问d3:位置文本元素依赖于元素之前的长度

EN

svg.selectAll("text")
  .data(data).enter()
  .append("text")
  .attr("x", function(d) {
    return x_pos;
  })
  .attr("y", 50)
  .style("display", "none")
  .text(function(d) { return d; });

svg.selectAll("text")
  .style("display", "block")
  .attr("x", function(d) {
    var c_pos = x_pos;
    x_pos = x_pos + this.getBBox().width + distance;
    return c_pos;
  });

//This will be your array of legends
var legendItems = [] 

var legendCount = legendItems.length;
var legendSectionWidth = width / (legendCount+1);
//This will be your "y" value going forward. You can assign anything you want. I have used the following if else case, you should replace it with your logic to calculate y.
var vert = 0;
if(legendPosition == "bottom"){
    if(showAxes)
        vert = height + legendVerticalPad + containerHeight*0.04;
    else
        vert = height + legendVerticalPad + containerHeight*0.02;
}

for(var i = 0; i < legendCount; i++){
    var text = svg.append('text')
        .attr('x', (i+1)*legendSectionWidth)
        .attr('y', vert)
        .attr('class', 'legend-text '+legendItems[i])
        .style('text-anchor', 'middle')
        .style('dominant-baseline', 'central')
        .text(function() {
            return legendItems[i];
        });

    var len = text[0][0].getComputedTextLength();

// you could use circles here, just change the width n height to rx and x and y to cx and cy// you could use circles here, just change the width n height to rx and x and y to cx and cy`enter code here`
//The value 5 is your choice, i use 5px between my rect and text
    svg.append('rect') 
        .attr('x', (i+1)*legendSectionWidth - len/2 - 5 - legendRectSize)
        .attr('y', vert - legendRectSize/2)
        .attr('width', legendRectSize)
        .attr('height', legendRectSize)
        .attr('class', function () { return 'legend '+ legendItems[i];} )
        .attr('label', function()  {
            return legendItems[i]; 
        })
}

var dataset = ["Africa","Asia", "Caribbean", "Central America", "Europe", "Middle East", "North America", "Oceania", "South America"];

d3.select('.foo').data(dataset)....

return i ? (i * 40 + dataset[i-1].length + 7) : i;