I'm using the UINavigationController toolbar. Before I display it, I resize my views so that they don't get blocked by the toolbar (I set the frame of the current view controller's view to the rect spanning from the bottom of the navigationBar to the top of the toolbar.
But not all of my view controllers have toolbarItems. So, when switching from a view controller that has items (controller A) to one that doesn't (controller B), I want to hide the toolbar. However, when I call setToolbarHidden:animated: in B's viewWillAppear:animated: method, the toolbar animates down during the push transition and shows the UIWindow background behind it.
This also happens in the reverse direction: when transitioning from B to A (via the back button), I want the toolbar to animate in to show A's toolbarItems again, but since A's view doesn't extend to the bottom of the screen, the UIWindow is visible during the pop transition.
That might not have been the best description, so here's a screenshot:
I have tried updating A's frame in its viewWillDisappear:animated: method, but it does strange things, since it seems to be called within the UINavigationController push animation block. Any insight would be appreciated.
Update: I tried hiding the toolbar in B's viewDidAppear:animated: instead, but the results weren't ideal. Using this solution, the toolbar doesn't get dismissed until the push transition completes. Since B doesn't have any toolbarItems, A's items get pushed to the left during the transition, leaving an empty toolbar on the screen before it disappears. Also, when going back to A, the UIWindow background will be visible unless I set the toolbar to visible in B's viewWillDisappear:animated:, which would mean that B has to know that A has toolbarItems.
Maybe the best practice would be to call setToolbarHidden:animated: in B's viewDidAppear?
Or you can change A's frame before pushing B to navigation controller in a pushViewController:animated: method in a custom UINavigationController subclass.
Since I never found a satisfactory solution to this involving animation, I ended up making my views extend down behind the toolbar to avoid showing the window. If your controller's view is a UITableView or UIScrollView, you can set its contentInset appropriately so that your content won't get covered up by the toolbar:
UIEdgeInsets edgeInsets = [[self tableView] contentInset];
if (![[self navigationController] isToolbarHidden]) {
edgeInsets.bottom = CGRectGetHeight([[[self navigationController] toolbar] frame]);
}
[[self tableView] setContentInset:edgeInsets];
Related
So before I push a new viewController onto the stack in a certain view, I set the navigationBar to hidden I notice that it disappears before the next screen gets pushed and the slide animation happens (because I need a UIToolbar at the top).
So question #1: is there a way to push a new view controller and setting the navigationbar to hidden, and not getting the hide animation until after the new view controller is on screen. it looks funny that the navigation bar hides then pushes the new view controller.
Once the new view controller is present, when I pop it off, I set the navigation bar back
[self.navigationController.navigationBar setHidden:NO];
But when it is popped, the navigationbar is not back any more. Is it because this navigationBar is for the current navigationController and not the new one that is being presented after the pop? (question #2)
Question 3: Realizing it isn't showing my navigationBar, in the viewController that gets presented after the pop, in its viewDidAppear, I added
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
[self.navigationController.navigationBar setHidden:NO];
}
which shows the navigationBar, but the view size is incorrect since it seems like once the navigation bar was hidden, the rest of the view took up the empty space, and then the navigationBar is on top of the content. Is there anything I can do about this? Or am I approaching it incorrectly with push and pop?(question #3).
Thanks!
I was running into the very same problem (only in reverse: I was starting from a NavigationBar being hidden and pushing a view where I wanted the NavigationBar visible), and there's actually an extremely easy fix.
Simply replace your calls:
[self.navigationController.navigationBar setHidden:NO];
with
[[self navigationController] setNavigationBarHidden:NO animated:YES];
In my code, I call these statements in the - (void)viewWillAppear:(BOOL)animated methods of each respective View Controller.
I just tried this solution in the order you are using (visible, then hidden), and it seems to work just as well.
Interesting issue. You could try changing the hidden property in viewWillAppear and viewWillDisappear, but it seems like that might not give the desired results either.
Can you present the view controller modally instead of making the navigation bar disappear? If it's the last view controller on the stack, that would be possible. It might also make more sense to the user to see a view controller presented differently. This might indicate to the user that navigating away from this view controller is no longer done with the Back Button. It could be more reasonable than having the navigation bar just disappear.
If you still wanted the view controller to slide in from the right, I don't think it can be done with a modal view controller. But, you could do that by animating a view that fills the screen. (You just add the view with a frame that has origin.x equal to the width of the screen. Then, in the animation, you change origin.x to 0.0. Let me know if you need more detail on this.)
However, I would recommend presenting the view controller in a different manner from the way a view is generally presented by a navigation controller. Because, essentially, you are no longer letting the user navigate away from this view as he/she generally would from within a navigation controller. (So, my response to question #3 would be 'yes'.)
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:
I have a custom UIControl subclass with a UIPickerView as inputView. When the control is tapped, it calls becomeFirstResponder and the picker view automatically slides up from the bottom of the screen, like the system keyboard. This is working great!
The problem is that I am using the custom control as the titleView of a UINavigationItem. It functions properly, but if the view controller is popped off the navigation controller stack while the picker view is visible, the animation is wonky.
