
force.start();
}
function nodeClicked (d) {
// AJAX CALL happens here and bunch of nodes.push({name: "new name"}) happen
}
force.on('tick', function(e) {
link
.attr('x1', function(d) { return d.source.x })
.attr('y1', function(d) { return d.source.y })
.attr('x2', function(d) { return d.target.x })
.attr('y2', function(d) { return d.target.y })
node.attr('transform', function(d, i) {
return 'translate('+ d.x +', '+ d.y +')';
})
svg.selectAll(".annotation").attr("transform", function(d) {
var labelx = d.x + 13;
return "translate(" + labelx + "," + d.y + ")";
})
});
Okay I got it, based on the docs (https://github.com/mbostock/d3/wiki/Selections#enter):
var update_sel = svg.selectAll("circle").data(data)
update_sel.attr(/* operate on old elements only */)
update_sel.enter().append("circle").attr(/* operate on new elements only */)
update_sel.attr(/* operate on old and new elements */)
update_sel.exit().remove() /* complete the enter-update-exit pattern */
From my code you can see I do enter() and then once again I add circle on node in a separate statement.
node = nodeGroup.selectAll(".node").data (nodes);
node.enter().append("svg:g")
.attr("class", "node")
.call(force.drag);
node.append('circle')
.attr('cx', function(d) { return d.x; })
.attr('cy', function(d) { return d.y; })
.attr('r', circleWidth )
.attr('fill', function(d, i) {
if (i>0) { return palette.pink }
else { return palette.blue }
});
Adding circle should be within the scope of enter() otherwise it happens to all nodes not only the new nodes therefore it should be :
node.enter().append("svg:g")
.attr("class", "node")
.call(force.drag)
.append('circle')
.attr('cx', function(d) { return d.x; })
.attr('cy', function(d) { return d.y; })
.attr('r', circleWidth )
.attr('fill', function(d, i) {
if (i>0) { return palette.pink }
else { return palette.blue }
});

D3 Get Variable Value

This is a very basic question, but how do I access the value of attributes in d3?
I just started learning today, so I haven't figured this out yet
Suppose I have this as part of my code here
http://jsfiddle.net/matthewpiatetsky/nCNyE/9/
var node = svg.selectAll("circle.node")
.data(nodes)
.enter().append("circle")
.attr("class", "node")
.attr("r", function (d) {
if (width < height){
return d.count * width/100;
} else {
return d.count * height/100;
}
})
.on("mouseover", animateFirstStep)
.on("mouseout",animateSecondStep)
.style("fill", function(d,i){return color(i);})
.call(force.drag);
For my animation the circle gets bigger when you mouse over it, and I want the circle to return to its normal size when you move the mouse away. However, i'm not sure how to get the value of the radius.
i set the value here
.attr("r", function (d) {
if (width < height){
return d.count * width/100;
} else {
return d.count * height/100;
}
I tried to do node.r and things like that, but i'm not sure what the correct syntax is
Thanks!
You can access an attribute of a selection with:
var node = svg.selectAll("circle.node")
.data(nodes)
.enter().append("circle")
.attr("class", "node")
.attr("r", function (d) { return rScale(d.count); })
.on("mouseover", function(d) {
d3.select(this)
.transition()
.duration(1000)
.attr('r', 1.8 * rScale(d.count));
})
.on("mouseout", function(d) {
d3.select(this)
.transition()
.duration(1000)
.attr('r', rScale(d.count));
})
.style("fill", function (d, i) {
return color(i);
})
.call(force.drag);
in this context, this points to the DOM element binded with d. Normally, the area of a circle must be proportional to the quantities that you are showing, take a look at the documentation of Quantitative Scales. A fork of your fiddle is here.

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