How to change selected column border color & width in Google Charts?

Question

I am using Google Charts. I want to change border color & width of selected column. By default stroke color is white and width is 1. I want to change border color to black and width to 2.

Code :

var data = google.visualization.arrayToDataTable(mydata);
var options = {
                    width: 600,
                    height: 400,
                    legend: {position: 'top', maxLines: 4},
                    bar: {groupWidth: '50%'},
                    isStacked: true
                    };
var chart = new google.visualization.ColumnChart(document.getElementById('mydiv'));
chart.draw(data, options);

Answer 1

You could set column style (border color & width) by applying Column styles on the selected column using select event as demonstrated below:

google.load("visualization", '1.1', { packages: ['corechart'] });
google.setOnLoadCallback(drawChart);
function drawChart() {

    var data = google.visualization.arrayToDataTable([
      ['Genre', 'Fantasy & Sci Fi', 'Romance', 'Mystery/Crime', 'General','Western', 'Literature'],
      ['2010', 10, 24, 20, 32, 18, 5],
      ['2020', 16, 22, 23, 30, 16, 9],
      ['2030', 28, 19, 29, 30, 12, 13]
    ]);

    var options = {
        width: 600,
        height: 400,
        legend: { position: 'top', maxLines: 3 },
        bar: { groupWidth: '75%' },
        isStacked: true,
    };

    var view = new google.visualization.DataView(data);
    var chart = new google.visualization.ColumnChart(document.getElementById('columnchart_stacked'));
    google.visualization.events.addListener(chart, 'select', function () {
        highlightBar(chart,options,view);
    });
    chart.draw(data, options);
}


function highlightBar(chart,options,view) {
    var selection = chart.getSelection();
    if (selection.length) {
        var row = selection[0].row;
        var column = selection[0].column;
        
        
        //1.insert style role column to highlight selected column 
        var styleRole = {
            type: 'string',
            role: 'style',
            calc: function(dt, i) {
                return (i == row) ? 'stroke-color: #000000; stroke-width: 2' : null;
            }
        };
        var indexes = [0, 1, 2, 3, 4, 5, 6];
        var styleColumn = findStyleRoleColumn(view)   
        if (styleColumn != -1 && column > styleColumn)
           indexes.splice(column, 0, styleRole);
        else     
           indexes.splice(column+1, 0, styleRole);
        view.setColumns(indexes);
        //2.redraw the chart
        chart.draw(view, options); 
    }
}

function findStyleRoleColumn(view) {
    for (var i = 0; i < view.getNumberOfColumns() ; i++) {
        if (view.getColumnRole(i) == "style") {
            return i;
        }
    }
    return -1;
}

<script type="text/javascript" src="https://www.google.com/jsapi?autoload={'modules':[{'name':'visualization','version':'1.1','packages':['corechart']}]}"></script>
<div id="columnchart_stacked" style="width: 600px; height: 420px;"></div>

JSFiddle

Answer 2

There is no build-in option to set this style, but you may ovveride these settings for stroke-color/width via CSS:

google.load('visualization', '1', {packages: ['corechart']});
google.setOnLoadCallback(drawStacked);

function drawStacked() {
      var data = new google.visualization.DataTable();
      data.addColumn('timeofday', 'Time of Day');
      data.addColumn('number', 'Motivation Level');
      data.addColumn('number', 'Energy Level');

      data.addRows([
        [{v: [8, 0, 0], f: '8 am'}, 1, .25],
        [{v: [9, 0, 0], f: '9 am'}, 2, .5],
        [{v: [10, 0, 0], f:'10 am'}, 3, 1],
        [{v: [11, 0, 0], f: '11 am'}, 4, 2.25],
        [{v: [12, 0, 0], f: '12 pm'}, 5, 2.25],
        [{v: [13, 0, 0], f: '1 pm'}, 6, 3],
        [{v: [14, 0, 0], f: '2 pm'}, 7, 4],
        [{v: [15, 0, 0], f: '3 pm'}, 8, 5.25],
        [{v: [16, 0, 0], f: '4 pm'}, 9, 7.5],
        [{v: [17, 0, 0], f: '5 pm'}, 10, 10],
      ]);

      var options = {
                    legend: {position: 'top', maxLines: 4},
                    
                    isStacked: true};

      var chart = new google.visualization.ColumnChart(document.getElementById('mydiv'));
      chart.draw(data, options);
    }

#mydiv svg>g>g>g>g>rect[stroke="#ffffff"][stroke-width="1"] {
  stroke: black !important;
  stroke-width: 2px !important;
}

<div id="mydiv"></div>
<script type="text/javascript" src="https://www.google.com/jsapi"></script>