src/offset.js

   1 (function( jQuery ) {
   2
   3 var rtable = /^t(?:able|d|h)$/i,
   4         rroot = /^(?:body|html)$/i;
   5
   6 if ( "getBoundingClientRect" in document.documentElement ) {
   7         jQuery.fn.offset = function( options ) {
   8                 var elem = this[0], box;
   9
  10                 if ( options ) {
  11                         return this.each(function( i ) {
  12                                 jQuery.offset.setOffset( this, options, i );
  13                         });
  14                 }
  15
  16                 if ( !elem || !elem.ownerDocument ) {
  17                         return null;
  18                 }
  19
  20                 if ( elem === elem.ownerDocument.body ) {
  21                         return jQuery.offset.bodyOffset( elem );
  22                 }
  23
  24                 try {
  25                         box = elem.getBoundingClientRect();
  26                 } catch(e) {}
  27
  28                 var doc = elem.ownerDocument,
  29                         docElem = doc.documentElement;
  30
  31                 // Make sure we're not dealing with a disconnected DOM node
  32                 if ( !box || !jQuery.contains( docElem, elem ) ) {
  33                         return box ? { top: box.top, left: box.left } : { top: 0, left: 0 };
  34                 }
  35
  36                 var body = doc.body,
  37                         win = getWindow(doc),
  38                         clientTop  = docElem.clientTop  || body.clientTop  || 0,
  39                         clientLeft = docElem.clientLeft || body.clientLeft || 0,
  40                         scrollTop  = (win.pageYOffset || jQuery.support.boxModel && docElem.scrollTop  || body.scrollTop ),
  41                         scrollLeft = (win.pageXOffset || jQuery.support.boxModel && docElem.scrollLeft || body.scrollLeft),
  42                         top  = box.top  + scrollTop  - clientTop,
  43                         left = box.left + scrollLeft - clientLeft;
  44
  45                 return { top: top, left: left };
  46         };
  47
  48 } else {
  49         jQuery.fn.offset = function( options ) {
  50                 var elem = this[0];
  51
  52                 if ( options ) {
  53                         return this.each(function( i ) {
  54                                 jQuery.offset.setOffset( this, options, i );
  55                         });
  56                 }
  57
  58                 if ( !elem || !elem.ownerDocument ) {
  59                         return null;
  60                 }
  61
  62                 if ( elem === elem.ownerDocument.body ) {
  63                         return jQuery.offset.bodyOffset( elem );
  64                 }
  65
  66                 jQuery.offset.initialize();
  67
  68                 var computedStyle,
  69                         offsetParent = elem.offsetParent,
  70                         prevOffsetParent = elem,
  71                         doc = elem.ownerDocument,
  72                         docElem = doc.documentElement,
  73                         body = doc.body,
  74                         defaultView = doc.defaultView,
  75                         prevComputedStyle = defaultView ? defaultView.getComputedStyle( elem, null ) : elem.currentStyle,
  76                         top = elem.offsetTop,
  77                         left = elem.offsetLeft;
  78
  79                 while ( (elem = elem.parentNode) && elem !== body && elem !== docElem ) {
  80                         if ( jQuery.offset.supportsFixedPosition && prevComputedStyle.position === "fixed" ) {
  81                                 break;
  82                         }
  83
  84                         computedStyle = defaultView ? defaultView.getComputedStyle(elem, null) : elem.currentStyle;
  85                         top  -= elem.scrollTop;
  86                         left -= elem.scrollLeft;
  87
  88                         if ( elem === offsetParent ) {
  89                                 top  += elem.offsetTop;
  90                                 left += elem.offsetLeft;
  91
  92                                 if ( jQuery.offset.doesNotAddBorder && !(jQuery.offset.doesAddBorderForTableAndCells && rtable.test(elem.nodeName)) ) {
  93                                         top  += parseFloat( computedStyle.borderTopWidth  ) || 0;
  94                                         left += parseFloat( computedStyle.borderLeftWidth ) || 0;
  95                                 }
  96
  97                                 prevOffsetParent = offsetParent;
  98                                 offsetParent = elem.offsetParent;
  99                         }
 100
