iOS 4 Alarm Clock App with Multitasking Support

Question

I\'m making an alarm clock app with multitasking support. However, I\'m stuck with some limitations of the sdk.

I need to play selected alarm sound whenever the ala

Answer 1

I would say what you want to do is not possible with the current restrictions of iOS. That said you can probably fake a progressive alarm by doing what the developer of Progressive Alarm Clock do to play the progressive alarm. By scheduling many local notifications, one after each other. He has divided the alarm sounds into chunks of say 10 s each with progressive volume levels. This is a very crude example to show how the progressive alarm can be faked.

UILocalNotification *notif1 = [[UILocalNotification alloc] init];
notif1.fireDate = [NSDate dateWithTimeIntervalSinceNow:15];
notif1.soundName = UILocalNotificationDefaultSoundName;
notif1.alertBody = @"Alarm";
[[UIApplication sharedApplication] scheduleLocalNotification:notif1];
[notif1 release];

UILocalNotification *notif2 = [[UILocalNotification alloc] init];
notif2.fireDate = [NSDate dateWithTimeIntervalSinceNow:20];
notif2.soundName = UILocalNotificationDefaultSoundName;
[[UIApplication sharedApplication] scheduleLocalNotification:notif2];
[notif2 release];

This will first display a notification and play the default sound after 15 seconds. After 5 seconds more the sound will be played again. By having a bunch of sound files where the volume is increasing the progressive sound can be faked just by scheduling more local notifications. This will of course only work if you have an alarm sound that can be easily divided into chunks, just like the bells in Progressive Alarm Clock. Unfortunately you can't cancel the alarm by tapping cancel in the notification. You have to start the application to do that.

Answer 2

Whatever the Progressive Alarm Clock developer is doing, it's not what Robert Höglund is describing, AFAIK, since the alarm will sound even if the phone is in silent, and UILocalNotification doesn't seem to have any way to allow for this. In addition, if you kill the app manually while an alarm is pending, the app will notify you that it needs to relaunch. This seems to suggest that it must be somehow running in the background.