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, offsetParent = elem.offsetParent;
  79                         }
  80
  81                         if ( jQuery.offset.subtractsBorderForOverflowNotVisible && computedStyle.overflow !== "visible" ) {
  82                                 top  += parseFloat( computedStyle.borderTopWidth  ) || 0;
  83                                 left += parseFloat( computedStyle.borderLeftWidth ) || 0;
  84                         }
  85
  86                         prevComputedStyle = computedStyle;
  87                 }
  88
  89                 if ( prevComputedStyle.position === "relative" || prevComputedStyle.position === "static" ) {
  90                         top  += body.offsetTop;
  91                         left += body.offsetLeft;
  92                 }
  93
  94                 if ( jQuery.offset.supportsFixedPosition && prevComputedStyle.position === "fixed" ) {
  95                         top  += Math.max( docElem.scrollTop, body.scrollTop );
  96                         left += Math.max( docElem.scrollLeft, body.scrollLeft );
  97                 }
  98
  99                 return { top: top, left: left };
 100         };
 101 }
 102
 103 jQuery.offset = {
 104         initialize: function() {
 105                 var body = document.body, container = document.createElement("div"), innerDiv, checkDiv, table, td, bodyMarginTop = parseFloat( jQuery.curCSS(body, "marginTop", true) ) || 0,
 106                         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>";
 107
 108                 jQuery.extend( container.style, { position: "absolute", top: 0, left: 0, margin: 0, border: 0, width: "1px", height: "1px", visibility: "hidden" } );
 109
 110                 container.innerHTML = html;
 111                 body.insertBefore( container, body.firstChild );
 112                 innerDiv = container.firstChild;
 113                 checkDiv = innerDiv.firstChild;
 114                 td = innerDiv.nextSibling.firstChild.firstChild;
 115
 116                 this.doesNotAddBorder = (checkDiv.offsetTop !== 5);
 117                 this.doesAddBorderForTableAndCells = (td.offsetTop === 5);
 118
 119                 checkDiv.style.position = "fixed", checkDiv.style.top = "20px";
 120                 // safari subtracts parent border width here which is 5px
 121                 this.supportsFixedPosition = (checkDiv.offsetTop === 20 || checkDiv.offsetTop === 15);
 122                 checkDiv.style.position = checkDiv.style.top = "";
 123
 124                 innerDiv.style.overflow = "hidden", innerDiv.style.position = "relative";
 125                 this.subtractsBorderForOverflowNotVisible = (checkDiv.offsetTop === -5);
 126
 127                 this.doesNotIncludeMarginInBodyOffset = (body.offsetTop !== bodyMarginTop);
 128
 129                 body.removeChild( container );
 130                 body = container = innerDiv = checkDiv = table = td = null;
 131                 jQuery.offset.initialize = jQuery.noop;
 132         },
 133
 134         bodyOffset: function( body ) {
 135                 var top = body.offsetTop, left = body.offsetLeft;
 136
 137                 jQuery.offset.initialize();
 138
 139                 if ( jQuery.offset.doesNotIncludeMarginInBodyOffset ) {
 140                         top  += parseFloat( jQuery.curCSS(body, "marginTop",  true) ) || 0;
 141                         left += parseFloat( jQuery.curCSS(body, "marginLeft", true) ) || 0;
 142                 }
 143
 144                 return { top: top, left: left };
 145         },
 146
 147         setOffset: function( elem, options, i ) {
 148                 // set position first, in-case top/left are set even on static elem
 149                 if ( /static/.test( jQuery.curCSS( elem, "position" ) ) ) {
 150                         elem.style.position = "relative";
 151                 }
 152                 var curElem   = jQuery( elem ),
 153                         curOffset = curElem.offset(),
 154                         curTop    = parseInt( jQuery.curCSS( elem, "top",  true ), 10 ) || 0,
 155                         curLeft   = parseInt( jQuery.curCSS( elem, "left", true ), 10 ) || 0;
 156
 157                 if ( jQuery.isFunction( options ) ) {
 158                         options = options.call( elem, i, curOffset );
 159                 }
 160
 161                 var props = {
