Detecting when camera's iris is open on iPhone - iphone

For a cutom camera overlay I need to find out, when the iris is opened, because my overlay will allways shown while the iris is close (and then animating to open).
Any ideas ?

You can listen for the PLCameraViewIrisAnimationDidEndNotification notification. Since this is not officially documented, you might be in violation of the Apple TOS, but I think so long as you write your code so that it's defensive against the possibility that the name or contract of this notification might change (so in the future you might not get the event) you'll probably be ok. In other words, use a timer or other technique to ensure that the thing you want done when the iris is open will definitely happen eventually even if you never get the notification...
Trivial example without the defensive programming. (Of course, you can register an interest only for this specific notification as well, see the docs for the notification center.)
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(notificationCallback:)
name:nil
object:nil
];
- (void) notificationCallback:(NSNotification *) notification {
if ([[notification name] isEqualToString:#"PLCameraViewIrisAnimationDidEndNotification"]) {
NSLog(#"Iris open");
// we don't need to listen any more
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
}

It seems that PLCameraViewIrisAnimationDidEndNotification no longer gets notified in iOS5.
I can't figure out what is a suitable solution when the iris has finished opening, there must another option rather than using a 3 second timer.
Check here: https://devforums.apple.com/message/561008#561008

I have a ViewController (ALImagePickerController) which holds, initializes and presents the UIImagePickerController as a child view controller (I have another child view controller for presenting the taken image which is not shown here) and I present (as a modal) the ALImagePickerController when I want to use the camera. So during this the viewDidAppear of the ViewContoller I add an animation to bring in the camera overlay gracefully as the shutter animation disappears.
#interface ALImagePickerController ()
#property (nonatomic) UIImagePickerController *cameraController;
#property (nonatomic) CameraOverlayView *overlayView;
....
#end
#implementation ALImagePickerController
....
- (void)viewDidLoad {
[super viewDidLoad];
[UIApplication sharedApplication].statusBarHidden = YES;
self.cameraController = [UIImagePickerController new];
self.cameraController.sourceType = UIImagePickerControllerSourceTypeCamera;
self.cameraController.delegate = self;
self.cameraController.allowsEditing = NO;
self.cameraController.showsCameraControls = NO;
....
self.overlayView = [CameraOverlayView new];
....
self.overlayView.alpha = 0;
self.cameraController.cameraOverlayView = self.overlayView;
....
// add as child view controller
[self addChildViewController:self.cameraController];
[self.view addSubview:self.cameraController.view];
[self.cameraController didMoveToParentViewController:self];
}
- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
[UIApplication sharedApplication].statusBarHidden = NO;
}
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
// smoothly bring in the overlay as the native camera shutter animation opens.
[UIView animateWithDuration:0.2 delay:0.3 options:UIViewAnimationCurveEaseOut animations:^{
self.overlayView.alpha = 1.f;
} completion:nil];
}
....
#end

The way I solved this problem is I initialize all the elements with the hidden property set to YES, then call a 3-second delayed selector after I call the camera, where I set all the elements to hidden = NO. It's not an ideal solution but it seems to work, and any lag after the iris is opened is negligible.

You should already know when the camera is ready to take a picture. At least the way I use a custom camera overlay, I init the view with something like self.sourceType = UIImagePickerControllerSourceTypeCamera; and the other usual setup, and the camera is ready (or "iris is open") at that point.
In summary, if one is using a custom camera overlay the way I am used to using it, one will know when the iris is open because it is under your control.

Related

iPhone Camera App - how to stay in Camera view?

