new offset method, faster and no more browser detection

diff --git a/src/offset.js b/src/offset.js
index 1ae3f2e..479f106 100644 (file)
--- a/src/offset.js
+++ b/src/offset.js
@@ -1,101 +1,86 @@
-// The Offset Method
-// Originally By Brandon Aaron, part of the Dimension Plugin
-// http://jquery.com/plugins/project/dimensions
-jQuery.fn.offset = function() {
-       var left = 0, top = 0, elem = this[0], results;
-
-       if ( elem ) with ( jQuery.browser ) {
-               var parent       = elem.parentNode,
-                   offsetChild  = elem,
-                   offsetParent = elem.offsetParent,
-                   doc          = elem.ownerDocument,
-                   safari2      = safari && parseInt(version) < 522 && !/adobeair/i.test(userAgent),
-                   css          = jQuery.curCSS,
-                   fixed        = css(elem, "position") == "fixed";
-
-               // Use getBoundingClientRect if available
-               if ( !(mozilla && elem == document.body) && elem.getBoundingClientRect ) {
-                       var box = elem.getBoundingClientRect();
-
-                       // Add the document scroll offsets
-                       add(box.left + Math.max(doc.documentElement.scrollLeft, doc.body.scrollLeft),
-                               box.top  + Math.max(doc.documentElement.scrollTop,  doc.body.scrollTop));
-
-                       // IE adds the HTML element's border, by default it is medium which is 2px
-                       // IE 6 and 7 quirks mode the border width is overwritable by the following css html { border: 0; }
-                       // IE 7 standards mode, the border is always 2px
-                       // This border/offset is typically represented by the clientLeft and clientTop properties
-                       // However, in IE6 and 7 quirks mode the clientLeft and clientTop properties are not updated when overwriting it via CSS
-                       // Therefore this method will be off by 2px in IE while in quirksmode
-                       add( -doc.documentElement.clientLeft, -doc.documentElement.clientTop );
-
-               // Otherwise loop through the offsetParents and parentNodes
-               } else {
-
-                       // Initial element offsets
-                       add( elem.offsetLeft, elem.offsetTop );
-
-                       // Get parent offsets
-                       while ( offsetParent ) {
-                               // Add offsetParent offsets
-                               add( offsetParent.offsetLeft, offsetParent.offsetTop );
-
-                               // Mozilla and Safari > 2 does not include the border on offset parents
-                               // However Mozilla adds the border for table or table cells
-                               if ( mozilla && !/^t(able|d|h)$/i.test(offsetParent.tagName) || safari && !safari2 )
-                                       border( offsetParent );
-
-                               // Add the document scroll offsets if position is fixed on any offsetParent
-                               if ( !fixed && css(offsetParent, "position") == "fixed" )
-                                       fixed = true;
-
-                               // Set offsetChild to previous offsetParent unless it is the body element
-                               offsetChild  = /^body$/i.test(offsetParent.tagName) ? offsetChild : offsetParent;
-                               // Get next offsetParent
-                               offsetParent = offsetParent.offsetParent;
+if ( document.documentElement["getBoundingClientRect"] )
+       jQuery.fn.offset = function() {
+               if ( !this[0] ) return { top: 0, left: 0 };
+               if ( this[0] === this[0].ownerDocument.body ) return jQuery.offset.bodyOffset( this[0] );
+               var box  = this[0].getBoundingClientRect(), doc = this[0].ownerDocument, docElem = doc.documentElement,
+                       top  = box.top  + (self.pageYOffset || jQuery.boxModel && docElem.scrollTop  || doc.body.scrollTop ) - docElem.clientTop,
+                       left = box.left + (self.pageXOffset || jQuery.boxModel && docElem.scrollLeft || doc.body.scrollLeft) - docElem.clientLeft;
+               return { top: top, left: left };
+       };
+else 
+       jQuery.fn.offset = function() {
+               if ( !this[0] ) return { top: 0, left: 0 };
+               if ( this[0] === this[0].ownerDocument.body ) return jQuery.offset.bodyOffset( this[0] );
+               jQuery.offset.initialized || jQuery.offset.initialize();
+
+               var elem = this[0], offsetParent = elem.offsetParent, prevOffsetParent = elem,
+                       doc = elem.ownerDocument, computedStyle, docElem = doc.documentElement,
+                       body = doc.body, defaultView = doc.defaultView,
+                       prevComputedStyle = defaultView.getComputedStyle(elem, null),
+                       top = elem.offsetTop, left = elem.offsetLeft;
+
+               while ( (elem = elem.parentNode) && elem !== body && elem !== docElem ) {
+                       computedStyle = defaultView.getComputedStyle(elem, null);
+                       top -= elem.scrollTop, left -= elem.scrollLeft;
+                       if ( elem === offsetParent ) {
+                               top += elem.offsetTop, left += elem.offsetLeft;
+                               if ( jQuery.offset.doesNotAddBorder && !(jQuery.offset.doesAddBorderForTableAndCells && /^t(able|d|h)$/i.test(elem.tagName)) )
+                                       top  += parseInt( computedStyle.borderTopWidth,  10) || 0,
+                                       left += parseInt( computedStyle.borderLeftWidth, 10) || 0;
+                               prevOffsetParent = offsetParent, offsetParent = elem.offsetParent;
                        }
+                       if ( jQuery.offset.subtractsBorderForOverflowNotVisible && computedStyle.overflow !== "visible" )
+                               top  += parseInt( computedStyle.borderTopWidth,  10) || 0,
+                               left += parseInt( computedStyle.borderLeftWidth, 10) || 0;
+                       prevComputedStyle = computedStyle;
+               }
 
