<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Subscripts and Superscripts metrics</title>
<link rel="help" href="https://w3c.github.io/mathml-core/#subscripts-and-superscripts-msub-msup-msubsup">
<meta name="assert" content="Verify metrics of scripted elements with tall scripts.">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/mathml/support/feature-detection.js"></script>
<style>
  math, mspace {
    font-size: 10px;
  }
</style>
<script>
  /* This test does not use any specific fonts and so the exact rules are not
  specified precisely. We assume reasonable values for script shifts and
  spacing. */

  function getBox(aId) {
    var box = document.getElementById(aId).getBoundingClientRect();
    box.middle = (box.bottom + box.top) / 2;
    return box;
  }

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

  var sizeArray = [50, 75, 100];

  function runTests() {
    test(function() {
      assert_true(MathMLFeatureDetection.has_mspace());

      var e = 1;
       assert_approx_equals(getBox("msubbase").middle, getBox("baseline").bottom, e, "msub base is placed on the baseline");
       assert_approx_equals(getBox("msupbase").middle, getBox("baseline").bottom, e, "msup base is placed on the baseline");
       assert_approx_equals(getBox("msubsupbase").middle, getBox("baseline").bottom, e, "msubsup base is placed on the baseline");
       assert_approx_equals(getBox("multibase").middle, getBox("baseline").bottom, e, "mmultiscripts baseis placed on the baseline");
    }, "Alignment on the baseline with different and large script heights");

    test(function() {
      assert_true(MathMLFeatureDetection.has_mspace());

      assert_greater_than(getBox("msubsub").top, getBox("msubbase").top, "msub: subscript is below the top of the base");
      assert_less_than(getBox("msupsup").bottom, getBox("msupbase").bottom, "msup: supscript is above the bottom of the base");
      assert_greater_than(getBox("msubsupsub").top, getBox("msubsupbase").top, "msubsup: subscript is below the top of the base");
      assert_less_than(getBox("msubsupsup").bottom, getBox("msubsupbase").bottom, "msubsup: supscript is above the bottom of the base");
      assert_greater_than(getBox("multipostsub").top, getBox("multibase").top, "mmultiscripts: postsubscript is below the top of the base");
      assert_less_than(getBox("multipostsup").bottom, getBox("multibase").bottom, "mmultiscripts: postsupscript is above the bottom of the base");
      assert_greater_than(getBox("multipresub").top, getBox("multibase").top, "mmultiscripts: presubscript is below the top of the base");
      assert_less_than(getBox("multipresup").bottom, getBox("multibase").bottom, "mmultiscripts: presupscript is above the bottom of the base");
    }, "Tall subscripts/superscripts are not placed too high/low");

    test(function() {
      assert_true(MathMLFeatureDetection.has_mspace());

      assert_greater_than(getBox("msubsupsub").top, getBox("msubsupsup").bottom, "msubsup: subscript is below the superscript");
      assert_greater_than(getBox("multipresub").top, getBox("multipresup").bottom, "mmultiscripts: presubscript is below the presuperscript");
      assert_greater_than(getBox("multipostsub").top, getBox("multipostsup").bottom, "mmultiscripts: postsubscript is below the postsuperscript");
    }, "No collisions for tall subscripts and superscripts");

    done();
  }
</script>
</head>
<body>
  <div id="log"></div>
  <p>
    <math>
      <mspace id="baseline" width="30px" height="2px" depth="0px" style="background: blue"/>
      <msub id="msub">
        <mspace id="msubbase" width="30px" height="15px" depth="15px" style="background: black"/>
        <mspace id="msubsub" width="10px" height="50px" depth="50px" style="background: black"/>
      </msub>
      <msup id="msup">
        <mspace id="msupbase" width="30px" height="15px" depth="15px" style="background: black"/>
        <mspace id="msupsup" width="10px" height="75px" depth="75px" style="background: black"/>
      </msup>
      <msubsup id="msubsup">
        <mspace id="msubsupbase" width="30px" height="15px" depth="15px" style="background: black"/>
        <mspace id="msubsupsub" width="10px" height="50px" depth="50px" style="background: black"/>
        <mspace id="msubsupsup" width="10px" height="75px" depth="75px" style="background: black"/>
      </msubsup>
      <mmultiscripts id="multi">
        <mspace id="multibase" width="30px" height="15px" depth="15px" style="background: black"/>
        <mspace id="multipostsub" width="10px" height="50px" depth="50px" style="background: black"/>
        <mspace id="multipostsup" width="10px" height="75px" depth="75px" style="background: black"/>
        <mprescripts/>
        <mspace id="multipresub" width="10px" height="50px" depth="50px" style="background: black"/>
        <mspace id="multipresup" width="10px" height="75px" depth="75px" style="background: black"/>
      </mmultiscripts>
    </math>
  </p>
</body>
</html>
