Properly displaying and dismissing fullscreen MPMo

问题:

I'm having lots of trouble displaying a fullscreen movie in my iPad app and then allowing the user to dismiss it with either the Done button or the "un-fullscreen" button on the player controls.

Initially I was using MPMoviePlayerViewController for the movie presentation, but I wasn't receiving the enter/exit fullscreen notifications from its MPMoviePlayerController object, so I switched to doing it myself.

I can make the movie appear fullscreen (although the transition is janky), but when either the "Done" or "un-fullscreen" buttons are pressed, no action is taken by the player. I've posted my code below:

- (void)startPlayingMovieWithURLString:(NSString *)movieURLString {
    // I get all of these callbacks **EXCEPT** the "willExitFullScreen:" callback.
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(willEnterFullScreen:) name:MPMoviePlayerWillEnterFullscreenNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(willExitFullScreen:) name:MPMoviePlayerWillExitFullscreenNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didFinishPlayback:) name:MPMoviePlayerPlaybackDidFinishNotification object:nil];

    [self.moviePlayerController setContentURL:someExistingURL];

        // "self" is a UIViewController subclass, and is presented as a "fullscreen" modal view controller from its parent
        // I'm setting the movie player's view's frame to take up the full rectangle of my view controller, but really I want the movie to be completely removed when the user presses "done" (that is, removed from the view hierarchy). Not sure when/where to do this.
    self.moviePlayerController.view.frame = self.view.frame;
    [self.view addSubview:self.moviePlayerController.view];
    [self.moviePlayerController setFullscreen:YES animated:YES];

}

And here is the code for my didFinish callback

- (void)didFinishPlayback:(NSNotification *)notification {
        // This ends up recursively telling the player that playback ended, thus calling this method, thus…well you get the picture.
        // What I'm trying to do here is just make the player go away and show my old UI again.
    [self.moviePlayerController setFullscreen:NO animated:YES];
}

So obviously I am doing something wrong but I've been up and down the documentation and I can't figure out how to make the movie just go away. I figured it would be more intuitive than this. What am I doing wrong?

回答1:

Here are how the events -> notifications work:

• User presses 'Done' button

  • MPMoviePlayerWillExitFullscreenNotification
  • MPMoviePlayerDidExitFullscreenNotification

• User presses 'Leave fullscreen' button on transport

  • MPMoviePlayerWillExitFullscreenNotification
  • MPMoviePlayerDidExitFullscreenNotification
  • Note that playback does not stop

• Movie reaches end

  • MPMoviePlayerPlaybackDidFinishNotification with the MPMoviePlayerPlaybackDidFinishReasonUserInfoKey set to MPMovieFinishReasonPlaybackEnded
  • If you call setFullscreen:NO animated:YES on your MoviePlayerController instance from this notification, you'll then get the WillExit and DidExit notifications.
  • Note that you don't get the PlaybackDidFinish notification when the user presses the Done or Leave Fullscreen buttons.

So, typically, if you want to get rid of the MoviePlayer's view, you need to put [self.moviePlayerController.view removeFromSuperview] in the DidExitFullscreen notification handler. WillExitFullscreen is too soon.

Here's my code:

- (void)willEnterFullscreen:(NSNotification*)notification {
    NSLog(@"willEnterFullscreen");
}

- (void)enteredFullscreen:(NSNotification*)notification {
    NSLog(@"enteredFullscreen");
}

- (void)willExitFullscreen:(NSNotification*)notification {
    NSLog(@"willExitFullscreen");
}

- (void)exitedFullscreen:(NSNotification*)notification {
    NSLog(@"exitedFullscreen");
    [self.movieController.view removeFromSuperview];
    self.movieController = nil;
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

- (void)playbackFinished:(NSNotification*)notification {
    NSNumber* reason = [[notification userInfo] objectForKey:MPMoviePlayerPlaybackDidFinishReasonUserInfoKey];
    switch ([reason intValue]) {
        case MPMovieFinishReasonPlaybackEnded:
            NSLog(@"playbackFinished. Reason: Playback Ended");         
                break;
        case MPMovieFinishReasonPlaybackError:
            NSLog(@"playbackFinished. Reason: Playback Error");
                break;
        case MPMovieFinishReasonUserExited:
            NSLog(@"playbackFinished. Reason: User Exited");
                break;
        default:
            break;
    }
    [self.movieController setFullscreen:NO animated:YES];
}

- (void)showMovie {
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(willEnterFullscreen:) name:MPMoviePlayerWillEnterFullscreenNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(willExitFullscreen:) name:MPMoviePlayerWillExitFullscreenNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(enteredFullscreen:) name:MPMoviePlayerDidEnterFullscreenNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(exitedFullscreen:) name:MPMoviePlayerDidExitFullscreenNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(playbackFinished:) name:MPMoviePlayerPlaybackDidFinishNotification object:nil];

    NSURL* movieURL =  [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"tron" ofType:@"mov"]];
    self.movieController = [[MPMoviePlayerController alloc] initWithContentURL:movieURL];
    self.movieController.view.frame = self.view.frame;
    [self.view addSubview:movieController.view];
    [self.movieController setFullscreen:YES animated:YES];
    [self.movieController play];
}

回答2:

Yes. That's great. There are really notifications mentioned above...

However, there are no MPMoviePlayerPlaybackWillFinishNotification somewhy!!! That's really a problem.

When you call the movie player as modal (no matter which of the following methods used presentViewController/presentModalViewController/presentVideoController), if you defined .fullScreen = YES, it's not expected to call MPMoviePlayerWillExitFullscreenNotification notification at all (obviously, because it's not cosidering we enter/exit from full screen, but only present/dismiss the controller).

But there are really no any notifications that the video is about to finish and close. That's needed (besides any other situations possible) to catch the moment when the transition of dismissing is started. (The transition, of course, starts before the MPMoviePlayerPlaybackDidFinishNotification called). And, at the same time, application:supportedInterfaceOrientationsForWindow: for previously shown controller is called before the notification, and there is no way to say the AppDelegate that our current controller must be shown already in another orientation.

So, since my video is fullscreen and also without any controls shown (this is kind of an intro, so I just until it finishes) my solution was just to have a timer which checks every short tick (0.1 seconds) what is the video current position... and it it's close to the end, then this is the moment for my own notification.