resize uinavigationbar push/pop viewcontroller size issue - iphone

i need to shrink the height of a UINavigationBar (attached to the UINavigationController)
i've done this via the UINavigationControllerDelegate's navigationController:didShowViewController method, and it's working fine.
the problem is the visible viewcontroller that's in the main view. it wasn't resizing itself to reflect the new navbar height. thus, the didShowViewController method also resizes the viewcontroller's view frame, which works fine.
however, when i go to push on a new ViewController, or pop, i always see the view shift down to the original position during the animated transition to the next view. then, due to the code i have in the didShowViewController in the NavControllerDelegate, it shifts it back up.
i'm curious as to the best way to ensure that the shift down never happens.
i tried placing the code that resizes the frame into the willShowViewController, but that doesn't do anything.
i've also made sure that the UIView's frame that is the view of the UIViewController that's being popped, is also of the proper/shifted dimensions. no go there.
it's like i need to intercept the drawing actions after the pushViewController is invoked, and before the UINavigationController's didShowViewController is called.
i've been staring at my code for hours & hours... not getting anywhere. hopefully this makes sense to someone out there.
thanks!!!

Another option I think would be to set the NavigationControllers navigationBarHidden equal to YES. This will hide the nav bar completely and then you can then draw whatever view you want in the place the bar would have resided. Just put controls on the view that wrap the navigation methods (push, pop, etc...). It might be a challenge to get it to have the same style as a nav bar though.

Related

Subview behaves strangely in navigation-based app

I'm currently developing an app for iphone (my first) and I used several UITableViewController for navigation.
I then used a subview attached to self.view.superview to get a non-scroll image at the top.
The subview is created in IB, simple UIView with an UIImageView in it.
I'm adding the subview in viewDidAppear and this functions well.
But as soon as I'm tapping a cell and the navigationController pushes the next View animated, the previous view (scrolling out of sight) becomes completely white and my subview moves animated to the center. It's only for a half second or so, because then it's gone due to the next view arriving, but it's really unnerving.
I tried removing the subview in viewWillDisappear, that removes the UIImageView, but the screen still becomes completely white.
Does anybody how to fix this?
Oh, and PS: I'm working only on the Simulator, because I have no Developer Account yet. And I cannot change everything to a ViewController because I have a deadline to meet.
You shouldn't be surprised that things go wrong when you mess with the views of view controllers that don't belong to you. Rather than using a table view controller, you should replace it with a custom UIViewController whose view acts as a container view for both the table view and the non-scrolling view above it.

Seeing a ViewController behind the displayed one

Is it possible to view the viewcontroller behind the displayed one? I have a viewcontroller with a scrollview, which has imageviews added as subviews and would like the view that presented this viewcontroller to be visible behind the presented view controller.
I have set all the views, the viewcontroller view too to have a clear color background, but still there is a black background. when I dismiss the viewcontroller, I see 2 layers being dismissed. one has alpha dropped, the other not.
Is there an easy way to make this effect possible?
Its not possible. When a new view controller is pushed or presented as modal view, the previous view controller will be removed from the display(may be UINavigationController/iOS hides it). The rule is only one view controller would be visible at a time. So you will see the color of your window(the black color you've mentioned) in the background.
What you could do is make a screenshot before displaying the other controller. and send this image to new controller to be displayed as background.
This will only work for static content, but you could do something like the curl display.
You can do this but the truth is what EmptyStack says.
You can use setFrame of the subView and add it on the viewController. Also use below method to set the index of the added View. By default currentView has Index 0.
[self.view insertSubview:myView atIndex:0];
or you can try below methods as per your logic
insertSubview:aboveSubview:
insertSubview:atIndex:
insertSubview:belowSubview:
addSubViews:
bringSubviewToFront:
removeFromSuperview:

iPhone landscape navigation back action shows vertical view transition?

