<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Space-like elements</title>
<link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
<link rel="help" href="https://w3c.github.io/mathml-core/#definition-of-space-like-elements">
<link rel="help" href="https://w3c.github.io/mathml-core/#operator-fence-separator-or-accent-mo">
<link rel="help" href="https://w3c.github.io/mathml-core/#layout-of-mrow">
<meta name="assert" content="Verify definition of space-like elements">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/mathml/support/feature-detection.js"></script>
<style>
  /* Default spacing of operator 'X' is 0.2777777777777778em so quite different
     from the measured/specified 0em and 1em. */
  math, math * {
      font: 25px/1 Ahem;
  }
  mn {
      color: black;
  }
  mo {
      color: yellow;
  }
  .testedElement, .testedElement * {
      color: blue !important;
      background: blue !important;
  }
</style>
<script>
  function spaceBefore(id) {
      var element = document.getElementById(id);
      var mnBeforeParent = element.parentNode.previousElementSibling;
      return element.getBoundingClientRect().left - mnBeforeParent.getBoundingClientRect().right;
  }

  function spaceAfter(id) {
      var element = document.getElementById(id);
      var mnAfterParent = element.parentNode.nextElementSibling;
      return mnAfterParent.getBoundingClientRect().left - element.getBoundingClientRect().right;
  }

  setup({ explicit_done: true });
  window.addEventListener("load", runTests);

  function runTests() {
      var epsilon = 1;
      var emToPx = 25;

      test(function() {
          assert_true(MathMLFeatureDetection.has_operator_spacing());
          assert_approx_equals(spaceBefore("maction1"), emToPx, epsilon);
          assert_approx_equals(spaceAfter("maction1"), emToPx, epsilon);
      }, "space-like maction");

      test(function() {
          assert_true(MathMLFeatureDetection.has_operator_spacing());
          assert_approx_equals(spaceBefore("maction2"), emToPx, epsilon);
          assert_approx_equals(spaceAfter("maction2"), emToPx, epsilon);
      }, "space-like maction (no first child)");

      test(function() {
          assert_approx_equals(spaceBefore("maction3"), 0, epsilon);
          assert_true(MathMLFeatureDetection.has_operator_spacing());
          assert_approx_equals(spaceAfter("maction3"), 2 * emToPx, epsilon);
      }, "non-space like maction (first child not space-like)");

      test(function() {
          assert_true(MathMLFeatureDetection.has_operator_spacing());
          assert_approx_equals(spaceBefore("semantics1"), emToPx, epsilon);
          assert_approx_equals(spaceAfter("semantics1"), emToPx, epsilon);
      }, "space-like semantics");

      test(function() {
          assert_true(MathMLFeatureDetection.has_operator_spacing());
          assert_approx_equals(spaceBefore("semantics2"), emToPx, epsilon);
          assert_approx_equals(spaceAfter("semantics2"), emToPx, epsilon);
      }, "space-like semantics (no first child)");

      test(function() {
          assert_true(MathMLFeatureDetection.has_operator_spacing());
          assert_approx_equals(spaceBefore("semantics3"), 0, epsilon);
          assert_approx_equals(spaceAfter("semantics3"), 2 * emToPx, epsilon);
      }, "non-space like semantics (first child not space-like)");

      done();
  }
</script>
</head>
<body>
  <div id="log"></div>
  <p>
    <math>
      <mn>X</mn>
      <mrow>
        <!-- maction is space-like when its first child exists and is space-like -->
        <maction id="maction1" class="testedElement" actiontype="statusline">
          <mtext>X</mtext>
          <mtext>STATUS MESSAGE</mtext>
        </maction>
        <mo lspace="1em" rspace="0em">X</mo>
      </mrow>
      <mn>X</mn>
    </math>
  </p>
  <p>
    <math>
      <mn>X</mn>
      <mrow>
        <!-- maction is not space-like when its first does not exist-like -->
        <maction id="maction2" class="testedElement" actiontype="statusline">
        </maction>
        <mo lspace="1em" rspace="0em">X</mo>
      </mrow>
      <mn>X</mn>
    </math>
  </p>
  <p>
    <math>
      <mn>X</mn>
      <mrow>
        <!-- maction is not space-like when its first is not space-like -->
        <maction id="maction3" class="testedElement" actiontype="statusline">
          <mn>1</mn>
          <mtext>STATUS MESSAGE</mtext>
        </maction>
        <mo lspace="1em" rspace="0em">X</mo>
      </mrow>
      <mn>X</mn>
    </math>
  </p>
  <p>
    <math>
      <mn>X</mn>
      <mrow>
        <!-- semantics is space-like when its first child exists and is space-like -->
        <semantics id="semantics1" class="testedElement" actiontype="statusline">
          <mtext>X</mtext>
          <annotation>TEXT ANNOTATION</annotation>
        </semantics>
        <mo lspace="1em" rspace="0em">X</mo>
      </mrow>
      <mn>X</mn>
    </math>
  </p>
  <p>
    <math>
      <mn>X</mn>
      <mrow>
        <!-- semantics is not space-like when its first does not exist-like -->
        <semantics id="semantics2" class="testedElement" actiontype="statusline">
        </semantics>
        <mo lspace="1em" rspace="0em">X</mo>
      </mrow>
      <mn>X</mn>
    </math>
  </p>
  <p>
    <math>
      <mn>X</mn>
      <mrow>
        <!-- semantics is not space-like when its first is not space-like -->
        <semantics id="semantics3" class="testedElement" actiontype="statusline">
          <mn>1</mn>
          <annotation>TEXT ANNOTATION</annotation>
        </semantics>
        <mo lspace="1em" rspace="0em">X</mo>
      </mrow>
      <mn>X</mn>
    </math>
  </p>
</body>
</html>
