I have a imageView in my storyboard. Now I want to set imageView to nil when the app will enter the background (applicationDidEnterBackground and applicationWillTerminate). But I couldn't find a good way to do this.
- (void)applicationDidEnterBackground:(UIApplication *)application
{
.... imageView.image = nil; ?
}
What is a good way to change a value of imageView from AppDelegate?
I solved the problem by adding this in viewDidLoad of my viewcontroller.m file:
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(removeImage)
name:UIApplicationDidEnterBackgroundNotification
object:nil];
And the removeImage function:
- (void) removeImage {
ImageView.image = nil;
}
Related
The scene auto pauses on applicationWillResignActive and auto unpauses when applicationDidBecomeActive is run. I am looking to either have the scene pause on applicationWillResignActive via the nsnotification and not auto resume when applicationDidBecomeActive is run. Any ideas? Thanks in advance.
AppDelegate
- (void)applicationDidBecomeActive:(UIApplication *)application {
// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
[[NSNotificationCenter defaultCenter] postNotificationName:#"backgroundPause" object:nil];
}
GameViewController
- (void)handleNotification:(NSNotification *)notification {
if ([notification.name isEqualToString:#"backgroundPause"]) {
SKView *skView = (SKView *)self.view;
skView.scene.paused = YES; //pauses scene
[self.lblPaused removeFromSuperview];//removes any lingering pause menu items
[self.lblPausedHelp removeFromSuperview];
self.lblPaused = [[UILabel alloc] init];
self.lblPaused.center = CGPointMake(self.view.frame.size.width/2 - 125, self.view.frame.size.height/2 - 40);
self.lblPaused.text = #"PAUSED";
[self.lblPaused setFont:[UIFont boldSystemFontOfSize:66]];
[self.lblPaused sizeToFit];
self.lblPaused.textColor = [UIColor blackColor];
[self.view addSubview:self.lblPaused];//adds pause label
self.lblPausedHelp = [[UILabel alloc] init];
self.lblPausedHelp.center = CGPointMake(self.view.frame.size.width/2 - 145, self.view.frame.size.height/2 + 40);
self.lblPausedHelp.text = #"tap anywhere to resume";
[self.lblPausedHelp setFont:[UIFont boldSystemFontOfSize:26]];
[self.lblPausedHelp sizeToFit];
self.lblPausedHelp.textColor = [UIColor blackColor];
[self.view addSubview:self.lblPausedHelp];//adds pause label
}
}
I'm pretty sure it's a bug in spritekit. No matter what you do, the game will unpause itself in applicationDidBecomeActive
I asked the same question here. pausing spritekit game on app launch / exit .. iOS8 You have to subclass SKScene and override the paused property to get it to work. It's weird you have to do that. It really shouldnt have so many problems, but thats the only way I could get my game to stay paused
EDIT: okay, I translated the code to objective-c. I hope this is useful to you because my objective-c was rustier than i expected.
AppDelegate.m
- (void)applicationWillResignActive:(UIApplication *)application {
[[NSNotificationCenter defaultCenter]postNotificationName:#"pauseGameScene" object:nil];
}
- (void)applicationDidBecomeActive:(UIApplication *)application {
[[NSNotificationCenter defaultCenter]postNotificationName:#"stayPausedNotification" object:nil];
}
SKView Subclass
#interface MySKView : SKView
- (void) setStayPaused;
#end
#implementation MySKView
bool _stayPaused = false;
- (void) setPaused:(BOOL)paused{
if (!_stayPaused) {
super.paused = paused;
}
_stayPaused = NO;
}
- (void) setStayPaused{
_stayPaused = YES;
}
#end
GameViewController
#interface GameViewController : UIViewController
-(void)pauseGame;
#end
#implementation GameViewController
SKScene *_scene;
MySKView *_skView;
-(void)pauseGame{
_skView.paused = YES;
_skView.scene.view.paused = YES;
}
- (void)viewDidLoad
{
[[NSNotificationCenter defaultCenter]addObserver:self selector:#selector(pauseGame) name:#"pauseGameScene" object:nil];
// Configure the view.
