无论鼠标悬停在哪里，始终显示工具提示

Question

我是JS和HTML的新手，所以我很难实施此更改：

我希望堆叠条形图的值始终显示，而不是依赖于鼠标悬停。

我将如何更改以下代码来实现这一目标？

var margin = {top: 20, right: 160, bottom: 35, left: 30};

var width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;

var svg = d3.select("body")
  .append("svg")
  .attr("width", width + margin.left + margin.right)
  .attr("height", height + margin.top + margin.bottom)
  .append("g")
  .attr("transform", "translate(" + margin.left + "," + margin.top + ")");


/* Data in strings like it would be if imported from a csv */

var data = [
  { year: "2006", redDelicious: "10", mcintosh: "15", oranges: "9", pears: "6" },
  { year: "2007", redDelicious: "12", mcintosh: "18", oranges: "9", pears: "4" },
  { year: "2008", redDelicious: "05", mcintosh: "20", oranges: "8", pears: "2" },
  { year: "2009", redDelicious: "01", mcintosh: "15", oranges: "5", pears: "4" },
  { year: "2010", redDelicious: "02", mcintosh: "10", oranges: "4", pears: "2" },
  { year: "2011", redDelicious: "03", mcintosh: "12", oranges: "6", pears: "3" },
  { year: "2012", redDelicious: "04", mcintosh: "15", oranges: "8", pears: "1" },
  { year: "2013", redDelicious: "06", mcintosh: "11", oranges: "9", pears: "4" },
  { year: "2014", redDelicious: "10", mcintosh: "13", oranges: "9", pears: "5" },
  { year: "2015", redDelicious: "16", mcintosh: "19", oranges: "6", pears: "9" },
  { year: "2016", redDelicious: "19", mcintosh: "17", oranges: "5", pears: "7" },
];

var parse = d3.time.format("%Y").parse;


// Transpose the data into layers
var dataset = d3.layout.stack()(["redDelicious", "mcintosh", "oranges", "pears"].map(function(fruit) {
  return data.map(function(d) {
    return {x: parse(d.year), y: +d[fruit]};
  });
}));


// Set x, y and colors
var x = d3.scale.ordinal()
  .domain(dataset[0].map(function(d) { return d.x; }))
  .rangeRoundBands([10, width-10], 0.02);

var y = d3.scale.linear()
  .domain([0, d3.max(dataset, function(d) {  return d3.max(d, function(d) { return d.y0 + d.y; });  })])
  .range([height, 0]);

var colors = ["b33040", "#d25c4d", "#f2b447", "#d9d574"];


// Define and draw axes
var yAxis = d3.svg.axis()
  .scale(y)
  .orient("left")
  .ticks(5)
  .tickSize(-width, 0, 0)
  .tickFormat( function(d) { return d } );

var xAxis = d3.svg.axis()
  .scale(x)
  .orient("bottom")
  .tickFormat(d3.time.format("%Y"));

svg.append("g")
  .attr("class", "y axis")
  .call(yAxis);

svg.append("g")
  .attr("class", "x axis")
  .attr("transform", "translate(0," + height + ")")
  .call(xAxis);


// Create groups for each series, rects for each segment 
var groups = svg.selectAll("g.cost")
  .data(dataset)
  .enter().append("g")
  .attr("class", "cost")
  .style("fill", function(d, i) { return colors[i]; });

var rect = groups.selectAll("rect")
  .data(function(d) { return d; })
  .enter()
  .append("rect")
  .attr("x", function(d) { return x(d.x); })
  .attr("y", function(d) { return y(d.y0 + d.y); })
  .attr("height", function(d) { return y(d.y0) - y(d.y0 + d.y); })
  .attr("width", x.rangeBand())
  .on("mouseover", function() { tooltip.style("display", null); })
  .on("mouseout", function() { tooltip.style("display", "none"); })
  .on("mousemove", function(d) {
    var xPosition = d3.mouse(this)[0] - 15;
    var yPosition = d3.mouse(this)[1] - 25;
    tooltip.attr("transform", "translate(" + xPosition + "," + yPosition + ")");
    tooltip.select("text").text(d.y);
  });


