nvd3/src/models/lineWithFocusChart.js

nv.models.lineWithFocusChart = function() {
  var margin = {top: 30, right: 30, bottom: 30, left: 60},
      margin2 = {top: 0, right: 30, bottom: 20, left: 60},
      color = nv.utils.defaultColor(),
      width = null,
      height = null,
      height2 = 100,
      showLegend = true,
      brushExtent = null,
      tooltips = true,
      tooltip = function(key, x, y, e, graph) {
        return '<h3>' + key + '</h3>' +
               '<p>' +  y + ' at ' + x + '</p>'
      };

  var lines = nv.models.line().clipEdge(true),
      lines2 = nv.models.line().interactive(false),
      x = lines.xScale(),
      y = lines.yScale(),
      x2 = lines2.xScale(),
      y2 = lines2.yScale(),
      xAxis = nv.models.axis().scale(x).orient('bottom').tickPadding(5),
      yAxis = nv.models.axis().scale(y).orient('left'),
      x2Axis = nv.models.axis().scale(x2).orient('bottom').tickPadding(5),
      y2Axis = nv.models.axis().scale(y2).orient('left'),
      legend = nv.models.legend().height(30),
      dispatch = d3.dispatch('tooltipShow', 'tooltipHide'),
      brush = d3.svg.brush().x(x2);


  var showTooltip = function(e, offsetElement) {
    var left = e.pos[0] + ( offsetElement.offsetLeft || 0 ),
        top = e.pos[1] + ( offsetElement.offsetTop || 0),
        x = xAxis.tickFormat()(lines.x()(e.point, e.pointIndex)),
        y = yAxis.tickFormat()(lines.y()(e.point, e.pointIndex)),
        content = tooltip(e.series.key, x, y, e, chart);

    nv.tooltip.show([left, top], content);
  };


  function chart(selection) {
    selection.each(function(data) {
      var container = d3.select(this),
          that = this;

      var availableWidth = (width  || parseInt(container.style('width')) || 960)
                             - margin.left - margin.right,
          availableHeight = (height || parseInt(container.style('height')) || 400)
                             - margin.top - margin.bottom - height2,
          availableHeight2 = height2 - margin2.top - margin2.bottom;


      brush.on('brush', onBrush);


      var wrap = container.selectAll('g.nv-wrap.nv-lineWithFocusChart').data([data]);
      var gEnter = wrap.enter().append('g').attr('class', 'nvd3 nv-wrap nv-lineWithFocusChart').append('g');

      gEnter.append('g').attr('class', 'nv-legendWrap');

      var focusEnter = gEnter.append('g').attr('class', 'nv-focus');
      focusEnter.append('g').attr('class', 'nv-x nv-axis');
      focusEnter.append('g').attr('class', 'nv-y nv-axis');
      focusEnter.append('g').attr('class', 'nv-linesWrap');

      var contextEnter = gEnter.append('g').attr('class', 'nv-context');
      contextEnter.append('g').attr('class', 'nv-x nv-axis');
      contextEnter.append('g').attr('class', 'nv-y nv-axis');
      contextEnter.append('g').attr('class', 'nv-linesWrap');
      contextEnter.append('g').attr('class', 'nv-brushBackground');
      contextEnter.append('g').attr('class', 'nv-x nv-brush');



      var g = wrap.select('g');




      if (showLegend) {
        legend.width(availableWidth);

        g.select('.nv-legendWrap')
            .datum(data)
            .call(legend);

        if ( margin.top != legend.height()) {
          margin.top = legend.height();
          availableHeight = (height || parseInt(container.style('height')) || 400)
                             - margin.top - margin.bottom - height2;
        }

        g.select('.nv-legendWrap')
            .attr('transform', 'translate(0,' + (-margin.top) +')')
      }


      lines
        .width(availableWidth)
        .height(availableHeight)
        .color(data.map(function(d,i) {
          return d.color || color(d, i);
        }).filter(function(d,i) { return !data[i].disabled }));

      lines2
        .defined(lines.defined())
        .width(availableWidth)
        .height(availableHeight2)
        .x(lines.x())
        .y(lines.y())
        .color(data.map(function(d,i) {
          return d.color || color(d, i);
        }).filter(function(d,i) { return !data[i].disabled }));


      g.attr('transform', 'translate(' + margin.left + ',' + margin.top + ')');