I've implemented the camera inside of my app with the default showsCameraControls = YES, and the issue I am having is when the user confirms that the image is a keeper, it dismisses the camera with [self.delegate didFinishWithCamera]. I would like to remain in the Camera view until the user is done taking photos. Without [self.delegate didFinishWithCamera], the app hangs after the user confirms they want to keep the photo and never returns back to the live camera feed. How do I remain in the camera view? Your help is appreciated!
#implementation PHFPhotoOverlayVC
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
self.imagePickerController = [[UIImagePickerController alloc] init];
self.imagePickerController.delegate = self;
}
return self;
}
- (void)setupImagePicker:(UIImagePickerControllerSourceType)sourceType
{
self.imagePickerController.sourceType = sourceType;
if (sourceType == UIImagePickerControllerSourceTypeCamera)
{
self.imagePickerController.mediaTypes =
[NSArray arrayWithObjects:(NSString *) kUTTypeImage, nil];
self.imagePickerController.showsCameraControls = YES;
#if false
if ([[self.imagePickerController.cameraOverlayView subviews] count] == 0)
{
CGRect overlayViewFrame = self.imagePickerController.cameraOverlayView.frame;
CGRect newFrame = CGRectMake(0.0,
CGRectGetHeight(overlayViewFrame) -
self.view.frame.size.height - 10.0,
CGRectGetWidth(overlayViewFrame),
self.view.frame.size.height + 10.0);
self.view.frame = newFrame;
[self.imagePickerController.cameraOverlayView addSubview:self.view];
}
#endif
}
}
#pragma mark -
#pragma mark UIImagePickerControllerDelegate
- (void) imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info
{
self.imagePickerController.mediaTypes =
[NSArray arrayWithObjects:(NSString *) kUTTypeImage, nil];
self.imagePickerController.showsCameraControls = YES;
UIImage *image = [info valueForKey:UIImagePickerControllerOriginalImage];
if (self.delegate)
[self.delegate didTakePicture:image];
[self.delegate didFinishWithCamera];
}
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
[self.delegate didFinishWithCamera];
}
#end
In order to achieve this, you will have to implement your own method for taking a picture, since this default button causes the view to dismiss itself.
Obviously, you can do this by setting showsCameraControls=NO, but then you'd have to recreate all the other functionality that you still want.
I've never done this, but it should be possible to leave showsCameraControls=YES and use the cameraOverlayView to simply layer an identical "Take Picture" button over the existing one. If you do that, you just need to have that button call the method -takePicture from the instance of your UIImagePickerViewController.
Hopefully that's enough, feel free to comment and ask for any clarification.
You're going to need to implement a custom camera - check out Apple's SquareCam example
You'll be using AVFoundation and will be able to implement any kind of custom behavior when a photo is taken (including just staying on that camera page) - you'll even have to save it to the Photo Library yourself (the SquareCam example shows you how to do this). This also means that if you need the crop/resize controls, you'll have to create them yourself, as well as a picker view (grid gallery view) if you want the user to be able to review their photos after taking them.
It's probably around intermediate level stuff - took me a few days to implement, but if your app is in any way focused on photos, this is definitely the way to go. Gives you complete control of the camera UI and behavior.
Oh, and yeah you'll have to implement the flash button, shutter button, shutter effect, tap to focus, and anything else yourself too. AVFoundation basically gives you a straight pipe to the camera lens (figuratively).

