When my iPhone app resigns active status, the sharedAccelerometer singleton instance of UIAccelerometer stops sending accelerometer:didAccelerate: messages to my delegate.
Is it at all possible to continue receiving those messages, similarly to how the CLLocationManagerDelegate continues to receive updates when the app is inactive?
I would prefer not to have to disable the idleTimer altogether if it can be helped.
No, not in the most recent available form of the iPhone SDK at least.
I would say that it is possible since this app is on the AppStore:
However, since you move differently in
bed during the different phases, the
Sleep Cycle alarm clock is able to use
the accelerometer in your iPhone to
monitor your movement and determine
which sleep phase you are in.
I can't believe it has to run all night with the screen turned on. EDIT: looks like it has to! :P
So they haven't got around that issue either. More chances that you can't achieve it then...
Have you read the documentation of the UIAccelerometer, does it mention anything there? If it just stops sending acceleration events there is not much you can do.
I would however try to set the accelerometer delegate again to my class when my app has lost focus (when the phone got locked). You can get that notification (lost focus notification) from the UIApplication. Try that just in case the accelerometer's delegate gets set to nil when the app loses focus.
Related
I am building a word game and I want to hide the board when application is suspended?
the code looks fine however it givs a strange behaviour!!,
when I suspend the app nothing will happen but when i resume the application then the board will hide!!
local onSystem = function( event )
if event.type == "applicationSuspend" then
print("suspend")
board_group.alpha = 0
end
end
Runtime:addEventListener( "system", onSystem )
Note: you might wonder how do I know how the application looks when suspended?
the answer is: by pressing the home button twice.
example
SpellTower in normal state
https://dzwonsemrish7.cloudfront.net/items/430k0c0b0y0b413d0b42/Image%202012.11.12%208:08:24%20AM.png?v=4822f549
SpellTower after pressing the home button twice
https://dzwonsemrish7.cloudfront.net/items/280a1y0r2U3W321y1B2z/Image%202012.11.12%208:08:31%20AM.png?v=09c37567
you can see how they are hiding the letters, this is exactly what I want to do for my game, the only difference is i am using Corona SDK
When you do board_group.alpha = 0 you only has set a variable, the result will only take effect after a screen update.
But since the application is suspended... it won't update! So, changing any graphics on applicationSuspend don't work.
I believe the reason is because the application is not considered as suspended. In normal objective c programming it means that applicationWillResignActive is called when the user double clicks on the home button. So what you want to do is to add that code for this part.
Here is a flow of events:
http://www.cocoanetics.com/2010/07/understanding-ios-4-backgrounding-and-delegate-messaging/
Corona seems to have these events:
"applicationStart" occurs when the application is launched and all code
in main.lua is executed.
"applicationExit" occurs when the user quits the application.
"applicationSuspend" occurs when the device needs to suspend the application such as during a phone call or if the phone goes to sleep
from inactivity. In the simulator, this corresponds to the simulator
running in the background. During suspension, no events (not even
enterFrame events) are sent to the application while suspended, so if
you have code that depends on time, you should account for the time
lost to an application being suspended.
"applicationResume" occurs when the application resumes after a suspend. On the phone, this occurs if the application was suspended
because of a phone call. On the simulator, this occurs when the simulator was in the background and now is the foreground application.
So my guess is that you have to implement it outside of the corona API.
According to the corona documents you can implement them in the delegate:
You can intercept UIApplicationDelegate events via your implementation
of the CoronaDelegate protocol.
This protocol conforms to the UIApplicationDelegate protocol. Corona's
internal delegate will call your protocol's method if it is
implemented.
Please keep in mind the following:
Methods that Apple has deprecated will be ignored.
In most cases, your class' version will be invoked after Corona's corresponding version of the UIApplicationDelegate method. There is one situation in which your version will be called before.
In situations where the app is about to suspend or go to the background, your method will be called before Corona's version, e.g.
applicationWillResignActive: and applicationDidEnterBackground:.
http://docs.coronalabs.com/native/enterprise/ios/CoronaDelegate.html
But this is just a guess. Hope it helps!
Edit:
I was thinking, something really simple you could do is catch it outside and present a "pause" screen, then just hide it when the application enters foreground.
So if you can't do that (for now), one other option is to save application state when the application is about to terminate, and then set UIApplicationExitsOnSuspend = true in your plist file. This will cause the application to exit instead of suspending, which will avoid any screenshots, effectively "hiding" the board, etc. The downfall is, the app will have to read the session state when it launches again... this is only useful if your application can be designed to actually exit without losing your state, and is quite honestly, a little extreme. That said, it may be the only way to effectively do what you're trying to do.
