Garbage Collection is deprecated. ARC it is now and so we have to update/change our Mac projects. Sometimes this is very easy and, of course, often it is harder. And sometimes it is even impossible.

And sometimes there is a need to provide code for both. This can be done with:

#if !__has_feature(objc_arc)
// retain, release etc. here
#endif

Never ever check for URLForUbiquityContainerIdentifier in a validateUserInterfaceItem call.

If Siri still is beta, than iCloud is alpha. That crap cost me two days until I realized that all me performance issues came from that. And do yourself a favor. Put those checks in a background thread. Especially at startup…

I’ve just submitted my latest App for review. CocoaBox is a sophisticated little tool for all iOS and OS X developers. Directly create new snippets with a hotkey out of and directly paste them into Xcode by keyboard with CocoaBox. Or attach unlimited files and tag and search for them.

And of course CocoaBox is iCloud enabled – means that you will have all your snippets and files in sync on all your Macs.

Currently two Apps of mine are stuck in review hell and I guess it has something to do with the iCloud support – but I don’t know what it is exactly and as always Apple is not able to communicate. So it may also take a while for CocoaBox to be approved :–(

As recently discovered – the iCloud and the sandboxing do not work without enabling ARC; or at least not when GC is enabled. Of course this is sometimes only a little bit of work, in most cases a lot of work and sometimes simply impossible for some resources or frameworks yet.

But there is a solution. One can simply disable ARC for those files:

Add compiler flag -fno-objc-arc in Targets > Build Phases > Compile Sources.

Concurrency. And concurrency. And once again: concurrency. The holy grail to writing good Apps. And the hardest part. At least to debug.

The simplest way to performe a task not on the main thread is:

[self performSelectorInBackground:@selector(myConcurrentAction) withObject:nil];

- (void) myConcurrentAction {
NSAutoreleasePool *pool = [NSAutoreleasePool new];

// do whatever needs to be done
// but only all things NOT GUI
// ensure that nothing else tries to access used objects meanwhile


[pool drain];
}

I needed a way to terminate an application from within another without using Apple Script or old Carbon stuff. I finally found this nifty solution:

if ([[NSWorkspace sharedWorkspace] respondsToSelector:@selector(runningApplications)]) {
for (NSRunningApplication *app in [[NSWorkspace sharedWorkspace] runningApplications])
if ([@"Suggestions" isEqualToString:[app localizedName]])
[app terminate];
}

NSValueTransfomers are a very handy solution to store a lots of information in a simple int for example. Combined with bindings one can display text in OS X label colors for example. Something I needed today:

@implementation MGIntToColorTransformer

+ (Class)transformedValueClass {

return [NSColor class];
}

+ (BOOL)allowsReverseTransformation {

return NO;
}

- (id)transformedValue:(id)value {

NSColor *color = nil;

switch ([value intValue]) {
case 0:
color = [NSColor colorWithCalibratedRed:0.298 green:0.298 blue:0.298 alpha:1.000]; // [NSColor blackColor] || [NSColor clearColor]
break;
case 1:
color = [NSColor colorWithCalibratedRed:0.924 green:0.372 blue:0.337 alpha:1.000]; // red
break;
case 2:
color = [NSColor colorWithCalibratedRed:0.907 green:0.628 blue:0.255 alpha:1.000]; // orange
break;
case 3:
color = [NSColor colorWithCalibratedRed:0.845 green:0.771 blue:0.254 alpha:1.000]; // yellow
break;
case 4:
color = [NSColor colorWithCalibratedRed:0.642 green:0.766 blue:0.254 alpha:1.000]; // green
break;
case 5:
color = [NSColor colorWithCalibratedRed:0.335 green:0.599 blue:0.937 alpha:1.000]; // blue
break;
case 6:
color = [NSColor colorWithCalibratedRed:0.712 green:0.522 blue:0.796 alpha:1.000]; // lavender
break;
case 7:
color = [NSColor colorWithCalibratedRed:0.624 green:0.624 blue:0.624 alpha:1.000]; // gray
break;
default:
color = [NSColor colorWithCalibratedRed:0.298 green:0.298 blue:0.298 alpha:1.000];
break;
}

return color;
}

@end