_skView = [[MySKView alloc]initWithFrame:self.view.frame];
_skView.showsFPS = YES;
_skView.showsNodeCount = YES;
/* Sprite Kit applies additional optimizations to improve rendering performance */
_skView.ignoresSiblingOrder = YES;
// Create and configure the scene.
_scene = [[GameScene alloc]initWithSize:_skView.frame.size];
_scene.scaleMode = SKSceneScaleModeAspectFill;
// Present the scene.
[self.view addSubview:_skView];
[_skView presentScene:_scene];
}
- (void)viewDidAppear:(BOOL)animated{
[[NSNotificationCenter defaultCenter]addObserver:_skView selector:#selector(setStayPaused) name:#"stayPausedNotification" object:nil];
}
#end
I am using Xcode 4.5 and targeting iOS 5 and above.
I have a popover that allows a user to change the background of the underlying view.
When tapping on the "button", it requires that I tap twice to see the change.
I am using NSNotification. I have tried Delegation, yet it does nothing.
Any help or tips would be greatly appreciated.
From viewWillAppear:
// nav button is for background image selection
navigationBtn.tag = buttonTag;
[navigationBtn setBackgroundImage:[UIImage imageNamed:tempImage] forState:UIControlStateNormal];
if (selectFlag) {
[navigationBtn addTarget:self action:#selector(BGSelected:) forControlEvents:UIControlEventTouchUpInside];
} else {
navigationBtn.adjustsImageWhenHighlighted = NO;
}
And the method for selection:
- (void)BGSelected:(id)sender {
self.bgtag = [sender tag];
SettingsDAO *settingsDao = [[SettingsDAO alloc] init];
if ([self.currentView isEqualToString:#"New_Journal"])
{
NSLog(#"Update Journals Background");
[settingsDao updateJournalBackgroundId:self.journalId withBackgroundId:self.bgtag];
}
// notification to let EntryView know the background has changed
[[NSNotificationCenter defaultCenter] postNotificationName:#"aBackgroundChanged"
object:self];
[settingsDao release];
}
the NSNotification Method:
- (void)aBackgroundChanged:(NSNotification *)notification {
[self invalidate];
[self reloadSettings];
}
If you are using storyboard, and your popover is a segue you can do like that:
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
// perform all the operations...ecc
[[(UIStoryboardPopoverSegue*)segue popoverController] setDelegate:self];
}
Then you have to make sure your caller controller has all the delegate methods.
Or, with NSNotification:
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
// perform all the operations...ecc
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:#selector(changeBackground:)
name:BackgroundHasChangedNotification
object:[segue destinationViewController]];
}
Then just remember to remove observer in dealloc, and in change background method:
-(void)changeBackground:(NSNotification*)notification {
NSDictionary *userInfo = notification.userInfo;
// I assume you are using background name
NSString *backgroundName = [userInfo objectForKey:BackgroundOneConstant];
// do the rest....
}
I'm working on application for video streaming. It is built with ARC for iOS5.
