Transitioning from UIImagePickerController to a second UIViewController - objective-c

Question

Still feeling pretty green in Objective-C - building my first "real" project and hit an architectural snag early on..
I'd like to present my views and navigation in a fully 'custom' environment - e.g. something where I hide all of the built-in UI controls (e.g. UINavigationController or UITabBar). One specific example (as in the title): moving from a 'main' view directly to a UIImagePickerController, and then right from the UIImagePickerController to a new third view.
Here are the three primary view controllers I'm working with:
MainViewController (custom subclass of UIViewController, contains my main Nav and is in general my primary or 'parent' controller)
ImageEditViewController (custom subclass of UIViewController wherein I overlay some controls on top of a stored image)
UIImagePickerController (built-in Apple class)
There are a couple of approaches I can image for this (but I can't figure out how to do either one):
Use a UINavigationController or UITabBar implementation, but somehow hide the system UI controls and implement my own. I am blocked on this approach because - simply - I don't know how to hide the system UI controls.
Call controller-to-controller or view-to-view transitions manually at specific points in the code. I sort of prefer this method but I can't figure out the best 'approach' to instantiating and managing and transitioning between my controllers. Example of things I don't know: how do I call a second view controller from my main view controller? How do I call a third view controller directly from the second? (Or at least transition to the third directly!)
I assume there is an easy solution here; just something I haven't learned yet about managing views and view controllers outside of Apple's helper classes.

Answer 1

What system UI controls are you talking about? The navigation bar?
You can just do myNavigationController.navigationBarHidden = YES; for a UINavigationCOntroller.
Documentation here.
As for the kind of navigation you should have, that really depends on your use case. Are you trying to achieve a hierarchy or workflow? Then perhaps a navigation controller is what you want. Is each view controller a separate piece that does not necessarily follow a workflow? Then a tab bar controller could work.
For tab bar you should be able to do something like:
myTabBarController.tabBar.hidden = YES;
[[myTabBarController.view.subviews objectAtIndex:0] setFrame:CGRectMake(0, 0, 320, 480)]; // or whatever your screen dimensions are

Answer 2

1.
For hiding navigation bar, it's quite easy:
self.navigationController.navigationBarHidden = YES;
For Hiding TabBar Use this:
- (void) hideTabBar:(UITabBarController *) tabbarcontroller {
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.5];
for(UIView *view in tabbarcontroller.view.subviews)
{
if([view isKindOfClass:[UITabBar class]])
{
[view setFrame:CGRectMake(view.frame.origin.x, 480, view.frame.size.width, view.frame.size.height)];
}
else
{
[view setFrame:CGRectMake(view.frame.origin.x, view.frame.origin.y, view.frame.size.width, 480)];
}
}
[UIView commitAnimations];
}
- (void) showTabBar:(UITabBarController *) tabbarcontroller {
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.5];
for(UIView *view in tabbarcontroller.view.subviews)
{
if([view isKindOfClass:[UITabBar class]])
{
[view setFrame:CGRectMake(view.frame.origin.x, 431, view.frame.size.width, view.frame.size.height)];
}
else
{
[view setFrame:CGRectMake(view.frame.origin.x, view.frame.origin.y, view.frame.size.width, 431)];
}
}
[UIView commitAnimations];
}
2.
If you want to easily be able to navigate backwards you should use a navigation controller, it will allow you to pop the view controller when you are done with it. Or you can do something like this (outside of navigation controller):
CustomViewController *controller = [[CustomViewController alloc] init];
[self presentModalViewController:controller animated:YES];