In Flash Builder I have an app for ios which will get Latitude and longitude using Geolocation every minute. I would like to run this in the background so I've added this to my Info.plist:
<key>UIBackgroundModes</key>
<array>
<string>location</string>
</array>
This works, but only for 16 minutes every time. After that it just goes into suspension. When I unlock the phone the app runs again as it's supposed to, but it hasn't got the data after 16 minutes until the unlock.
http://blogs.adobe.com/airodynamics/2012/05/04/air-ios-background-behavior/
This link gave me some ideas. I added:
NativeApplication.nativeApplication.executeInBackground = true;
to my initial function, but no difference. Then I tried this:
<key>UIApplicationExitsOnSuspend</key>
<false/>
but yet again no change.
My last possible idea is that this app is running on the device in development mode, not as distribution. Could that effect the background mode as the app has not been checked over by Apple?
Thanks
EDIT:
I have now tested my app in testFlight and it does the same thing, suspending after 16 minutes.
So the reason for this is due to not moving while testing. Ran my app while I went for a 30 minute walk with the phone locked and it worked the whole time.
To change this you would need to access the CLLocation manager and change pausesLocationUpdatesAutomatically to false. Unfortunately I haven't found a way to change this within flash builder.
Related
I'm working on a radio alarm clock, and i have some issues.
I am using local notifications for the alarms, so it has a gentle fallback if the app is not running.
I am well aware of the limitations of the device, and i know what i can and cannot do when the device has gone into background.
But my question is this:
I have seen other apps starting an audio streamer when i've locked the device. How is this possible? May this be inside an execution-timeframe?
How is the best way to implement this? Is it any way i can activate a streaming session when the device is locked?
Edit
To clarify: I know how i make audio play in the background. But the issue is triggering the audio-playback when an local notification or some other event fires.
One app that seems to do this, is Radio Alarm Clock. I haven't tried it for long period of times yet. But it seems to do this. A video demo of the app: http://www.youtube.com/watch?v=KJQiFOcdBWk
Have you already declared your background task?
Support for some types of background execution must be declared in advance by the app that uses them. An app declares support for a service using its Info.plist file. Add the UIBackgroundModes key to your Info.plist file and set its value to an array containing one or more of the following strings:
audio — The app plays audible content to the user while in the background. (This content includes streaming audio or video content using AirPlay.)
iOS App Programming Guide - Implementing Long Running Background Tasks
You can add this by clicking on your main project icon, then under the Info tab you can add "Required Background Modes" to the "Custom iOS Target Properties" section. "App Plays Audio" will be one of the three default values.
Big Edit With New Answer:
If everything else is already in order, you can keep your app running in the background using the UIApplication method
- (UIBackgroundTaskIdentifier)beginBackgroundTaskWithExpirationHandler:(void (^)(void))handler
detailed here: UIApplication Class Reference
with an example here: Hour 21: Building Background-Aware Applications
This allows you to run an instance of NSTimer which triggers your music player. The difference between this approach and UILocalNotifications is that this method never lets the app fully enter the background mode, the music player exists the entire time which subverts the need to create it from the background, which looks to be impossible.
There may be limitations to how long of a timer you can set, I haven't tested this past 14 minutes out.
I'm trying to build an alarm app that can fire an alarm while in locked-screen mode (the app is in the foreground, but the screen is locked). The alarm has to be triggered by a NSTimer not by uilocalnotification.
In iOS 4 I used the 'play silent sound every 10 seconds' hack to prevent the app from going to deep sleep and the timer events worked fine. However, in iOS 5 this doesn't seem to work.
Any ideas? Or this should work and I'm doing something wrong?
It seems that you actually can use the 'play silent audio' hack in iOS 5, but the audio has to be audible meaning you can't play it at volume set to 0.0.
You can use github.com/marcop/iPhoneInsomnia and set the volume to greater than 0, but it still doesn't work because the sound file is so short that the system kills your application before the timer is triggered and replays the sound. I solved this by setting the numberOfLoops of the audioPlayer to -1 (infinite repeat). Then it should work.
And you should also set the UIBackgroundMode plist key to an array of one string called "audio"
It's probably a dirty workaround, but in the past I have used the proximity sensor to turn off the screen instead of locking the phone. Simply place the phone upside down and the screen will turn itself off.
[[UIDevice currentDevice] setProximityMonitoringEnabled:YES];
This will allow you to retain full control over the device, while the screen does turn off.
My app is checking some algorithm in the background, after something like 30 minutes
my application seems to be like close (iphone turn to sleep mode i think). I need the app
to run this algorithm as long as it is in the background.