how to display UIActivityIndicatorView BEFORE rotation begins

I'd like to display an activity indicator BEFORE the work undertaken by willAnimateRotationToInterfaceOrientation:duration: begins. Most of the time in my app, this work is quickly completed and there would be no need for an activity indicator, but occasionally (first rotation, i.e. before I have cached data, when working with a large file) there can be a noticeable delay. Rather than re-architect my app to cope with this uncommon case, I'd rather just show the UIActivityIndicatorView while the app generates a cache and updates the display.
The problem is (or seems to be) that the display is not updated between the willRotateToInterfaceOrientation:duration and the willAnimateRotationToInterfaceOrientation:duration: method. So asking iOS to show UIActivityIndicator view in willRotate method doesn't actually affect the display until after the willAnimateRotation method.
The following code illustrates the issue. When run, the activity indicator appears only very briefly and AFTER the simulateHardWorkNeededToGetDisplayInShapeBeforeRotation method has completed.
Am I missing something obvious? And if not, any smart ideas as to how I could work around this issue?
Update: While suggestions about farming the heavy lifting off to another thread etc. are generally helpful, in my particular case I kind of do want to block the main thread to do my lifting. In the app, I have a tableView all of whose heights need to be recalculated. When - which is not a very common use case or I wouldn't even be considering this approach - there are very many rows, all the new heights are calculated (and then cached) during a [tableView reloadData]. If I farm the lifting off and let the rotate proceed, then after the rotate and before the lifting, my tableView hasn't been re-loaded. In the portrait to landscape case, for example, it doesn't occupy the full width. Of course, there are other workarounds, e.g. building a tableView with just a few rows prior to the rotate and then reloading the real one over that etc.
Example code to illustrate the issue:
#implementation ActivityIndicatorViewController
#synthesize activityIndicatorView = _pgActivityIndicatorView;
#synthesize label = _pgLabel;
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}
- (void) willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration;
{
NSLog(#"willRotate");
[self showActivityIndicatorView];
}
- (void) willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration;
{
NSLog(#"willAnimateRotation");
[self simulateHardWorkNeededToGetDisplayInShapeBeforeRotation];
}
- (void) didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation;
{
NSLog(#"didRotate");
[self hideActivityIndicatorView];
}
- (void) simulateHardWorkNeededToGetDisplayInShapeBeforeRotation;
{
NSLog(#"Starting simulated work");
NSDate* date = [NSDate date];
while (fabs([date timeIntervalSinceNow]) < 2.0)
{
//
}
NSLog(#"Finished simulated work");
}
- (void) showActivityIndicatorView;
{
NSLog(#"showActivity");
if (![self activityIndicatorView])
{
UIActivityIndicatorView* activityIndicatorView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
[self setActivityIndicatorView:activityIndicatorView];
[[self activityIndicatorView] setCenter:[[self view] center]];
[[self activityIndicatorView] startAnimating];
[[self view] addSubview: [self activityIndicatorView]];
}
// in shipping code, an animation with delay would be used to ensure no indicator would show in the good cases
[[self activityIndicatorView] setHidden:NO];
}
- (void) hideActivityIndicatorView;
{
NSLog(#"hideActivity");
[[self activityIndicatorView] setHidden:YES];
}
- (void) dealloc;
{
[_pgActivityIndicatorView release];
[super dealloc];
}
- (void) viewDidLoad;
{
UILabel* label = [[UILabel alloc] initWithFrame:CGRectMake(50.0, 50.0, 0.0, 0.0)];
[label setText:#"Activity Indicator and Rotate"];
[label setTextAlignment: UITextAlignmentCenter];
[label sizeToFit];
[[self view] addSubview:label];
[self setLabel:label];
[label release];
}
#end
The app doesn't update the screen to show the UIActivityIndicatorView until the main run loop regains control. When a rotation event happens, the willRotate... and willAnimateRotation... methods are called in one pass through the main run loop. So you block on the hard work method before displaying the activity indicator.
To make this work, you need to push the hard work over to another thread. I would put the call to the hard work method in the willRotate... method. That method would call back to this view controller when the work is completed so the view can be updated. I would put show the activity indicator in the willAnimateRotation... method. I wouldn't bother with a didRotateFrom... method. I recommend reading the Threaded Programming Guide.
Edit in response to a comment: You can effectively block user interaction by having the willAnimateRotation... method put a non functioning interface on screen such as a view displaying a dark overlay over and the UIActivityIndicatorView. Then when the heavy lifting is done, this overlay is removed, and the interface becomes active again. Then the drawing code will have the opportunity to properly add and animate the activity indicator.
More digging (first in Matt Neuberg's Programming iPhone 4) and then this helpful question on forcing Core Animation to run its thread from stackoverflow and I have a solution that seems to be working well. Both Neuberg and Apple issue strong caution about this approach because of the potential for unwelcome side effects. In testing so far, it seems to be OK for my particular case.
Changing the code above as follows implements the change. The key addition is [CATransaction flush], forcing the UIActivityIndicatorView to start displaying even though the run loop won't be ended until after the willAnimateRotationToInterfaceOrientation:duration method completes.
- (void) willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration;
{
NSLog(#"willRotate");
[self showActivityIndicatorView];
[CATransaction flush]; // this starts the animation right away, w/o waiting for end of the run loop
}
- (void) willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration;
{
NSLog(#"willAnimateRotation");
[self simulateHardWorkNeededToGetDisplayInShapeBeforeRotation];
[self hideActivityIndicatorView];
}
- (void) didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation;
{
NSLog(#"didRotate");
}
Try performing you work on a second thread after showing the activity view.
[self showActivityIndicatorView];
[self performSelector:#selector(simulateHardWorkNeededToGetDisplayInShapeBeforeRotation) withObject:nil afterDelay:0.01];
Either execute the heavy lifting in a background thread and post the results in the foreground thread to update the UI (UIKit is only thread safe since iOS 4.0):
[self performSelectorInBackground:#selector(simulateHardWorkNeededToGetDisplayInShapeBeforeRotation) withObject:nil]
Or you can schedule the heavy lifting method to be executed after the rotation took place:
[self performSelector:#selector(simulateHardWorkNeededToGetDisplayInShapeBeforeRotation) withObject:nil afterDelay:0.4]
But these are only hacks and the real solution is to have proper background processing if your UI needs heavy processing to get updated, may it be in portrait or landscape. NSOperation and NSOperationQueue is a good place to start.

