Question

I have a simple app which consists of 2 views. Top view has a accelerometer delegates. when user shakes while top view is on the screen. then pushviewcontroller is called and subview will appear. the problem is when subview is appeard, i shake it, it still catches the shake action and results me an error. So help me. thanks in advance.

- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration {
const float violence = 1.2;
static BOOL beenhere;
BOOL shake = FALSE;

if (beenhere) return;
beenhere = TRUE;

if (acceleration.x > violence || acceleration.x < (-1* violence))
    shake = TRUE;
if (acceleration.y > violence || acceleration.y < (-1* violence))
    shake = TRUE;
if (acceleration.z > violence || acceleration.z < (-1* violence))
    shake = TRUE;
if (shake) {
    [self playSound:@"suzu"];

    if ([[NSUserDefaults standardUserDefaults] boolForKey:@"noVib"] == NO) {
        AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);
    }
    [[UIAccelerometer sharedAccelerometer] setDelegate:nil];
    [self presentModalViewController:mMoviePlayer animated:YES];
    [self play]; 
}

when play method called and video has finished, pushviewcontroller will be called and the sub view will appear

below is a class that handles all the movieplayer stuff.

- (void) initPlayer{
if (mMoviePlayer != nil){
    [mMoviePlayer release];
}

mMoviePlayer = [[MoviePlayerViewController alloc] initWithContentURL:[self createURL]];
[[NSNotificationCenter defaultCenter] removeObserver:mMoviePlayer 
                                                name:MPMoviePlayerPlaybackDidFinishNotification object:mMoviePlayer.moviePlayer];
[mMoviePlayer.moviePlayer setShouldAutoplay:NO];
mMoviePlayer.moviePlayer.backgroundView.backgroundColor = [UIColor blackColor];
mMoviePlayer.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
mMoviePlayer.moviePlayer.controlStyle = MPMovieControlStyleNone;

[[NSNotificationCenter defaultCenter] addObserver:self 
                                         selector:@selector(moviePlayBackDidFinish:) 
                                             name:MPMoviePlayerPlaybackDidFinishNotification 
                                           object:mMoviePlayer.moviePlayer];

[[NSNotificationCenter defaultCenter] addObserver:self 
                                         selector:@selector(moviePreloadDidFinish:) 
                                             name:MPMoviePlayerLoadStateDidChangeNotification 
                                           object:mMoviePlayer.moviePlayer];

- (void) moviePlayBackDidFinish:(NSNotification*)notification

{

[[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:NO];        
[[NSNotificationCenter defaultCenter] removeObserver:self
                                                name:MPMoviePlayerPlaybackDidFinishNotification
                                              object:mMoviePlayer.moviePlayer];
[self dismissModalViewControllerAnimated:YES];
[mMoviePlayer release];
mMoviePlayer = nil;
[self toNext];

}

Answer 1

The first thing that comes into my mind is to keep track if the mMoviePlayer is pushed or not.

if (shake && mPlayerPushed) {
    [self playSound:@"suzu"];

    if ([[NSUserDefaults standardUserDefaults] boolForKey:@"noVib"] == NO) {
        AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);
    }
    [[UIAccelerometer sharedAccelerometer] setDelegate:nil];
    [self presentModalViewController:mMoviePlayer animated:YES];
    [self play]; 
    mPlayerPushed = YES;
}

in the moviePlayBackDidFinish method after you call dismissModalViewControllerAnimated:YES you should set the mPlayerPushed to NO.

or you could use the property modal view controller to see if a modal view is displayed. This i haven’t tested yet but it should work.

modalViewController: The controller for the active modal view—that is,
the view that is temporarily displayed on top of the view managed by
the receiver. (read-only)

@property(nonatomic, readonly) UIViewController *modalViewController

so instead of the bool mPlayerPushed you will have:

if(shake && something.modalviewController == nil){ present mMoviePlayer }