-                       // Get parent scroll offsets
-                       while ( parent && parent.tagName && !/^body|html$/i.test(parent.tagName) ) {
-                               // Remove parent scroll UNLESS that parent is inline or a table to work around Opera inline/table scrollLeft/Top bug
-                               if ( !/^inline|table.*$/i.test(css(parent, "display")) )
-                                       // Subtract parent scroll offsets
-                                       add( -parent.scrollLeft, -parent.scrollTop );
+               if ( prevComputedStyle.position === "relative" || prevComputedStyle.position === "static" )
+                       top  += body.offsetTop,
+                       left += body.offsetLeft;
 
-                               // Mozilla does not add the border for a parent that has overflow != visible
-                               if ( mozilla && css(parent, "overflow") != "visible" )
-                                       border( parent );
+               if ( prevComputedStyle.position === "fixed" )
+                       top  += Math.max(docElem.scrollTop, body.scrollTop),
+                       left += Math.max(docElem.scrollLeft, body.scrollLeft);
 
-                               // Get next parent
-                               parent = parent.parentNode;
-                       }
+               return { top: top, left: left };
+       };
 
-                       // Safari <= 2 doubles body offsets with a fixed position element/offsetParent or absolutely positioned offsetChild
-                       // Mozilla doubles body offsets with a non-absolutely positioned offsetChild
-                       if ( (safari2 && (fixed || css(offsetChild, "position") == "absolute")) ||
-                               (mozilla && css(offsetChild, "position") != "absolute") )
-                                       add( -doc.body.offsetLeft, -doc.body.offsetTop );
+jQuery.offset = {
+       initialize: function() {
+               if ( this.initialized ) return;
+               var body = document.body, container = document.createElement('div'), innerDiv, checkDiv, table, rules, prop, bodyMarginTop = body.style.marginTop,
+                       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>';
 
-                       // Add the document scroll offsets if position is fixed
-                       if ( fixed )
-                               add(Math.max(doc.documentElement.scrollLeft, doc.body.scrollLeft),
-                                       Math.max(doc.documentElement.scrollTop,  doc.body.scrollTop));
-               }
+               rules = { position: 'absolute', top: 0, left: 0, margin: 0, border: 0, width: '1px', height: '1px', visibility: 'hidden' }
+               for ( prop in rules ) container.style[prop] = rules[prop];
 
-               // Return an object with top and left properties
-               results = { top: top, left: left };
-       }
+               container.innerHTML = html;
+               body.insertBefore(container, body.firstChild);
+               innerDiv = container.firstChild, checkDiv = innerDiv.firstChild, td = innerDiv.nextSibling.firstChild.firstChild;
 
-       function border(elem) {
-               add( jQuery.curCSS(elem, "borderLeftWidth", true), jQuery.curCSS(elem, "borderTopWidth", true) );
-       }
+               this.doesNotAddBorder = (checkDiv.offsetTop !== 5);
+               this.doesAddBorderForTableAndCells = (td.offsetTop === 5);
 
