my app has tabBarController with 3 views and in one of them I want to popup a web browser with the ability to return back to the application. To do that I am using UINavigationController.
In myAppDelegate.h I have defined the property UINavigationController *nav and in myAppDelegate.m I have #synthesize nav.
In the class where the webPopup function resides upon pressing the button my code comes to this function.
- (IBAction)showWeb:(id)sender {
myAppDelegate *app=[[UINavigationController alloc] initWIthRootViewController:self];
// because I want to return back to the same view
webController *web = [[webController alloc] initWithStyle:UITableViewStypeGrouped];
[app.nav pushViewController:web animated:YES];
app.nav.view.frame = CGRect(,0,320,430);
[self.view.window addSUbview:app.nav.view];
}
The web popup occurs but it is moved vertically, when I press "back button" my former view appears as well and it is also shifted vertically from what it was before.
After going back and forth few times the thing hangs.
Questions:
1. what can cause the shift?
2. how to avoid when I go "back" to see the title(test from the "back"button, I think this might cause a shift when I go back.
3. how to find out why it hangs after few attempt?
Thanks.
Victor
The line:
myAppDelegate *app=[[UINavigationController alloc] initWIthRootViewController:self];
makes no sense to me. Surely your compiler is warning you about that? What is "myAppDelegate" defined as? Classes should have a capital letter at the front, by the way.
Also, the line
[self.view.window addSUbview:app.nav.view];
is highly suspect, because the UIWindow for your application should have only one child UIView. You shouldn't just add more views willy nilly and expect things to work. It is possible to change the child UIView by removing the old one and adding a new one, but you don't seem to be doing that. Having more than one child UIView of UIWindow gets you into trouble very quickly -- for example, device orientation changing can break.
I'm not exactly clear as to why the app delegate (or the window for that matter) needs to be messed with at all to do what you are trying to do. Sounds like you should just be using standard Nav View Controllers and Web Views.
Also, you are alloc init'ing w/o any memory management.
Related
Required:
I want to enable iOS7 swipe to back feature with custom navigation back button item.
Current Implementation:
After researching a lot, I found the following solution to be best:
Set the delegate of the gesture recognizer as follows
self.navigationController.interactivePopGestureRecognizer.delegate = (id<UIGestureRecognizerDelegate>)self;
This, creates a lot of bugs as mentioned in this stackoverflow answer. To avoid that, subclassing the UINavigationController seems to be the only feasible option. I did that as mentioned in this blog by Keighl.
Problem:
Basic swipe to back feature is working, but the strange thing is that, sometimes, the same viewController that is being dismissed, appears again after the pop action is completed.
i.e. suppose the navigation stack looks like A -> B. Popping B will again bring up B. This keeps on happening until eventually the viewController B actually gets dismissed and A appears.
This happens to all views in all viewController objects and not just to a specific one.
Also, I have ensured that the push method is called only once at all places.
I also tried logging the navigation stack at each point, but there is only one instance of each viewController.
Point to note:
I need to disable the swipe feature in certain views. I did this by writing the code to disable and enable the swipe gesture in viewDidAppear and viewDidDisappear respectively.
Please provide your valuable suggestions or a solution to this problem. Thanks!
Short answer: You should add a UIScreenEdgePanGestureRecognizer to your view controller if you want to add a pop gesture where none exists. Modifying the existing interactivePopGestureRecognizer is probably not the right approach. Do this:
[self addGestureRecognizer:({
UIScreenEdgePanGestureRecognizer *gesture =
[[UIScreenEdgePanGestureRecognizer alloc]
initWithTarget:self action:#selector(pop)];
gesture;
})];
and
-(void)pop {
// pop your view controller here
}
Long answer: Forcing the interactivePopGestureRecognizer.delegate is what breaks your code.
If you need to cast self as such:
self.navigationController.interactivePopGestureRecognizer.delegate =
(id<UIGestureRecognizerDelegate>)self;
...it is because self is not a UIGestureRecognizerDelegate. The following should compile, link, build and run or you are setting yourself up for trouble:
self.navigationController.interactivePopGestureRecognizer.delegate = self;
Note that being a UIGestureRecognizerDelegate specifically allows you to tweak a gesture's behavior at runtime, assuming you are implementing one of the following and ensuring that the tweak applies to a gesture you own:
gestureRecognizerShouldBegin:
gestureRecognizer:shouldReceiveTouch:
gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer:
gestureRecognizer:shouldRequireFailureOfGestureRecognizer:
gestureRecognizer:shouldBeRequiredToFailByGestureRecognizer:
By constantly changing the delegate of that interactivePopGestureRecognizer you did not create, all you are doing is preventing the iOS behavior to take place.
