I try to let the Watch vibrate from within my code:
WKInterfaceDevice.current().play(.success)
but nothing happens. I also tried to ensure to be on the main thread:
DispatchQueue.main.async {
WKInterfaceDevice.current().play(.success)
}
still nothing. Am I missing something here? I expected it to be an easy task, but I fail completely...
Maybe your watch app is not in the active state? Citing the official documentation:
This method has no effect when called while your shared WKExtension object's applicationState property is either background or inactive. By default, you cannot play haptic feedback in the background. The only exception are apps with an active workout session.
So, unless you have a running HKWorkoutSession, if your app is in background you're not allowed to play haptic.
Alternatively, instead of HKWorkoutSession you could use WKExtendedRuntimeSession to support running the app in the background so sounds and haptics work. This needs to be done using either the Physical therapy or Smart alarm session type.
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.
Is there a way to determine whether VoiceOver is currently announcing and when it stops. I've tried UIAccessibilityVoiceOverStatusChanged but my understanding is that this is only if you switch VoiceOver on or off. Any help would be greatly appreciated. thanks.
We use otherAudioIsPlaying, the problem is some app's running in the background like some pedometer monitors etc. turn on the audio it seems and never release it so even though nothing is actually being spoken or played otherAudioIsPlaying always returns 1 until you remove the other application from the background. So now not only can you not play music but you have no idea that another application in the background will mess up this test. Apple really needs to put in an API to determine if Voice Over is currently speaking or not.
These are all the Accessibility booleans that I found in the documentation:
UIAccessibilityPostNotification
UIAccessibilityIsVoiceOverRunning
UIAccessibilityIsMonoAudioEnabled
UIAccessibilityIsClosedCaptioningEnabled
UIAccessibilityRegisterGestureConflictWithZoom
I don't think that there are any booleans to do what you are talking about.
You could use the audio session's "OtherAudioIsPlaying" property to check if another system process is using the audio hardware at the moment. It should be "true" if VoiceOver is speaking and "false" if not.
Actually this might not work properly if the user is playing music in the background. But most users running VoiceOver will usually not have any other audio enabled permanently, since it makes it harder to understand what VoiceOver is saying.
Here is an example for usage:
UInt32 otherAudioIsPlaying;
UInt32 propertySize = sizeof(otherAudioIsPlaying);
AudioSessionGetProperty(kAudioSessionProperty_OtherAudioIsPlaying,&propertySize, &otherAudioIsPlaying);
if(otherAudioIsPlaying) {
// other application is generating sound output (including VoiceOver)
// but might also be any other app (like iPod App)
}
When press the lock button in app,system will call :
-(void) applicationWillResignActive:(UIApplication *)application and
-(void) applicationDidEnterBackground:(UIApplication *)application
So how can I do to make my app only resignActive but not enter background,and I can run my timer when screen locked(Timer can't execute in background mode).
One method is set the property "Application does not run in background" in .plist to YES,it worked, but my app can never enter background again,however I want it will enter background when press the home button.
Update: I want to play some music in my app at a certain time,just like a music alarm,and I still want it works fine when the screen locked,because keep the screen on may waste a lot of battery,and I don't need to do any thing when user press the home button and exit my app.
Open your Info.plist file and add Application does not run in background. Set value to YES.
Application must have special privileges to do any processing in background such as Audio service/Voip service/Location service.
"I can run my timer when screen locked(Timer can't execute in background mode)"
you cannot run a timer in background which will keep running without using any tentrum and doing so...apple will not accept your application on appstore - that's the worst side if you are targeting appstore...
You can not prevent your app from entering the background. This is decided by the operating system (iOS) and is out of control from applications. However, from reading your updated question, I don't think this is what you need to do.
You can execute background tasks with [UIApplication beginBackgroundTaskWithExpirationHandler;] (see reference). If you want to have something happening after a certain interval, check out [UIApplication scheduleLocalNotification:].
Some services such as VOIP, Audio and CoreLocation are allowed to run in background. Using these for other than their intended purposes (for example, playing silent audio) may risk your app being rejected.