 162                         top:  (options.top  - curOffset.top)  + curTop,
 163                         left: (options.left - curOffset.left) + curLeft
 164                 };
 165
 166                 if ( "using" in options ) {
 167                         options.using.call( elem, props );
 168                 } else {
 169                         curElem.css( props );
 170                 }
 171         }
 172 };
 173
 174
 175 jQuery.fn.extend({
 176         position: function() {
 177                 if ( !this[0] ) {
 178                         return null;
 179                 }
 180
 181                 var elem = this[0],
 182
 183                 // Get *real* offsetParent
 184                 offsetParent = this.offsetParent(),
 185
 186                 // Get correct offsets
 187                 offset       = this.offset(),
 188                 parentOffset = /^body|html$/i.test(offsetParent[0].nodeName) ? { top: 0, left: 0 } : offsetParent.offset();
 189
 190                 // Subtract element margins
 191                 // note: when an element has margin: auto the offsetLeft and marginLeft
 192                 // are the same in Safari causing offset.left to incorrectly be 0
 193                 offset.top  -= parseFloat( jQuery.curCSS(elem, "marginTop",  true) ) || 0;
 194                 offset.left -= parseFloat( jQuery.curCSS(elem, "marginLeft", true) ) || 0;
 195
 196                 // Add offsetParent borders
 197                 parentOffset.top  += parseFloat( jQuery.curCSS(offsetParent[0], "borderTopWidth",  true) ) || 0;
 198                 parentOffset.left += parseFloat( jQuery.curCSS(offsetParent[0], "borderLeftWidth", true) ) || 0;
 199
 200                 // Subtract the two offsets
 201                 return {
 202                         top:  offset.top  - parentOffset.top,
 203                         left: offset.left - parentOffset.left
 204                 };
 205         },
 206
 207         offsetParent: function() {
 208                 return this.map(function() {
 209                         var offsetParent = this.offsetParent || document.body;
 210                         while ( offsetParent && (!/^body|html$/i.test(offsetParent.nodeName) && jQuery.css(offsetParent, "position") === "static") ) {
 211                                 offsetParent = offsetParent.offsetParent;
 212                         }
 213                         return offsetParent;
 214                 });
 215         }
 216 });
 217
 218
 219 // Create scrollLeft and scrollTop methods
 220 jQuery.each( ["Left", "Top"], function( i, name ) {
 221         var method = "scroll" + name;
 222
 223         jQuery.fn[ method ] = function(val) {
 224                 var elem = this[0], win;
 225
 226                 if ( !elem ) {
 227                         return null;
 228                 }
 229
 230                 if ( val !== undefined ) {
 231                         // Set the scroll offset
 232                         return this.each(function() {
 233                                 win = getWindow( this );
 234
 235                                 if ( win ) {
 236                                         win.scrollTo(
 237                                                 !i ? val : jQuery(win).scrollLeft(),
 238                                                  i ? val : jQuery(win).scrollTop()
 239                                         );
 240
 241                                 } else {
 242                                         this[ method ] = val;
 243                                 }
 244                         });
 245                 } else {
 246                         win = getWindow( elem );
 247
 248                         // Return the scroll offset
 249                         return win ? ("pageXOffset" in win) ? win[ i ? "pageYOffset" : "pageXOffset" ] :
 250                                 jQuery.support.boxModel && win.document.documentElement[ method ] ||
 251                                         win.document.body[ method ] :
 252                                 elem[ method ];
 253                 }
 254         };
 255 });
 256
 257 function getWindow( elem ) {
 258         return ("scrollTo" in elem && elem.document) ?
 259                 elem :
 260                 elem.nodeType === 9 ?
 261                         elem.defaultView || elem.parentWindow :
 262                         false;
 263 }