testing/web-platform/tests/css/css-backgrounds/background-attachment-353.html

   1 <!DOCTYPE html>
   2 <html class="reftest-wait">
   3   <meta charset="UTF-8">
   4
   5   <title>CSS Background and Borders Test: 'background-attachment: local' and 'overflow: hidden'</title>
   6
   7   <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
   8   <link rel="help" href="http://www.w3.org/TR/css3-background/#the-background-attachment">
   9   <link rel="match" href="../reference/ref-filled-green-100px-square.xht">
  10   <script src="/common/reftest-wait.js"></script>
  11   <link rel="preload" as="image" href="support/100x100-gr-rr.png" onload="takeScreenshot()" />
  12   <link rel="stylesheet" type="text/css" href="/fonts/ahem.css">
  13
  14   <!--
  15
  16   More info:
  17
  18   Re: [css3-background] background-attachment: local
  19   http://lists.w3.org/Archives/Public/www-style/2013May/0542.html
  20
  21   -->
  22
  23   <meta content="This test checks that when an element has 'background-attachment: local', then the background image is fixed with regard to what is the element's scrollable area and not to its viewport. In this test, what would be the scrollable area for the div#target element is where the red area of its background image 100x100-gr-rr.png is and such area is clipped due to 'overflow: hidden'." name="assert">
  24
  25   <style>
  26   div#control
  27     {
  28       background-color: red;
  29       border: solid green;
  30       border-width: 50px 0 0 50px;
  31       height: 50px;
  32       margin-bottom: -100px;
  33       width: 50px;
  34     }
  35
  36   div#target
  37     {
  38       background-attachment: local;
  39       background-image: url("support/100x100-gr-rr.png");
  40       background-repeat: no-repeat;
  41       background-position: center;
  42       font-family: Ahem;
  43       font-size: 100px;
  44       line-height: 1;
  45       height: 100px;
  46       overflow: hidden;
  47       width: 100px;
  48     }
  49   </style>
  50
  51   <body>
  52
  53   <p>Test passes if there is a filled green square and <strong>no red</strong>.
  54
  55   <div id="control"></div>
  56
  57   <div id="target">&nbsp;&nbsp;<br>&nbsp;&nbsp;</div>
  58
  59   <!--
  60
  61   div#control is
  62
  63   (0px, 0px)              (100px, 0px)
  64   +.......................+
  65   |                       |
  66   |                       |
  67   |     green  area       |
  68   |                       |
  69   |                       |
  70   |     green  area       |
  71   |                       |
  72   |             +........+|
  73   |   green     |  red   ||
  74   |    area     | area   ||
  75   |             |        ||
  76   |             +........+|
  77   +.......................+
  78 (0px, 100px)            (100px, 100px)
  79
  80
  81   =   =   =   =   =   =   =
  82
  83
  84   div#target with background-position: top left
  85
  86   (0px, 0px)              (100px, 0px)
  87   +.......................+
  88   | +........+            |
  89   | | green  |    red     |
  90   | |  area  |    area    |
  91   | |        |            |
  92   | +........+            |
  93   |                       |
  94   |      red  area        |
  95   |                       |
  96   |                       |
  97   |      red  area        |
  98   |                       |
  99   |                       |
 100   +.......................+
 101 (0px, 100px)            (100px, 100px)
 102
 103
 104   =   =   =   =   =   =   =
 105
 106
 107   div#target with background-position: center
 108
 109   (0px, 0px)              (100px, 0px)
 110   +.......................+
 111   |                       |
 112   |     green  area       |
 113   |                       |   overflowed
 114   |                       |      area
 115   |     green  area       |        |
 116   |                       |        V
 117   |           +...........| ...........+
 118   |           | +........+|             |
 119   |   green   | |  green ||     red     |
 120   |    area   | |  area  ||    area     |
 121   |           | |        ||             |
 122   |           | +........+|             |
 123   +.......................+             |
 124               |                         |
 125               |        red  area        |   <==  overflowed
 126               |                         |   <==     area
 127               |        red  area        |
 128               |                         |
 129               |                         |
 130               +.........................+
 131
 132   -->