I have used UITabbar control to navigate to the top level pages of my app. Each top level page navigates to 5 other pages using command buttons to drill deeper. When the user selects the next tabbar item, instead of navigating to the root, they end up on the page they were last reading in the hierarchy. I am using XCode 4 and Tab Bars have been created using IB.
How can I change this behavior so that the tab bar button always navigates to the top level page? Your help would be very much appreciated since I have spent many days trying to resolve this issue.
I believe this will work if your tabs have UINavigationController at their root
//somewhere in the initialization process
tabBarController.delegate = self
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController{
UINavigationController *navController = (UINavigationController *)viewController;
if([navController.viewControllers count]>0)
[navController popToRootViewControllerAnimated:NO];
}
I have implemented UITabBar with each button loading a separate view controller and each of those view controllers having a navigation controller as a drill-down interface. When each button on the tab bar is clicked, the UIViewController is loaded and it is responsible for handling the drill down.
This sounds like what you want to do. Since I'm not sure what you mean by "page", I don't know how you are implementing the change that happens when a button is tapped on the tab bar. It sounds like you have one UIViewController and that's not quite how the UITabBar was designed to function. I could be wrong, so I think a little more explanation is needed.
If you are implementing with multiple UIViewControllers, You may want to think about whether a user is going to want to remain buried in the drill down even on changing tabs. Not sure what you App does, but this may be desired behavior.
Related
I am wondering the following:
What is the best way to set up a searchbar that is available in all child view controllers of the navigation controller on the ipad (Hence in the entire application in my case).
A perfect example in which this is done is the IMDB application on the iPad, where each view controller with its presented views shows a search bar in the navigation bar that uses the same datasource.
I found the following post on this topic: Same UISearchBar for entire app?
However,I am not completely satisfied with the answer yet. I would like to know whether it is possible to show it in the navigation bar everywhere using either the function:
[self.navigationItem setTitleView:mySearchBar];
or:
[self.navigationItem setTitleView:mySearchBar];
searchDisplayController.displaysSearchBarInNavigationBar = YES;
at a specific location, hence not in each view controller. I thought of adding the search bar in the prepareforsegue function every time, but there must be a more convenient and nicer way.
Also, if you would suggest to work with container view controllers, how would this work with other navigation items? Can one adjust the size of the view UIsearchbar when more navigation bar items (buttons) are presented for a certain view controller?
I have a storyboarded app with a chain of tableviews followed by a detail view. Kind of the classic iPhone app. There are 4 tabs and each one leads to a navigation controller.
The issue is I really want to avoid unnecessary glue code since the app is basically finished. If it was possible to connect the Search and Favorites (bottom two off the tab bar) controller as 'Root View Controllers' to the same UIViewController I would be done. However, this won't work since a view controller can only be the root view controller to one tab. So as you can see I've instituted two dummy UIViewControllers that forward you to the UIViewController in the middle. Now, unfortunately, I have to write code to make that central view controller a fake root view controller to disable the appearance of the back button, and prevent popping to the blank root when you double-tap the tab bar.
Has anyone got a more elegant solution?
This appears to be a flaw in Storyboards. One workaround would be to use simple view controllers for each navigation controller's rootViewController. Put a UIContainerView in each that points to the UIViewController you want to share.
I've set up a really simple project using storyboards including two views as shown here: http://i.stack.imgur.com/iRx21.png. The navigation can be done by either selecting a cell in the custom table view or hitting the back button labelled with "<<". Everything works fine except the following:
when I switch between the views, every time an instantiation happens. The profiling shows an increasing number of view objects. I would like to keep only one of each view and instantiation should be happen only once. What am I doing wrong? (I'm using ARC.)
Thanks in advance!
You should not link your back button to the parent view controller. This is what causes the new instantiation.
The way to go is to embed the table view into UINavigationController (in IB, choose Editor -> Imbed In -> Navigation Controller. Then change your segue to a Push segue. You can of course hide the navigation bar etc. to make things look exactly as you like. Then, link the back button to the controller with an IBAction and in the handler do a simple
[self.navigationController popViewControllerAnimated:YES];
This would be the appropriate logic of what you are doing. Of course, you can also push the web view modally and then handle the button click with
[self dismissModalViewControllerAnimated:YES];
Hi there and thank you in advice for your help. I have a really strange problem while working with ViewControllers in Xcode4. First of all I have to say that I'm not using storyboards and I prefer to create any UI element programmatically. So I've set a UIButton and I want that, when pressed, it brings me to a new view controller. This is the code I'm using for a button:
-(void)settingsAndExportHandle:(UIButton *)buttonSender {
SettingsViewController* settingView = [[SettingsViewController alloc] initWithNibName:#"SettingsViewController" bundle:nil];
settingView.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:settingView animated:YES];
}
This buttons is initialized and allocated in the viewDidLoad method of the RootViewController. I want to switch to the other view controller (in this case SettingsViewController) when I press the button.
