offset: added fixed position support and fixed opera issue with borders on absolute...

diff --git a/src/offset.js b/src/offset.js
index 20805de..a06c36c 100644 (file)
--- a/src/offset.js
+++ b/src/offset.js
@@ -5,11 +5,13 @@ 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, 
                    offsetParent = elem.offsetParent, 
                    doc          = elem.ownerDocument,
-                   safari2      = safari && parseInt(version) < 522;
+                   safari2      = safari && parseInt(version) < 522,
+                   position     = jQuery.css(elem, "position"),
+                   absolute     = position == "absolute",
+                   fixed        = position == "fixed";
        
                // Use getBoundingClientRect if available
                if ( elem.getBoundingClientRect ) {
@@ -43,12 +45,26 @@ jQuery.fn.offset = function() {
                        
                                // 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]$/i.test(offsetParent.tagName) || safari && parseInt(version) >= 522 )
+                               if ( mozilla && /^t[d|h]$/i.test(parent.tagName) || !safari2 )
                                        border( offsetParent );
+                                       
+                               // Get offsetParent's position
+                               position = jQuery.css(offsetParent, "position");
                                
                                // Safari <= 2 doubles body offsets with an absolutely positioned element or parent
-                               if ( safari2 && !absolute && jQuery.css(offsetParent, "position") == "absolute" )
+                               if ( safari2 && !absolute && position == "absolute" )
                                        absolute = true;
+                               
+                               // Opera adds border for fixed, relative and absolute parent elements
+                               if (opera && /^fixed|relative|absolute$/i.test(position))
+                                       add( 
+                                               -parseInt(jQuery.css(elem, "borderLeftWidth")),
+                                               -parseInt(jQuery.css(elem, "borderTopWidth"))
+                                       );
+                                       
+                               // Add the document scroll offsets if position is fixed
+                               if ( !fixed && position == "fixed" )
+                                       fixed = true;
                        
                                // Get next offsetParent
                                offsetParent = offsetParent.offsetParent;
@@ -69,9 +85,16 @@ jQuery.fn.offset = function() {
                                parent = parent.parentNode;
                        }
                
-                       // Safari doubles body offsets with an absolutely positioned element or parent
-                       if ( safari2 && absolute )
+                       // Safari <= 2 doubles body offsets with an absolute or fixed positioned element or parent
+                       if ( safari2 && (absolute || fixed) )
                                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
@@ -86,6 +109,6 @@ jQuery.fn.offset = function() {
 
        function add(l, t) {
                left += parseInt(l) || 0;
-               top += parseInt(t) || 0;
+               top  += parseInt(t) || 0;
        }
 };