Why isn't the rootViewController of my modally presented (form sheet) navController aware of it's smaller size when presented modally? - ios

Question

I am working on an iPad app with a few different modal views, and this code is pretty common:
UIViewController *v1 = [[UIViewController alloc] init];
UINavigationController *nav1 = [[UINavigationController alloc] initWithRootViewController:v1];
nav1.modalPresentationStyle = UIModalPresentationFormSheet;
[self presentViewController:nav1 animated:YES completion:nil];
It could be that I am doing this wrong, but this is how I am presenting a navController-nested vc modally.
The problem is that within the v1 class, any reference to self.frame/bounds results in full screen dimensions:768x1024. Even though the navController clearly isn't being displayed with that size.
What should I be doing to make it so that the v1 vc knows how big it actually is? So that if I wanted to add, say, a tableView, it would know how big it should be?
Thanks!
EDIT:
I have tried a few more things, and still don't have a solution to this problem. I have made a simple sample project to illustrate the problem I am having. I just have one view and this is the core of the code:
- (void)viewDidLoad
{
[super viewDidLoad];
NSLog(#"Frame: %#", NSStringFromCGRect(self.view.frame));
NSLog(#"Bounds: %#", NSStringFromCGRect(self.view.bounds));
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(self.view.frame.size.width - 400, 0, 400, 400);
button.backgroundColor = [UIColor redColor];
[button addTarget:self action:#selector(presentModal) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button];
}
- (void)presentModal {
SSViewController *view = [[SSViewController alloc] init];
UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:view];
nav.modalPresentationStyle = UIModalPresentationFormSheet;
[self.navigationController presentViewController:nav animated:YES completion:nil];
}
When this view loads, I have a big red button that is up against the top right corner of my view. When I press the button, it loads the same VC in a modal view embedded in a navController. The button shows up nearly off screen because the frame hasn't changed. It still shows as full screen. Here is a link to the project.

Answer 1

Not sure why you're having the issue you're having. I'm using the following code:
- (void)presentNewView {
NewViewController *newVC = [[NewViewController alloc] initWithNibName:nil bundle:nil];
newVC.view.backgroundColor = [UIColor redColor];
UINavigationController *newNC = [[UINavigationController alloc] initWithRootViewController:newVC];
newNC.modalPresentationStyle = UIModalPresentationFormSheet;
[self.navigationController presentViewController:newNC animated:YES completion:NULL];
}
.. it results in the following in the simulator:
.. and when I print out the first ViewController's frame and bounds (I thought it might be an issue with the two) I get the following:
frame height: 1024.000000
frame width: 768.000000
bounds height: 1024.000000
bounds width: 768.000000
.. and when I print out the presented ViewController's frame/bounds I get the following:
frame height: 620.000000
frame width: 540.000000
bounds height: 620.000000
bounds width: 540.000000
How are you determining the size of the frame exactly? Any reference within the v1 class that was presented modally SHOULD know its actual size, like I showed above.
EDIT
The major difference I found with my code and yours, is that in my code I created a subclass of my view controller "NewViewController" and was printing out the frame from within that class. The class itself seems to be aware of its correct bounds, but the class the presented it seems not to be. This is demonstrated by printing the view property from the ViewController class that presented it:
NewViewController's View From Presenting Class: frame = (0 0; 768 1024)
..compared to printing out the self.view from within the ViewDidAppear method of NewViewController itself:
NewViewController's View Did Appear: frame = (0 0; 540 576)
Moral of the story, if you are going to be presenting a UIViewController in the way you've shown, you're likely going to want to subclass UIViewController anyway so you can customize it however you want, so within that file if you reference self.view or self.bounds you will be getting the ACTUAL view/bounds.
EDIT #2
Based on the project you provided, the reason why you are having that issue is because you are printing out the frame/bounds of the view in viewDidLoad as opposed to viewDid/viewWillAppear. Adding those NSLog statements to VWA or VDA provides you the correct frame, so as I said in my initial edit, you should be fine accessing the view of the modal correctly at that point.

Answer 2

It's a new feature of iOS7. If you embed a UIViewController in navigation bar, it won't get smaller, because by default navigation bar is translucent.
You will see it if you change the background color of a view controller, that the top part of it is actually behind the navigation bar.
To lay out the v1 view controller underneath the navigation bar, you can use following code:
if ([v1 respondsToSelector:#selector(edgesForExtendedLayout)]) {
v1.edgesForExtendedLayout = UIRectEdgeNone;
}
It will behave just as in iOS6.

Answer 3

when presenting view controllers modally from a child view controller (one that has lass than the full screen and is a child of another view controller..) it is important to do this so that the modal controller knows the size of the canvas its appearing in
childViewController.definesPresentationContext = YES;
modalViewControllerWhichIsAboutToBePushed.modalPresentationStyle = UIModalPresentationCurrentContext