global lastTrack

on run
  set lastTrack to -1
end run

on idle
  tell application "iTunes"
    try
      if player state is playing then
        if current track's database ID is not lastTrack then
          -- track has changed
          set lastTrack to current track's database ID
          beep
        end if
      else
        -- do nothing/something when idle
      end if
    end try
  end tell
  return 0.1 -- interval
end idle

#import <Cocoa/Cocoa.h>

@interface iTunesLink : NSObject
- (id) init;
@end

@implementation iTunesLink
- (id) init {
    NSDistributedNotificationCenter *dnc = [NSDistributedNotificationCenter defaultCenter];
    [dnc addObserver:self selector:@selector(trigger:) name:@"com.apple.iTunes.playerInfo" object:nil];
    return self;
}

- (void) trigger:(NSNotification *)notification {
    NSString *myScript = [NSString stringWithFormat:
        @"tell application \\"Finder\\"\\ndisplay dialog (\\"iTunes mi želi nešto reći!\\")\\nend tell"];
    NSAppleScript *as = [[[NSAppleScript alloc] initWithSource:myScript] autorelease];
    [as executeAndReturnError:nil];
}
@end

int main(int argc, char *argv[])
{
	iTunesLink *connection;
	connection = [[[iTunesLink alloc] init] autorelease];
	return NSApplicationMain(argc, (const char **) argv);
}

script NazivProjektaAppDelegate
	property parent : class "NSObject"
	property dnc : class "NSDistributedNotificationCenter"
	
	on awakeFromNib()
		set dnc to dnc's defaultCenter
		tell dnc to addObserver_selector_name_object_(me, "trigger:", "com.apple.iTunes.playerInfo", missing value)
	end awakeFromNib
	
	on trigger_()
		display dialog ("iTunes mi želi nešto reći!")
	end trigger_
	
	on applicationWillFinishLaunching_(aNotification)
		-- Insert code here to initialize your application before any files are opened 
	end applicationWillFinishLaunching_
	
	on applicationShouldTerminate_(sender)
		-- Insert code here to do any housekeeping before your application quits 
		return current application's NSTerminateNow
	end applicationShouldTerminate_
end script