iOS: How to access the `UIKeyboard`?

I want to get a pointer reference to UIKeyboard *keyboard to the keyboard on screen so that I can add a transparent subview to it, covering it completely, to achieve the effect of disabling the UIKeyboard without hiding it.
In doing this, can I assume that there's only one UIKeyboard on the screen at a time? I.e., is it a singleton? Where's the method [UIKeyboard sharedInstance]. Brownie points if you implement that method via a category. Or, even more brownie points if you convince me why it's a bad idea to assume only one keyboard and give me a better solution.
Try this:
// my func
- (void) findKeyboard {
// Locate non-UIWindow.
UIWindow *keyboardWindow = nil;
for (UIWindow *testWindow in [[UIApplication sharedApplication] windows]) {
if (![[testWindow class] isEqual:[UIWindow class]]) {
keyboardWindow = testWindow;
break;
}
}
// Locate UIKeyboard.
UIView *foundKeyboard = nil;
for (UIView *possibleKeyboard in [keyboardWindow subviews]) {
// iOS 4 sticks the UIKeyboard inside a UIPeripheralHostView.
if ([[possibleKeyboard description] hasPrefix:#"<UIPeripheralHostView"]) {
possibleKeyboard = [[possibleKeyboard subviews] objectAtIndex:0];
}
if ([[possibleKeyboard description] hasPrefix:#"<UIKeyboard"]) {
foundKeyboard = possibleKeyboard;
break;
}
}
}
How about using -[UIApplication beginIgnoringInteractionEvents]?
Also, another trick to get the view containing the keyboard is to initialize a dummy view with CGRectZero and set it as the inputAccessoryView of your UITextField or UITextView. Then, get its superview. Still, such shenanigans is private/undocumented, but I've heard of apps doing that and getting accepted anyhow. I mean, how else would Instagram be able to make their comment keyboard interactive (dismiss on swipe) like the Messages keyboard?
I found that developerdoug's answer wasn't working on iOS 7, but by modifying things slightly I managed to get access to what I needed. Here's the code I used:
-(UIView*)findKeyboard
{
UIView *keyboard = nil;
for (UIWindow* window in [UIApplication sharedApplication].windows)
{
for (UIView *possibleKeyboard in window.subviews)
{
if ([[possibleKeyboard description] hasPrefix:#"<UIPeripheralHostView"])
{
keyboard = possibleKeyboard;
break;
}
}
}
return keyboard;
}
From what I could make out, in iOS 7 the keyboard is composed of a UIPeripheralHostView containing two subviews: a UIKBInputBackdropView (which provides the blur effect on whatever's underneath the keyboard) and a UIKeyboardAutomatic (which provides the character keys). Manipulating the UIPeripheralHostView seems to be equivalent to manipulating the entire keyboard.
Discaimer: I have no idea whether Apple will accept an app that uses this technique, nor whether it will still work in future SDKs.
Be aware, Apple has made it clear that applications which modify private view hierarchies without explicit approval beforehand will be rejected. Take a look in the Apple Developer Forums for various developers' experience on the issue.
If you're just trying to disable the keyboard (prevent it from receiving touches), you might try adding a transparent UIView that is the full size of the screen for the current orientation. If you add it as a subview of the main window, it might work. Apple hasn't made any public method of disabling the keyboard that I'm aware of - you might want to use one of your support incidents with Apple, maybe they will let you in on the solution.
For an app I am currently developing I am using a really quick and easy method:
Add this in the header file:
// Add in interface
UIWindow * _window;
// Add as property
#property (strong, nonatomic) IBOutlet UIView * _keyboard;
Then add this code in the bottom of the keyboardWillShow function:
-(void) keyboardWillShow: (NSNotification *) notification {
.... // other keyboard will show code //
_window = [UIApplication sharedApplication].windows.lastObject;
[NSTimer scheduledTimerWithTimeInterval:0.05
target:self
selector:#selector(allocateKeyboard)
userInfo:nil
repeats:NO];
}
This code look for when the keyboard is raised and then allocates the current window. I have then added a timer to allocate the keyboard as there were some issues when allocated immediately.
- (void)allocateKeyboard {
if (!_keyboard) {
if (_window.subviews.count) {
// The keyboard is always the 0th subview
_keyboard = _window.subviews[0];
}
}
}
We now have the keyboard allocated which gives you direct "access" to the keyboard as the question asks.
Hope this helps
Under iOS 8 it appears you have to jump down the chain more than in the past. The following works for me to get the keyboard, although with custom keyboards available and such I wouldn't rely on this working unless you're running in a controlled environment.
- (UIView *)findKeyboard {
for (UIWindow* window in [UIApplication sharedApplication].windows) {
UIView *inputSetContainer = [self viewWithPrefix:#"<UIInputSetContainerView" inView:window];
if (inputSetContainer) {
UIView *inputSetHost = [self viewWithPrefix:#"<UIInputSetHostView" inView:inputSetContainer];
if (inputSetHost) {
UIView *kbinputbackdrop = [self viewWithPrefix:#"<_UIKBCompatInput" inView:inputSetHost];
if (kbinputbackdrop) {
UIView *theKeyboard = [self viewWithPrefix:#"<UIKeyboard" inView:kbinputbackdrop];
return theKeyboard;
}
}
}
}
return nil;
}
- (UIView *)viewWithPrefix:(NSString *)prefix inView:(UIView *)view {
for (UIView *subview in view.subviews) {
if ([[subview description] hasPrefix:prefix]) {
return subview;
}
}
return nil;
}