From the documentation
UINavigationController -interactivePopGestureRecognizer
The gesture recognizer responsible for popping the top view controller off the navigation stack. (read-only)
In plain English: Use this value is you need to combine that gesture with your own gesture. But you are not supposed to modify its behavior:
...You can use this property to retrieve the gesture recognizer and tie it to the behavior of other gesture recognizers in your user interface...
I have a game setup screen which uses UINavigation and am trying to reset or clear the UINavigation once a person has selected a color.
My app's current process can be best described in the following diagram:
Start application -> New game -> Pick character -> Pick Color -> Start game
Up until "Pick Color" I use the UINavigation, however when a color is picked I want to clear the UINavigation history.
The reason for doing this is so that you can't go back once you've started the game and want the UINavigation to with a clean slate with no indication that you can go back (and this also includes going back to the main menu screen).
The way I am doing it right now is thusly;
[self.navigationController popToRootViewControllerAnimated:YES];
GameDashboardVC *dashboard = [[GameDashboardVC alloc] initWithNibName:#"GameDashboardVC" bundle:nil];
dashboard.title = #"Dashboard";
dashboard.managedObjectContext = self.managedObjectContext;
[self.navigationController pushViewController:dashboard animated:YES];
[dashboard release];
The problem is that it pops to the rootViewController but it never pushes the dashboard onto the stack.
I've tried:
[self.parentViewController.navigationController pushViewController....]
The only thing I haven't tried is putting my dashboard push inside the root view controller itself, but I am concerned because I am not sure if it should even be there.
Therefore, where is the correct place to put this kind of functionality, and how do I clear the UINavigation's stack.
Thank you for your time/help.
I solved the problem now to my satisfaction.
I put the following code inside my initWithNibName method:
self.navigationItem.hidesBackButton = YES;
This hid the back button and I didn't have to pop anything, but I think for memory reasons it might be useful to keep the idea of removing un-necessary items from the stack.
But for now the above will do.
If you want reset the UINavigation History, reinitialise the navigation controller.
if you using UINavigationController from AppDelegate class. You can reinitialise the navigation history.
appDelegate.navigationController=[[UINavigationController alloc]init];
Above code will reset the navigationController history..
New to obj-c and cocoa, working a on a simple game as my first (mac os x) app. I have a menu view and a game view:
MenuView.h/m
MenuViewController.h/m
GameView.h/m
GameViewController.h/m
I want the menu to be displayed by default, and when the play button (which is in the MenuView) is clicked I want the menu to go away and the game to appear. I understand actions and outlets, but I don't know where to start on making the views swap themselves out. Any help? It seems like I would need to somehow make my MenuViewController talk to my MainController?
Peter Hosey,
If you are looking at the MenuViewController as a sort of "main" view controller, at the moment the play button is clicked, you could initialize an instance of GameViewController:
- (IBAction)gameButtonClicked {
GameViewController *game = [[GameViewController alloc] init];
// we put the game view as the MenuViewController's view
[self setView:game.view];
[game release];
}
Of course, you need to import the "GameViewController.h" to access it.
If you want them in the same window and at the same size, you can put both views into a tabless tab view. Just switch the tab to switch which view is visible.
Another way would be to put them in different windows and use a window controller rather than a view controller for each one. Among other things, this makes it easy to make the game window user-resizable without disturbing the size of the menu window.
Since you want your MenuViewController to be what calls and takes care of GameViewController, I'd suggest something similar to what Rafael said. Try putting an instance of GameViewController in your Interface Builder file, but making it hidden. When they press the "Play" button to activate the game, simply send the GameViewController to the front and make it visible. It's a bit clumsy, but it works. Remember to hide all the buttons and interactions regarding your menu though. You don't want to accidentally activate the high scores list when playing a game!
Also, I'd recommend looking into Utility applications. (They're one of the template types you're given when you create a new project.) They're built to switch between two seperate view controllers, and it might just be what you're looking for.
I'm getting better and better with doing things for the iPhone in xcode, but here I have ran into a dead end.
I'm trying to build an app with two views: the main one and one for settings. I want to be able to switch between the two of them. Since I need every pixel in the main view I have built a switchView class that simply switch between the two views when I press a button (so much smaller than a tabView), which is working fine.
