src/offset.js

   1 if ( "getBoundingClientRect" in document.documentElement ) {
   2         jQuery.fn.offset = function( options ) {
   3                 var elem = this[0];
   4                 if ( !elem || !elem.ownerDocument ) { return null; }
   5                 if ( options ) {
   6                         return this.each(function() {
   7                                 jQuery.offset.setOffset( this, options );
   8                         });
   9                 }
  10                 if ( elem === elem.ownerDocument.body ) {
  11                         return jQuery.offset.bodyOffset( elem );
  12                 }
  13
  14                 var box = elem.getBoundingClientRect(), doc = elem.ownerDocument, body = doc.body, docElem = doc.documentElement,
  15                         clientTop = docElem.clientTop || body.clientTop || 0, clientLeft = docElem.clientLeft || body.clientLeft || 0,
  16                         top  = box.top  + (self.pageYOffset || jQuery.support.boxModel && docElem.scrollTop  || body.scrollTop ) - clientTop,
  17                         left = box.left + (self.pageXOffset || jQuery.support.boxModel && docElem.scrollLeft || body.scrollLeft) - clientLeft;
  18                 return { top: top, left: left };
  19         };
  20 } else {
  21         jQuery.fn.offset = function( options ) {
  22                 var elem = this[0];
  23                 if ( !elem || !elem.ownerDocument ) { return null; }
  24                 if ( options ) {
  25                         return this.each(function() {
  26                                 jQuery.offset.setOffset( this, options );
  27                         });
  28                 }
  29                 if ( elem === elem.ownerDocument.body ) {
  30                         return jQuery.offset.bodyOffset( elem );
  31                 }
  32
  33                 jQuery.offset.initialize();
  34
  35                 var offsetParent = elem.offsetParent, prevOffsetParent = elem,
  36                         doc = elem.ownerDocument, computedStyle, docElem = doc.documentElement,
  37                         body = doc.body, defaultView = doc.defaultView,
  38                         prevComputedStyle = defaultView.getComputedStyle( elem, null ),
  39                         top = elem.offsetTop, left = elem.offsetLeft;
  40
  41                 while ( (elem = elem.parentNode) && elem !== body && elem !== docElem ) {
  42                         if ( jQuery.offset.supportsFixedPosition && prevComputedStyle.position === "fixed" ) { break; }
  43
  44                         computedStyle = defaultView.getComputedStyle(elem, null);
  45                         top  -= elem.scrollTop;
  46                         left -= elem.scrollLeft;
  47
  48                         if ( elem === offsetParent ) {
  49                                 top  += elem.offsetTop;
  50                                 left += elem.offsetLeft;
  51
  52                                 if ( jQuery.offset.doesNotAddBorder && !(jQuery.offset.doesAddBorderForTableAndCells && /^t(able|d|h)$/i.test(elem.nodeName)) ) {
  53                                         top  += parseFloat( computedStyle.borderTopWidth  ) || 0;
  54                                         left += parseFloat( computedStyle.borderLeftWidth ) || 0;
  55                                 }
  56
  57                                 prevOffsetParent = offsetParent, offsetParent = elem.offsetParent;
  58                         }
  59
  60                         if ( jQuery.offset.subtractsBorderForOverflowNotVisible && computedStyle.overflow !== "visible" ) {
  61                                 top  += parseFloat( computedStyle.borderTopWidth  ) || 0;
  62                                 left += parseFloat( computedStyle.borderLeftWidth ) || 0;
  63                         }
  64
  65                         prevComputedStyle = computedStyle;
  66                 }
  67
  68                 if ( prevComputedStyle.position === "relative" || prevComputedStyle.position === "static" ) {
  69                         top  += body.offsetTop;
  70                         left += body.offsetLeft;
  71                 }
  72
  73                 if ( jQuery.offset.supportsFixedPosition && prevComputedStyle.position === "fixed" ) {
  74                         top  += Math.max( docElem.scrollTop, body.scrollTop );
  75                         left += Math.max( docElem.scrollLeft, body.scrollLeft );
  76                 }
  77
  78                 return { top: top, left: left };
  79         };
  80 }
  81
  82 jQuery.offset = {
  83         initialize: function() {
  84                 var body = document.body, container = document.createElement('div'), innerDiv, checkDiv, table, td, bodyMarginTop = parseFloat( jQuery.curCSS(body, 'marginTop', true) ) || 0,
  85                         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>';
  86
  87                 jQuery.extend( container.style, { position: 'absolute', top: 0, left: 0, margin: 0, border: 0, width: '1px', height: '1px', visibility: 'hidden' } );
  88
  89                 container.innerHTML = html;
  90                 body.insertBefore( container, body.firstChild );
  91                 innerDiv = container.firstChild;
  92                 checkDiv = innerDiv.firstChild;
  93                 td = innerDiv.nextSibling.firstChild.firstChild;
  94
  95                 this.doesNotAddBorder = (checkDiv.offsetTop !== 5);
  96                 this.doesAddBorderForTableAndCells = (td.offsetTop === 5);
  97
  98                 checkDiv.style.position = 'fixed', checkDiv.style.top = '20px';
  99                 // safari subtracts parent border width here which is 5px
 100                 this.supportsFixedPosition = (checkDiv.offsetTop === 20 || checkDiv.offsetTop === 15);
 101                 checkDiv.style.position = checkDiv.style.top = '';
 102