The strange thing is that when I press the button, the animation that flips the controllers goes well, but when it finishes I obtain the EXACT same things that I had on the RootViewControllers (same custom views, same buttons, same all!). The question is: what I'm missing?? I have to say that I use ARC (automatic reference counting) so I can't release or dealloc the views and buttons I've created on my RootViewController.
Any help will be appreciated. Thank you all!
Pushing and and modally presenting view controllers does not deallocate the view controller that presented them. It simply adds the additional view controller to the stack. You'll need to implement a callback method so that when the user hits the button to flip back to root view controller, your settings view controller lets the root view controller know what's about to happen so you can call a method you've written to reset the interface back to whatever state you need it at. You may also be able to use viewWillAppear: but that's a little messy.
However, according to the Apple Human Interface Guidelines, the user expects that when they push a view controller or modally present it, the view controller they were on will save state and be exactly the way they left it when they came back. It's disconcerting and annoying when state is not preserved while in a navigation controller context. It is especially annoying when it's modally presented.
Think about this - A user is in a hypothetical Mail app. They start typing out an email and set a font size and a color. They tap on the add attachment button, which brings up a modal view controller that allows them to select a picture. They select the picture and the modal view is dismissed, and in your implementation, the mail composing interface would have reset and the email content would be gone or at the very least the selected font size and color would be back to the default. That's not a good experience.
I'm running into a problem with an iPad app where I would like to have UINavigationControllers in both of the views within a UISplitView. I've looked through other similar questions here, but most link to a tutorial online that doesn't completely solve the problem. Here's a 2-minute walkthrough to re-create the problem I'm having:
Create a New Project in XCode, starting from the Split View-based Application template.
Add the following NSLog statement as the first line within the DetailViewController's willHideViewController method:
NSLog(#"toolbar: %#", toolbar);
If you run the application now, the log will show that the DetailViewController's toolbar is alive and well. Now...
Open MainWindow.xib and expand the SplitViewController.
Drag a Navigation Controller from the library on top of the DetailViewController.
Expand the new Navigation Controller and change the class of the UIViewController within to a DetailViewController.
Ctrl-drag from the SplitViewController to the DetailViewController and assign it as the delegate.
Save MainWindow.xib and run the app again.
At this point, the detail view has a navigation bar and an empty toolbar. If you view the logs, you should find that the toolbar is null. Why is this? Am I missing some sort of connection in Interface Builder? Is the navigation bar the problem for some reason?
Unlike the tutorial at http://www.cimgf.com/2010/05/24/fixing-the-uisplitviewcontroller-template/, I would like to keep both the navigation bar and the toolbar (preferably with the toolbar at the top when in portrait and not visible when in landscape), so that I still have a functional "Back" button when the iPad is in portrait orientation.
Does anyone have any suggestions for fixing this problem? An example project with this sort of set-up would be ideal.
You can certainly use a navigation controller on the detail view of a split view controller. In fact, the iPad Settings app uses this approach. Probably the best way to get this setup is to create a new project in Xcode 4.x and select the "Master-Detail Application" template. It will generate a split view controller with 2 navigation controllers, one for the left view and one for the right view.
To your toolbar question, to keep things simple I would put a toolbar in the bottom. You can still put bar button items on the top navigation bar, although you can only put them in the left, middle, or right. If you need lots of items on the top bar, one way is to add a toolbar to the detail view and hide the navigation bar in the viewWillAppear event of the detail view class.
Here is an example on how to hide the navigation bar and show the toolbar:
- (void) viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
self.navigationController.toolbarHidden = NO;
self.navigationController.navigationBarHidden = YES;
}
I've found the built-in UISplitViewController to behave badly when trying to combine it with most of the other built-in view controller subclasses. Matt Gemmell's MGSplitViewController is a lot more flexible and has worked pretty well for me, despite the odd glitches (though those are at least fixable as the source code is provided).