One of the many challenges of building a usable black theme for Mac OS X is making it work with web pages. If you use Safari, the buttons, scrollbars, and other interface widgets on web pages get their marching orders from the system's graphics files—the same ones that regular applications use.

So, if a web page has a pushbutton, the button will by default take on the style of the active theme. If you're running Crystal Black, this means that the button inherits the Crystal Black style. We like this.

Color for the button's text, on the other hand, gets its marching orders from the browser's default Cascading Style Sheet (CSS) file—which, naturally, makes the text black, and therefore unreadable on top of a black button. We don't like this.

On first glance, the solution seems to merely design a special CSS file for Crystal Black and make Safari use it. And that does work for many web sites and many buttons. However, many folks who design web pages like to fiddle with the CSS style for their pages' buttons, and such fiddling means that there's nothing "mere" about designer a Crystal Black style sheet.

Further, many Mac applications these days have views that are simply embedded web content using Apple's WebKit framework. The practical implication here is that Mac apps don't know how to read a Crystal Black CSS file, so Crystal Black must do some fiddling under the hood to avoid having unreadable buttons in such web views.

Then there's Safari itself. I really wanted to theme the Web Inspector—the incredibly useful built-in website viewer/debugger/designer assistant—with the Crystal Black look and feel, but it wasn't immediately obvious how to do this. I assumed that the tool was just a part of Safari, and therefore built with classes and widgets from the Cocoa AppKit (which is the framework all Cocoa apps are built with). However, when I began to inspect the Inspector, I discovered that everything contained within its borders was simply web content: HTML, CSS, JavaScript, and images.

In other words, the Web Inspector tool is nothing but an intricate, sophisticated, and extremely well designed web page!

Having built a Crystal Black CSS file for web pages in general, and with my past expertise in CSS, I attacked this challenge with relish! It reminded me of the time I realized that Dashboard widgets are, at their core, nothing but little web pages (as are simply apps for the iPhone). In tackling this one, the main question was, How should the various elements look? And the hardest part was inspecting the various parts in of the Inspector in great detail to determine which CSS rules governed their default appearance and behavior.

As I discovered, the WebKit has a a sub-framework called "WebCore," which in turn has a folder of resources specifically for the Web Inspector. In the Inspector folder, among other things, is a suite of CSS files that handle different aspects of the Inspector's design and behavior. Of these, the primary one I needed to tweak was called simply "inspector.css."

Besides controlling the usual attributes of a web page—document elements, text elements, image elements, layout elements, form elements, and so on—this style sheet applies various advanced CSS properties that serve the purpose that in years past would have been handled by many individual images. As I've described this CSS 3.0 magic previously, there's no longer a need for using graphics and JavaScript to add box shadows, rounded box corners, borders, gradients, and reflections to your web pages.

Naturally, since the open-source WebKit project was initiated by Apple, and since that project zoomed ahead of all other browser engines in developing new ways to design with CSS, that's how the Web Inspector is built. This approach—using a command syntax rather than images to design a user interface—is one that Apple has been adopting for its desktop applications. In recent years, Apple has been adding new classes and methods to the AppKit that make it a trivial matter to build a window frame, a border, a toolbar, or a button using code rather than individual graphics. 

While this is a logical and efficient approach, it also presents challenges for theming Mac applications, a challenge that Crystal Black is often unable or unwilling to overcome. (The story of all the challenges in building Crystal Black are described in this article.)

Not so with the Web Inspector, fortunately.

The Inspector does use a few images in its design, but most of the toolbar, separators, and section headers are built with CSS gradients. Very cool indeed!

This bit of Crystal Black will eventually be bundled with the whole theme, but for now I offer it as a free download. Admittedly, the audience for such software is small—you have to like Crystal Black, and you have to be a regular user of the Web Inspector—but it might be of interest to others who are curious about how such things are done.

One caveat in viewing the screenshots... The scrollbars that appear, as well as the HUD window style, are part of the overall Crystal Black theme and are not part of the Web Inspector theme itself.

Enjoy!

Update 4/18/11: The full Crystal Black 1.0 theme is now available from the Crystal Black website.

Installing Crystal Black for Web Inspector

The download contains a small application that you can use to install—and to uninstall—the theme. Simply double-click and select "Install" to apply the theme. Or select "Uninstall" to restore the default CSS files and graphics.

After installing or uninstalling the theme, you'll need to quit and restart Safari for the theme to take effect.

Crystal Black for the Web Inspector (Download file is 1.0MB)