Handle d3 drag events only after long click

user_11321180 0
Viewed 82

I have code to handle dragging in d3.

And I want to emit drag events only after 1000ms.(long click)

This is needed for mobile device for better UX.

var mouseover_node = null;
var svg = d3.select('body').append('svg').attr('width', 1000).attr('height', 1000);
var rect = svg.selectAll('rect')
  .data([0, 2, 3])
  .enter().append('rect')
  .attr('x', function(x) { return +x * 0; })
  .attr('y', function(y) {  return +y * 120; })
  .attr('width', function() { return 100; })
  .attr('height', function() { return 100; })
  .attr('fill', function(x) {  if(x == 0){return'red';}else return 'blue'; });


rect.on("mouseover", (d) => {this.mouseover_node = d})
  .on("mouseout", (d) => {this.mouseover_node = null})
  .call(d3.drag()
    .on("start", function () {
        console.log('start');
        return false;
        })
    .on("drag", function () {
        console.log('drag');
        })
    .on("end",  (sourceElement,index,svgItems) => {
        console.log('end drag with mouseover: ' + this.mouseover_node);
        })
);

How can we do this in JavaScript?

d3.js svg javascript
1 Answers

maybe use Date.now() in "start" and "drag" and check whether elapsed time is bigger than 1000ms.

var click_start, drag_start;

rect.call(
  d3.drag()
    .on("start", function () {
      console.log("start");
      click_start = Date.now();
    })
    .on("drag", function () {
      drag_start = Date.now();
      if (drag_start - click_start >= 1000) {
        console.log("drag");
      }
    })
);
user_70899410
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