How to make line clickable on google line chart

Question

I want to make a google line chart with a clickable lines but I seem to only be able to make the data points clickable. Is it possible to also make the line between the data points clickable?

Answer 1

use config option focusTarget: 'category'

when the line is clicked, the closest point will be selected.

although, in my current browser, I have to hold the point of the mouse,
~ 2px above the line before it will let me click.

but it does work versus focusTarget: 'datum',
which only allows the point to be clicked

see following, working snippet...

google.charts.load('current', {
  callback: function () {
    var data = new google.visualization.DataTable();
    data.addColumn('number', 'X');
    data.addColumn('number', 'Y');
    data.addRows([
      [0, 0],
      [6, 11],
      [12, 30],
      [18, 52],
      [24, 60],
      [30, 55],
      [36, 62],
      [42, 63],
      [48, 72],
      [54, 71],
      [60, 64],
      [66, 70]
    ]);

    // clickable line
    new google.visualization.LineChart(document.getElementById('chart_div0')).draw(data, {
      focusTarget: 'category'
    });

    // point only
    new google.visualization.LineChart(document.getElementById('chart_div1')).draw(data, {
      focusTarget: 'datum'
    });
  },
  packages:['corechart']
});

<script src="https://www.gstatic.com/charts/loader.js"></script>
<div>click line</div>
<div id="chart_div0"></div>
<div>point only</div>
<div id="chart_div1"></div>

EDIT

if focusTarget: 'category' doesn't work out,
another option would be to use the 'click' event

although, nothing is focused nor is a tooltip displayed, the line is still clickable.
but the location of the click needs to be fairly precise.
you can use targetID to determine what / which line was clicked...

see following snippet...

google.charts.load('current', {
  callback: function () {
    var data = new google.visualization.DataTable();
    data.addColumn('number', 'X0');
    data.addColumn('number', 'Y0');
    data.addColumn('number', 'Y1');
    data.addRows([
      [0, 0, 0],
      [6, 11, 7],
      [12, 30, 13],
      [18, 52, 19],
      [24, 60, 25],
      [30, 55, 31],
      [36, 62, 37],
      [42, 63, 43],
      [48, 72, 49],
      [54, 71, 55],
      [60, 64, 61],
      [66, 70, 67]
    ]);

    var chart = new google.visualization.LineChart(document.getElementById('chart_div1'));

    google.visualization.events.addListener(chart, 'click', function (props) {
      if (props.targetID.indexOf('line') > -1) {
        var hAxis = chart.getChartLayoutInterface().getHAxisValue(props.x);
        var vAxis = chart.getChartLayoutInterface().getVAxisValue(props.y);
        document.getElementById('chart_div0').innerHTML = props.targetID + ' clicked at [' + hAxis + ', ' + vAxis + ']';
      }
    });

    chart.draw(data, {
      lineSize: 3,
      pointSize: 5
    });
  },
  packages:['corechart']
});

<script src="https://www.gstatic.com/charts/loader.js"></script>
<div id="chart_div0">line click result shown here</div>
<div id="chart_div1"></div>