CODEWITHSUNDEEP
javascriptd3.jsbar-chartlinegraph
E.C
E.C

Reputation: 67

How to freeze and unfreeze hover line on click in D3

my friend and I each created a chart using D3 and we combined it together looking something like this: http://jsfiddle.net/vertaire/vba1ryzp/5/

We were hoping to remove the slider and replace it with the line hover in the line graph. The hover line returns the year whenever you move the mouse, currently.

  chart1.append('svg:rect') // append a rect to catch mouse movements on canvas
  .attr('width', chart1_width) // can't catch mouse events on a g element
  .attr('height', chart1_height)
  .attr('fill', 'none')
  .attr('pointer-events', 'all')
  .on('mouseout', function(){ // on mouse out hide line, circles and text
        d3.select(".mouseLine")
            .style("opacity", "0");
        d3.selectAll(".mouseCircle circle")
            .style("opacity", "0");
      d3.selectAll(".mouseCircle text")
            .style("opacity", "0");
  })
  .on('mouseover', function(){ // on mouse in show line, circles and text
        d3.select(".mouseLine")
            .style("opacity", "1");
         d3.selectAll(".mouseCircle circle")
            .style("opacity", "1");
        d3.selectAll(".mouseCircle text")
            .style("opacity", "1");
  })
  .on('mousemove', function() { // mouse moving over canvas
      d3.select(".mouseLine")
      .attr("d", function(){
          yRange = y.range(); // range of y axis
          var xCoor = d3.mouse(this)[0]; // mouse position in x
          var xDate = x.invert(xCoor); // date corresponding to mouse x 
          d3.selectAll('.mouseCircle') // for each circle group
              .each(function(d,i){
                 var rightIdx = bisect(data[1].values, xDate); // find date in data that right off mouse
                 yVal = data[i].values[rightIdx-1].VALUE;
                 yCoor = y(yVal); 
                 var interSect = get_line_intersection(xCoor,  // get the intersection of our vertical line and the data line
                      yRange[0], 
                      xCoor, 
                      yRange[1],
                      x(data[i].values[rightIdx-1].YEAR),
                      y(data[i].values[rightIdx-1].VALUE),
                      x(data[i].values[rightIdx].YEAR),
                      y(data[i].values[rightIdx].VALUE));

              d3.select(this) // move the circle to intersection
                  .attr('transform', 'translate(' + interSect.x + ',' + interSect.y + ')');

              d3.select(this.children[1]) // write coordinates out
                  .text(xDate.getFullYear() + "," + yVal);
                  yearCurrent = xDate.getFullYear();
                  console.log(yearCurrent)
                  return yearCurrent;

              });

          return "M"+ xCoor +"," + yRange[0] + "L" + xCoor + "," + yRange[1]; // position vertical line
      });
  });  

});

I was wondering how I would be able to make it so that when I perform a mouse click, it will freeze the hover line in it's current place return the year of the frozen position, and unfreeze it when I click again?

Upvotes: 0

Views: 716

Answers (1)

Rihards Fridrihsons
Rihards Fridrihsons

Reputation: 854

Yes, http://jsfiddle.net/vertaire/vba1ryzp/6/

basically added global variable frozen which toggles on click and mousemove function does its job only when its unfrozen status.

var frozen = false;

...

 .on('click', function(){ // on mouse click toggle frozen status
            frozen = !frozen;
      })


.on('mousemove', function() { // mouse moving over canvas
      if(!frozen) {
      ...
      }
  });

Upvotes: 0

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