 103                 innerDiv.style.overflow = 'hidden', innerDiv.style.position = 'relative';
 104                 this.subtractsBorderForOverflowNotVisible = (checkDiv.offsetTop === -5);
 105
 106                 this.doesNotIncludeMarginInBodyOffset = (body.offsetTop !== bodyMarginTop);
 107
 108                 body.removeChild( container );
 109                 body = container = innerDiv = checkDiv = table = td = null;
 110                 jQuery.offset.initialize = function(){};
 111         },
 112
 113         bodyOffset: function( body ) {
 114                 var top = body.offsetTop, left = body.offsetLeft;
 115
 116                 jQuery.offset.initialize();
 117
 118                 if ( jQuery.offset.doesNotIncludeMarginInBodyOffset ) {
 119                         top  += parseFloat( jQuery.curCSS(body, 'marginTop',  true) ) || 0;
 120                         left += parseFloat( jQuery.curCSS(body, 'marginLeft', true) ) || 0;
 121                 }
 122
 123                 return { top: top, left: left };
 124         },
 125
 126         setOffset: function( elem, options ) {
 127                 // set position first, in-case top/left are set even on static elem
 128                 if ( /static/.test( jQuery.curCSS( elem, 'position' ) ) ) {
 129                         elem.style.position = 'relative';
 130                 }
 131                 var curElem   = jQuery( elem ),
 132                         curOffset = curElem.offset(),
 133                         curTop    = parseInt( jQuery.curCSS( elem, 'top',  true ), 10 ) || 0,
 134                         curLeft   = parseInt( jQuery.curCSS( elem, 'left', true ), 10)  || 0,
 135                         props     = {
 136                                 top:  (options.top  - curOffset.top)  + curTop,
 137                                 left: (options.left - curOffset.left) + curLeft
 138                         };
 139
 140                 if ( 'using' in options ) {
 141                         options.using.call( elem, props );
 142                 } else {
 143                         curElem.css( props );
 144                 }
 145         }
 146 };
 147
 148
 149 jQuery.fn.extend({
 150         position: function() {
 151                 if ( !this[0] ) { return null; }
 152
 153                 var elem = this[0],
 154
 155                 // Get *real* offsetParent
 156                 offsetParent = this.offsetParent(),
 157
 158                 // Get correct offsets
 159                 offset       = this.offset(),
 160                 parentOffset = /^body|html$/i.test(offsetParent[0].nodeName) ? { top: 0, left: 0 } : offsetParent.offset();
 161
 162                 // Subtract element margins
 163                 // note: when an element has margin: auto the offsetLeft and marginLeft
 164                 // are the same in Safari causing offset.left to incorrectly be 0
 165                 offset.top  -= parseFloat( jQuery.curCSS(elem, 'marginTop',  true) ) || 0;
 166                 offset.left -= parseFloat( jQuery.curCSS(elem, 'marginLeft', true) ) || 0;
 167
 168                 // Add offsetParent borders
 169                 parentOffset.top  += parseFloat( jQuery.curCSS(offsetParent[0], 'borderTopWidth',  true) ) || 0;
 170                 parentOffset.left += parseFloat( jQuery.curCSS(offsetParent[0], 'borderLeftWidth', true) ) || 0;
 171
 172                 // Subtract the two offsets
 173                 return {
 174                         top:  offset.top  - parentOffset.top,
 175                         left: offset.left - parentOffset.left
 176                 };
 177         },
 178
 179         offsetParent: function() {
 180                 return this.map(function(){
 181                         var offsetParent = this.offsetParent || document.body;
 182                         while ( offsetParent && (!/^body|html$/i.test(offsetParent.nodeName) && jQuery.css(offsetParent, 'position') === 'static') ) {
 183                                 offsetParent = offsetParent.offsetParent;
 184                         }
 185                         return offsetParent;
 186                 });
 187         }
 188 });
 189
 190
 191 // Create scrollLeft and scrollTop methods
 192 jQuery.each( ['Left', 'Top'], function(i, name) {
 193         var method = 'scroll' + name;
 194
 195         jQuery.fn[ method ] = function(val) {
 196                 var elem = this[0], win;
 197
 198                 if ( !elem ) { return null; }
 199
 200                 if ( val !== undefined ) {
 201                         // Set the scroll offset
 202                         return this.each(function() {
 203                                 win = getWindow( this );
 204
 205                                 win ?
 206                                         win.scrollTo(
 207                                                 !i ? val : jQuery(win).scrollLeft(),
 208                                                  i ? val : jQuery(win).scrollTop()
 209                                         ) :
 210                                         this[ method ] = val;
 211                         });
 212                 } else {
 213                         win = getWindow( elem );
 214
 215                         // Return the scroll offset
 216                         return win ? ('pageXOffset' in win) ? win[ i ? 'pageYOffset' : 'pageXOffset' ] :
 217                                 jQuery.support.boxModel && win.document.documentElement[ method ] ||
 218                                         win.document.body[ method ] :
 219                                 elem[ method ];
 220                 }
 221         };
 222 });
 223
 224 function getWindow( elem ) {
 225         return ("scrollTo" in elem && elem.document) ?
 226                 elem :
 227                 elem.nodeType === 9 ?
 228                         elem.defaultView || elem.parentWindow :
 229                         false;
 230 }