test_meta_viewport_change_content_among_multiple.html

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<!DOCTYPE HTML>

<html>

<head>

  <meta charset="utf-8">

  <title>content attribute changes among multiple meta viewport tags</title>

  <script src="/tests/SimpleTest/SimpleTest.js"></script>

  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>

  <meta id="first" name="viewport" content="width=980">

  <meta id="second" name="viewport" content="width=device-width, initial-scale=1">

  <script src="viewport_helpers.js"></script>

</head>

<body>

  <script type="application/javascript">

    "use strict";

    add_task(async function change_content_attribute() {

      await SpecialPowers.pushPrefEnv(scaleRatio(1.0));

      let info = getViewportInfo(800, 480);

      // The second meta tag is the one we use.

      is(info.defaultZoom, 1, "initial zoom is 1");

      is(info.width, 800, "width should be 800");

      is(info.height, 480, "height should be 480");

      // Change the content of the first one.

      // eslint-disable-next-line no-undef

      first.setAttribute("content", "width=640");

      // Now the first one is prior to the second one.

      info = getViewportInfo(800, 480);

      fuzzeq(info.defaultZoom, 800/640, "initial scale is calculated based on width");

      is(info.minZoom, 0.25, "minimum scale defaults to the absolute minimum");

      is(info.maxZoom, 10, "maximum scale defaults to the absolute maximum");

      is(info.width, 640, "width is the default width");

      is(info.height, 480*640/800, "height is proportional to displayHeight");

      // Cleat the second content.

      // eslint-disable-next-line no-undef

      second.setAttribute("content", "");

      // The second one is prior to the first one, but the content is empty so

      // that we should behave as if there is no meta viewport tag.

      info = getViewportInfo(800, 480);

      is(info.defaultZoom, 0.25, "initial scale is clamped to the default mimumim scale");

      is(info.minZoom, 0.25, "minimum scale defaults to the absolute minimum");

      is(info.maxZoom, 10, "maximum scale defaults to the absolute maximum");

      is(info.width, 980, "width should be 980");

      is(info.height,588, "height is proportional to displayHeight");

});

  </script>

</body>

</html>