Feeds

A better way to build OS X preferences

Behind the interface

5 things you didn’t know about cloud backup

Mac Secrets Welcome to Dave Jewell’s new Mac Secrets column, focused at Apple Mac developers — particularly those using Cocoa. Here, on a regular basis, Dave will introduce you to unknown and undocumented aspects of the Foundation and AppKit class libraries that Apple has, er, neglected to tell you about…

In my opinion, there’s no sense in re-inventing the wheel if Apple has already done the job for you. Over the coming months you’ll find there are an amazing number of undocumented wheels within the Apple libraries that let you get on with writing great applications without having to reinvent what Apple have already done. They are just waiting for you to set ’em spinning!

At this point, a few folks will doubtless be sharpening their quill pens (or even wooden stakes!) and preparing to chastise me for using undocumented features. After all, it’s possible that the techniques I’m going to describe may not work in some future version of the operating system, right? That’s true, but I’d offer a couple of counter arguments in return.

First, Leopard (OS X 10.5) has only recently been released, and is likely to be good for several years — it’s very unlikely that minor system updates would impact what I’m describing here. And if they do, I’ll obviously make every effort to bring you a workaround.

Next, and more importantly, you can spend more time making your great Mac application even greater — and surely that’s what we’d all like to see, including Apple. Right, Apple?

Implementing preference dialogs

Let’s start by taking a look at preference dialogs. As you’ll know, the standard way of building a preference dialog is to create a window complete with toolbar buttons for each “page” of preferences. You can see an example of this in the advanced portion of the Safari preferences dialog box (below).

Mac preferences windows

A preference dialog box from Safari

In recent years, the mechanics of automatically saving and loading your application preferences have become easier, largely due to the introduction of Cocoa bindings. You can read more on this here. What I’m concerned with in this article, however, is the user interface rather than persistence issues.

There are really two undocumented classes we need to focus on here. These are NSPreferences and NSPreferencesModule. You can think of the former as a sort of supervisory class that handles the display of the preferences window. Most of the real work is done by this class, but — for our purposes — the interface is extremely simple. You will typically have one subclass of NSPreferences, and it will be instantiated by AppKit, not by you.

The other class, NSPreferencesModule, corresponds to one page of your tabbed preferences dialog. If you’ve got three preference categories (for example), then you’ll need three subclasses of NSPreferencesModule. Again, you don’t need to instantiate them.

Build a business case: developing custom apps

More from The Register

next story
The Return of BSOD: Does ANYONE trust Microsoft patches?
Sysadmins, you're either fighting fires or seen as incompetents now
Linux turns 23 and Linus Torvalds celebrates as only he can
No, not with swearing, but by controlling the release cycle
Why has the web gone to hell? Market chaos and HUMAN NATURE
Tim Berners-Lee isn't happy, but we should be
China hopes home-grown OS will oust Microsoft
Doesn't much like Apple or Google, either
Apple promises to lift Curse of the Drained iPhone 5 Battery
Have you tried turning it off and...? Never mind, here's a replacement
Sin COS to tan Windows? Chinese operating system to debut in autumn – report
Development alliance working on desktop, mobe software
Eat up Martha! Microsoft slings handwriting recog into OneNote on Android
Freehand input on non-Windows kit for the first time
Linux kernel devs made to finger their dongles before contributing code
Two-factor auth enabled for Kernel.org repositories
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Endpoint data privacy in the cloud is easier than you think
Innovations in encryption and storage resolve issues of data privacy and key requirements for companies to look for in a solution.
Scale data protection with your virtual environment
To scale at the rate of virtualization growth, data protection solutions need to adopt new capabilities and simplify current features.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?