Note that there is nothing you can do to prevent your application from entering the background. It is just that some tasks are allowed to execute in the background. Because of this, you cannot do GUI operations and NSTimers will probably not fire (at least I know some cases where they don't).
It would help knowing what you want to run in the background in order to suggest a solution.
Unless you are playing audio BEFORE the move to background you cannot start audio playback when the app is moved to the background or the screen is locked (which has some weird specifics) suffice to say, its as if you were in the background without actually receiving the applicationDidEnterBackground notification.
The best you can do is schedule a local notification, but in this case your music is limited to 30 seconds and must be part of your application bundle.
I have an app, that will keep track of everything the user do in the iPod app. To do this, I added few observers to NSNotificationCenter, like MPMusicPlayerControllerNowPlayingItemDidChangeNotification. But my problem is, I only get those notifications when my app is in the foreground, if its in the background, the system add the notification to a queue, and then the next time my app becomes active it delivers it to me. I have no interest in this queue, since I want to receive real-time notifications.
Is there any way for me to get those notifications even if my app is in suspended state? I want to run just 3 lines of code everytime I get this NowPlayingItemDidChange notifications for example.
Here is where I add the observer.
MPMusicPlayerController *iPodMediaPlayer = [MPMusicPlayerController iPodMusicPlayer];
NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
[notificationCenter addObserver: self selector: #selector(handle_NowPlayingItemChanged:) name:MPMusicPlayerControllerNowPlayingItemDidChangeNotification
object:iPodMediaPlayer];
[iPodMediaPlayer beginGeneratingPlaybackNotifications];
Also, if I add another kind of object to the observer instead of iPodMediaPlayer, the observer won't call the method.
Thanks a lot,
Abras
iOS applications are suspended when they are not in the foreground. There are three exceptions to this rule. You can have code execute in the background if your application is
a) Playing audio. This means the application itself is actually generating audio. My understanding is that the MPMediaPlayerController iPodMusicPlayer object only controls the playback of the external iPod process, rather than playing audio from the app itself. Perhaps you could have some success if you called applicationMusicPlayer instead of iPodMusicPlayer and set the appropriate background flags in your applications Info.plist. This seems like the most legitimate way to get your application to work, but you wouldn't be able to control iPod playback from the iPod app, only your app and the system audio controls.
b) Get your app to monitor the location. If the app is using the GPS it can continue to execute in the background. Downside to this is that the GPS will drain battery, and users might be creeped out that you're requesting their location.
c) Ask UIApplication for extra time. If you use UIApplication's beginBackgroundTask method, your application will continue to run for a finite amount of time in the background. If your users are going to come into your application once every ten minutes or so, this could work as well.
Hope that helps.
Multitasking in iOS is currently a very restricted one. You may start a background task using beginBackgroundTaskWithExpirationHandler: method (of an UIApplication object), but it is intended to finish a finite-length task before going suspended. All background tasks may expire (and get terminated) before it finishes its job. You can check how much longer your application can run by checking backgroundTimeRemaining property of the application object.
As I explained here iOS receive Media Player Notifications when app is in background, there seems no way to get notifications from iPodMusicPlayer.
About Omar Raul Qazi answer:
a) i tried and I had no success. The music kept going down when pressing home button. I think this background flag only works for normal AudioSessions and not for MPMusicPlayer...
b) I am not sure this would work and I don't think Apple would like it when looking for approval
c) You can run in background only synchronous task. You cannot wait there for a notification. Am I wrong?
I'm using the SoundEngine provided with Apple's crash landing example.
After an interruption such as an incoming phone call or an alarm I call to applicationWillResignActive: inside my delegate, in order to pause the game and save the state of it. After the interruption ends I return to my game but the sound is gone. Even if i reinitialize it with SoundEngine_Initialize() the game still wont reproduce any of the sounds, unless i restart my app.
How can I restore my game sounds after the interruption ?
Have you looked at the sound manager class used by 71squared ? You can likely just use their sound manager as is... but if you wanted to role your own, you can look at thier code as I know they have solved this in their code.
http://www.71squared.com/2010/01/latest-sound-manager-class/