What I want to happen:
everything is pushed off screen to the right at the same time
What actually happens:
first, the background view and navigation bar slide off screen, the picker remains in place
then, after they are gone, the picker slides off to the right also
When I use the custom control inside the view controller's main view, it animates away just like the standard keyboard. So it seems as though this is a function of "coming from" the navigation bar, which is animated separately from the views inside.
How can I fix this, so that the inputView slides out with the rest of the content?
Turns out this can be fixed by calling endEditing: on the UINavigationController's view. In other words, within a view controller:
[self.navigationController.view endEditing:YES];
This causes the input view to slide down while the rest of the view slides off to the right. Not exactly the same as the system keyboard, but not obviously weird.
I have a tabbar -> navigationcontroller structure. In one of these tabs, I want to switch between two UIViewControllers (a KalViewController and a UITableViewController to be be exact), using a UISegmentedControl located in the Navigation Bar.
Currently, I have a third UIViewController, that pops and pushes the appropriate ViewControllers on segment value change. I don't think thats the right way to do it and it also destroys the navigation stack (when I tap on the bar item, the navigation controller goes the root controller, which won't work). And there's even another bug, related to the Kal Component.
So, what's the right way to do it?
The right way to do it is to have the controller handling the UISegmentedControl add the views of the controllers as subviews.
[self.view addSubview:controller.view];
It's your responsibility to send viewWillAppear: and so on.
EDIT: The offset you're talking about can be adjusted using:
controller.view.frame = CGRectMake(x, y, width, height);
EDIT 2: In response to tc.'s comment:
From the documentation of UISplitViewController:
Message Forwarding to Its Child View Controllers
A split view controller interposes itself between the application’s window and its child view controllers. As a result, all messages to the visible view controllers must flow through the split view controller. This works generally as you might expect and the flow of messages should be relatively intuitive. For example, view appearance and disappearance messages are sent only when the corresponding child view controller actually appears on screen. Thus, when a split view controller is first displayed in a portrait orientation, it calls the viewWillAppear: and viewDidAppear: methods of only the view controller that is shown initially. The view controller that is presented using a popover does not receive those messages until the popover is shown or until the split view controller rotates to a landscape orientation.
This is not magical and there is no reason why you wouldn't be able to write a similar controller yourself. In fact I've done it and it worked just fine.
I've come across this twice now.
Sometimes using the following line of code:
[self.navigationController presentModalViewController:aViewController animated:YES];
displays the view, but the navigation bar is then hidden.
I can write:
[self.navigationController setNavigationBarHidden:NO];
to my hearts content, everywhere I can think of with no effect.
Has anyone ran into this?
Am I doing something silly?
No, I ran into this as well. The problem is that when you present a modal view controller with a UIViewController based class, it does not extend the calling navigation controller's nav bar onto the modal. The modal view covers the entire screen. What I ended up doing to solve the problem was to create a UINavigationController and push the UIViewController based class onto it, and then do presentModalViewController to the navigation controller's instance.
like:
UIViewController *vc = [[UIViewController alloc] init];
UINavigationController *cntrol = [[UINavigationController alloc] initWithRootViewController:vc];
[self presentModalViewController:cntrol animated:YES];
[cntrol release];
That allowed me to have a nav bar at the top.
I am not sure if that will help in your particular case, the only other thing I would suggest is to replicate the behavior of the modal with a UIAnimation that stops 44px below the top of the phone. That would keep the original navigation bar visible.
#HeatMiser shows a great way to get around the "bug" surrounding the inability to display items on the nav bar. I'm not sure, however, if this is strictly a bug in Presentation, since modal operations ought to trump the underlying view's interface theme. Having the modal operation's theme mimic the underlying UI theme is fine, but wrapping the true modal view with a navigation view feels wrong to me (extra view object just to get a little more behavior).
Instead, the following worked for me and gives the same behavior as "New Message" does in the Mail program (on the iPhone).
In IB, place a UIToolBar at the top of the modal screen (mimicking the navigation bar) with "Cancel" and "Save" UIBarButtonItem's and a Flexible Space Bar Button Item in between to get the buttons to align left and right. Then, add a UILabel centered over the UIToolBar (The Font Helvetica, Bold, Size 18 appears to match the Navigation Bar Title). Connect the buttons to IBAction's on the modal's UIViewController, and you're done.
If there is a navigation controller active, then you should just use
[self.navigationController pushViewControllerAnimated:how];
to slide another view controller in, while giving yourself and the user into a consistent user interface complete with 'automatic' back button support.
Once a navigation controller is in use, presenting a modal view controller should only be done to enlarge the usable area on the screen. And then, you should really use a fancy animation to let the user know that you are stepping away from the "task" or "steps" that the navigation controller was embodying.
Maybe this is obvious, but once you're done with the modal view and want to dismiss it, you should do something like this in your modal vc:
[parentController dismissModalViewControllerAnimated:YES];
Where parentController is a reference to the vc from where you are presenting the modal view.