      /*
      var focusLinesWrap = g.select('.nv-focus .nv-linesWrap')
          .datum(data.filter(function(d) { return !d.disabled }))

      d3.transition(focusLinesWrap).call(lines);
     */


      xAxis
        .ticks( availableWidth / 100 )
        .tickSize(-availableHeight, 0);

      yAxis
        .ticks( availableHeight / 36 )
        .tickSize( -availableWidth, 0);

      g.select('.nv-focus .nv-x.nv-axis')
          .attr('transform', 'translate(0,' + y.range()[0] + ')');


/*
      d3.transition(g.select('.nv-focus .nv-x.nv-axis'))
          .call(xAxis);


      d3.transition(g.select('.nv-focus .nv-y.nv-axis'))
          .call(yAxis);
         */



      g.select('.nv-context')
          .attr('transform', 'translate(0,' + ( availableHeight + margin.bottom + margin2.top) + ')')

      var contextLinesWrap = g.select('.nv-context .nv-linesWrap')
          .datum(data.filter(function(d) { return !d.disabled }))

      d3.transition(contextLinesWrap).call(lines2);



      if (brushExtent) brush.extent(brushExtent);

      var brushBG = g.select('.nv-brushBackground').selectAll('g')
          .data([brushExtent || brush.extent()])

      var brushBGenter = brushBG.enter()
          .append('g');

      brushBGenter.append('rect')
          .attr('class', 'left')
          .attr('x', 0)
          .attr('y', 0)
          .attr('height', availableHeight2);

      brushBGenter.append('rect')
          .attr('class', 'right')
          .attr('x', 0)
          .attr('y', 0)
          .attr('height', availableHeight2);


      function updateBrushBG() {
        //nv.log('test', brush.empty(), brush.extent());
        if (!brush.empty()) brush.extent(brushExtent);
        brushBG
            .data([brush.empty() ? x2.domain() : brushExtent])
            //.data([brush.empty() ? xi.domain() : brush.extent()])
            .each(function(d,i) {
              var leftWidth = x2(d[0]) - x.range()[0],
                  rightWidth = x.range()[1] - x2(d[1]);
              d3.select(this).select('.left')
                .attr('width',  leftWidth < 0 ? 0 : leftWidth);

              d3.select(this).select('.right')
                .attr('x', x2(d[1]))
                .attr('width', rightWidth < 0 ? 0 : rightWidth);
            });
      }



      gBrush = g.select('.nv-x.nv-brush')
          .call(brush);
      gBrush.selectAll('rect')
          //.attr('y', -5)
          .attr('height', availableHeight2);
      gBrush.selectAll('.resize').append('path').attr('d', resizePath);


      //if (brushExtent) onBrush();
      onBrush();



      x2Axis
        //.tickFormat(xAxis.tickFormat())  //exposing x2Axis so user can set differently
        .ticks( availableWidth / 100 )
        .tickSize(-availableHeight2, 0);

      g.select('.nv-context .nv-x.nv-axis')
          .attr('transform', 'translate(0,' + y2.range()[0] + ')');
      d3.transition(g.select('.nv-context .nv-x.nv-axis'))
          .call(x2Axis);


      y2Axis
        //.tickFormat(yAxis.tickFormat())  //exposing y2Axis so user can set differently
        .ticks( availableHeight2 / 36 )
        .tickSize( -availableWidth, 0);

      d3.transition(g.select('.nv-context .nv-y.nv-axis'))
          .call(y2Axis);



      g.select('.nv-focus .nv-x.nv-axis')
          .attr('transform', 'translate(0,' + y.range()[0] + ')');
      g.select('.nv-context .nv-x.nv-axis')
          .attr('transform', 'translate(0,' + y2.range()[0] + ')');


      legend.dispatch.on('legendClick', function(d,i) { 
        d.disabled = !d.disabled;

        if (!data.filter(function(d) { return !d.disabled }).length) {
          data.map(function(d) {
            d.disabled = false;
            wrap.selectAll('.nv-series').classed('disabled', false);
            return d;
          });
        }

        selection.transition().call(chart);
      });


/*
      //
      legend.dispatch.on('legendMouseover', function(d, i) {
        d.hover = true;
        selection.transition().call(chart)
      });

      legend.dispatch.on('legendMouseout', function(d, i) {
        d.hover = false;
        selection.transition().call(chart)
      });
*/

      lines.dispatch.on('elementMouseover.tooltip', function(e) {
        e.pos = [e.pos[0] +  margin.left, e.pos[1] + margin.top];
        dispatch.tooltipShow(e);
      });
      if (tooltips) dispatch.on('tooltipShow', function(e) { showTooltip(e, that.parentNode) } ); // TODO: maybe merge with above?

