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