Do you have any idea how to set this 20 minutes timer to recount by some action?
maybe NSRunloop or something else?
You can't reset this timer or continue to run in the background on a stock OS iPhone (except for a limited amount of time, or if your is legitimately of 3 types, VoIP, audio or GPS).
The user can reset this timer by bringing your app to the foreground, perhaps after a notification or something.
I need to get the user's location even if the phone goes to sleep/screen lock mode. I've tried enabling location services in background mode by adding key to the info.plist file, but this method requires iOS >= 4.0. Is there any alternate method to get the location manager working in screen lock mode
Yes. Have a look at this:
http://github.com/marcop/iPhoneInsomnia
It keeps the iDevice awake by registering your app as an audioplayer and playing a silent sample every 5 seconds. AFIK, this is the only way to do it in iOS < 4.0.
It seems like a hack, so I don't know what Apple thinks of it, still there are a lot of apps in the AppStore that apparently does this.
I have used:
[UIApplication sharedApplication].idleTimerDisabled = YES;
in a number of Apps developed and running under iPhone OS 2.x and never had any problems with it. They were clock apps so needed to run constantly and ignore the iPhone's idle Timer setting.
However, trying to achieve the same with a new App running OS 3.0 (and which needs to be deployed under 3.0 as it uses some 3.0 APIs) I've found the idle Timer to be either ignored or inconsistent.
My App plays music from the iPod library and when the music is playing it auto-locks regardless of the above setting. But once you unlock it, it then doesn't auto-lock again unless you play music again, in which case it locks again after the iPhone auto-lock time setting.
I'm amazed no-one else has come across this as I imagine it would affect a large number of Apps.
Just to clarify:
1. The above code is in ApplicationDidFinishLaunching
2. I know that the phone won't auto-lock when testing from xCode regardless of settings
If anyone has any thoughts I'd be very grateful...
Our app uses the MPMediaPLayer. We also had the idleTimerDisabled=YES code in the ApplicationFinishedLaunching, which works EXCEPT if untethered, and there is already a current nowPlayingItem which is left playing (or unpaused, if paused at app startup). Obviously this is all with the Settings -> General -> Autolock set to some timed value.
By adding idleTimerDisabled=NO, immedately followed by idleTimerDisabled=YES in one of the other bits of code AFTER we had figured out what bit of music we would get playing seemed to solve the problem. Just setting it to YES was insufficient.. and subsequent queries had always indicated the correct value (YES).. so it appears the Apple code ignores the setting of the value IF there is a current piece of music and that is not changed by your code.. but does notice a change of value.
This is all under iOS 3.0.
Even in 2015, using iOS 8.2, this bug is still alive and kicking.
Here's my solution, using XCode 6.2.
iPhone - phone goes to sleep even if idleTimerDisabled is YES
Basically, even now, in 2015, the only way to safely make sure that the device doesn't go to sleep is to repeatedly call a piece of code to keep the device awake.
-(void)callEveryTwentySeconds
{
// DON'T let the device go to sleep during our sync
[[UIApplication sharedApplication] setIdleTimerDisabled:NO];
[[UIApplication sharedApplication] setIdleTimerDisabled:YES];
}
Sounds like a bug, file with Radar - I am not too surprised this has not been seen much as there are probably not a lot of apps that try to lock the screen open and play music.
Having same issue. It does work when the device is plugged in. You can press lock button on top, and my NSTimer fires later and causes a vibrate. However if the device is not plugged in pressing the lock button puts the device to sleep. Any solution would be greatly appreciated.
iCodeblog posted about the idletimer, I said it didn't work, and the person who develops 'cute clock' was nice enough to reply. You have to do a hack, play a 1 second or longer silent sound every 10 or so seconds with NSTimer. This keeps the device awake even if the user hits the lock button.
I develop Seconds - Interval Timer for iPhone and iPod touch and I've had no end of trouble with this. The idea of my app is that people create timers based on a number of intervals where each interval can have it's own playlist or track played.
In iOS3 I had the problem that I couldn't disable the idle timer by just setting idleTimerDisabled = YES. In the end I came up with the same solution as Neil whereby I would periodically set it to NO, then immediately to YES again. This seemed to work.
I'm now updating the app to iOS4 (I know, iOS5 is just around the corner...) and now I have the opposite problem. If the MPMediaPlayer changes track before the idle timer reaches it's limit it gets reset. I've just tested this by creating an interval in my app that was 55 seconds, my auto-lock was set to a minute. At 50 seconds the screen dimmed as it prepared to lock, but at 55 seconds when the music changed it went back to full brightness and then didn't lock as it should.
Overall, the implementation of this seems flakey at best.