Now I'm a bit deeper in development and want the settings view to be a table view from where I can navigate to the next level of detail. I have done this before, but without the switch view.
My problem is that I get the table view (in settings) to work, but once I try to push my view controller nothing happens. While debugging I can see that it works through the code (eg didSelectRowAtIndexPath is working) but no new view pops up. Neither any error message.
I have the switchView added in my MainWindow.xib and then do a
[window addSubview:switchViewController.view]; in my AppDelegate to load the main view.
Where should I put the root controller for the navigation for the table view? Because I guess that's the problem I have?
Below the code that results in nothing...
ViewsAppDelegate *delegate =[[UIApplication sharedApplication] delegate];
[delegate.settingsNavController pushViewController:settingsDetailViewController animated:YES];
Happy for any suggestions that could lead me to the right track. Spent way too much time to solve this.
I might be misunderstanding what you're after, but let me try...
When you created your project you should have gotten your MainViewController and an AppDelegate both spun up and created for you. From the snippet you've provided it looks to me like your instantiating a new (and possibly second) app delegate from within your MainViewController.
Rather than doing this, I would suggest that you move your NavigationController up one level to the AppDelegate supplied by the SDK. Then in your MainViewController, add the existing AppDelegate as an IBOutlet and tie them all together in IB. Once you've done that, using the navigation controller should go much more smoothly.
For example, my MainWindow.xib has several objects, and I've highlighted the two that I think you're probably concerned with...
http://www.freeimagehosting.net/uploads/f50268da03.png
*Sorry for the link - I can't post images yet.
Then, from my AppDelegate I customize my applicationDidFinishLaunchingWithOptions like so...
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
navController.viewControllers = [NSArray arrayWithObject:mainMenuController];
// Override point for customization after app launch
[window addSubview:navController.view];
[window makeKeyAndVisible];
return YES;
}
That keeps the navController up at the highest level (where I think it belongs) and allows you to push and pop views throughout the entire app while keeping that history of what's on the stack.
Hope that helps - I might have completely misunderstood what you were after.
Good Luck!
Bob
UPDATE: See my answer to this question first. This appears to be a bug. A minimal test case has been created and a report has been filed with Apple. (Fixed as of iPhone OS 3.1.)
Here's a puzzler from the "I'm so close!" department.
I have a Tab Bar-based iPhone app. Each tab features a UINavigationController with the usual suspects (nav bar, table view ... which in turn can lead to another VC, etc.).
Now, one of those lower-level VCs is to be used in portait and landscape modes. But there's a problem. Our landscape-friendly VC's shouldAutorotateToInterfaceOrientation: won't get called out-of-the-box! What to do?
Here's what we do. In my Tab Bar Controller, which I have implemented in its own file, I have this:
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
return [self.selectedViewController shouldAutorotateToInterfaceOrientation:interfaceOrientation];
}
This ends up propagating the request to my landscape-friendly VC, which also responds to this message. All my other VCs don't implement this method, so they simply go with the default portrait orientation.
Problem solved!!! Yay!
Well, not quite. :(
Seems like things don't go so well when my landscape-friendly VC is invoked from within the depths of the tab bar controller's MoreNavigationController.
I decided to compare/contrast between a VC called from within one of the first four tab bar UINavigationControllers ... and that same VC called from within the MoreNavigationController. This is going to be a bit ultra-detailed, so bear with me. Hopefully the play by play proves useful for sleuthing things out.
When the app loads, there are several initial calls to the tab bar controller's shouldAutorotate... method. In these early cases, selectedViewController is nil. However, we eventually finish loading, the initial tab item is selected, and all is well.
Right. First, let's pick one of the first four tab bar items and drill down to our VC.
We'll pick third nav bar item, so that's the third nav controller. We drill down to our VC that supports rotation. A quick inspection confirms that the parent is indeed the third nav controller from our tab bar's view controller list. Good!
Let's rotate the device. The tab bar controller is asked to autorotate (see the above code). We observe that selectedViewController is also that third nav controller, plus the nav controller's top and visible view controllers are both set to our trusty VC that supports rotation.
Thus, the tab bar controller will forward the shouldAutorotate message over to the third nav controller ... but our rotation-friendly VC ultimately gets the message. (I'm not doing anything special here. Maybe the desired VC gets the message because it's the top and/or visible VC?) In any event, we rotate to landscape, things are resized, and all is well. "Great Success!"