To display view I use MPMoviePlayerViewController this way:
.h
#interface EpisodesTableViewController : UITableViewController<EpisodeUrlResolverDelegate> {
NSTimeInterval playbackTime;
EpisodeUrlResolver *episodeUrlResolver;
}
#property (strong, nonatomic) MPMoviePlayerViewController *player;
#end
.m
#implementation EpisodesTableViewController
#synthesize episodes, player;
- (void)viewDidLoad
{
[super viewDidLoad];
episodeUrlResolver = [[Soap4MeEpisodeUrlResolver alloc] init];
[episodeUrlResolver setDelegate:self];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(willEnterForeground) name:#"WillEnterForeground" object:nil]; [[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(willEnterBackground) name:#"WillEnterBackground" object:nil];
}
- (void)viewDidUnload
{
episodeUrlResolver = nil;
player = nil;
[[NSNotificationCenter defaultCenter] removeObserver:self name:#"WillEnterForeground" object:nil];
[[NSNotificationCenter defaultCenter] removeObserver:self name:#"WillEnterBackground" object:nil];
[super viewDidUnload];
}
- (void)url:(NSURL *)url WasResolvedForEpisode:(Episode *)episode {
player = [[MPMoviePlayerViewController alloc] initWithContentURL:url];
player.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
player.moviePlayer.allowsAirPlay = YES;
[self presentModalViewController:player animated:YES];
}
- (void)willEnterBackground {
if (player) {
playbackTime = player.moviePlayer.currentPlaybackTime;
}
}
- (void)willEnterForeground {
if (!player)
return;
if(player.moviePlayer.playbackState == MPMoviePlaybackStateInterrupted || player.moviePlayer.playbackState == MPMoviePlaybackStateStopped || player.moviePlayer.playbackState == MPMoviePlaybackStatePaused)
{
[self continuePlayback];
}
}
- (void)continuePlayback {
[self presentModalViewController:player animated:YES];
[player.moviePlayer setInitialPlaybackTime:playbackTime];
NSLog(#"%f", player.moviePlayer.initialPlaybackTime);
[player.moviePlayer play];
}
Few words about presented code:
when url for video is resolved I create the MPMoviePlayerViewController object for video playback. Playback is started. Then when app is going background with home button MPMoviePlayerViewController automatically pauses playback and dissapears from screen (weird behavior, as for me). Thats why I have to save playback time when app is going background and show existing MPMoviePlayerViewController again with restored playback time when app is back to foreground.
It works fine when user presses home button and then is going back to application.
But it doesn't work when user locks the device. WillEnterBackground notification is fired when
applicationWillEnterForeground is called, so for locking event it is called too.
But in case when user locks the device MPMoviePlayerViewController wasn't being dismissed properly as in situation when user presses home button. It is hidden from the screen, but calling the code
[self presentModalViewController:player animated:YES];
throws the exception
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Application tried to present modally an active controller <EpisodesTableViewController: 0x91b3950>.'
I tried to change the code to dismiss controller:
- (void)willEnterForeground {
if (!player)
return;
if(player.moviePlayer.playbackState == MPMoviePlaybackStateInterrupted || player.moviePlayer.playbackState == MPMoviePlaybackStateStopped || player.moviePlayer.playbackState == MPMoviePlaybackStatePaused)
{
if (self.presentedViewController) {
[self dismissViewControllerAnimated:YES completion:^{
[self continuePlayback];
}];
}
else {
[self continuePlayback];
}
}
}
Now it doesn't throw the exception, but displays warning
wait_fences: failed to receive reply: 10004003
Also completion block is never called.
How to properly to solve the background/foreground continue playing with modally displayed MPMoviePlayerViewController?
Thanks for replies.
I solved the problem.
Method -willEnterBackground should look like:
- (void)willEnterBackground {
if (player) {
playbackTime = player.moviePlayer.currentPlaybackTime;
[self dismissModalViewControllerAnimated:NO];
}
}
We have to dismiss MPMoviePlayerViewController manually when app is entering background mode.
Pay attention to use only
[self dismissModalViewControllerAnimated:NO];
instead of
[self dismissMoviePlayerViewControllerAnimated];
Thats because MPMoviePlayerViewController was shown with
[self presentModalViewController:player animated:YES];
I have a MPMoviePlayerController subclass that should show the controls when playback is finished. I have attached a responder to the MPMoviePlayerPlaybackDidFinishNotification notification and tried setting the control style as follows:
[self setControlStyle:MPMovieControlStyleEmbedded];
This is not working. In essence, at the end of the video I want to controls to show.
How can I show controls programatically?
