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