Skip to main content

iOS Dev: Dismissing MPMoviePlayerViewController

Image

If you have used the MPMoviePlayerViewController to play videos in iOS, chances are you have gotten a little frustrated by its rigidness. A couple of issues I personally encountered were:
  • When presented modally, the view controller did not respect the modal transition style I had chosen for it.
  • When the video finished playing, the view controller dismissed itself automatically. I wanted it to remain visible until the user pressed the Done button.
A couple of hours of browsing for the solution to no avail, I decided to try out sort of a hack, which turned out to work great.
 The trick is to remove the MPMoviePlayerViewController instance from the MPMoviePlayerPlaybackDidFinishNotification notification observers, and instead handle it yourself. Seems like this view controller listens to this notification and auto dismisses itself when it’s fired.
In my application, I present a thumbnail of the video. When touched, the video is played.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
- (void)playVideo:(NSString*)aVideoUrl
{
    // Initialize the movie player view controller with a video URL string
    MPMoviePlayerViewController *playerVC = [[[MPMoviePlayerViewController alloc] initWithContentURL:[NSURLURLWithString:aVideoUrl]] autorelease];

    // Remove the movie player view controller from the "playback did finish" notification observers
    [[NSNotificationCenterdefaultCenter] removeObserver:playerVC
                                                    name:MPMoviePlayerPlaybackDidFinishNotification
                                                  object:playerVC.moviePlayer];

    // Register this class as an observer instead
    [[NSNotificationCenterdefaultCenter] addObserver:self
                                             selector:@selector(movieFinishedCallback:)
                                                 name:MPMoviePlayerPlaybackDidFinishNotification
                                               object:playerVC.moviePlayer];

    // Set the modal transition style of your choice
    playerVC.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;

    // Present the movie player view controller
    [selfpresentModalViewController:playerVC animated:YES];

    // Start playback
    [playerVC.moviePlayer prepareToPlay];
    [playerVC.moviePlayer play];
}
In the code above, an instance of MPMoviePlayerViewController is created, and then removed from the observers of the MPMoviePlayerDidFinishNotification immediately; in its place, the current class is added as an observer, with a selector named movieFinishedCallback: (described below).
In addition, the modalTransitionStyle property of the view controller is set. The documentation suggests you to use the presentMoviePlayerViewControllerAnimated method to present it, in order to use the standard movie player transition. But if you want to use different transition, you must use the regular presentModalViewController method.
Back to the observer notification. Now that the view controller is no longer an observer, it won’t dismiss itself, ever, even if the Done button is pressed. So you must implement the code to dismiss it.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
- (void)movieFinishedCallback:(NSNotification*)aNotification
{
    // Obtain the reason why the movie playback finished
    NSNumber*finishReason = [[aNotification userInfo] objectForKey:MPMoviePlayerPlaybackDidFinishReasonUserInfoKey];

    // Dismiss the view controller ONLY when the reason is not "playback ended"
    if([finishReason intValue] != MPMovieFinishReasonPlaybackEnded)
    {
        MPMoviePlayerController *moviePlayer = [aNotification object];

        // Remove this class from the observers
        [[NSNotificationCenterdefaultCenter] removeObserver:self
                                                        name:MPMoviePlayerPlaybackDidFinishNotification
                                                      object:moviePlayer];

        // Dismiss the view controller
        [selfdismissModalViewControllerAnimated:YES];
    }
}
In my case, my original problem was that I wanted the video to stay visible until the user deliberately pressed the Done button. In the code above, the notification’s “playback finished reason” is examined: if the video playback ended normally, then the notification is ignored; if the video playback ended for another reason (i.e. an error or the user exited), then the view controller is dismissed.
As an added bonus, by dismissing the view controller using the dismissModalViewControllerAnimated: method, the modal transition style set earlier is respected.
The code is kinda messy, but I hope you get the idea. Perhaps it would be desirable to encapsulate this code by extending the MPMoviePlayerViewController class.
Reference Source : Here
Image
Thanks :)
KeepCoding:)


Comments

Popular posts from this blog

WPF-MVVM: RelayCommand Implementation

In WPF if we are implementing MVVM pattern then we need to play with Command rather than Events. You can use ICommand interface to create each command class. Implementation of ICommand in a class gives you CanExecute(), Execute() methods which take part in the action performed by Command.   Rather than making Command Class for each Command we can implement a generic Relay Command to get Command. Below is a RelayCommand class that we will implement.   ///   <summary>      ///  To register commands in MMVM pattern      ///   </summary>      class   RelayCommands  :  ICommand     {          readonly   Action < object > _execute;          readonly   Predicate < object > _canExecute;  ...

iOS Dev: Encryption in Objective-C

Hello Friends: In this Article/Post, I introduced the one encryption technique in Objective-C.  Encryption Component Features in all  Symmetric Encryption: AES, Blowfish, Twofish, RC2, ARC4, DES, 3DES, PBES1, PBES2. Hash Algorithms :  SHA-1 , SHA256, SHA384, SHA512, MD2, MD4, MD5, HAVAL. Hash Algorithms: RIPEMD128, RIPEMD160, RIPEMD256, RIPEMD320. Encoding: Base64, hex, quoted-printable,  URL-encoding . HMAC with any supported hash algorithm: HMAC-MD5,  HMAC-SHA1 , etc. Password-based Key Derivation Functions: PBKDF1, PBKDF2 PKCS7 -- P7S and P7M creation, decryption, verification. Public key encryption/decryption with digital certificates. Digital signature creation/verification with digital certificates. Bzip2 in-memory compression. Encrypt / decrypt strings or byte data. Return encrypted data as Base64, quoted-printable, or hex-encoded strings. Hash strings or binary data using SHA1, MD2, MD5, HAVAL, SHA384, or SHA512. Public-key encryp...

iPhonegap: Developing a PhoneGap Application

Tutorial: Developing a PhoneGap Application Reference :  Here In this tutorial, you create a fully functional employee directory application with  PhoneGap . You will learn: How to use different local data storage strategies. How to use several PhoneGap APIs such as Geolocation, Contacts, and Camera. How to handle specific mobile problems such as touch events, scrolling, styling, page transitions, etc. How to build an application using a single page architecture and HTML templates. How to build (compile and package) an application for 6 platforms using  PhoneGap Build . To complete this tutorial, all you need is a code editor, a modern browser, and a connection to the Internet. A working knowledge of HTML and JavaScript is assumed, but you don’t need to be a JavaScript guru. Setting Up Download the assets for the workshop  here . Unzip the file anywhere on your file system. If your code editor allows you to “open a directory”, open the phonegap...