NOTE: The controller is NOT in fullscreen mode.
Kindly find my full Code about this , it's working with me
add .h class add this
#property(strong,nonatomic) MPMoviePlayerViewController * moviePlayer;
at .m class add this code "pass the movie URl"
-(void) playMovie:(NSString *)filePath
{
NSURL *theOutputURL = [NSURL fileURLWithPath:filePath];
if(_moviePlayer)
[_moviePlayer.moviePlayer setContentURL:theOutputURL];
else
_moviePlayer = [[MPMoviePlayerViewController alloc] initWithContentURL:theOutputURL];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(myMovieFinishedCallback:)
name:MPMoviePlayerPlaybackDidFinishNotification
object:_moviePlayer.moviePlayer];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(moviePlayerPlaybackStateDidChange:) name:MPMoviePlayerPlaybackStateDidChangeNotification object:_moviePlayer.moviePlayer];
if (![_moviePlayer.moviePlayer isPreparedToPlay])
[_moviePlayer.moviePlayer prepareToPlay];
_moviePlayer.moviePlayer.movieSourceType = MPMovieSourceTypeFile;
[_moviePlayer.moviePlayer setFullscreen:YES];
_moviePlayer.moviePlayer.controlStyle=MPMovieControlStyleEmbedded;
[_moviePlayer.moviePlayer setContentURL:theOutputURL];
_moviePlayer.view.frame = CGRectMake(0, 0, [[UIScreen mainScreen]bounds].size.width, [[UIScreen mainScreen]bounds].size.height);
[_moviePlayer shouldAutorotateToInterfaceOrientation: AVCaptureVideoOrientationLandscapeRight];
[self.view addSubview:_moviePlayer.view];
}
- (void) moviePlayerPlaybackStateDidChange: (NSNotification *) notification {
if (_moviePlayer.moviePlayer.playbackState == MPMoviePlaybackStateStopped) {
[_moviePlayer.moviePlayer setContentURL:[_moviePlayer.moviePlayer contentURL]];
[_moviePlayer.moviePlayer play];
}
}
-(void)myMovieFinishedCallback:(NSNotification*)aNotification
{
// to add your code after playback is finished
}
I am trying to use the notification system in order to have a detail view in a Splitviewcontroller to update the tableview. I declared the notification as follows:
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(pushView:) name:#"pushView" object:nil];
and the selector itself:
- (void) pushView:(UIViewController *) viewController {
[self.navigationController pushViewController:viewController animated:YES];
}
Now, in the detailview I create the view-controller and call create the notification:
ArticleTableViewController *articleTableView = [[ArticleTableViewController alloc] initWithCategory:catInt];
[[NSNotificationCenter defaultCenter] postNotificationName:#"pushView" object:articleTableView];
I assumed that that would work, but I get the error:
* Terminating app due to uncaught
exception
'NSInvalidArgumentException', reason:
'-[NSConcreteNotification
setParentViewController:]:
unrecognized selector sent to instance
0x5a3a290'
So I guess I am doing something wrong in how including the detailViewController in the notification to be used to push in.
The method definition for handling the notification seems to be wrong.
- (void) pushView:(UIViewController *) viewController
should be,
- (void) pushView:(NSNotification *) notification
The actual notification is passed as the argument, not any view controllers. To achieve what you want, try the following.
- (void) pushView:(NSNotification *) notification
NSDictionary *userInfo = [notification userInfo];
UIViewController *viewController = (UIViewController *)[userInfo objectForKey:#"ViewController"];
[self.navigationController pushViewController:viewController animated:YES];
}
And while posting the notification,
ArticleTableViewController *articleTableView = [[ArticleTableViewController alloc] initWithCategory:catInt];
NSDictionary *userInfo = [NSDictionary dictionaryWithObject:articleTableView forKey:#"ViewController"];
[[NSNotificationCenter defaultCenter] postNotificationName:#"pushView" object:nil userInfo:userInfo];