src/offset.js

   1 if ( "getBoundingClientRect" in document.documentElement ) {
   2         jQuery.fn.offset = function() {
   3                 var elem = this[0];
   4                 if ( !elem || !elem.ownerDocument ) { return null; }
   5                 if ( elem === elem.ownerDocument.body ) {
   6                         return jQuery.offset.bodyOffset( elem );
   7                 }
   8
   9                 var box = elem.getBoundingClientRect(), doc = elem.ownerDocument, body = doc.body, docElem = doc.documentElement,
  10                         clientTop = docElem.clientTop || body.clientTop || 0, clientLeft = docElem.clientLeft || body.clientLeft || 0,
  11                         top  = box.top  + (self.pageYOffset || jQuery.support.boxModel && docElem.scrollTop  || body.scrollTop ) - clientTop,
  12                         left = box.left + (self.pageXOffset || jQuery.support.boxModel && docElem.scrollLeft || body.scrollLeft) - clientLeft;
  13                 return { top: top, left: left };
  14         };
  15 } else {
  16         jQuery.fn.offset = function() {
  17                 var elem = this[0];
  18                 if ( !elem || !elem.ownerDocument ) { return null; }
  19                 if ( elem === elem.ownerDocument.body ) {
  20                         return jQuery.offset.bodyOffset( elem );
  21                 }
  22
  23                 jQuery.offset.initialize();
  24
  25                 var offsetParent = elem.offsetParent, prevOffsetParent = elem,
  26                         doc = elem.ownerDocument, computedStyle, docElem = doc.documentElement,
  27                         body = doc.body, defaultView = doc.defaultView,
  28                         prevComputedStyle = defaultView.getComputedStyle(elem, null),
  29                         top = elem.offsetTop, left = elem.offsetLeft;
  30
  31                 while ( (elem = elem.parentNode) && elem !== body && elem !== docElem ) {
  32                         if ( jQuery.offset.supportsFixedPosition && prevComputedStyle.position === "fixed" ) { break; }
  33
  34                         computedStyle = defaultView.getComputedStyle(elem, null);
  35                         top -= elem.scrollTop;
  36                         left -= elem.scrollLeft;
  37
  38                         if ( elem === offsetParent ) {
  39                                 top += elem.offsetTop;
  40                                 left += elem.offsetLeft;
  41
  42                                 if ( jQuery.offset.doesNotAddBorder && !(jQuery.offset.doesAddBorderForTableAndCells && /^t(able|d|h)$/i.test(elem.nodeName)) ) {
  43                                         top  += parseFloat( computedStyle.borderTopWidth  ) || 0;
  44                                         left += parseFloat( computedStyle.borderLeftWidth ) || 0;
  45                                 }
  46
  47                                 prevOffsetParent = offsetParent, offsetParent = elem.offsetParent;
  48                         }
  49
  50                         if ( jQuery.offset.subtractsBorderForOverflowNotVisible && computedStyle.overflow !== "visible" ) {
  51                                 top  += parseFloat( computedStyle.borderTopWidth  ) || 0;
  52                                 left += parseFloat( computedStyle.borderLeftWidth ) || 0;
  53                         }
  54
  55                         prevComputedStyle = computedStyle;
  56                 }
  57
  58                 if ( prevComputedStyle.position === "relative" || prevComputedStyle.position === "static" ) {
  59                         top  += body.offsetTop;
  60                         left += body.offsetLeft;
  61                 }
  62
  63                 if ( jQuery.offset.supportsFixedPosition && prevComputedStyle.position === "fixed" ) {
  64                         top  += Math.max( docElem.scrollTop, body.scrollTop );
  65                         left += Math.max( docElem.scrollLeft, body.scrollLeft );
  66                 }
  67
  68                 return { top: top, left: left };
  69         };
  70 }
  71
  72 jQuery.offset = {
  73         initialize: function() {
  74                 var body = document.body, container = document.createElement('div'), innerDiv, checkDiv, table, td, bodyMarginTop = parseFloat( jQuery.curCSS(body, 'marginTop', true) ) || 0,
  75                         html = '<div style="position:absolute;top:0;left:0;margin:0;border:5px solid #000;padding:0;width:1px;height:1px;"><div></div></div><table style="position:absolute;top:0;left:0;margin:0;border:5px solid #000;padding:0;width:1px;height:1px;" cellpadding="0" cellspacing="0"><tr><td></td></tr></table>';
  76
  77                 jQuery.extend( container.style, { position: 'absolute', top: 0, left: 0, margin: 0, border: 0, width: '1px', height: '1px', visibility: 'hidden' } );
  78
  79                 container.innerHTML = html;
  80                 body.insertBefore( container, body.firstChild );
  81                 innerDiv = container.firstChild;
  82                 checkDiv = innerDiv.firstChild;
  83                 td = innerDiv.nextSibling.firstChild.firstChild;
  84
  85                 this.doesNotAddBorder = (checkDiv.offsetTop !== 5);
