iOS - App in Background vs Local Notifcations - ios

I'm building a project which is something like an Alarm Clock app. I know there are inherit limitations here (as compared to the built-in Apple Clock app) but I'm trying to assess if these limitations will be a blocker.
In the end, I need to be able to schedule an alarm/notification at a certain time, and have it sound when the phone is locked. Furthermore, I want to be able to interact with the app from the lock screen (including shake and volume gestures).
Does this require me having the app run in the background, and scheduling LocalNotifications? If its in the background, and the LocalNotification fires on the lock screen, is it possible for the User to interact with the application? i.e. With the app SleepCycle, you can shake the phone from the lock screen to trigger a Snooze. Is that sort of functionality possible only because the app is running in the background (in the case of that app, I know it's running in the background)

yes. you need to be running in the background for interacting on the lock screen

Related

How to create background services to run even when the app is killed, in iOS?

I need to create a android equivalent functionality in iOS, which records GPS and other sensor readings even when the app is killed, in iOS that would be, when the app is swiped from the app switcher.
In android, the Service class is able to do this. The notification stays there in the notification panel and you cannot swipe it, unless the app allows you to do so..
Many apps add widgets to the notification panel using this functionality like, clean master. Clean master widget floats in the notification panel and does most of the functionality which the app does it self.
IOS does not has any background service concept. Yes, you can use GPS location when user app in background but it will not work when your app is totally close.

IOS App and Background

I have a music signal processor app I want to publish and it needs to run in the back ground. I used to Info-plist to do so with UIBackgroundModes. It runs on IOS7 or less, and the problem I am having is once the phone locks and the app goes into the background I can't get it to come out of the background and its keeps running with the red banner at the top. Some of this I have learned as I go, but I have noticed some run on a timer, but I want mine, since its a music processor to keep going until the phone either unlocks or whatever interrupted it stops.
The app is basically a stomp box used with iRig. If that helps.
Thanks
Can you clarify about what you mean when the phone locks, the app goes into the background and yo can't get it to come out of the background? Are you saying like the app is playing music while the app is locked?

Shake functionality in a music application

I have developed a small music app by using AVPlayer and MPMediaPickerControlLibrary with all the normal required functionalities for a music app. The app is also capable of running in the background when the screen is locked.
Now, what I want is to start the app when the screen is locked through a shake and soon as the app starts the current song should start playing.
I am not able to achieve this from a long time
Any suggestions on this will be highly appreciated or any other workaround apart from shake to turn on the music in the app when the screen is locked in iPhone.
Thanks in advance.
You need to implement the a CMMotionManager object, but keeping it running all the time in background will be a major power consumption issue.
Modifying the updateInterval property to reduce the number of updates will defeat the purpose, given that you may miss a shake in background.
Now, if the app was terminated by the user, then no motionManager object will be available until the user launches the app again.

Changing the behavior of the iOS Lockscreen

Is there a way to change the behavior of the iOS Lockscreen? For instance, can an app, if active, provide a user with dynamic content, such as pictures, as the phone's background, and, in addition, allow a user to swipe left (in addition to swiping right, if they want to unlock the phone) to engage said content?
Is there a way to change the behavior of the iOS Lockscreen?
No.
For instance, can an app, if active...
No.
iOS doesn't provide any API that would allow the sort of thing that you describe. It might be possible to modify or replace the lock screen if you jailbreak your phone -- all bets are off at that point. But an app that uses the Apple-provided API has no way to modify the lock screen.
Also, note that if the device is locked, your app won't be active. You may have intended a looser definition of "active," but looking at the linked chart of app states will help you understand that what you're looking to do isn't achievable with the current API. Apps have to be active to receive events, but a locked phone implies that your app will be in an inactive, background, or suspended state if it's running at all.
No. (Not if you're talking about an 'app' in the sense of the App Store)
The only way an app can interact with the lock screen is through notifications, and cannot alter the standard lock screen interface.
You can alter the lock screen with a MobileSubstrate tweak on a jailbroken phone, but this requires reverse-engineering SpringBoard (the iOS launcher app), can be quite complicated and obviously cannot be distributed through the App Store

Keep app running while iOS device locked?

I have an app that makes heavy use of video out. In a typical use-case, I'll have an iPad connected to an external monitor. I just want the external monitor on; the iPad display does not need to stay on.
The ideal case would be for someone to connect to an external monitor, then lock their iPad. But that pauses my app. (Currently, I'm calling setIdleTimerDisabled to keep the iPad from locking up and pausing my app.)
I'd like to give the user the option of locking the iPad, but still having my app running and sending images to video out. (Note: I'm not talking about keeping my app running when it's not in the foreground. I just want to keep it running while it's in the foreground, but the device is locked.)
Is this possible?
I would say no, it is not possible. Here's why:
The docs read:
Pressing the Sleep/Wake button is another type of interruption that causes your app to be deactivated temporarily. When the user presses this button, the system disables touch events, moves the app to the background but sets the value of the app’s applicationState property to UIApplicationStateInactive (as opposed to UIApplicationStateBackground), and finally locks the screen.
Something interesting to note in the docs above is that a bit further down under "What to do when an interruption occurs" Apple recommends that you stop doing certain tasks.
In response to this change, your app should do the following in its applicationWillResignActive: method:
Stop timers and other periodic tasks.
Stop any running metadata queries.
Do not initiate any new tasks.
Pause movie playback (except when playing back over AirPlay).
Enter into a pause state if your app is a game.
Throttle back OpenGL ES frame rates.
Suspend any dispatch queues or operation queues executing non-critical code. (You can continue processing network requests and other time-sensitive background tasks while inactive.)
This tells me that Apple doesn't want or expect your app to be doing much of anything in this state, other than preparing to be fully backgrounded.
On a related note here's a thread that shows how to determine whether you've hit the Sleep/Wake button or not:
Is it possible to distinguish between locking the device and sending an app to background?

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