src/offset.js

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