I am creating player application, which is playing audio streams through internet. I want to add alarm functionality in my app - in particular time my player begins to play audio stream, I am trying to use UILocalNotification mechanism. But I've difficulties with it when my application in background mode, I can't call 'play' method, when notification is receiced (can't without user interaction). May be it is impossible?
But I bought this application:
http://itunes.apple.com/us/app/radio-alarm-clock-mp3-radio/id380271167?mt=8
And it seems like radio can start playing when local notification is received. Alarm can start playing radio when my app is in background mode.
Earlier I was trying to use NSTimer for this, but when my app goes to background, timer stops. If I use beginBackgroundTaskWithExpirationHandler: it works only 10 minutes. My app has special flag in plist, what is is audio application, and can playing music in background. In this case timers are working. But if I stop playing and go to background, timer is not working.
When I use \Radio Alarm Clock' application, I hear 'white noise' from dinamic, when music in not playing. May be it is the secret of this application?
Can you help me with my problem? Thanks.
maybe it's too late.
I had a look to the app you've mentioned at http://itunes.apple.com/us/app/radio-alarm-clock-mp3-radio/id380271167?mt=8 and yes, I think you are absolutely right, the only way to achieve that the application remains active while in background is to play a fake sound while it is in the background, which should be prohibited by Apple.
I've also seen that they don't use the remote iPod control, and this was strange at a first look.
At the end my opinion is that they do the following:
Avoid the call to beginReceivingRemoteControlEvents which allows to activate the iPod controls while in background (in fact they don't have it)
In this way, the status bar doesn't show the play icon while
the app plays audio
When the app goes in background, it probably plays a no sound periodically (once every 10 secs for example), in this way the app remains active
I saw that they also avoided to manage interruptions, for example in case another app is in foreground and plays music. Again Apple should have rejected the app for that reason, cos it is against the rules to follow while in background, but maybe they didn't see it during the acceptance tests.
So my interpretation is that they have intentionally missed to activate the iPod controls, just to avoid to show the play icon in the status bar while in background. In this way, the users are unaware that the app is active and is doing something strange after they close it.
In addition you can see that the app doesn't interrupt when another app plays in foreground a sound or audio, because otherwise they risk that the app doesn't restart on time when the alarm shpould fire.
That's just my idea of how they do that, and I think this is the only way for an audio app on iOS to remain active while it is in background and is supposed to be halted (well, in case Apple doesn't see the trick).
Have you tried adding this to appdelegate.m
- (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification {
// Call your method in here.
}
if you have can you add code for us to see what your doing.
Related
One would think it would be essential for a VoIP app to obey the same rules as the stock phone app but it turns out to be almost impossible to implement ringing correctly. Several things I tried:
Local push notifications with ring sound.
Good: obeys both Silent and DND modes.
Bad: the sound can be no longer than 30 seconds, and it only vibrates once when the notification appears. So to achieve the ringing effect the notification has to be re-pushed e.g. every 6 seconds, effectively spamming the notification center. Also push notifications do not sound/vibrate if the app is active so the app has to detect that and ring differently.
AudioServicesPlayAlertSound().
Good: proper API seemingly designed specifically for this task. Obeys silent mode.
Bad: completely ignores Do Not Disturb mode, the sound and vibration come right through.
Use AVFoundation to play the ring sound.
Good the sound plays.
Bad: does not support vibration, does not support silent/DND modes. Essentially not usable as a ringer.
Is there a better way? Or did Apple completely miss this use case?
As you say in your 3 options, only a UILocalNotification actually obeys silent/DND mode.
The problems with it can be solved.
Spamming the notification center: I think that works quite well. You can cancel your previous notification immediately before you fire off a new one, so there will always be only 1 outstanding notification.
[[UIApplication sharedApplication] cancelAllLocalNotifications];
Vibration problem: You should be able to call this: AudioServicesPlaySystemSound(kSystemSoundID_Vibrate); in the same place where you call your local notification over and over again with a timer until the call ends or the users acknowledges the call. With the VOIP background setting on it should work in the background.
As you stated in option 2 the vibrate will not follow DND mode, but it's just vibration. If you spam the notification center that will vibrate once every time the notification comes in so you may not need to explicitly start vibrating if that's enough for you.