 101                         if ( jQuery.offset.subtractsBorderForOverflowNotVisible && computedStyle.overflow !== "visible" ) {
 102                                 top  += parseFloat( computedStyle.borderTopWidth  ) || 0;
 103                                 left += parseFloat( computedStyle.borderLeftWidth ) || 0;
 104                         }
 105
 106                         prevComputedStyle = computedStyle;
 107                 }
 108
 109                 if ( prevComputedStyle.position === "relative" || prevComputedStyle.position === "static" ) {
 110                         top  += body.offsetTop;
 111                         left += body.offsetLeft;
 112                 }
 113
 114                 if ( jQuery.offset.supportsFixedPosition && prevComputedStyle.position === "fixed" ) {
 115                         top  += Math.max( docElem.scrollTop, body.scrollTop );
 116                         left += Math.max( docElem.scrollLeft, body.scrollLeft );
 117                 }
 118
 119                 return { top: top, left: left };
 120         };
 121 }
 122
 123 jQuery.offset = {
 124         initialize: function() {
 125                 var body = document.body, container = document.createElement("div"), innerDiv, checkDiv, table, td, bodyMarginTop = parseFloat( jQuery.css(body, "marginTop") ) || 0,
 126                         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>";
 127
 128                 jQuery.extend( container.style, { position: "absolute", top: 0, left: 0, margin: 0, border: 0, width: "1px", height: "1px", visibility: "hidden" } );
 129
 130                 container.innerHTML = html;
 131                 body.insertBefore( container, body.firstChild );
 132                 innerDiv = container.firstChild;
 133                 checkDiv = innerDiv.firstChild;
 134                 td = innerDiv.nextSibling.firstChild.firstChild;
 135
 136                 this.doesNotAddBorder = (checkDiv.offsetTop !== 5);
 137                 this.doesAddBorderForTableAndCells = (td.offsetTop === 5);
 138
 139                 checkDiv.style.position = "fixed";
 140                 checkDiv.style.top = "20px";
 141
 142                 // safari subtracts parent border width here which is 5px
 143                 this.supportsFixedPosition = (checkDiv.offsetTop === 20 || checkDiv.offsetTop === 15);
 144                 checkDiv.style.position = checkDiv.style.top = "";
 145
 146                 innerDiv.style.overflow = "hidden";
 147                 innerDiv.style.position = "relative";
 148
 149                 this.subtractsBorderForOverflowNotVisible = (checkDiv.offsetTop === -5);
 150
 151                 this.doesNotIncludeMarginInBodyOffset = (body.offsetTop !== bodyMarginTop);
 152
 153                 body.removeChild( container );
 154                 body = container = innerDiv = checkDiv = table = td = null;
 155                 jQuery.offset.initialize = jQuery.noop;
 156         },
 157
 158         bodyOffset: function( body ) {
 159                 var top = body.offsetTop,
 160                         left = body.offsetLeft;
 161
 162                 jQuery.offset.initialize();
 163
 164                 if ( jQuery.offset.doesNotIncludeMarginInBodyOffset ) {
 165                         top  += parseFloat( jQuery.css(body, "marginTop") ) || 0;
 166                         left += parseFloat( jQuery.css(body, "marginLeft") ) || 0;
 167                 }
 168
 169                 return { top: top, left: left };
 170         },
 171
 172         setOffset: function( elem, options, i ) {
 173                 var position = jQuery.css( elem, "position" );
 174
 175                 // set position first, in-case top/left are set even on static elem
 176                 if ( position === "static" ) {
 177                         elem.style.position = "relative";
 178                 }
 179
 180                 var curElem = jQuery( elem ),
 181                         curOffset = curElem.offset(),
 182                         curCSSTop = jQuery.css( elem, "top" ),
 183                         curCSSLeft = jQuery.css( elem, "left" ),
 184                         calculatePosition = (position === "absolute" && jQuery.inArray('auto', [curCSSTop, curCSSLeft]) > -1),
 185                         props = {}, curPosition = {}, curTop, curLeft;
 186
 187                 // need to be able to calculate position if either top or left is auto and position is absolute
 188                 if ( calculatePosition ) {
 189                         curPosition = curElem.position();
 190                 }
 191
 192                 curTop  = calculatePosition ? curPosition.top  : parseInt( curCSSTop,  10 ) || 0;
 193                 curLeft = calculatePosition ? curPosition.left : parseInt( curCSSLeft, 10 ) || 0;
