How to change track position on lock screen/control center? - ios

Question

When playing a song with the ios 7 music app the user can use slider to change song position in the lock screen/the control center. Slider is active:
But when playing music in my app user can't do it. Slider isn't active:
How can i enable these feature in my app?

Answer 1

You can change track position with help of MPRemoteCommandCenter on iOS 9.1 and higher.
if (floor(NSFoundationVersionNumber) > NSFoundationVersionNumber_iOS_9_0) {
MPRemoteCommandCenter *commandCenter = [MPRemoteCommandCenter sharedCommandCenter];
[commandCenter.changePlaybackPositionCommand setEnabled:true];
[commandCenter.changePlaybackPositionCommand addTarget:self action:#selector(changedThumbSliderOnLockScreen:)];
}
and method
- (MPRemoteCommandHandlerStatus)changedThumbSliderOnLockScreen:(MPChangePlaybackPositionCommandEvent *)event
{
// change position
[self setCurrentPlaybackTime:event.positionTime];
// update MPNowPlayingInfoPropertyElapsedPlaybackTime
[[MPNowPlayingInfoCenter defaultCenter] setNowPlayingInfo:songInfo];
return MPRemoteCommandHandlerStatusSuccess;
}

Answer 2

swift4
You can change track position with help of MPRemoteCommandCenter on iOS 9.1 and higher.
let commandCenter = MPRemoteCommandCenter.shared()
commandCenter.changePlaybackPositionCommand.isEnabled = true
commandCenter.changePlaybackPositionCommand.addTarget(
self, action:#selector(changePlaybackPositionCommand(_:)))
and method
#objc func changePlaybackPositionCommand(_ event:
MPChangePlaybackPositionCommandEvent) -> MPRemoteCommandHandlerStatus {
let time = event.positionTime
//use time to update your track time
return MPRemoteCommandHandlerStatus.success
}
Note that you have to do that for every command in commandCenter if you want that commend to be enabled.

Answer 3

I was looking for the same thing but I don't think this is possible see this post:
How to enable audio scrubber in iOS Lock Screen control panel?
Also popular apps like Spotify and Soundcloud don't have this implemented.
If you are looking for a way to show the current music on the lock screen you need to do the following.
First when you play a new track update the NowPlayingInfo :
NSMutableDictionary *songInfo = [[NSMutableDictionary alloc] init];
[songInfo setObject:trackTitle forKey:MPMediaItemPropertyTitle];
[songInfo setObject:artistName forKey:MPMediaItemPropertyArtist];
[songInfo setObject:duration forKey:MPMediaItemPropertyPlaybackDuration];
[songInfo setObject:releaseDate forKey:MPMediaItemPropertyReleaseDate];
[songInfo setValue:playbackRate forKey:MPNowPlayingInfoPropertyPlaybackRate];
[songInfo setObject:elapsedTime forKey:MPNowPlayingInfoPropertyElapsedPlaybackTime];
[songInfo setObject:albumArtImage forKey:MPMediaItemPropertyArtwork];
[[MPNowPlayingInfoCenter defaultCenter] setNowPlayingInfo:songInfo];
To handle events from the Lockscreen, you first need to tell your app to start receiving events from the remote control. I do this in the application didFinishLaunchingWithOptions of my AppDelegate using the following code
// Turn on remote control event delivery
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
Next you need to implement remoteControlReceivedWithEvent method to handle the captured events. In APPDelegate add the following method
- (void)remoteControlReceivedWithEvent:(UIEvent *)receivedEvent {
if (receivedEvent.type == UIEventTypeRemoteControl) {
switch (receivedEvent.subtype) {
case UIEventSubtypeRemoteControlPause:
//pause code here
break;
case UIEventSubtypeRemoteControlPlay:
//play code here
break;
case UIEventSubtypeRemoteControlPreviousTrack:
// previous track code here
break;
case UIEventSubtypeRemoteControlNextTrack:
//next track code here
break;
default:
break;
}
}
}
More info on MPNowPlayingInfoCenter from the apple docs -> https://developer.apple.com/library/ios/documentation/mediaplayer/reference/MPNowPlayingInfoCenter_Class