src/css/support.js

   1 define( [
   2         "../core",
   3         "../var/document",
   4         "../var/documentElement",
   5         "../var/support"
   6 ], function( jQuery, document, documentElement, support ) {
   7
   8 "use strict";
   9
  10 ( function() {
  11
  12         // Executing both pixelPosition & boxSizingReliable tests require only one layout
  13         // so they're executed at the same time to save the second computation.
  14         function computeStyleTests() {
  15
  16                 // This is a singleton, we need to execute it only once
  17                 if ( !div ) {
  18                         return;
  19                 }
  20
  21                 container.style.cssText = "position:absolute;left:-11111px;width:60px;" +
  22                         "margin-top:1px;padding:0;border:0";
  23                 div.style.cssText =
  24                         "position:relative;display:block;box-sizing:border-box;overflow:scroll;" +
  25                         "margin:auto;border:1px;padding:1px;" +
  26                         "width:60%;top:1%";
  27                 documentElement.appendChild( container ).appendChild( div );
  28
  29                 var divStyle = window.getComputedStyle( div );
  30                 pixelPositionVal = divStyle.top !== "1%";
  31
  32                 // Support: Android 4.0 - 4.3 only, Firefox <=3 - 44
  33                 reliableMarginLeftVal = roundPixelMeasures( divStyle.marginLeft ) === 12;
  34
  35                 // Support: Android 4.0 - 4.3 only, Safari <=9.1 - 10.1, iOS <=7.0 - 9.3
  36                 // Some styles come back with percentage values, even though they shouldn't
  37                 div.style.right = "60%";
  38                 pixelBoxStylesVal = roundPixelMeasures( divStyle.right ) === 36;
  39
  40                 // Support: IE 9 - 11 only
  41                 // Detect misreporting of content dimensions for box-sizing:border-box elements
  42                 boxSizingReliableVal = roundPixelMeasures( divStyle.width ) === 36;
  43
  44                 // Support: IE 9 only
  45                 // Detect overflow:scroll screwiness (gh-3699)
  46                 // Support: Chrome <=64
  47                 // Don't get tricked when zoom affects offsetWidth (gh-4029)
  48                 div.style.position = "absolute";
  49                 scrollboxSizeVal = roundPixelMeasures( div.offsetWidth / 3 ) === 12 || "absolute";
  50
  51                 documentElement.removeChild( container );
  52
  53                 // Nullify the div so it wouldn't be stored in the memory and
  54                 // it will also be a sign that checks already performed
  55                 div = null;
  56         }
  57
  58         function roundPixelMeasures( measure ) {
  59                 return Math.round( parseFloat( measure ) );
  60         }
  61
  62         var pixelPositionVal, boxSizingReliableVal, scrollboxSizeVal, pixelBoxStylesVal,
  63                 reliableMarginLeftVal,
  64                 container = document.createElement( "div" ),
  65                 div = document.createElement( "div" );
  66
  67         // Finish early in limited (non-browser) environments
  68         if ( !div.style ) {
  69                 return;
  70         }
  71
  72         // Support: IE <=9 - 11 only
  73         // Style of cloned element affects source element cloned (#8908)
  74         div.style.backgroundClip = "content-box";
  75         div.cloneNode( true ).style.backgroundClip = "";
  76         support.clearCloneStyle = div.style.backgroundClip === "content-box";
  77
  78         jQuery.extend( support, {
  79                 boxSizingReliable: function() {
  80                         computeStyleTests();
  81                         return boxSizingReliableVal;
  82                 },
  83                 pixelBoxStyles: function() {
  84                         computeStyleTests();
  85                         return pixelBoxStylesVal;
  86                 },
  87                 pixelPosition: function() {
  88                         computeStyleTests();
  89                         return pixelPositionVal;
  90                 },
  91                 reliableMarginLeft: function() {
  92                         computeStyleTests();
  93                         return reliableMarginLeftVal;
  94                 },
  95                 scrollboxSize: function() {
  96                         computeStyleTests();
  97                         return scrollboxSizeVal;
  98                 }
  99         } );
 100 } )();
 101
 102 return support;
 103
 104 } );