css/css-tables/width-distribution/computing-column-measure-2.html

<!doctype html>
<script src='/resources/testharness.js'></script>
<script src='/resources/testharnessreport.js'></script>
<link rel="author" title="Richard Townsend" href="Richard.Townsend@arm.com" />
<link rel="help" href="https://drafts.csswg.org/css-tables-3/#computing-column-measures" />
<style type="text/css">
td {
    padding: 0;
}
div {
    /* Bug does not happen when the table's containing block is less
       than (100+200+300)=600px, so make sure sure that it's larger. */
    width: 750px;
}
</style>
<div>
    <h1>Width Distribution</h1>
    <h4>"Computing column measures"</h4>
    <p>This is testing that the table's auto columns are correctly recalculated after removing and adding a <code>col</code> element.
         <a href="https://www.w3.org/TR/CSS2/tables.html#auto-table-layout">Spec Text</a></p>

    <hr/>

    <table id="one" style="border: 1px solid orange">
        <colgroup>
            <col style="width: 100px" />
            <col style="width: 200px" />
            <col style="width: 300px;" id="hideable" />
        </colgroup>
        <tr>
            <td>100</td>
            <td>200</td>
            <td>300</td>
        </tr>
    </table>

    <table id="two" style="border: 1px solid orange">
        <colgroup>
            <col style="width: 100px; display: none;" id="displayable" />
            <col style="width: 200px;" />
            <col style="width: auto;" />
        </colgroup>
        <tr>
            <td>100</td>
            <td>200</td>
            <td>300</td>
        </tr>
    </table>

    <table id="ref" style="border: 1px solid orange">
        <colgroup>
            <col style="width: 100px;" />
            <col style="width: 200px;" />
            <col style="width: auto;" />
        </colgroup>
        <tr>
            <td>100</td>
            <td>200</td>
            <td>300</td>
        </tr>
    </table>

</div>
<script>
    test(function() {
        var one = document.getElementById('one');
        var two = document.getElementById('two');
        var ref = document.getElementById('ref');

        // Force initial layout.
        assert_greater_than(one.offsetWidth, ref.offsetWidth);

        // Display two's colgroup and hide one's.
        document.getElementById('displayable').style.display = 'table-column';
        document.getElementById('hideable').style.display = 'none';

        // Both tables should now match the reference.
        assert_equals(one.offsetWidth, ref.offsetWidth);
        assert_equals(two.offsetWidth, ref.offsetWidth);
    }, "Table recalculations should match the reference");
</script>