Added more unit tests for offset. Fixed an offset issue relating to table header...

[jquery.git] / src / offset.js

diff --git a/src/offset.js b/src/offset.js
index f59fb9b..2570358 100644 (file)
--- a/src/offset.js
+++ b/src/offset.js
@@ -5,59 +5,59 @@ jQuery.fn.offset = function() {
        var left = 0, top = 0, elem = this[0], results;
        
        if ( elem ) with ( jQuery.browser ) {
-               var     absolute     = jQuery.css(elem, "position") == "absolute", 
-                   parent       = elem.parentNode, 
+               var parent       = elem.parentNode, 
+                   offsetChild  = elem,
                    offsetParent = elem.offsetParent, 
                    doc          = elem.ownerDocument,
-                   safari2      = safari && parseInt(version) < 522;
+                   safari2      = safari && parseInt(version) < 522,
+                   fixed        = jQuery.css(elem, "position") == "fixed";
        
                // Use getBoundingClientRect if available
                if ( 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)
-                       );
+                       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 IE 7 quirks mode the border width is overwritable by the following css html { border: 0; }
+                       // 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
-                       if ( msie ) {
-                               var border = jQuery("html").css("borderWidth");
-                               border = (border == "medium" || jQuery.boxModel && parseInt(version) >= 7) && 2 || border;
-                               add( -border, -border );
-                       }
+                       // 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 cells
-                               if ( mozilla && /^t[d|h]$/i.test(parent.tagName) || !safari2 )
+                               // However Mozilla adds the border for table or table cells
+                               if ( mozilla && !/^t(able|d|h)$/i.test(offsetParent.tagName) || safari && !safari2 )
                                        border( offsetParent );
-                               
-                               // Safari <= 2 doubles body offsets with an absolutely positioned element or parent
-                               if ( safari2 && !absolute && jQuery.css(offsetParent, "position") == "absolute" )
-                                       absolute = true;
+                                       
+                               // Add the document scroll offsets if position is fixed on any offsetParent
+                               if ( !fixed && jQuery.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;
                        }
                
                        // Get parent scroll offsets
                        while ( parent.tagName && !/^body|html$/i.test(parent.tagName) ) {
-                               // Work around opera inline/table scrollLeft/Top bug
-                               if ( !/^inline|table-row.*$/i.test(jQuery.css(parent, "display")) )
+                               // 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(jQuery.css(parent, "display")) )
                                        // Subtract parent scroll offsets
                                        add( -parent.scrollLeft, -parent.scrollTop );
                        
@@ -69,9 +69,16 @@ jQuery.fn.offset = function() {
                                parent = parent.parentNode;
                        }
                
-                       // Safari doubles body offsets with an absolutely positioned element or parent
-                       if ( safari2 && absolute )
-                               add( -doc.body.offsetLeft, -doc.body.offsetTop );
+                       // 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 || jQuery.css(offsetChild, "position") == "absolute")) || 
+                               (mozilla && jQuery.css(offsetChild, "position") != "absoltue") )
+                                       add( -doc.body.offsetLeft, -doc.body.offsetTop );
+                       
+                       // 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));
                }
 
                // Return an object with top and left properties