AppController.m

#import "AppController.h"
#define IS_CAPS_LOCK(x)		(x & alphaLock)

@implementation AppController

+ (void)initialize {
    [[NSUserDefaults standardUserDefaults] registerDefaults:[NSDictionary dictionaryWithObjects:[NSArray arrayWithObject:[NSNumber numberWithBool:NO]] forKeys:[NSArray arrayWithObject:CLStateOfAlarm]]];
}

- (void)awakeFromNib {
    NSStatusBar *bar = [NSStatusBar systemStatusBar];
    menuItem = [bar statusItemWithLength:NSVariableStatusItemLength];
    [menuItem retain]; // keep it!
    menuItem.button.title = NSLocalizedString(@"📢",@""); // title
    menuItem.button.cell.highlighted = YES; // behave like main menu
    [menuItem setMenu:menuItemMenu];
    
    isAlarming = NO;
    alarmIsEnabled = [[[NSUserDefaults standardUserDefaults] objectForKey:CLStateOfAlarm] boolValue];
    
    sound = [[NSSound soundNamed:@"Alarm"] retain];
    
    // Set menu state
    if (alarmIsEnabled) {
        [enabledMenuItem setTitle:NSLocalizedString(@"Deactivate warning",@"")];
        [enabledMenuItem setTag:1];
    } else {
        [enabledMenuItem setTitle:NSLocalizedString(@"Activate warning",@"")];
        [enabledMenuItem setTag:0];
    }
    [quitMenuItem setTitle:[NSLocalizedString(@"Quit",@"") stringByAppendingString:@" Carbon CapsBeeper"]];
}

- (IBAction)menuChanged:(id)sender {
    if ([enabledMenuItem tag] == 0) { // Activate alarm
        [enabledMenuItem setTitle:NSLocalizedString(@"Deactivate warning",@"")];
        [self setAlarmIsEnabled:YES];
        [enabledMenuItem setTag:1];
    } else { // Deactivate alarm
        [enabledMenuItem setTitle:NSLocalizedString(@"Activate warning",@"")];
        [self setAlarmIsEnabled:NO];
        [enabledMenuItem setTag:0];
    }
}

- (void)setAlarmIsEnabled:(BOOL)aBool {
    if (aBool != alarmIsEnabled) {
        if (aBool == YES) {
            timer = [[NSTimer scheduledTimerWithTimeInterval:0.1
                                                      target:self
                                                    selector:@selector(checkCapsLock:)
                                                    userInfo:nil
                                                     repeats:YES] retain];
        } else {
            if ([sound isPlaying])
                [sound stop];
            isAlarming = NO;
            [timer invalidate];
            [timer release];
            timer = nil;
        }
        alarmIsEnabled = aBool;
    }
}

- (BOOL)alarmIsEnabled {
    return alarmIsEnabled;
}

- (void)checkCapsLock:(NSTimer *)aTimer {
    int keyModifier = GetCurrentKeyModifiers();  // the only real Carbon function
    if ( IS_CAPS_LOCK(keyModifier) && !isAlarming) {
        isAlarming = YES;
        [sound play];
    }
    else if ( !IS_CAPS_LOCK(keyModifier) && isAlarming) {
        isAlarming = NO;
        [sound stop];
    }
}

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
    alarmIsEnabled = !alarmIsEnabled;
    [self setAlarmIsEnabled:!alarmIsEnabled];
}

- (void)applicationWillTerminate:(NSNotification *)aNotification {
    [[NSStatusBar systemStatusBar] removeStatusItem:menuItem];
    [[NSUserDefaults standardUserDefaults] setObject:[NSNumber numberWithBool:[self alarmIsEnabled]] forKey:CLStateOfAlarm];
}

- (void)dealloc {
    [self setAlarmIsEnabled:NO];
    [menuItem release];
    [sound release];
    
    [super dealloc];
}

- (IBAction)openWebsite:(id)sender {
    [[NSWorkspace sharedWorkspace] openURL:[NSURL URLWithString:@"https://github.com/henrik242/ccb"]];
}

@end