css/css-break/widows-orphans-013.html

<!DOCTYPE html>

  <meta charset="UTF-8">

  <title>CSS Fragmentation level 3 Test: 'orphans', 'widows' and content distribution in columns</title>

  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
  <link rel="help" href="https://www.w3.org/TR/css-break-3/#widows-orphans">
  <link rel="match" href="reference/widows-orphans-013-ref.html">

  <!--
  Date created: November 26th 2020
  Last modified: December 6th 2020
  -->

  <!--

  Bug 137367: Implement orphans and widows
  https://bugzilla.mozilla.org/show_bug.cgi?id=137367

  -->

  <meta name="assert" content="When column boxes are filled sequentially, their content should be distributed and fragmented in accordance with the 'orphans' and the 'widows' declarations. In the test, since the 3rd column box was going to get only 1 line box, then a class B break point should occur between the '15' and the '16' so that there is a minimum of 4 line boxes at the top of the 3rd column box. In doing so, the 'orphans: 6' declaration is still honored.">

  <style>
  div
    {
      border: orange solid 4px;
      font-size: 20px;
      line-height: 1.3; /* computes to 26px */
      height: 234px; /* Therefore, exactly 9 line boxes */
      margin-bottom: 1em;
      padding: 0.5em; /* computes to 10px */
      width: 460px;

      columns: 4 auto;

      column-fill: auto;

      column-gap: 1em; /* computes to 20px */

      column-rule: blue solid 4px;
    }

  div#test
    {
      orphans: 6;
      widows: 4;
    }

  div#reference
    {
      orphans: 1;
      widows: 1;
    }
  </style>

  <p>Test passes if the numbers inside both orange-bordered rectangles are <strong>distributed identically</strong>.

  <div id="test">1<br>2<br>3<br>4<br>5<br>6<br>7<br>8<br>9<br>10<br>11<br>12<br>13<br>14<br>15<br>16<br>17<br>18<br>19</div>

  <div id="reference">1<br>2<br>3<br>4<br>5<br>6<br>7<br>8<br>9<br>10<br>11<br>12<br>13<br>14<br>15<br><br><br><br>16<br>17<br>18<br>19</div>