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="" name="flags">
  24   <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">
  25
  26   <style>
  27   div#control
  28     {
  29       background-color: red;
  30       border: solid green;
  31       border-width: 50px 0 0 50px;
  32       height: 50px;
  33       margin-bottom: -100px;
  34       width: 50px;
  35     }
  36
  37   div#target
  38     {
  39       background-attachment: local;
  40       background-image: url("support/100x100-gr-rr.png");
  41       background-repeat: no-repeat;
  42       background-position: center;
  43       font-family: Ahem;
  44       font-size: 100px;
  45       line-height: 1;
  46       height: 100px;
  47       overflow: hidden;
  48       width: 100px;
  49     }
  50   </style>
  51
  52   <body>
  53
  54   <p>Test passes if there is a filled green square and <strong>no red</strong>.
  55
  56   <div id="control"></div>
  57
  58   <div id="target">&nbsp;&nbsp;<br>&nbsp;&nbsp;</div>
  59
  60   <!--
  61
  62   div#control is
  63
  64   (0px, 0px)              (100px, 0px)
  65   +.......................+
  66   |                       |
  67   |                       |
  68   |     green  area       |
  69   |                       |
  70   |                       |
  71   |     green  area       |
  72   |                       |
  73   |             +........+|
  74   |   green     |  red   ||
  75   |    area     | area   ||
  76   |             |        ||
  77   |             +........+|
  78   +.......................+
  79 (0px, 100px)            (100px, 100px)
  80
  81
  82   =   =   =   =   =   =   =
  83
  84
  85   div#target with background-position: top left
  86
  87   (0px, 0px)              (100px, 0px)
  88   +.......................+
  89   | +........+            |
  90   | | green  |    red     |
  91   | |  area  |    area    |
  92   | |        |            |
  93   | +........+            |
  94   |                       |
  95   |      red  area        |
  96   |                       |
  97   |                       |
  98   |      red  area        |
  99   |                       |
 100   |                       |
 101   +.......................+
 102 (0px, 100px)            (100px, 100px)
 103
 104
 105   =   =   =   =   =   =   =
 106
 107
 108   div#target with background-position: center
 109
 110   (0px, 0px)              (100px, 0px)
 111   +.......................+
 112   |                       |
 113   |     green  area       |
 114   |                       |   overflowed
 115   |                       |      area
 116   |     green  area       |        |
 117   |                       |        V
 118   |           +...........| ...........+
 119   |           | +........+|             |
 120   |   green   | |  green ||     red     |
 121   |    area   | |  area  ||    area     |
 122   |           | |        ||             |
 123   |           | +........+|             |
 124   +.......................+             |
 125               |                         |
 126               |        red  area        |   <==  overflowed
 127               |                         |   <==     area
 128               |        red  area        |
 129               |                         |
 130               |                         |
 131               +.........................+
 132
 133   -->