First look at css hooks. These hooks provide a way to change how jQuery handles getti...

They are similar in concept to the special event hooks. Return false from the hook to revert control back to jQuery's normal processes for getting and setting certain css properties.

diff --git a/src/css.js b/src/css.js
index cb65c0b..497303a 100644 (file)
--- a/src/css.js
+++ b/src/css.js
@@ -25,7 +25,7 @@ jQuery.fn.css = function( name, value ) {
                if ( value === undefined ) {
                        return jQuery.curCSS( elem, name );
                }
-               
+
                if ( typeof value === "number" && !rexclude.test(name) ) {
                        value += "px";
                }
@@ -35,22 +35,30 @@ jQuery.fn.css = function( name, value ) {
 };
 
 jQuery.extend({
-       style: function( elem, name, value ) {
-               // don't set styles on text and comment nodes
-               if ( !elem || elem.nodeType === 3 || elem.nodeType === 8 ) {
-                       return undefined;
-               }
-
-               // ignore negative width and height values #1599
-               if ( (name === "width" || name === "height") && parseFloat(value) < 0 ) {
-                       value = undefined;
-               }
+       cssHooks: {
+               opacity: {
+                       get: function( elem, force ) {
+                               var style = elem.style;
+                               if ( jQuery.support.opacity && !style.filter ) {
+                                       return false; // move along, nothing to see here
+                               }
+
+                               // IE uses filters for opacity
+                               var ret = ropacity.test(elem.currentStyle.filter || "") ?
+                                                       (parseFloat(RegExp.$1) / 100) + "" :
+                                                       "";
+
+                               return ret === "" ?
+                                       "1" :
+                                       ret;
+                       },
+
+                       set: function( elem, value ) {
+                               var style = elem.style;
+                               if ( jQuery.support.opacity && !style.filter ) {
+                                       return false; // move along, nothing to see here
+                               }
 
-               var style = elem.style || elem, set = value !== undefined;
-
-               // IE uses filters for opacity
-               if ( !jQuery.support.opacity && name === "opacity" && style.filter ) {
-                       if ( set ) {
                                // IE has trouble with opacity if it does not have layout
                                // Force it by setting the zoom level
                                style.zoom = 1;
@@ -60,12 +68,22 @@ jQuery.extend({
                                var filter = style.filter || jQuery.curCSS( elem, "filter" ) || "";
                                style.filter = ralpha.test(filter) ? filter.replace(ralpha, opacity) : opacity;
                        }
+               }
+       },
+
+       style: function( elem, name, value ) {
+               // don't set styles on text and comment nodes
+               if ( !elem || elem.nodeType === 3 || elem.nodeType === 8 ) {
+                       return undefined;
+               }
 
-                       return style.filter && style.filter.indexOf("opacity=") >= 0 ?
-                               (parseFloat( ropacity.exec(style.filter)[1] ) / 100) + "":
-                               "";
+               // ignore negative width and height values #1599
+               if ( (name === "width" || name === "height") && parseFloat(value) < 0 ) {
+                       value = undefined;
                }
 
+               var style = elem.style || elem, set = value !== undefined;
+
                // Make sure we're using the right name for getting the float value
                if ( rfloat.test( name ) ) {
                        name = styleFloat;
@@ -73,8 +91,19 @@ jQuery.extend({
 
                name = name.replace(rdashAlpha, fcamelCase);
 
+               var hooks = jQuery.cssHooks[name] || {};
+
                if ( set ) {
-                       style[ name ] = value;
+                       if ( !('set' in hooks) || hooks.set( elem, value ) === false ) {
+                               style[ name ] = value;
+                       }
+               }
+
+               if ( 'get' in hooks ) {
+                       var cssHookReturn = hooks.get( elem, false );
+                       if ( cssHookReturn !== false ) {
+                               return cssHookReturn;
+                       }
                }
 
                return style[ name ];
@@ -98,24 +127,17 @@ jQuery.extend({
        },
 
        curCSS: function( elem, name, force ) {
-               var ret, style = elem.style, filter;
-
-               // IE uses filters for opacity
-               if ( !jQuery.support.opacity && name === "opacity" && elem.currentStyle ) {
-                       ret = ropacity.test(elem.currentStyle.filter || "") ?
-                               (parseFloat(RegExp.$1) / 100) + "" :
-                               "";
-
-                       return ret === "" ?
-                               "1" :
-                               ret;
-               }
+               var ret, style = elem.style, filter, hooks = jQuery.cssHooks[name] || {};
 
                // Make sure we're using the right name for getting the float value
                if ( rfloat.test( name ) ) {
                        name = styleFloat;
                }
 
+               if ( 'get' in hooks && ( ret = hooks.get( elem, force ) ) !== false ) {
+                       return ret;
+               }
+
                if ( !force && style && style[ name ] ) {
                        ret = style[ name ];