Mac OS X

Computing / iphone / Mac OS X — 3 Comments
20
Feb 11

Why I am uninstalling Xcode 4 gm seed Beta

The person who helps tutor me into iOS happiness recommended that I try Xcode 4's beta. He felt is was ripe and ready to go. I followed his advice, installing Xcode in a separate directory than Xcode 3 (.2.5). Today I am uninstalling Xcode 4's beta. Here's are some of my impressions from my experience:

  1. Git integration: great step forward here. Xcode embraces the Git version control system and detects existing command-line setups. Only thing is that Xcode only allows you to commit to your local repository. There is no push capability.
  2. Adding files – source code or images – is a huge issue. Drag and drop does not work properly and mostly ends up with an error message. More crippling is the fact that if you use the navigation menu to import files into your project, it imports them into a purgatory area that appears above the root project icon in the file listings view. What causes the real issue is the fact that if you then try to move those files back into the project by dragging them, they will be copied into the project. There is no way to delete them from the purgatory state inside Xcode. If you try to compile the project, the compiler will complain about duplicate files (even images) with the same name. If you delete the file from the command line or finder, you are stuck with 'ghostly' listings. The project will compile but the clutter grows.
  3. Xcode 4 sets up a new project structure, different than Xcode 3. It has fewer folders and overall seems a bit more cluttered to my newb eyes. Adding groups is also unintuitive as the only way to name a new group is by creating it first, and then single-clicking its name.
  4. Project properties are a huge step forward. Configuring Xcode to use libraries and set up apps on the iPhone and iPad is now outside of the source plists and in a pleasant user experience.
  5. Xcode 4 integrates Interface Builder into the IDE's window; no longer a separate app. It uninstalled Xcode 3's version of Interface Builder and if you try to open xib files in Xcode 3 it opens Xcode 4's version. That would still be cool had it not for the fact that the new Xcode 4 Interface Builder has issues in detecting properties in the files you create in Xcode 4.  

In summary – Xcode 4 works, mostly. It does crash – but gracefully. Yet I would recommend against installing it for serious development and even more, against installing it side by side with Xcode 3. 

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Computing / iphone / Mac OS X — 1 Comment
30
Jan 11

Private methods in Objective-C

Coming from the Java world, I love, care and embrace all things private, including private methods. Objective-C supports the feature but it appears to me (based on very shallow Googling) that there is not too much familiarity (or use) with it. I looked in a book I recently acquired, Learn Objective-C for Java Developers (Learn Series). While not a book a perfect book, it does cover the how-to of private methods in Objective-C.  

The key to the approach is to leverage Objective-C categories. Categories are a mind-blowingly nifty in the fact that they allow you, among other things, to augment objects you did not create with your own methods. While there are other ways of 'hiding' private methods, most of them result in warnings in Xcode. So here goes…

Say you have an object called CoolWidget. You create the header file (CoolWidget.h)for it as usual, i.e.:

@interface CoolWidget:NSObject
{
    int publicVar;

    @private
    int somePrivateVar;
}

// public methods
-(void) doSomething:(BOOL)cool;

@end

To add private methods to it, you would create a category for the object in a separate header file (CoolWidget+Private.h):

@interface CoolWidget (Private)

// private methods
-(void) doSomethingPrivate:(BOOL)cooler;

@end

All that's left for you to do is to include the additional header file, CoolWidget+Private.h in your implementation file, CoolWidget.m (though categories are often/normally implemented in their own .m file).

Update:

As my friend Glenn Barnett points out in his tweet, there is no such think as private methods in Objective-C. Unlike C++ or Java, there is no real 'enforcement' of access to the methods. Privacy, overall, is purely by convention. 

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Computing / Mac OS X — No Comments
10
Nov 09

Brother HL-2070N issues with OS X

I love my laser printer, a Brother HL-2070N. It is fast, has a network interface and on my Mac it installed itself automagically. Sadly, on my wife’s Mac it installed alright but all print jobs failed. Even tinkering with CUPS did not work. Luckily I found the solution on this Apple support page.

The solution is essentially to install a new version of the open source driver set called Gutenprint. The problem I faced was that the version I tried to install, 5.2.4, did not install fully. I tried the Gutenprint uninstaller that comes in the same dmg file but it failed to work. Downloading the previous version, 5.2.3, and installing it worked just fine. All that was left to do was add the printer as usual (using JetDirect/Socket) and instead of using the default Brother HL-2070N drivers, to use the “Brother HL1270N – CUPS + Gutenprint 5.2.3″ driver.

Hope this helps and thanks to the folks from the Apple forums. This was a doozy to solve.

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