MPMoviePlayer dismiss when pressed

I have a MPMoviePlayer setup to play an intro movie to my application. That works just great, the only problem is that it lasts for 14 seconds, and I want to give my users a chance to skip the intro by pressing anywhere on the movie.
I have hidden the movie controls, as they are not needed.
Code:
NSString *introPath = [[NSBundle mainBundle] pathForResource:#"intro" ofType:#"mov"];
intro = [[MPMoviePlayerController alloc] initWithContentURL:[NSURL fileURLWithPath:introPath]];
[intro setMovieControlMode:MPMovieControlModeHidden];
[intro play];
Thank you!
EDIT: My initial solution won't work, because the movie is shown in a second window, layered on top of the app's main window (it's very rare to have more than one window in the view hierarchy on the iPhone). This solution, based on Apple's MoviePlayer sample code, does work:
. . .
// assuming you have prepared your movie player, as in the question
[self.intro play];
NSArray* windows = [[UIApplication sharedApplication] windows];
// There should be more than one window, because the movie plays in its own window
if ([windows count] > 1)
{
// The movie's window is the one that is active
UIWindow* moviePlayerWindow = [[UIApplication sharedApplication] keyWindow];
// Now we create an invisible control with the same size as the window
UIControl* overlay = [[[UIControl alloc] initWithFrame:moviePlayerWindow.frame]autorelease];
// We want to get notified whenever the overlay control is touched
[overlay addTarget:self action:#selector(movieWindowTouched:) forControlEvents:UIControlEventTouchDown];
// Add the overlay to the window's subviews
[moviePlayerWindow addSubview:overlay];
}
. . .
// This is the method we registered to be called when the movie window is touched
-(void)movieWindowTouched:(UIControl*)sender
{
[self.intro stop];
}
NB: You must save the reference to the movie player in an instance variable, and it's most convenient to declare a property that we can use to access it. That's why is use self.intro instead of just intro in the example. If you don't know how to declare an instance variable and a property, there is plenty of information on this site and elsewhere.
**** ORIGINAL ANSWER BELOW
(Doesn't work in this case, but in many similar scenarios, so I'll leave it as a warning and/or inspiring example.)
. . . if nothing else works I'd recommend subclassing UIWindow and making sure that your app delegate instantiates that instead of a normal UIWindow. You can intercept touches in that class and send a notification or cancel the movie directly (if you've stored a pointer to the MPMoviePlayer in an ivar on your window subclass).
#interface MyWindow : UIWindow {
}
#end
#implementation MyWindow
// All touch events get passed through this method
-(UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
// The screen has been touched, send a notification or stop the movie
return [super hitTest:point withEvent:event];
}
#end

