gecko-dev/layout/reftests/xul/object-position-png-001.xul

<?xml version="1.0"?>
<!--
     Any copyright is dedicated to the Public Domain.
     http://creativecommons.org/publicdomain/zero/1.0/
-->
<window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
  <style xmlns="http://www.w3.org/1999/xhtml"><![CDATA[
      window { padding: 8px; }
      image {
        background: lightgray;
        margin-right: 2px;
        object-fit: contain;
        float: left;
        width: 20px;
        height: 20px;
      }

      .op_y-7  { object-position: 50%  -7% }
      .op_y13  { object-position: 50%  13% }
      .op_y23  { object-position: 50%  23% }
      .op_y50  { object-position: 50%  50% }
      .op_y75  { object-position: 50%  75% }
      .op_y88  { object-position: 50%  88% }
      .op_y111 { object-position: 50% 111% }

  ]]></style>
  <hbox>
    <image src="colors-16x8.png" class="op_y-7"/>
    <image src="colors-16x8.png" class="op_y13"/>
    <image src="colors-16x8.png" class="op_y23"/>
    <image src="colors-16x8.png" class="op_y50"/>
    <image src="colors-16x8.png" class="op_y75"/>
    <image src="colors-16x8.png" class="op_y88"/>
    <image src="colors-16x8.png" class="op_y111"/>
  </hbox>
</window>