Prevent mouseout action after click on an element with D3.js

Question

I would like to prevent the mouseout action of an element when the user click on this element. For an example see this JSFiddle (the circle disappear even if I click on the label).

Is there an easy way to achieve my objective with d3.js? Thank you!

The JSFiddle example code:

var svg = d3.select("#content")
                        .append("svg")
            .attr("width", 600)
            .attr("height", 400);
var g = svg.append("g");
var text = g.append("text")
                            .text("Click me")
              .style("fill", "Blue")
              .attr("x", 50)
              .attr("y", 50)
              .on("mouseover", mouseover)
              .on("mouseout", mouseout)
              .on("click", click);

var circle = g.append("circle")
                                .style("fill", "Orange")
                .attr("cx", 150)
                .attr("cy", 90)
                .attr("r", 15)
                .classed("hide", true)
                .classed("someClass", true);

function mouseover(p){
    d3.selectAll("circle.someClass").classed("hide", false);
}
function mouseout(p){
    d3.selectAll("circle.someClass").classed("hide", true);
}
function click(p){
    d3.selectAll("circle.someClass").classed("hide", false);
}

Answer 1

If you plan to only have one element that controls the circle, use a "flag". Messing with conditionally registering/unregistering events is not a good idea.

Check this updated version of your fiddle:

https://jsfiddle.net/cze9rqf7/

var svg = d3.select("#content")
          .append("svg")
          .attr("width", 600)
          .attr("height", 400);
var g = svg.append("g");
var text = g.append("text")
          .text("Click me")
          .style("fill", "Blue")
          .attr("x", 50)
          .attr("y", 50)
          .on("mouseover", mouseover)
          .on("mouseout", mouseout)
          .on("click", click);

var circle = g.append("circle")
          .style("fill", "Orange")
          .attr("cx", 150)
          .attr("cy", 90)
          .attr("r", 15)
          .classed("hide", true)
          .classed("someClass", true);

var isClicked = false;

function mouseover(p){
    d3.selectAll("circle.someClass").classed("hide", false);
}

function mouseout(p){
    if(!isClicked) {
        d3.selectAll("circle.someClass").classed("hide", true);
    }
}

function click(p){
    isClicked = !isClicked;
    d3.selectAll("circle.someClass").classed("hide", false);
}

EDITS For Comments

If you need to "remember" state per element, instead of using a global, you should be using data-binding on those elements:

var text = g.append("text")
  .datum({isClicked: false})
  .text("Click me")
  ...

function mouseout(p){
    // p is the data-bound object
    if(!p.isClicked) {
        var className = d3.select(this).attr("class");
        d3.selectAll("circle."+className).classed("hide", true);
  }
}

function click(p){
    // on click edit the data-bound object
    p.isClicked = !p.isClicked;
    var className = d3.select(this).attr("class");
    d3.selectAll("circle."+className).classed("hide", false);
}

Updated fiddle here.

Answer 2

Here is an answer without any "flag":

Given that you have many labels, one option is removing the mouseout for the clicked element:

d3.select(this).on("mouseout", null);

Here is your updated fiddle: https://jsfiddle.net/gerardofurtado/38p18pLt/

And the same code in the Stack snippet:

var svg = d3.select("body")
  .append("svg")
  .attr("width", 600)
  .attr("height", 400);
var g = svg.append("g");
var text = g.append("text")
  .text("Click me")
  .style("fill", "Blue")
  .attr("x", 50)
  .attr("y", 50)
  .classed("someClass", true)
  .on("mouseover", mouseover)
  .on("mouseout", mouseout)
  .on("click", click);

var text2 = g.append("text")
  .text("Click me")
  .style("fill", "Blue")
  .attr("x", 50)
  .attr("y", 150)
  .classed("someClass2", true)
  .on("mouseover", mouseover)
  .on("mouseout", mouseout)
  .on("click", click);

var circle = g.append("circle")
  .style("fill", "Orange")
  .attr("cx", 150)
  .attr("cy", 90)
  .attr("r", 15)
  .classed("hide", true)
  .classed("someClass", true);

var circle2 = g.append("circle")
  .style("fill", "Green")
  .attr("cx", 250)
  .attr("cy", 90)
  .attr("r", 15)
  .classed("hide", true)
  .classed("someClass2", true);

function mouseover(p) {
  var className = d3.select(this).attr("class");
  d3.selectAll("circle." + className).classed("hide", false);
}

function mouseout(p) {
  var className = d3.select(this).attr("class");
  d3.selectAll("circle." + className).classed("hide", true);
}

function click(p) {
  d3.select(this).on("mouseout", null);
  var className = d3.select(this).attr("class");
  d3.selectAll("circle." + className).classed("hide", false);
}

.hide {
  display: none;
}

text {
  cursor: pointer;
}

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

You can also toggle the click, making the mouseout work again:

if(d3.select(this)[0][0].__onmouseout){
    d3.select(this).on("mouseout", null);
} else {
    d3.select(this).on("mouseout", mouseout);
}

Here is the fiddle with the "toggle" function: https://jsfiddle.net/gerardofurtado/4zb9gL9r/1/

And the same code in the Stack snippet:

var svg = d3.select("body")
  .append("svg")
  .attr("width", 600)
  .attr("height", 400);
var g = svg.append("g");
var text = g.append("text")
  .text("Click me")
  .style("fill", "Blue")
  .attr("x", 50)
  .attr("y", 50)
  .classed("someClass", true)
  .on("mouseover", mouseover)
  .on("mouseout", mouseout)
  .on("click", click);

var text2 = g.append("text")
  .text("Click me")
  .style("fill", "Blue")
  .attr("x", 50)
  .attr("y", 150)
  .classed("someClass2", true)
  .on("mouseover", mouseover)
  .on("mouseout", mouseout)
  .on("click", click);

var circle = g.append("circle")
  .style("fill", "Orange")
  .attr("cx", 150)
  .attr("cy", 90)
  .attr("r", 15)
  .classed("hide", true)
  .classed("someClass", true);

var circle2 = g.append("circle")
  .style("fill", "Green")
  .attr("cx", 250)
  .attr("cy", 90)
  .attr("r", 15)
  .classed("hide", true)
  .classed("someClass2", true);

function mouseover(p) {
  var className = d3.select(this).attr("class");
  d3.selectAll("circle." + className).classed("hide", false);
}

function mouseout(p) {
  var className = d3.select(this).attr("class");
  d3.selectAll("circle." + className).classed("hide", true);
}

function click(p) {
  if (d3.select(this)[0][0].__onmouseout) {
    d3.select(this).on("mouseout", null);
  } else {
    d3.select(this).on("mouseout", mouseout);
  }
  var className = d3.select(this).attr("class");
  d3.selectAll("circle." + className).classed("hide", false);
}

.hide {
  display: none;
}

text {
  cursor: pointer;
}

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