dismissModalViewController not working as expected

[Kilby]

Hello All,

I have a problem that I'm helping someone can shed some light on. I'm sure it is something very simple, but I just can't see it and could really use an extra set of eyes to help find this bug.

The app I'm working on uses UIImagePickerController to present a camera preview with the stock camera UI hidden. This preview implements a cameraOverlay view with a few buttons to perform my required tasks, one of which is to dismiss the camera preview.

For some reason, the function to dismiss the camera view will not work when being called by the button in the overlay view. I can NSLog the function and see that it is in fact being called by the button, but simply doesn't allow the dismissModalViewController to work. I have tested the function by having an NSTimer call it a few seconds after it loads, and it works fine, just not when I call it from the button in the cameraOverlay.

My viewController (CameraTestViewController.m) calls the UIImagePicker as shown below with the press of a button.

-(IBAction) getPhoto:(id) sender {
	
	
	OverlayView *overlay = [[OverlayView alloc] initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, SCREEN_HEIGTH)];
	picker = [[UIImagePickerController alloc] init];
	picker.delegate = self;
	picker.sourceType = UIImagePickerControllerSourceTypeCamera;
	picker.cameraDevice = UIImagePickerControllerCameraDeviceFront;
	picker.cameraOverlayView = overlay;
	picker.showsCameraControls = NO;
	picker.toolbarHidden = YES;
	[self presentModalViewController:picker animated:NO];
	//[self performSelector:@selector(doCancel) withObject:nil afterDelay:10];

}

I dismiss the camera view with this method elsewhere in the viewController

-(void)doCancel
{	
	NSLog (@"doCancel method has been called");
	[picker dismissModalViewControllerAnimated:YES];
}

Then in my OverlayView.m class, I set up the required buttons and provide a method that calls the dismissing of the modal view controller.

- (id)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
		// Clear the background of the overlay:
		self.opaque = NO;
		self.backgroundColor = [UIColor clearColor];

                  ...

myButton04 = [UIButton buttonWithType:UIButtonTypeCustom];
		myButton04.frame = CGRectMake(10, 447, 44, 13);
		[myButton04 setTitle:@"" forState:UIControlStateNormal];
		[myButton04 addTarget:self action:@selector(scanButton05TouchUpInside) forControlEvents:UIControlEventTouchUpInside];
		[myButton04 setImage:[UIImage imageNamed:@"camControlsBack.png"] forState:UIControlStateNormal];
		[self addSubview:myButton04];

                  ...

    }
	
    return self;
	
}


- (void) scanButton05TouchUpInside {

	NSLog(@"BACK BUTTON HAS BEEN PRESSED");
	CameraTestViewController *baseViewController = [[CameraTestViewController alloc] init];
	[baseViewController doCancel];

}

ANY help on this would be most appreciated. I'm sick of having a purple forehead from beating my head against the wall over this one.

THANKS!

[Kilby]

Any Ideas anyone?

Why would my 'doCanel' method work while being called from an NSTimer for testing purposes, but not when I press the button in the OverlayView?

[Smokin Joe]

I think you may need to access your parentViewController (the ViewController that is setting up your overlayViewController) through your application Delegate.

I was having an issue where a parentViewController would alloc and add a childViewController to the superview. However, there were some interactions within the childViewController that I wanted to trigger actions in my parentViewController. To do this, within my childViewController:

	ProjectAppDelegate *appDelegate = (ProjectAppDelegate *)[[UIApplication sharedApplication]delegate];
	ParentViewController *pvc = appDelegate.viewController;
	[pvc methodInParentViewController];

With the above code, I assume that the *viewController object exists and is your ParentViewController.

Essentially, if you have to traverse BACK through layers of ViewControllers, I'd suggest using the ApplicationDelegate.