      lines.dispatch.on('elementMouseout.tooltip', function(e) {
        dispatch.tooltipHide(e);
      });
      if (tooltips) dispatch.on('tooltipHide', nv.tooltip.cleanup);



      // Taken from crossfilter (http://square.github.com/crossfilter/)
      function resizePath(d) {
        var e = +(d == 'e'),
            x = e ? 1 : -1,
            y = availableHeight2 / 3;
        return 'M' + (.5 * x) + ',' + y
            + 'A6,6 0 0 ' + e + ' ' + (6.5 * x) + ',' + (y + 6)
            + 'V' + (2 * y - 6)
            + 'A6,6 0 0 ' + e + ' ' + (.5 * x) + ',' + (2 * y)
            + 'Z'
            + 'M' + (2.5 * x) + ',' + (y + 8)
            + 'V' + (2 * y - 8)
            + 'M' + (4.5 * x) + ',' + (y + 8)
            + 'V' + (2 * y - 8);
      }



      function onBrush() {
        //nv.log(brush.empty(), brush.extent(), x2(brush.extent()[0]), x2(brush.extent()[1]));

  /*
        focusLinesWrap.call(lines)
        //var focusLinesWrap = g.select('.focus .linesWrap')
        g.select('.nv-focus .nv-x.nv-axis').call(xAxis);
        g.select('.nv-focus .nv-y.nv-axis').call(yAxis);
      }
  */
        brushExtent = brush.empty() ? null : brush.extent();
        extent = brush.empty() ? x2.domain() : brush.extent();

        updateBrushBG();



        var focusLinesWrap = g.select('.nv-focus .nv-linesWrap')
            .datum(
              data
                .filter(function(d) { return !d.disabled })
                .map(function(d,i) {
                  return {
                    key: d.key,
                    values: d.values.filter(function(d,i) {
                      return lines.x()(d,i) >= extent[0] && lines.x()(d,i) <= extent[1];
                    })
                  }
                })
            )

        d3.transition(focusLinesWrap).call(lines);


        /*
        var contextLinesWrap = g.select('.context .linesWrap')
            .datum(data.filter(function(d) { return !d.disabled }))

        d3.transition(contextLinesWrap).call(lines2);
       */


        d3.transition(g.select('.nv-focus .nv-x.nv-axis'))
            .call(xAxis);

        d3.transition(g.select('.nv-focus .nv-y.nv-axis'))
            .call(yAxis);
      }



    });



    //TODO: decide if this is a good idea, and if it should be in all models
    chart.update = function() { chart(selection) };
    chart.container = this; // I need a reference to the container in order to have outside code check if the chart is visible or not


    return chart;
  }


  chart.dispatch = dispatch;
  chart.legend = legend;
  chart.xAxis = xAxis;
  chart.yAxis = yAxis;
  chart.x2Axis = x2Axis;
  chart.y2Axis = y2Axis;

  d3.rebind(chart, lines, 'defined', 'isArea', 'x', 'y', 'size', 'xDomain', 'yDomain', 'forceX', 'forceY', 'interactive', 'clipEdge', 'clipVoronoi', 'id');


  chart.margin = function(_) {
    if (!arguments.length) return margin;
    margin = _;
    return chart;
  };

  chart.margin2 = function(_) {
    if (!arguments.length) return margin2;
    margin2 = _;
    return chart;
  };

  chart.width = function(_) {
    if (!arguments.length) return width;
    width = _;
    return chart;
  };

  chart.height = function(_) {
    if (!arguments.length) return height;
    height = _;
    return chart;
  };

  chart.color = function(_) {
    if (!arguments.length) return color;
    color =nv.utils.getColor(_);
    legend.color(color);
    return chart;
  };

  chart.showLegend = function(_) {
    if (!arguments.length) return showLegend;
    showLegend = _;
    return chart;
  };

  chart.tooltips = function(_) {
    if (!arguments.length) return tooltips;
    tooltips = _;
    return chart;
  };

  chart.tooltipContent = function(_) {
    if (!arguments.length) return tooltip;
    tooltip = _;
    return chart;
  };

  chart.interpolate = function(_) {
    if (!arguments.length) return lines.interpolate();
    lines.interpolate(_);
    lines2.interpolate(_);
    return chart;
  };

  return chart;
}