pause button when pressed again to resume reloading view controllers - iphone

Question

I am using AVAudioplayer to play audio files, play/pause button to toggle between play and pause and NSTimer with audio player to synchronize view controllers one after another. I have a total of 10 or 11 view controllers to load one after the other.
When play button is pressed the very first time it starts NSTimer, starts playing an audio file and based on NSTimer, view controllers will load one after the other. When pause button is pressed again to resume it resumes everything from that point audio file, NSTimer and view controllers from the same point where it was paused which is good. However, at the same time it starts loading the view controllers again one after the other from the beginning based on NSTimer which is not good.
It is reloading view controllers with this statement
self.timer = [NSTimer scheduledTimerWithTimeInterval:11.0
target:self
selector:#selector(displayviewsAction:)
userInfo:nil
repeats:NO];
So my issue is that I need to stop the loading of view controllers again from the beginning when pause button is pressed again to resume playback.
-(void)playpauseAction:(id)sender
{
if ([audioPlayer isPlaying]) {
[sender setImage:[UIImage imageNamed:#"Play Icon.png"] forState:UIControlStateSelected];
[audioPlayer pause];
[self pauseTimer];
} else {
[sender setImage:[UIImage imageNamed:#"pause.png"] forState:UIControlStateNormal];
[audioPlayer play];
[self resumeTimer];
self.timer = [NSTimer scheduledTimerWithTimeInterval:11.0
target:self
selector:#selector(displayviewsAction:)
userInfo:nil
repeats:NO];
}
}
-(void)pauseTimer{
pauseStart = [[NSDate dateWithTimeIntervalSinceNow:0] retain];
previousFireDate = [[timer fireDate] retain];
[timer setFireDate:[NSDate distantFuture]];
}
-(void)resumeTimer{
float pauseTime = -1*[pauseStart timeIntervalSinceNow];
[timer setFireDate:[previousFireDate initWithTimeInterval:pauseTime sinceDate:previousFireDate]];
[pauseStart release];
[previousFireDate release];
}
- (void)displayviewsAction:(id)sender
{
First *firstController = [[First alloc] init];
firstController.view.frame = CGRectMake(0, 0, 320, 480);
CATransition *transitionAnimation = [CATransition animation];
[transitionAnimation setDuration:1];
[transitionAnimation setType:kCATransitionFade];
[transitionAnimation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn]];
[self.view.layer addAnimation:transitionAnimation forKey:kCATransitionFade];
[self.view addSubview:firstController.view];
[self.view addSubview:toolbar];
[firstController release];
self.timer = [NSTimer scheduledTimerWithTimeInterval:23 target:self selector:#selector(Second) userInfo:nil repeats:NO];
}
Can anyone give an idea on how to stop the loading of view controllers again from the beginning when pause button is pressed again to resume playback.

Answer 1

I gather you're trying to display FirstViewController after 11 seconds have elapsed in the audio track.
You can set you timer up to poll (every .5 - 1.0 seconds) and if the audioPlayer's elapsed time is greater than 11.0, perform your action.
-(void)playpauseAction:(id)sender
{
if ([audioPlayer isPlaying]){
[sender setImage:[UIImage imageNamed:#"Play Icon.png"] forState:UIControlStateSelected];
[audioPlayer pause];
[self.timer invalidate]; // stop the polling timer
} else {
[sender setImage:[UIImage imageNamed:#"pause.png"] forState:UIControlStateNormal];
[audioPlayer play];
// start/resume the timer
self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0 /* polling interval */
target:self
selector:#selector(tryToDisplayViews:)
userInfo:nil
repeats:YES]; /* REPEAT = YES */
}
}
// the new polled method
-(void)tryToDisplayViews:(id)sender {
// need last current time as a new variable to ensure that we only add the view once
// and not every time the method fires with currentTime > 11.0
if( audioPlayer.currentTime > 11.0 && lastCurrentTime < 11.0) {
[self displayviewsAction:nil];
}
// you can add the second view here in a similar fashion
// if(audioPlayer.currentTime > (23.0+11.0) && lastCurrentTime < (23.0+11.0) ) {}
lastCurrentTime = audioPlayer.currentTime;
}
This also get's rid of your resumeTimer/pauseTimer actions, you don't need to count the time paused.