src/offset.js

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