Other ideas would be to see if you can add a large black layer to the screen, even though the application is suspending; perhaps this will somehow trigger an internal screen update by natively setting setNeedsDisplay. Also, instead of modifying the alpha, you might consider temporarily removing all of your layers and see if that has a similar effect.
I have a application that periodically (via an NSTimer) asks for the users location using locationManager:startUpdatingLocation I want the locationManager to run in the background so have entered "UIBackgroundModes = location" in the info.plist file.
My question is I am not seeing the results I expected, am I right in thinking that when I press the home button the application delegate calls "applicationDidEnterBackground" but although locationManager is allowed to continue my NSTimer is getting suspended (and as a consequence its not calling startUpdatingLocation to periodically query the devices position). Any ideas / solutions would be much appreciated ...
Gary.
All NSTimers are invalidated when entering the background. You need check via the CLLocationManager for any changes.
Just keep the startUpdateLocation running, you delegate will receive any major changes of the location.
When running in the background, you will only receive location changes based on cell towers.
If you read the documentation for -applicationDidEnterBackground: you'll find that yes, your timers are invalidated. Furthermore, the iOS Application Programming Guide tells you exactly how to track location from the background.
I can't find any information on this but really need to know for sure if it doesn't happen, or if the documentation that proves it does happen is just too hard to find!
The background story:
When my app is running on an iPhone that has a weak 3G signal, and therefore switches backwards and forwards from a weak 3G to a strong 2G and vice-versa, it seems to freeze (the app, a complete freeze for 5-10 seconds). I have had reports of this from far and wide but it's something I can't replicate as my 3G signal is too strong in my area!
If I squeeze my iPhone 4 tightly, then I can dim the signal enough that I get an alert telling me that there is no cellular data network ... before it switches to 2G briefly. This DOES cause a freeze, and I tracked it down to the alert causing the app delegate method "applicationDidBecomeActive" to be called after the alert is dismissed, but no "applicationWillResignActive" as I had expected when thinking of the normal suspend/resume process.
I changed some of the logic in my code to deal with this, and that problem is now resolved.
The question:
Are any app delegate methods called when the phone switches from 3G to 2G and vice-versa? Does the app momentarily lose it's active state and then regain it like it does in the above situation? The problem above seems to replicate exactly what my users are experience EXCEPT from the fact that I get the "no cellular data network" alert which obviously changes things a bit. They don't get this alert, but they still get the freeze.
Thanks
You might be able to track this using Reachability.
You can find it here.
In iPhone OS 3.0, UIApplication allows you to set a applicationSupportsShakeToEdit flag. The documentation says "The default value is YES. Set the property to NO if you don’t want your application to display the Undo and Redo buttons when users shake the device."
This is all great and it ties in to the new NSUndoManager class nicely. However - I don't want to use the built in NSUndoManager in my app! I'm writing a drawing app, and I already have an undo/redo manager that does some fancy stuff (it manages the data required for each undo operation, and will page it to disk if the app is low on memory). I'd much rather just listen for a notification from the UIApplication and trigger undo myself. (I could just make a bogus NSUndoManager, but I also don't want the "Are you sure?" panel to show...)
Does anyone know if such a notification exists? I figure it must - but I can't find it documented anywhere. Is there a way to monitor all notifications going through the app, maybe?
Thanks!
You may well have solved this issue by now, but in case someone comes across this searching for a Shake solution as I did I laid out how you can get the 3.0 Shake event messsages easily in this thread:
How do I detect when someone shakes an iPhone?
It outlines how you can respond to shake without using an UndoManager or presenting the Undo API. Even if you set applicationSupportsShakeToEdit to NO, these events will still be received..
I have a clock program that needs to stay alive all night. I use the idletimer disabled function, but getting a text, missed call, or other notification overrides the idletimer setting back to enabled and allows the phone to sleep. I am thinking that I either need to disable the popups somehow while my app is running, or do something else to keep the phone awake (and running my app) through the popups.
Ideas?
Developing with Iphone 3GS and 3.1.2
How about a timer that periodically disables the idletimer?
You can't do this, at least not with public APIs for App Store inclusion. An incoming phone call will terminate you app and you cannot prevent this.
If you aren't worried about App Store rules, then write a daemon and run your app as a background task.
Although a good idea, the timer does not work. As long as the text message popup is not dismissed manually the phone will go to sleep no matter what idleTimerDisabled state is. Does this make sense, and is there a way to prevent sleep even when a popup is on the screen.