iPhone - Splash Screen with progress bar

I tried to create a SplashView which display the Default.png in the background and a UIProgressBar in front. But the splash screen is not being updated...
Inside my view controller I load first the splash view with a parameter how many steps my initialisation has and then I start a second thread via NSTimer and after each initialisation step I tell the SplashView to display the new progress value.
All looks good in theory, but when running this app the progress bar is not being updated (the method of the splash screen receives the values, I can see it in the logs). I also tried to add usleep(10000); in between to give the view updates a bit time and also instead of using the progress bar I drew directly on the view and called [self setNeedsDisplay]; but all didn't work :/
What am I doing wrong?
Thanks for your help!
Tom
Here is some code:
SPLASHSCREEN:
- (id)initWithFrame:(CGRect)frame withStepCount:(int)stepCount {
if (self = [super initWithFrame:frame]) {
// Initialization code
background = [[UIImageView alloc] initWithFrame: [self bounds]];
[background setImage: [UIImage imageWithContentsOfFile: [NSString stringWithFormat:#"%#/%#", [[NSBundle mainBundle] resourcePath], #"Default.png"]]];
[self addSubview: background];
progressView = [[UIProgressView alloc] initWithProgressViewStyle:UIProgressViewStyleBar];
[progressView setFrame:CGRectMake(60.0f, 222.0f, 200.0f, 20.0f)];
[progressView setProgress: 0.0f];
stepValue = 1.0f / (float)stepCount;
[self addSubview:progressView];
}
return self;
}
- (void)tick {
value += stepValue;
[progressView setProgress: value];
}
VIEWCONTROLLER:
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
splashView = [[SplashView alloc] initWithFrame: CGRectMake(0.0f, 0.0f, 320.0f, 480.0f) withStepCount:9];
[self setView: splashView];
NSTimer* delayTimer;
delayTimer = [NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:#selector(finishInitialization) userInfo:nil repeats:NO];
}
return self;
}
- (void)finishInitialization {
// do some stuff, like allocation, opening a db, creating views, heavy stuff...
[splashView tick]; // this should update the progress bar...
// do some stuff, like allocation, opening a db, creating views, heavy stuff...
[splashView tick]; // this should update the progress bar...
// init done... set the right view and release the SplashView
}
As mentioned in another answer, for some finite amount of time, as your app is being launched, Default.png is displayed and you have no control over it. However, if in your AppDelegate, you create a new view that displays the same Default.png, you can create a seamless transition from the original Default.png to a view that you can add a progress bar to.
Now, presumably, you have created a view or similar and you are updating a progress bar every so often in order to give the user some feedback. The challenge here is that your view is only drawn when it gets called to do a drawRect. If, however, you go from AppDelegate to some initialization code to a viewcontroller's viewDidLoad, without the run loop getting a chance to figure out which views need to have drawRect called on, then your view will never display its status bar.
Therefore in order to accomplish what you want, you have to either make sure that drawRect gets called, such as by pushing off a lot of your initialization code into other threads or timer tasks, or you can force the drawing by calling drawRect yourself, after setting up contexts and such.
If you go with the background tasks, then make sure your initialization code is thread-safe.
Default.png is just a graphic, a static image shown while the application is launching. If you want to show further progress, you'll have to show everything at the applicationDidLaunch phase. Show your modal "Splash Screen" there first (Create a view controller, add its view as a subview of your main window) and dismiss it when you are done whatever additional loading you needed to do.
Also, you need to do update your progress bar in a seperate thread. Updating your GUI in the same thread where a lot of business is going on is (in my opinion, but I could be wrong) a bad idea.
The main thread is, as far as I know, the only one that can safely do GUI things, and its event loop (that is, the main application thread's) is the one that does the actual displaying after you've called -setNeedsDisplay. Spawn a new thread to do your loading, and update the progress on the main thread.