src/offset.js

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