Programmatically powering off an iPhone? - iphone

Is it possible to programmatically power off an iPhone or does Apple disallow this?
If Apple disallows this, is it possible to programmatically mute the sound on an iPhone?

The iPhone applications you create with the official SDK are sandboxes in and of themselves. Walled off sandboxes with barbed wire.
You won't be able to turn off the power. And muting sounds other than your own applications' sounds amounts to being able to turn off the iPod playback.

I don't have any evidence for that, but this would involve modifying the "UserExperience" - which is something that Apple never would allow (and why still many people jailbreak their phones).
And this involves "power off" as well as "mute sound" - because both could destroy the UX (you wait for an important call, but application X broke the sound).

Is it possible to programmatically power off apple iPhone or does apple dissalow this. If apple disallow this is it possible to programmatically mute the sound on iPhone?
Apple prevents you from affecting the functionality of other apps and the core phone functions. When in doubt, if you want to do something phone-wide, you can't.
Plus, to mute the phone, you'd also have to figure out some way of making the physical mute switch on the side of the phone match the phone's mute setting. That's not going to happen with software!

I'm not sure how powering down the device and muting the device are reasonable alternatives in your app, but the bottom line is that you can't power down the device. However, you can mute the sound of your own app or the iPod app using the MPMusicPlayerController class.
The code looks like this for your app:
MPMusicPlayerController *player = [MPMusicPlayerController applicationMusicPlayer];
player.volume = 0.0f;
And, this for the iPod:
MPMusicPlayerController *player = [MPMusicPlayerController iPodMusicPlayer];
player.volume = 0.0f;

Anything you do that affects anything external to your application wont make it through the approval process (besides push notifications). You can certainly mute the sound in your app by simply pausing, stopping, or setting the volume to zero for all sounds you are playing. If you mean make the phone be mute globally, no.

You can't turn the device off through software. You can set the music playback volume with the MPMusicPlayerController class, the docs suggest you can't change the volume of the
iPod player though.

Related

How to disable iOS System Sounds

I am working on an iPad app that connects with an accessory that plays sound. When the iPad is connected to the accessory, I would like to mute all system sounds but allow other sounds (iPod).
Part of the reason for this is that the accessory is such that it is intended to be used during a live performance. Clearly it would be annoying to have e-mail, alert, or any other system sound running through and amplified (crazy loud).
I have looked at using AVAudioSession (read Audio Sessions to learn more) and tried all of the AudioSessionCategories. None of these categories will mute the system sound, instead it will only allow you to mute application sounds (iPod) - not useful for my purposes.
I also found docs on "System Sound Services", but this only allows you to play system sounds. There is no api here to disable system sounds while your app is running.
A final note, we have made it easy to adjust the iPad level (volume) by including the MPVolumeView, but we expect the user to want to play iPod music. If while playing iPod music (or music from another app) and an e-mail comes through, you'd be amazed how LOUD / ANNOYING that e-mail suddenly becomes when going through our accessory. It's even possible it could damage equipment. :D
It is possible to change the system sounds, which turns out to be the ringer btw, using the AVSystemController. However, AVSystemController exists in the private Celestial framework. Since this framework is referenced by UIKit, it is still possible to use this class without directly referencing it.
Apple prohibits using private API's, so that alone makes this a bad idea. Given my circumstance, I think they may make an exception, BUT I will likely abandon this course since after taking it I realized that it didn't fix my problem. It does indeed mute the sounds, but as soon as I plug in to my accessory, the system sounds come out at max volume even though the ringer volume is set to 0. This leads me to believe the answer to solving my problem is in the MFI documentation.
Anyhow, here is how to change the ringer using private framework / api (which will get your app rejected without some kind of special permission).
short answer:
[[AVSystemController sharedAVSystemController] setVolumeTo:0 forCategory:#"Ringtone"];
answer without having to directly reference Celestial frameork / AVSystemController.h:
- (void) setSystemVolumeLevelTo:(float)newVolumeLevel
{
Class avSystemControllerClass = NSClassFromString(#"AVSystemController");
id avSystemControllerInstance = [avSystemControllerClass performSelector:#selector(sharedAVSystemController)];
NSString *soundCategory = #"Ringtone";
NSInvocation *volumeInvocation = [NSInvocation invocationWithMethodSignature:
[avSystemControllerClass instanceMethodSignatureForSelector:
#selector(setVolumeTo:forCategory:)]];
[volumeInvocation setTarget:avSystemControllerInstance];
[volumeInvocation setSelector:#selector(setVolumeTo:forCategory:)];
[volumeInvocation setArgument:&newVolumeLevel atIndex:2];
[volumeInvocation setArgument:&soundCategory atIndex:3];
[volumeInvocation invoke];
}
Using MediaPlayer framework, we can set the level of SYSTEM sound
[[MPMusicPlayerController applicationMusicPlayer] setVolume:0];
Best you can do is encourage your users to go into airplane mode.

