update: function()

in kitsune/sumo/static/sumo/js/rickshaw_utils.js [1160:1226]
54 lines of code
18 McCabe index (conditional complexity)

    update: function (e) {

      e = e || this.lastEvent;
      if (!e) { return; }
      this.lastEvent = e;

      if (!e.target.nodeName.match(/^(path|svg|rect)$/)) { return; }

      var i;
      var graph = this.graph;

      var eventX = e.offsetX || e.layerX;
      var eventY = e.offsetY || e.layerY;

      var points = [];
      var data = this.graph.stackedData[0];

      // The x value in the units of the graph that corresponds to the pointer.
      var domainX = graph.x.invert(eventX);
      var xMin = graph.window.xMin || data[0].x;
      var xMax = graph.window.xMax || data.slice(-1)[0].x;
      var domainIndexScale = d3.scale.linear()
        .domain([xMin, xMax])
        .range([0, data.length - 1]);

      var dataIndex = Math.round(domainIndexScale(domainX)) || 0;
      // clamp dataIndex between 0 and length;
      dataIndex = Math.max(0, Math.min(dataIndex, data.length - 1));

      // Sometimes the data has holes in it. In that case, the dataIndex
      // will be wrong. Walk around the graph until we are at about the
      // right point.
      while (dataIndex >= 0 && dataIndex < data.length - 1) {
        if (data[dataIndex].x <= domainX && domainX <= data[dataIndex + 1].x) {
          // the right one.
          break;
        }

        // Move to the left or right, as appropratiate.
        if (data[dataIndex].x > domainX) { dataIndex -= 1; } else { dataIndex += 1; }
      }

      // Choose the closer of the two points.
      if (data[dataIndex + 1] &&
        data[dataIndex + 1].x - domainX < domainX - data[dataIndex].x) {
        dataIndex += 1;
      }

      var activeSeries = graph.series.active();

      for (i = 0; i < graph.stackedData.length; i += 1) {
        points.push({
          x: graph.stackedData[i][dataIndex].x,
          y: graph.stackedData[i][dataIndex].y,
          series: activeSeries[i]
        });
      }

      if (this.visible) {
        this.render({
          eventX: eventX,
          eventY: eventY,
          x: points[0].x,
          points: points
        });
      }
    },