I have a regular UINavigationController and I push a series of UIViewController into the stack. The view transition for push controller is horizontal animation transition:
[self.navigationController pushViewController:controller animated:YES];
However, when I press the Back button on the navigation bar, the view transition animation is vertical (vertically dropping down the previous controller/view).
I don't seem to find any way to make this horizontal. This happens only in Landscape mode. Portrait mode the transition all happens as horizontal flip transition.
Can anyone shed any light on this?
Thanks
I had the same problem. When I pressed back to get to the first view I saw a vertical animation instead of the normal horizontal one.
I found an answer based on Apple's NavBar sample code. I edited the sample code to add "shouldAutorotateToInterfaceOrientation" to all the view controllers, and made it return YES.
When I ran it I noticed the correct animation was used when pressing "Back".
FIX:
It seems like you need to use your own subclassed UIViewController within the navigation controller, and add shouldAutorotateToInterfaceOrientation. Presumably the default UIViewController isn't returning the correct orientation so the wrong animation is used.
BACKGROUND:
I checked all the differences between my code and Apple's, and I found out that my navigation controller was a subclass of UINavigationController, where I perform all the work. By default IB had added a UIViewController inside this, and I left it alone. I noticed that the NavBar sample code had its own class set (MainViewController). So I made Xcode create a new UIViewController subclass with no xib, then set it up in the Class option in the Identity panel in IB.
I hope this makes sense and helps!

iPhone: Presenting Modal View Shifts Views of Calling ViewController

I have two view controllers myViewControllerA and myViewControllerB.
myViewControllerA has modalTransitionStyle = UIModalTransitionStyleFlipHorizontal.
Then I call presentModalViewController:animated: to load myViewControllerB. After calling dismissModalViewControllerAnimated:, suddenly all the views of myViewControllerA display shifted up by the height of the status bar.When I repeat the process, the views of myViewControllerA display properly once more.
So, the problems appears only upon the first call of the modal view controller. After dismissing and calling it again everything looks fine again.
What can cause this?
I know this is an old question, but it could still be helpful to someone.
The solution is so simple, its easy to pass it.
When you remove the simulated status bar of that view in Interface Builder, the frame still has a height of 460 (it should be 480, the height of the iphone screen)
Go to the Size tab (ruler icon), in the Attributes inspector, and set the frame to 480 again.

Contents of UIScrollView shifted after dismissing ModalViewController

I have a paged scrollview. Each page has a viewcontroller (buttonViewController) that manages a grid of buttons. If you press one of the buttons, the buttonViewController pops up another viewcontroller (detailViewController) modally.
The problem is, when I dismiss the modal view controller, the visible buttonViewController is shifted down by what looks like about 20 pixels. The weird thing is that only the visible page is shifted. If I scroll over to another page that is already loaded, it is still in the correct position.
My question is basically the same as dismissing modalViewController moves main view buttons around iphone
However, the accepted answer to that question assumed that the status bar is hidden. I am not hiding the status bar in my application.
Any other ideas?
One more note: The shift only happens the first time I launch a modal view controller. If I keep opening and closing the modal view controller, everything stays the same.
One further note: if I add the following code:
CGRect frame = self.view.frame;
frame.origin.y=0;
self.view.frame = frame;
after I dismiss the modal view controller, then I can work around the problem. The frame seems to move by 20pixels in y. I still don't know what's causing the move though.
Well I had this problem and it was due to the way my first viewController was set up (on the UIWindow), it is very weird since this had never happened to me before, the behavior I was observing was that when you add a subview at point (0,0) it would overlap with the status bar, which is not usual, usually the views know about the status bar and they behave appropriately. As a side effect, when one pushes a modal view that takes off the status bar, after dismissing it I saw the same problem you are seeing. What I did to fix was to set the UIWindows view to my controllers view in the nib, this seemed to fix everything. Once again I don't know why simply adding to the window programmatically with CGRectMake(0,0,320,460) had this odd behavior, since I have been doing this for all my previous projects and saw the correct behavior. But when I set it up in the nib, it worked as expected. Maybe this is your problem as well.
Turns out this was related to:
ModalViewController doesn't display during animation when paged scrollView is scrolled
I had mismatched the heights of some of my viewcontrollers, and that was throwing everything off.
Some of the views had heights of 460pixels, some had 480pixels. For some reason, this made it shift by 20pixels evertime a modal view controller disappeared. Once I made everything 460pixels, everything worked great.