  86                 this.doesAddBorderForTableAndCells = (td.offsetTop === 5);
  87
  88                 checkDiv.style.position = 'fixed', checkDiv.style.top = '20px';
  89                 // safari subtracts parent border width here which is 5px
  90                 this.supportsFixedPosition = (checkDiv.offsetTop === 20 || checkDiv.offsetTop === 15);
  91                 checkDiv.style.position = checkDiv.style.top = '';
  92
  93                 innerDiv.style.overflow = 'hidden', innerDiv.style.position = 'relative';
  94                 this.subtractsBorderForOverflowNotVisible = (checkDiv.offsetTop === -5);
  95
  96                 this.doesNotIncludeMarginInBodyOffset = (body.offsetTop !== bodyMarginTop);
  97
  98                 body.removeChild( container );
  99                 body = container = innerDiv = checkDiv = table = td = null;
 100                 jQuery.offset.initialize = function(){};
 101         },
 102
 103         bodyOffset: function(body) {
 104                 var top = body.offsetTop, left = body.offsetLeft;
 105
 106                 jQuery.offset.initialize();
 107
 108                 if ( jQuery.offset.doesNotIncludeMarginInBodyOffset ) {
 109                         top  += parseFloat( jQuery.curCSS(body, 'marginTop',  true) ) || 0;
 110                         left += parseFloat( jQuery.curCSS(body, 'marginLeft', true) ) || 0;
 111                 }
 112
 113                 return { top: top, left: left };
 114         }
 115 };
 116
 117
 118 jQuery.fn.extend({
 119         position: function() {
 120                 if ( !this[0] ) { return null; }
 121
 122                 var elem = this[0],
 123
 124                 // Get *real* offsetParent
 125                 offsetParent = this.offsetParent(),
 126
 127                 // Get correct offsets
 128                 offset       = this.offset(),
 129                 parentOffset = /^body|html$/i.test(offsetParent[0].nodeName) ? { top: 0, left: 0 } : offsetParent.offset();
 130
 131                 // Subtract element margins
 132                 // note: when an element has margin: auto the offsetLeft and marginLeft
 133                 // are the same in Safari causing offset.left to incorrectly be 0
 134                 offset.top  -= parseFloat( jQuery.curCSS(elem, 'marginTop',  true) ) || 0;
 135                 offset.left -= parseFloat( jQuery.curCSS(elem, 'marginLeft', true) ) || 0;
 136
 137                 // Add offsetParent borders
 138                 parentOffset.top  += parseFloat( jQuery.curCSS(offsetParent[0], 'borderTopWidth',  true) ) || 0;
 139                 parentOffset.left += parseFloat( jQuery.curCSS(offsetParent[0], 'borderLeftWidth', true) ) || 0;
 140
 141                 // Subtract the two offsets
 142                 return {
 143                         top:  offset.top  - parentOffset.top,
 144                         left: offset.left - parentOffset.left
 145                 };
 146         },
 147
 148         offsetParent: function() {
 149                 return this.map(function(){
 150                         var offsetParent = this.offsetParent || document.body;
 151                         while ( offsetParent && (!/^body|html$/i.test(offsetParent.nodeName) && jQuery.css(offsetParent, 'position') === 'static') ) {
 152                                 offsetParent = offsetParent.offsetParent;
 153                         }
 154                         return offsetParent;
 155                 });
 156         }
 157 });
 158
 159
 160 // Create scrollLeft and scrollTop methods
 161 jQuery.each( ['Left', 'Top'], function(i, name) {
 162         var method = 'scroll' + name;
 163
 164         jQuery.fn[ method ] = function(val) {
 165                 var elem = this[0], win;
 166
 167                 if ( !elem ) { return null; }
 168
 169                 if ( val !== undefined ) {
 170                         // Set the scroll offset
 171                         return this.each(function() {
 172                                 win = getWindow( this );
 173
 174                                 win ?
 175                                         win.scrollTo(
 176                                                 !i ? val : jQuery(win).scrollLeft(),
 177                                                  i ? val : jQuery(win).scrollTop()
 178                                         ) :
 179                                         this[ method ] = val;
 180                         });
 181                 } else {
 182                         win = getWindow( elem );
 183
 184                         // Return the scroll offset
 185                         return win ? ('pageXOffset' in win) ? win[ i ? 'pageYOffset' : 'pageXOffset' ] :
 186                                 jQuery.support.boxModel && win.document.documentElement[ method ] ||
 187                                         win.document.body[ method ] :
 188                                 elem[ method ];
 189                 }
 190         };
 191 });
 192
 193 function getWindow( elem ) {
 194         return ("scrollTo" in elem && elem.document) ?
 195                 elem :
 196                 elem.nodeType === 9 ?
 197                         elem.defaultView || elem.parentWindow :
 198                         false;
 199 }