I'm developing on iOS SDK 4.3.
I have an horizontally-scrolling paged gallery that can display images or videos from a remote feed. For the paged views I'm using the publicly available ATPagingView: pages are reused similarly to TableViewCells. But for the videos I'm using a single MPMoviePlayerController, whose .view property I assign to the several pages as a subview (I know, I know...):
moviePlayerController = [[MPMoviePlayerController alloc] init];
moviePlayerController.repeatMode = MPMovieRepeatModeNone;
moviePlayerController.controlStyle = MPMovieControlStyleEmbedded;
moviePlayerController.shouldAutoplay = false;
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(movieLoadStateChangeAction:) name:MPMoviePlayerLoadStateDidChangeNotification object:nil];
You can see I've registered for MoviePlayer event LoadState notifications.
When a new page goes onscreen, I start loading a video if needed:
- (void)currentPageDidChangeInPagingView:(ATPagingView *)pagingView
{
if (pagingView.currentPageIndex < 0)
return;
NSLog(#"currentPageDidChangeInPagingView");
GalleryPageView *currentPage = (GalleryPageView *)[pagingView viewForPageAtIndex:pagingView.currentPageIndex];
if (![currentPage.gestureRecognizers count]) {
UITapGestureRecognizer *recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(resetZoom)];
recognizer.numberOfTapsRequired = 2;
[currentPage.zoomView addGestureRecognizer:recognizer];
recognizer.delegate = self;
[recognizer release];
}
moviePlayButton.hidden = YES;
[activityView stopAnimating];
FeedItem *feedItem = (FeedItem *)[dataRoot objectAtIndex:pagingView.currentPageIndex];
if (feedItem.contentType == FeedContentTypeMovie) {
moviePlayerController.contentURL = [NSURL URLWithString:feedItem.movieUrl];
[moviePlayerController prepareToPlay];
[activityView startAnimating];
}
Now, IFF the first page contains a video, even after I call moviePlayerController.prepareToPlay, it doesn't load: no loadState event is fired. Following pages instead work as expected.
I've tried to pre-load a fixed video on MPlayerController initialization, but in that case the fixed video is correctly loaded (MPMovieLoadState == 3), while video on first page causes a change to MPMovieLoadStateUnknown.
The movie URL is correct.
When I scroll back from page 2 to page 1, first video is loaded (MPMovieLoadState == 3), but it doesn't show.
What do you suggest investigating? Is the shared-view architecture so horrible? It works for the following pages, after all. Is there any known weird behavior by prepareToPlay? For example, is it possible MPC gets angry if the view is "mistreated" by anyone, and then it refuses to load stuff? How else would you explain MPMovieLoadStateUnknown? I'm pretty sure there is no other ghost instance of MPC messing around (I've read it could be a problem).
Thank you and sorry for the long post.
I had to end up using AVPlayer because of something very similar to this in my code.
I had the same problem. In iOS7 this does not happen, but in iOS 6 loadState is 3, which is not contemplated in:
enum {
MPMovieLoadStateUnknown = 0,
MPMovieLoadStatePlayable = 1 << 0,
MPMovieLoadStatePlaythroughOK = 1 << 1, // Playback will be automatically started in this state when shouldAutoplay is YES
MPMovieLoadStateStalled = 1 << 2, // Playback will be automatically paused in this state, if started
};
typedef NSInteger MPMovieLoadState;
I had autoplay set to NO and use prepareToPlay waiting for the notifications to play, so when MPMoviePlayerLoadStateDidChangeNotification is received, before playing, I check the loadState like this:
if (self.moviePlayerC.loadState & MPMovieLoadStatePlayable || self.moviePlayerC.loadState & MPMovieLoadStatePlaythroughOK)
Maybe in iOS6 loadState is a bitWise value that can contains several states at the same time.