iPod Volume Level Affects App Volume Level

I am writing an iPad app that uses the "Flite" text-to-speech engine to announce specific events. The Flite engine uses an AVAudioPlayer instance to play the speech audio once it renders. For fun, I decided to add some simple controls to my app to allow the user to control iPod playback (next, prev, play/pause and volume - the basics) while my app is running using MPMusicPlayerController (of course).
The problem I am having is that when I adjust the iPod volume using MPMusicPlayerController, all of my audio is affected, including other sound effects and the speech audio. I set the volume for these other audio players (AVAudioPlayer instances) to 1.0 before playing the sound but it seems that the volume is always capped at whatever the iPod player volume is set to...
Is this normal? And what can I do to get around it? I want my app's audio to play at system full volume regardless of the volume level of the iPod player. (Example: The user had set the system volume to 80% of the device's max. I want my app to play audio at 100% of that 80% while allowing the user to adjust the iPod audio playback to 0-100% of that 80%.) Note: I am not interested in "ducking" but setting the iPod volume lower at all times while my app is running (background music).
I also have the problem, that -sometimes- when you first launch the app and press play on the iPod player (which sends the [player play] call), the iPod does not respond. If I press the home button, go into the iPod app and start playback then, once returning to my app, it works fine. What the deal with that?
Thanks in advance for any help!!
It could be something to do with the audio session category you've specified. Check out the Audio Session Programming Guide to see if you've chosen the right category.
The volume buttons on the side control the system volume and by extension the volume of your app's sounds.
I guess it's considered to be the Master volume control.
you can set the volume for specific samples or sounds using the AVItem's setVolume
[item setVolume]
You can create an AVItem to reference an existing sound file in your application or on the iphone. The code is pretty simple and looks like this -->
AVItem *item [[AVItem alloc]
initWithPath:#"the file"];
[item setVolume];
btw, this will not affect the rest of the audio channel (instantiated by some kinda AVController object) and the volume that you've set in your code will not be displayed on you screen so im not sure if you can change it at run time.

MPMusicPlayerController doesn't respect device mute switch?

I'm using the MPMusicPlayerController application music player, created like:
appMusicPlayer = [MPMusicPlayerController applicationMusicPlayer];
The issue is that it will play music no matter which setting the device mute switch is in, it doesn't seem to care either way. Is there some audio session mode I need to be in to have it respect the mute switch?
Yes. You want to use one of the following constants for your Audio Session Category:
kAudioSessionCategory_AmbientSound
kAudioSessionCategory_SoloAmbientSound
These are the ones that go silent when the Ring/Silent switch is set to silent.
Fwiw I'm seeing the same problem. I suspect that, like the iPod app itself, it will never respect the mute switch.
Try using iPodMusicPlayer instead of applicationMusicPlayer.

Anyone know if it's possible to use custom sounds on the iTouch piezo speaker?

I'm obviously not trying to play full spectrum audio, but is there some way to customize the iPhone/iTouch system alert sounds to play a little melody on the piezo speaker? The functionality is clearly present, so I guess the question is has Apple made it available for developer use...
Thanks,
-S
There are quite a few predefined sounds you can use in the 0-2000 range. For example, the keyboard click can be called like such:
AudioServicesPlayAlertSound(1104);
There is also a way to play a custom melody on the first-generation iPod touch, but it's not pretty.
It isn't. Sorry.
Only thing you can do from an application is this (you can use any SoundID for this, really):
AudioServicesPlayAlertSound(kSystemSoundID_Vibrate);
Discussion
Depending on the particular iPhone OS device, this function plays a short sound and may invoke vibration. Calling this function does the following on various iPhone OS devices:
iPhone—plays the specified sound and, if the user has configured the Settings application for vibration on ring, invokes vibration.
iPod touch, original—plays a short alert melody.
iPod touch, 2nd generation—plays the specified sound.

iPhone (SDK 2.2): adusting playback volume while NOT actively playing music w/ AVFoundation?

So I have an app which plays many short sound clips. I need to know when the sounds are finished playing, and I need to use mp3s, so I'm using AVFoundation for the sound playback.
When a sound is actively playing, and the user uses the hardware volume buttons, the playback volume changes. Problem is, the app is NOT constantly playing sounds, and when it's not, and the hardware buttons are used, the RINGER volume gets adjusted instead.
How do I set it up so, as long as the app is running, the user can adjust the playback volume?
Thanks!
Turns out this can be accomplished by allocating an AVAudioPlayer with any valid sound file and calling the prepareToPlay method, without ever calling the play method.
Works perfectly.
Start an AudioSession and don't stop it when you're not playing sounds.
so you want to disable ringer playback volume as long as the app is running? therefore the hardware controls will only adjust the app playback sounds?
i dont think this is possible unless you are "always playing sound" for example, many games are always playing background music or what have you.
You might be able to accomplish this by constantly playing a 0 volume sound as long as your app is running. You could then play your sound clips over it.
How do I play multiple sounds simultaneously?