// Draw legend
var legend = svg.selectAll(".legend")
  .data(colors)
  .enter().append("g")
  .attr("class", "legend")
  .attr("transform", function(d, i) { return "translate(30," + i * 19 + ")"; });
 
legend.append("rect")
  .attr("x", width - 18)
  .attr("width", 18)
  .attr("height", 18)
  .style("fill", function(d, i) {return colors.slice().reverse()[i];});
 
legend.append("text")
  .attr("x", width + 5)
  .attr("y", 9)
  .attr("dy", ".35em")
  .style("text-anchor", "start")
  .text(function(d, i) { 
    switch (i) {
      case 0: return "Anjou pears";
      case 1: return "Naval oranges";
      case 2: return "McIntosh apples";
      case 3: return "Red Delicious apples";
    }
  });


// Prep the tooltip bits, initial display is hidden
var tooltip = svg.append("g")
  .attr("class", "tooltip")
  .style("display", "none");
    
tooltip.append("rect")
  .attr("width", 30)
  .attr("height", 20)
  .attr("fill", "white")
  .style("opacity", 0.5);

tooltip.append("text")
  .attr("x", 15)
  .attr("dy", "1.2em")
  .style("text-anchor", "middle")
  .attr("font-size", "12px")
  .attr("font-weight", "bold");

svg {
  font: 10px sans-serif;
  shape-rendering: crispEdges;
}

.axis path,
.axis line {
  fill: none;
  stroke: #000;
}

path.domain {
  stroke: none;
}

.y .tick line {
  stroke: #ddd;
}

<script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>

Answer 1

我想您需要为每个矩形结果添加标签（工具提示）。经过很少的计算，我得到了：

http://jsfiddle.net/5o4jefap/87/

这是修改后的部分，没有附加鼠标事件：

var rect = groups.selectAll("rect")
   .data(function(d) { return d; })
  .enter()
  .append("g")
  .attr('class', 'tooltip')
  .append('rect')
  .attr("x", function(d) { return x(d.x); })
  .attr("y", function(d) { return y(d.y0 + d.y); })
  .attr("height", function(d) { return y(d.y0) - y(d.y0 + d.y); })
  .attr("width", x.rangeBand())

 groups.selectAll('.tooltip')
    .append("rect")
    .attr('width', 15)
    .attr('height', 15)
    .attr('fill', 'white')
    .style("opacity", 0.5)
    .attr('y',  function(d) { 
        var rectY = y(d.y0 + d.y),
            rectHalfHeight =  ((y(d.y0) - y(d.y0 + d.y)) / 2),
            tooltipHalfHeight = (this.getBBox().height / 2);

        return rectY + rectHalfHeight - tooltipHalfHeight; 
    })
   .attr("x", function(d) { 
        var rectX = x(d.x),
            rectHalfWidth =  (x.rangeBand() / 2),
            tooltipHalfWidth = (this.getBBox().width / 2);

        return rectX + rectHalfWidth - tooltipHalfWidth;
    })

  groups.selectAll('.tooltip')
      .append('text')
      .attr("x", function(d) { 
           var rectX = x(d.x),
               rectHalfWidth =  (x.rangeBand() / 2),
               tooltipHalfWidth = (this.getBBox().width / 2);

           return rectX + rectHalfWidth - tooltipHalfWidth;
       })
     .attr("y", function(d) { 
            var rectY = y(d.y0 + d.y),
                rectHalfHeight =  ((y(d.y0) - y(d.y0 + d.y)) / 2),
                tooltipHalfHeight = (this.getBBox().height / 2);

            return rectY + rectHalfHeight - tooltipHalfHeight; 
       })
     .attr("dy", '5px')
     .style("text-anchor", "middle")
     .attr("font-size", "12px")
     .attr("font-weight", "bold")
     .text(function (data) {
          return data.y;
      } );