-       function add(l, t) {
-               left += parseInt(l, 10) || 0;
-               top += parseInt(t, 10) || 0;
-       }
+               innerDiv.style.overflow = 'hidden', innerDiv.style.position = 'relative';
+               this.subtractsBorderForOverflowNotVisible = (checkDiv.offsetTop === -5);
+
+               body.style.marginTop = '1px';
+               this.doesNotIncludeMarginInBodyOffset = (body.offsetTop === 0);
+               body.style.marginTop = bodyMarginTop;
 
-       return results;
+               body.removeChild(container);
+               this.initialized = true;
+       },
+
+       bodyOffset: function(body) {
+               jQuery.offset.initialized || jQuery.offset.initialize();
+               var top = body.offsetTop, left = body.offsetLeft;
+               if ( jQuery.offset.doesNotIncludeMarginInBodyOffset )
+                       top  += parseInt( jQuery.curCSS(body, 'marginTop',  true), 10 ) || 0,
+                       left += parseInt( jQuery.curCSS(body, 'marginLeft', true), 10 ) || 0;
+               return { top: top, left: left };
+       }
 };
 
 
@@ -114,11 +99,11 @@ jQuery.fn.extend({
                        // Subtract element margins
                        // note: when an element has margin: auto the offsetLeft and marginLeft 
                        // are the same in Safari causing offset.left to incorrectly be 0
-                       offset.top  -= num( this, 'marginTop' );
+                       offset.top  -= num( this, 'marginTop'  );
                        offset.left -= num( this, 'marginLeft' );
 
                        // Add offsetParent borders
-                       parentOffset.top  += num( offsetParent, 'borderTopWidth' );
+                       parentOffset.top  += num( offsetParent, 'borderTopWidth'  );
                        parentOffset.left += num( offsetParent, 'borderLeftWidth' );
 
                        // Subtract the two offsets

diff --git a/test/data/offset/body.html b/test/data/offset/body.html
new file mode 100644 (file)
index 0000000..1f13dd5
--- /dev/null
+++ b/test/data/offset/body.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
+       "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
+<html>
+       <head>
+               <meta http-equiv="Content-type" content="text/html; charset=utf-8">
+               <title>body</title>
+               <style type="text/css" media="screen">
+                       body { margin: 1px; padding: 5px; }
+                       #marker { position: absolute; border: 2px solid #000; width: 50px; height: 50px; background: #ccc; }
+               </style>
+               <script type="text/javascript" src="../../../dist/jquery.js"></script>
+               <script type="text/javascript" charset="utf-8">
+                       $(function() {
+                               $('body').click(function() {
+                                       $('#marker').css( $(this).offset() );
+                                       return false;
+                               });
+                       });
+               </script>
+       </head>
+       <body>
+               <div id="marker"></div>
+       </body>
+</html>
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diff --git a/test/unit/offset.js b/test/unit/offset.js
index 8eacec9..096bcb5 100644 (file)
--- a/test/unit/offset.js
+++ b/test/unit/offset.js
@@ -126,10 +126,10 @@ if ( !jQuery.browser.msie || (jQuery.browser.msie && parseInt(jQuery.browser.ver
                var $w = testwin["fixed"].$;
        
                equals( $w('#fixed-1').offset().top, 1001, "jQuery('#fixed-1').offset().top" );
-               equals( $w('#fixed-1').offset().left, jQuery.browser.msie ? 994 : 1001, "jQuery('#fixed-1').offset().left" );
+               equals( $w('#fixed-1').offset().left, 1001, "jQuery('#fixed-1').offset().left" );
        
                equals( $w('#fixed-2').offset().top, 1021, "jQuery('#fixed-2').offset().top" );
-               equals( $w('#fixed-2').offset().left, jQuery.browser.msie ? 1014 : 1021, "jQuery('#fixed-2').offset().left" );
+               equals( $w('#fixed-2').offset().left, 1021, "jQuery('#fixed-2').offset().left" );
        
                testwin["fixed"].close();
        });
@@ -161,4 +161,13 @@ testwin("scroll", function() {
        equals( $w('#scroll-1-1').offset().left, 11, "jQuery('#scroll-1-1').offset().left" );
        
        testwin["scroll"].close();
+});
+
+testwin("body", function() {
+       var $w = testwin["body"].$;
+       
+       equals( $w('body').offset().top, 1, "jQuery('#body').offset().top" );
+       equals( $w('body').offset().left, 1, "jQuery('#body').offset().left" );
+       
+       testwin["body"].close();
 });
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