Question

I m struggling with this issue for so long but not able to find any solution for this

The issue i have is when i pause the audioplayer i want views to be paused from updating so i used timer invalidate to pause the views from loading but when i resume play only Audioplayer is resumed not the views cause i invalidated the timer.

Now i how i can resume updating views from that point where view was paused. By starting the timer again i can start updating views again but how program will know that at what view it was paused and it should resume updating views from that point. There are multiple views involved displayed code for only two.

 -(void)playpauseAction:(id)sender 
{
  if  

  ([audioPlayer isPlaying]){

 [sender setImage:[UIImage imageNamed:@"play.png"] forState:UIControlStateSelected];

 [audioPlayer pause];

 [timer invalidate];

  } else {

 [sender setImage:[UIImage imageNamed:@"pause.png"] forState:UIControlStateNormal];

 [audioPlayer play];

 self.timer = [NSTimer scheduledTimerWithTimeInterval:11 target:self selector:@selector(displayviewsAction:) userInfo:nil repeats:NO];
  }  

}

- (void)displayviewsAction:(id)sender

FirstViewController *viewController = [[FirstViewController alloc] init];

viewController.view.frame = CGRectMake(0, 0, 320, 480);

[self.view addSubview:viewController.view];

[self.view addSubview:toolbar];

[viewController release];

self.timer = [NSTimer scheduledTimerWithTimeInterval:23 target:self selector:@selector(secondViewController) userInfo:nil repeats:NO];

-(void)secondViewController {
SecondViewController *secondController = [[SecondViewController alloc] init];

secondController.view.frame = CGRectMake(0, 0, 320, 480);

[self.view addSubview:secondController.view]; 

[self.view addSubview:toolbar];

[secondController release];

self.timer = [NSTimer scheduledTimerWithTimeInterval:27 target:self selector:@selector(ThirdviewController) userInfo:nil repeats:NO];
}

Thanks and appreciate for your answers and helping me out with this issue.

Answer 1

Use a background thread to basically bind the view to the player, something like this:

UIImageView* imageView;   //the view that gets updated

int current_selected_image_index = 0;
float time_for_next_image = 0.0;

AVAudioPlayer* audioPlayer;

NSArray* image_times;   //an array of float values representing each 
                        //time when the view should update

NSArray* image_names;   //an array of the image file names 

-(void)update_view
{
    UIImage* next_image_to_play = [image_names objectAtIndex:current_selected_image_index];
    imageView.image = next_image_to_play;
}

-(void)bind_view_to_audioplayer
{
    while(audioPlayer.isPlaying)
    {
        float currentPlayingTime = (float)audioPlayer.currentTime;
        if(currentPlayingTime >= time_for_next_image)
        {
            current_selected_image_index++;
            [self performSelectorOnMainThread:@selector(update_view) withObject:nil waitUntilDone:NO];
            time_for_next_image = [image_times objectAtIndex:[current_selected_image_index+1)];
        }
        [NSThread sleep:0.2];
    }
}

-(void)init_audio
{
current_selected_image_index = 0;
time_for_next_image = [image_times objectAtIndex:1];
 } 

-(void)play_audio
{
    [audioPlayer play];
    [self performSelectorInBackground:@selector(bind_view_to_audioplayer) withObject:nil];
}

-(void)pause_audio
{
    [audioPlayer pause];
    //that's all, the background thread exits because audioPlayer.isPlaying == NO
    //the value of current_selected_image_index stays where it is, so [self play_audio] picks up 
    //where it left off.
}

also, add self as observer for the audioPlayerDidFinishPlaying:successfully: notification to reset when the audioplayer finishes playing.