Related
I'm animating a view (by revealing it) after which I need to post a notification (once the animation completes). However the way the app's designed, there's another notification sent out when the view is hidden (via animation). So essentially I have a 'showView' and a 'hideView' method. Each do something like so:
[NSAnimationContext runAnimationGroup:^(NSAnimationContext *context) {
[context setDuration: 0.25];
[[myView animator] setAlphaValue: 0];
} completionHandler:^{
// post notification now
}];
The problem is that in another thread in the background, I have a periodic timer which performs a 'sanity check' to see if the view needs to be hidden if it's not needed. It's an aggressive approach but necessary as many components of the app respond to different events and scenarios. Due to this I at times get a 'race condition' where the user has clicked to 'showView' but at the same time one of our threads feel the view should be immediately hidden.
When both post a notification on the main thread, the app hangs indefinitely in a SpinLock. I could completely avoid this situation if I was able to figure out if the animation block above was 'cancelled' (i.e. another animation block executed on the same view). In such situations I would not post the notification, which would then not force a check.
Long story short: I need to be able to check if the 'completionHandler' was called after animation successfully ended or if it was cancelled. I know in iOS this is possible but I can't find any way to do this in OS X. Please help.
I encountered a similar problem. I solved it by using a currentAnimationUUID instance variable.
NSUUID *animationUUID = [[NSUUID alloc] init];
self.currentAnimationUUID = animationUUID;
[NSAnimationContext runAnimationGroup:^(NSAnimationContext *context) {
// set properties to animate
} completionHandler:^{
BOOL isCancelled = ![self.currentAnimationUUID isEqual:animationUUID];
if (isCancelled) {
return;
}
self.currentAnimationUUID = nil;
// do stuff
}];
Swift version:
let animationUUID = UUID()
currentAnimationUUID = animationUUID
NSAnimationContext.runAnimationGroup({ context in
// set properties to animate
}, completionHandler: {
let isCancelled = self.currentAnimationUUID != animationUUID
guard !isCancelled else {
return
}
self.currentAnimationUUID = nil
// do stuff
})
I'm trying to embed a Youtube video using a mixture of this technique, and this Youtube SDK blog post in a universal app. The iPhone version, using the same code, works fine.
On the iPad the video does embed, and it plays fine in it's embedded form, but as soon as you tap the full screen button the app crashes (buttons do not respond, the device does not rotate). The music from the Youtube video keeps playing.
There is no error message logged but the app does register as 'Paused' or hung in xCode. Every time it crashes com.apple.libdispatch-manager is on thread 2. Ask me questions and I'll give you more information about the error, but I'm not sure where to start.
I have tried:
changing the size of the UIWebView frame
the UIWebView is in a UIScrollView, but if I take it out of the scrollview and add it to the view the problem is identical.
changing the video
changing the html that I use in the UIWebView from this to this, with no result
changing the format of the youtube link from ?v=uniqueID to /v/uniqueID
checking the presenting view is the rootviewcontroller (it is, but the video is embedded in a modal, which is not the rootviewcontroller).
I am building for iOS 5.1, this doesn't happen if running on iOS6.
The View that the video is embedded in is modal, both on the phone and the iPad. There's no hackery or unusual things happening in the app.
There seems to be talk of Evernote's app having a similar problem, but I don't know if it is related or not.
For your reference, here is the YouTubeView subclass (which subclasses UIWebView):
- (YouTubeView *)initWithStringAsURL:(NSString *)urlString frame:(CGRect)frame;
{
if (self = [super init])
{
// Create webview with requested frame size
self = [[YouTubeView alloc] initWithFrame:frame];
// HTML to embed YouTube video
// NSString *youTubeVideoHTML = #"<html><head>
// <body style=\"margin:0\">
// <embed id=\"yt\" src=\"%#\"
// type=\"application/x-shockwave-flash\"
// width=\"%0.0f\" height=\"%0.0f\">
// </embed>
// </body>
// </html>";
NSString *youTubeVideoHTML = #"<html><head><meta name = \"viewport\" content = \"initial-scale = 1.0, user-scalable = no, width = %0.0f\"/></head><body style=\"background:#FFF;margin-top:0px;margin-left:0px\"><div><object width=\"%0.0f\" height=\"%0.0f\"><param name=\"movie\" value=\"%#\"></param><param name=\"wmode\" value=\"transparent\"></param><embed src=\"%#\"type=\"application/x-shockwave-flash\" wmode=\"transparent\" width=\"%0.0f\" height=\"%0.0f\"></embed></object></div></body></html>";
// Populate HTML with the URL and requested frame size
// NSString *html = [NSString stringWithFormat:youTubeVideoHTML, urlString, frame.size.width, frame.size.height];
NSLog(#"html:\n %#", youTubeVideoHTML);
NSString *html = [NSString stringWithFormat:youTubeVideoHTML, frame.size.width, frame.size.width, frame.size.height, urlString, urlString, frame.size.width, frame.size.height];
NSLog(#"html:\n %#", html);
// Load the html into the webview
[self loadHTMLString:html baseURL:nil];
}
return self;
}
Modal view on iOS 5.0 and iOS 5.1 is the problem that causes crash on full screen video, AFAIK. They just changed hierarchy of views in that version of iOS (parentViewController and presentingViewController) and that is the aftermath. I asked about it long time ago here and one more same question is here and still no one knows what to do.
