D3 Examples - Canvas area charts with button zoom

xxxxxxxxxx
 
<!DOCTYPE html>
<head>
<meta charset="utf-8">
<style>
​
  /* to prevent browser overscrolling */
  html {
    overflow: hidden;
  }
​
  /* for retina display */
  canvas, #zoom-rectangle {
    width: 960px;
    height: 500px;
  }
  
  #zoom-rectangle {
    position: relative;
    top: -500px;
  }
​
</style>
</head>
<body>
<canvas width="1920" height="1000"></canvas>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
​
var canvas = document.querySelector("canvas"),
    context = canvas.getContext("2d");
​
var margin = {top: 20, right: 20, bottom: 30, left: 50},
    width = canvas.width - margin.left - margin.right,
    height = canvas.height - margin.top - margin.bottom;
​
context.translate(margin.left, margin.top);
​
var parseDate = d3.timeParse("%Y/%m/%d %H:%M");
​
var color = d3.scaleOrdinal()
  .domain(["PVkW", "TBLkW"])
  .range(["rgba(249, 208, 87, 1.0)", "rgba(54, 174, 175, 0.6)"]);
​
var x = d3.scaleTime()
    .range([0, width]);
​
var x2 = d3.scaleTime()   // for zooming
    .range([0, width]);
​
var y = d3.scaleLinear()
    .range([height, 0]);
​
var area = d3.area()
    .x(function(d) { return x(d.date); })
    .y0(y(0))
    .y1(function(d) { return y(d.kW); })
    .curve(d3.curveStep)
    .context(context);
  
var zoomRect = d3.select(document.body).append("svg")
  //     .attr("width", this.svgDims.width)
  //     .attr("height", this.svgDims.height)
  .attr("id", "zoom-rectangle");
​
d3.csv("kW.csv", type, function(error, data) {
  if (error) throw error;
​
  var sources = data.columns.slice(1).map(function(id) {
    return {
      id: id,
      values: data.map(function(d) {
        return {date: d.date, kW: d[id]};
      })
    };
  });
​
  var len = sources.length;
​
  x.domain(d3.extent(data, function(d) { return d.date; }));
  x2.domain(x.domain());
  y.domain([
    0,
    d3.max(sources, function(c) { return d3.max(c.values, function(v) { return v.kW; }); })
  ]);
  color.domain(sources.map(function(c) { return c.id; }));
​
  var zoom = d3.zoom()
    .scaleExtent([1, Infinity])
    .translateExtent([[0, 0], [width, height]])
    .extent([[0, 0], [width, height]])
      .on("zoom", zoomed);
  
  zoomRect.call(zoom);
​
  function draw() {
    context.clearRect(-margin.left, -margin.top, canvas.width, canvas.height);
​
    context.save();
​
    // clip path
    context.beginPath()
    context.rect(0, 0, width, height);
    context.clip();
​
    for (i=0; i<len; i++) {
      context.beginPath();
      area(sources[i].values);
      context.fillStyle = color(sources[i].id);
      context.fill();
    }
​
    context.restore();
  }
​
  draw();
​
  function zoomed() {
     var t = d3.event.transform;
     x = t.rescaleX(x2);
​
     draw();
  }
});
​
function type(d, _, columns) {
  d.date = parseDate(d.date);
  for (var i = 1, n = columns.length, c; i < n; ++i) d[c = columns[i]] = +d[c];
  return d;
}
​
var date = parseDate("2015/02/07 12:00");
var kW = 466.0;
var buttonSVG = zoomRect.append('svg')
    .attr("x", x(date))
    .attr("y", y(kW));
  
var button = buttonSVG.append('g')
    .html(
    `
    <circle class="st0 celestial-ring ripple-priority" cx="15" cy="15" r="12" />
    <line class="st2" x1="15" y1="10" x2="15" y2="12"/>
    <line class="st2" x1="15" y1="20" x2="15" y2="18"/>
    <line class="st2" x1="9" y1="15" x2="12" y2="15"/>
    <line class="st2" x1="20" y1="15" x2="18" y2="15"/>
    <circle class="hit-area" cx="15" cy="15" r="50" />
    `
    );
  
​
  
  
  
//   createParentAnnotationContainer() {
//     self = this;
//     self.pointX = self.xScale(this.date);
​
//     this.$annotationCard = this.$annotationGroup.append('svg')
//       .datum(this.data)
//       .attr("class", d => { return `annotation ${d.category}`;})
//       .attr('x', self.pointX)
//       .attr('y',
//             d => {
//       let kW;
//       if (d.yPositionOverride) {
//         kW = (d.yPositionOverride === 'consumption') ? this.values.consumption : d.yPositionOverride;
//       } else {
//         kW = this.values.production;
//       }
//       self.pointY = this.yScale(kW)
//       return this.pointY;
//     });
//   }
  
//  createIconButton() {
//     this.$iconButton = this.$annotationCard.append('g')
//       .attr("class", d => { return `iconButton ${d.category}`; })
//       .html(d => { return this.pickIcon(d.category); })
//       .on("mouseover", () => {
//         this.setActive(true, true);
//       })
//       .on("mouseout", () => {
//         this.setActive(false, true);
//       })
//       .on("mousedown", () => {
//         event.stopPropagation();
//         if (this.zoomLevel === 0) {
//           event.stopPropagation();
//           appModel.requestZoomToExtent(this.zoomToExtent[0], this.zoomToExtent[1]);
//           if (this.compareCurves) {
//             document.getElementById("threshold").style.visibility = 'hidden';
//           }
//           // this.setActive(!this.isActive, true);
//         } else {
//           event.stopPropagation();
//           appModel.requestZoomOut();
//           appModel.setLiquidFunVisibility(false);
//           document.getElementById("threshold").style.visibility = 'visible';
//         }
//       });
//   }
​
</script>
</body>
</html>
​
    