Good luck.
I'm currently working on an app which reminds the user, when he gets to an certain location. I want this app working in background as well and searched for solutions.
In the AppStore i found the App called Sleep Cycle, which tracks your activities during your sleep. When you set the alarm, and running the App in the Background you get this screen red bar on the top of the Display of your iPhone.
http://i.stack.imgur.com/uEejp.jpg
Does anybody know what kind of Backgroundmode this is, and how i can transfer it to my app?
Thanks
To have such a red bar I use audio background mode and also I record sound in background. Since Sleep Cycle asks user to allow access to microphone I believe it also records audio in background
I am creating an alarm clock app that requires some user action within the app in order to turn the alarm off. Below is a picture of what another app, Sleep Cycle, does when you turn an alarm on and press the home screen (i.e. background the app).
Here is an image link (I can't post an image yet, no rep despite my many attempts to answer people's questions today) for the effect I want to re-create.
Those that have used iPhone's Personal Hotspot and connected a device will notice that it is the same effect, where a notification appears at the top of the UI - pushing everything down by around 20-40 points. This is highly desirable to an alarm clock app as it encourages the user to keep the app in the foreground so that the app can easily be entered when waking up (instead of relying on the 30 second sound window allowed by local notifications)
Does anyone have any ideas on how to implement this functionality. I assume that it must go somewhere in the:
- (void)applicationDidEnterBackground:(UIApplication *)application
tag within the AppDelegate, but I'm not sure what exactly I need to be reading up on. So if anyone has a link to some relevant Developer Docs that would also be extremely helpful.
Many thanks for your help,
Ryan
There are a handful of built in 'background modes' that change the status bar's appearance depending on what functionality an app provides whilst it's in the background. The one you've identified (a red status bar) is triggered when an app records audio whilst in the background. I presume Sleep Cycle must be acting as though it records audio just for this purpose. Other background modes include VoIP (which I think uses a blue status bar). Check out Apple's documentation on supporting these various background modes
In your case, you'd want to add audio to the UIBackgroundModes property in your Info.plist file.
But note that it wouldn't be unreasonable for Apple to reject an app during review if it pretends to perform one of these background tasks but doesn't. For example, there have been apps in the past that tried playing a silent audio clip continuously in order to stay awake in the background - needless to say Apple got wise to this and the app in question had to change its behaviour.
I created a music app that is wired up to MPNowPlayingInfoCenter. I have a bunch of methods that do various things (next, pause, etc). However, when I hit the next button in MPNowPlayingInfoCenter, the app responds immediately and calls the method instantly when the app is active. However, when the app is playing the background and I hit next from MPNowPlayingInfoCenter, it responds but after a few seconds.
Has anyone else experienced this or have any idea what the culprit might be here?
You shouldn't use any graphics code from the background - iOS will kill your app if you do so too much as it takes away from the resources available to foreground apps. It'll also cripple your other background routines.
I implemented Push notifications in iOS. I want my application to play a music (about 15sec) when I send a push message. I am currently getting the push message, and the music is being played only if the app is in the foreground.
If the app is in the background, it shows up a notification, and when i tap it, it then plays the music.
But how do I get the functionality of automatically playing the music? I think this can be done because, in iOS, Audio apps can run in the background. So I just want the music to be played when the app goes to background, and it receives a push.
Can anyone help me with this please?
Thanks,
Nithin
Yes, there are two ways to do this.
The traditional way before iOS 7 is to register for audio playing background mode and play a silent sound forever, this will keep your app running in the background for a long time until the user kills it, or it is killed due to low memory.
This way has many drawbacks, the user must launch your app once so that you can start playing the sound and every time the iPhone is shut off, the user need to relaunch your app when he turn on the iPhone.
Also this will consume a lot of battery. 20%-30% a day for an iPhone 5.
The new way after iOS 7.0 is to exploit background fetch and remote notification, you can play your sound while performing a background fetch, which has a 30 seconds running time. Also you can trigger a background fetch with a push notification.
This is an article about background fetch and push notification http://www.objc.io/issue-5/multitasking.html