 194
 195                 if ( jQuery.isFunction( options ) ) {
 196                         options = options.call( elem, i, curOffset );
 197                 }
 198
 199                 if (options.top != null) {
 200                         props.top = (options.top - curOffset.top) + curTop;
 201                 }
 202                 if (options.left != null) {
 203                         props.left = (options.left - curOffset.left) + curLeft;
 204                 }
 205
 206                 if ( "using" in options ) {
 207                         options.using.call( elem, props );
 208                 } else {
 209                         curElem.css( props );
 210                 }
 211         }
 212 };
 213
 214
 215 jQuery.fn.extend({
 216         position: function() {
 217                 if ( !this[0] ) {
 218                         return null;
 219                 }
 220
 221                 var elem = this[0],
 222
 223                 // Get *real* offsetParent
 224                 offsetParent = this.offsetParent(),
 225
 226                 // Get correct offsets
 227                 offset       = this.offset(),
 228                 parentOffset = rroot.test(offsetParent[0].nodeName) ? { top: 0, left: 0 } : offsetParent.offset();
 229
 230                 // Subtract element margins
 231                 // note: when an element has margin: auto the offsetLeft and marginLeft
 232                 // are the same in Safari causing offset.left to incorrectly be 0
 233                 offset.top  -= parseFloat( jQuery.css(elem, "marginTop") ) || 0;
 234                 offset.left -= parseFloat( jQuery.css(elem, "marginLeft") ) || 0;
 235
 236                 // Add offsetParent borders
 237                 parentOffset.top  += parseFloat( jQuery.css(offsetParent[0], "borderTopWidth") ) || 0;
 238                 parentOffset.left += parseFloat( jQuery.css(offsetParent[0], "borderLeftWidth") ) || 0;
 239
 240                 // Subtract the two offsets
 241                 return {
 242                         top:  offset.top  - parentOffset.top,
 243                         left: offset.left - parentOffset.left
 244                 };
 245         },
 246
 247         offsetParent: function() {
 248                 return this.map(function() {
 249                         var offsetParent = this.offsetParent || document.body;
 250                         while ( offsetParent && (!rroot.test(offsetParent.nodeName) && jQuery.css(offsetParent, "position") === "static") ) {
 251                                 offsetParent = offsetParent.offsetParent;
 252                         }
 253                         return offsetParent;
 254                 });
 255         }
 256 });
 257
 258
 259 // Create scrollLeft and scrollTop methods
 260 jQuery.each( ["Left", "Top"], function( i, name ) {
 261         var method = "scroll" + name;
 262
 263         jQuery.fn[ method ] = function(val) {
 264                 var elem = this[0], win;
 265
 266                 if ( !elem ) {
 267                         return null;
 268                 }
 269
 270                 if ( val !== undefined ) {
 271                         // Set the scroll offset
 272                         return this.each(function() {
 273                                 win = getWindow( this );
 274
 275                                 if ( win ) {
 276                                         win.scrollTo(
 277                                                 !i ? val : jQuery(win).scrollLeft(),
 278                                                  i ? val : jQuery(win).scrollTop()
 279                                         );
 280
 281                                 } else {
 282                                         this[ method ] = val;
 283                                 }
 284                         });
 285                 } else {
 286                         win = getWindow( elem );
 287
 288                         // Return the scroll offset
 289                         return win ? ("pageXOffset" in win) ? win[ i ? "pageYOffset" : "pageXOffset" ] :
 290                                 jQuery.support.boxModel && win.document.documentElement[ method ] ||
 291                                         win.document.body[ method ] :
 292                                 elem[ method ];
 293                 }
 294         };
 295 });
 296
 297 function getWindow( elem ) {
 298         return jQuery.isWindow( elem ) ?
 299                 elem :
 300                 elem.nodeType === 9 ?
 301                         elem.defaultView || elem.parentWindow :
 302                         false;
 303 }
 304
 305 })( jQuery );