Radically simplified the whole theming mechanism. Theming can now be done declaratively with less typing, better readability, easier maintenance.

Also fixed some oversights in the existing themes: text was not dimmed in disabled state for segmented controls, text was not dimmed for default buttons in disabled state in HUD (IIRC).

AppKit/Themes/BlendKit/BKThemeDescriptor.j

@@ -219,3 +219,132 @@ function BKLabelFromIdentifier(anIdentifier)
     return label;
 }
 
+
+
+PatternIsVertical = YES,
+PatternIsHorizontal = NO;
+    
+/*
+    To create a simple color with a pattern image:
+        PatternColor(name, width, height)
+        
+    To create a color with a three part pattern image:
+        PatternColor(slices, orientation)
+        
+    where slices is an array of three [name, width, height] arrays,
+    and orientation is PatternIsVertical or PatternIsHorizontal.
+    
+    To create a color with a nine part pattern image:
+        PatternColor(slices);
+        
+    where slices is an array of nine [name, width, height] arrays.    
+*/
+function PatternColor()
+{
+    if (arguments.length < 3)
+    {
+        var slices = arguments[0],
+            imageSlices = [];
+            
+        for (var i = 0; i < slices.length; ++i)
+        {
+            var slice = slices[i];
+            
+            imageSlices.push(slice ? [_CPCibCustomResource imageResourceWithName:slice[0] size:CGSizeMake(slice[1], slice[2])] : nil);
+        }
+        
+        if (arguments.length == 2)
+            return [CPColor colorWithPatternImage:[[CPThreePartImage alloc] initWithImageSlices:imageSlices isVertical:arguments[1]]];
+        else
+            return [CPColor colorWithPatternImage:[[CPNinePartImage alloc] initWithImageSlices:imageSlices]];
+    }
+    else if (arguments.length == 3)
+    {
+        return [CPColor colorWithPatternImage:[_CPCibCustomResource imageResourceWithName:arguments[0] size:CGSizeMake(arguments[1], arguments[2])]];
+    }
+    else
+    {
+        return nil;
+    }
+}
+
+function SetThemeValues(object, values)
+{
+    for (var i = 0; i < values.length; ++i)
+    {
+        var attributeValueState = values[i],
+            attribute = attributeValueState[0],
+            value = attributeValueState[1],
+            state = attributeValueState[2];
+            
+        if (state)
+            [object setValue:value forThemeAttribute:attribute inState:state];
+        else
+            [object setValue:value forThemeAttribute:attribute];
+    }
+}
+
+function SetHUDThemeValues(object, values, overrides)
+{
+    for (var i = 0; i < values.length; ++i)
+    {
+        var attributeValueState = values[i],
+            attribute = attributeValueState[0],
+            value = attributeValueState[1],
+            state = attributeValueState[2];
+            
+        if (attribute == "text-color" || attribute == "text-shadow-color")
+        {
+            var whiteValue = attribute == "text-color" ? 1.0 : 0.0,
+                alpha = (state && (state & CPThemeStateDisabled)) ? 0.6 : 1.0;
+            
+            value = [CPColor colorWithCalibratedWhite:whiteValue alpha:alpha];
+        }
+        else if (typeof(value) === "object" && value.hasOwnProperty("isa") && [value isKindOfClass:CPColor])
+        {
+            var pattern = [value patternImage];
+            
+            if (pattern)
+            {
+                if ([pattern isThreePartImage] || [pattern isNinePartImage])
+                {
+                    var slices = [pattern imageSlices],
+                        newSlices = [];
+                    
+                    for (var sliceIndex = 0; sliceIndex < slices.length; ++sliceIndex)
+                    {
+                        var slice = slices[sliceIndex],
+                            filename = "HUD/" + [[slice filename] lastPathComponent],
+                            size = [slice size];
+                        
+                        newSlices.push([filename, size.width, size.height]);
+                    }
+                    
+                    if ([pattern isThreePartImage])
+                        value = PatternColor(newSlices, [pattern isVertical]);
+                    else
+                        value = PatternColor(newSlices);
+                }
+                else
+                {
+                    var filename = "HUD/" + [[pattern filename] lastPathComponent],
+                        size = [pattern size];
+                    
+                    value = PatternColor(filename, size.width, size.height);
+                }
+            }
+        }
+        else if (attribute == "text-shadow-offset")
+        {
+            value = CGSizeMake(-1.0, -1.0);
+        }
+        
+        if (state)
+            [object setValue:value forThemeAttribute:attribute inState:state];
+        else
+            [object setValue:value forThemeAttribute:attribute];
+    }
+    
+    if (overrides)
+        SetThemeValues(object, overrides);
+}