First of all, they fixed it in 6.0, I guess, that's good.
For 5.1 we changed design a little and avoided modal view. Do it, if it is possible in your situation.
Disclaimer: I'm relatively new to iOS programming, and am trying to teach myself the basics as I go along just for fun... so be gentle :-)
I'm building an app that plays a series of .mp3 files strung together using AVAudioplayer. So far, that part is working good. IBActions, and IBOutlets hooked up. Click the button, and the audio plays.
My problem is this:
My play button has been added directly to the main.storyboard, set and custom with it's initial state defined in Interface Builder. When I click the play, I want to change the image of the button to indicate that it's playing. However, as soon as the audio starts, it almost seems like the view is... paused, or something. The button image stays the same, until the audio done playing. Only then, will the button image update itself -- hardly useful.
I've also just tried to set the image of of another random UIImageView that's not attached to this particular button. Same experience. As soon as I comment out my playAudioArray method, the button swaps work immediately.
-(IBAction)start_playing:(UIButton*)pressed_button {
[_btn_start setImage:[UIImage imageNamed:#"btn_on-active"] forState:UIControlStateNormal];
[self playAudioArray];
}
I hope I've left enough to go on... Any thoughts / comments / suggestions??
Thanks a million
- Drew
#
Update:
I've found that updating the view breaks down when I have my audio player in a lopp. This code works fine...
if (audioPlayer.playing == YES) {
[audioPlayer pause];
[sender setImage:[UIImage imageNamed:#"btn_on.png"] forState:UIControlStateNormal];
[_btn_stop setImage:[UIImage imageNamed:#"btn_off.png"] forState:UIControlStateNormal];
} else {
NSString *path = [[NSBundle mainBundle] pathForResource:#"audio_file1" ofType:#"mp3"];
audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL];
audioPlayer.volume = 1.0;
audioPlayer.numberOfLoops = 0;
[audioPlayer setMeteringEnabled: YES];
[audioPlayer play];
//changes the image when the button is pressed
[sender setImage:[UIImage imageNamed:#"btn_on.png"] forState:UIControlStateNormal];
[_btn_stop setImage:[UIImage imageNamed:#"btn_off.png"] forState:UIControlStateNormal];
}
But this code doesn't below doesn't.
} else {
//changes the image when the button is pressed
[sender setImage:[UIImage imageNamed:#"btn_on.png"] forState:UIControlStateNormal];
[_btn_stop setImage:[UIImage imageNamed:#"btn_off.png"] forState:UIControlStateNormal];
NSArray *theSoundArray = [NSArray arrayWithObjects:#"audio1",#"audio2",#"audio3",nil];
for (int i = 0; i < totalSoundsInQueue;) {
NSString *sound = [theSoundArray objectAtIndex:i];
// Wait until the audio player is not playing anything
while(![audioPlayer isPlaying]){
NSString *path = [[NSBundle mainBundle] pathForResource:#"mom" ofType:#"mp3"];
audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL];
audioPlayer.volume = 1.0;
audioPlayer.numberOfLoops = 0;
[audioPlayer setMeteringEnabled: YES];
[audioPlayer play];
i++;
}
}
}
The audio plays fine, loops through all my sounds and no errors occur. Only, the 'on-state' of my button only gets set AFTER the loop is done playing. I've tried this with a number of different types of looping methods. For, for each, while... every time I start to loop through sounds audio playback works great, but the display looses all focus.
Which reminds me. Once I'm in the loop, my "Stop" button looses it's a clickable (tappable) nature. Until the loop has finished running. If I'm not in a loop, the stop button works fine, no problems.
Sorry if I'm making a total newb mistake here... thoughts / comments anyone?
Your for loop is tying up the main thread, making it your UI unresponsive. Instead of running the for loop continuously, set yourself as the delegate of AVAudioPlayer. Once the audio player is done playing it will send the delegate the message - (void) audioPlayerDidReachEnd; (which you'll have to implement). Then you can play the next audio file in the queue in that implementation. You really want to set yourself up as the delegate anyway. AVAudioPlayer will send your delegate messages for interruptions (like a call coming in) and decode errors. You want to handle these events gracefully.
I think the reason the audio is playing fine is that is has a higher priority and runs on a separate thread. The reason the UI becomes un-responsive is even though animations/UI changes occur on a separate thread, they're initiated from the main thread. But all UI changes are queued to the end of a run-loop (so optimizations can be made). However, that run loop never ends because your for loop never ends until all the audio files are played. The audio files can be played in order because they're initiated in that for loop and run on a separate thread. Makes sense? In general, you really don't want to tie up the main thread.
I'm new to iOS development so please bear with me.
I'm making a photo-grid using a table view and scroll view.
My question is how could I load an activity indicator until an image downloads from a server and then display the image and remove the activity indicator?
I'm trying to stay away from third-party library's as I want to understand how it works.
Place an Activity Indicator (via Interface Builder or manually) on your view. Set the property to "hide when not animating".
When doing server call, call [activityIndicator startAnimating] (IBOutlet property).
When returning with actual image, call [activityIndicator stopAnimating]. When stopping, it wil automatically hide.
You can also use the activity indicator in the iPhon/Pad status bar. To do this, use [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
Set to NO for hiding it ... (obviously)
Take a look at dowloading an image async for a sample of dl'ing an image.
You would stop the activity indicator in the didReceiveData function.
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCsQFjAA&url=https%3A%2F%2Fgithub.com%2Fjakemarsh%2FJMImageCache&ei=UEp7U_W2GoWB8gWShIGgBQ&usg=AFQjCNEc0a59K2wEOlZ2IbapWhVc87kHmg&bvm=bv.67229260,d.dGc
here you could find JMImage cache files that you could use for downloading images.
You have to change UIImageView+JMImageCache.m file
if(i) {
dispatch_async(dispatch_get_main_queue(), ^{
safeSelf.jm_imageURL = nil;
safeSelf.image = i;
[safeSelf setNeedsLayout];
[safeSelf setNeedsDisplay];
if (completionBlock) {
completionBlock(i).
}
});
then use method
enter code here
{
[yourImageView setImageWithURL:[NSURL URLWithString:urlString] placeholder:[UIImage imageNamed:#"placeholder"] completionBlock:^(UIImage *image)
{
// remove added activity indicator here
}failureBlock:^(NSURLRequest *req,NSURLResponse *resp,NSError *error)
{
// show error message
}];
}
I have quick question. I am using the following code to launch camera and record video on iOS 4.x devices, it works great. I want to use the same code on iPad 2 device as iPad 2 has video recording facility. Will it work? Can someone please guide me?
if ([types containsObject:(id)kUTTypeMovie])
{
UIImagePickerController *pickerController = [[[UIImagePickerController alloc] init] autorelease];
pickerController.delegate = self;
pickerController.videoQuality = appDelegate.settingsCtrler.quality;
pickerController.sourceType = UIImagePickerControllerSourceTypeCamera;
pickerController.showsCameraControls = YES;
pickerController.mediaTypes = [NSArray arrayWithObject:(id)kUTTypeMovie];
pickerController.videoMaximumDuration = maxDuration;
[appDelegate hideFloatingBar];
[self presentModalViewController:pickerController animated:YES];
}
Thank you in Advance!
If it builds on iOS 4.3 you should be OK - although I don't have an iPad2 to test it on. I would wrap the logic in a test though:
if([picker isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
// Your code here.
}
so that it doesn't try and present a camera when one isn't available.