Now let's hit that back button and pop the VC stack, leaving landscape mode in the process. The tab bar controller is queried again.
Time for a little aside here. The topViewController for our nav controller is still that rotation-friendly VC, but visibleViewController is now set to UISnapshotModalViewController! Heh. Never saw this one before ... but Erica Sadun has. Looks like it's for "disappearing view controllers" (which in this case is certainly true - it's disappearing alright).
As I keep stepping through, the visible VC stays as Snapshot, but the top VC eventually changes to the next VC on the stack, since my special VC is eventually gone. Fair enough.
So that's the scenario where everything works well.
Now let's try the same test, only this time we're going to go to the MoreNavigationController (the More tab bar item) and drill down to the same VC class as before. In my case it happens to be the 7th one in the tab bar controller's VC list.
We enter the rotation-aware VC and ... this time it gets asked to rotate directly! The Tab Bar Controller is not asked for permission to rotate at all. Hmm.
A quick check of the parent VC shows it is a MoreNavigationController. OK, that makes sense.
Now let's try to rotate the device. NOTHING GETS CALLED. None of our breakpoints get hit. Not in our VC. Not in our tab bar controller. (Huh?!?!)
O-kaaaay. Let's pop the stack, go back into the same VC and try to rotate again. Weird. NOW we get a call in the Tab Bar Controller asking for autorotation permission. Here, the selected Controller is our trusty Nav controller (#7), but this time its visibleViewController and topViewController are SET TO NIL!
Once we continue from here, a mysterious message appears in the debugger console:
Using two-stage rotation animation. To
use the smoother single-stage
animation, this application must
remove two-stage method
implementations.
Mysterious because I'm not using two-stage rotation animation! No SecondHalf method variants are in play anywhere in my source code.
Alas, my rotation-aware VC is never told that rotation is occurring (even though rotation does occur on-screen), so of course my view is all fouled up as a result. Mayhem and sadness ensue. :(
We won't even bother popping the stack at this point.
I think the View Controller doc hints at the possible problem:
If you want to perform custom
animations during an orientation
change, you can do so in one of two
ways. Orientation changes used to
occur in two steps, with notifications
occurring at the beginning, middle,
and end points of the rotation.
However, in iPhone OS 3.0, support was
added for performing orientation
changes in one step. Using a one-step
orientation change tends to be faster
than the older two-step process and is
generally recommended for any new
code.
I wonder if MoreNavigationController is still responding to the two-step process, and is thus tripping up any attempts to use the one-step process? Note that, if you respond to the two-step messages, the one-step variant will not work (again, per the docs). I'm not responding to them, but I have a sneaking suspicion something behind-the-scenes IS.
In fact, if I comment out the single-step method, and try to respond to willAnimateSecondHalfOfRotationFromInterfaceOrientation:duration:, I do get the memo! But it still doesn't pop off the stack very cleanly (in terms of visuals). Even stranger: willAnimateFirstHalfOfRotationFromInterfaceOrientation:duration: is NOT called, even when I tried to sneak a call to self (using the FirstHalf message) in shouldAutorotateToInterfaceOrientation:. It returns immediately during a trace, as if I never even defined it. Sigh.
So that's the play-by-play.
In summary, has anyone successfully handled one-step device rotation for a VC invoked from within a Tab Bar Controller's MoreNavigationController? Inquiring minds want to know!
Apple advises against subclassing UITabBarController, so I found an easy way to handle autorotation using categories instead. It doesn't fix your bug with the More... view controllers, but I think it's a more Apple-friendly way of getting the job done (and means less subclassing for you).
To make every tab in my application autorotate properly, I've defined -shouldAutorotateToInterfaceOrientation: in my custom view controllers, but they are all inside UINavigationControllers within a UITabBarController, so the message won't get sent down the chain to my VC until those two also respond. So I added the following lines to my app delegate files:
Added to the bottom of MyAppDelegate.h
#interface UITabBarController (MyApp)
#end
#interface UINavigationController (MyApp)
#end
Added to the bottom of MyAppDelegate.m
#implementation UITabBarController (MyApp)
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation {
return YES;
}
#end
#implementation UINavigationController (MyApp)
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation {
return YES;
}
#end
It appears we have a bug. I have created a reproducible, minimal test case, and reported it via Apple Bug Reporter (RADAR Problem 7139857).
Update: This has been fixed as of iPhone OS 3.1.
The essential problem is:
View controllers already on a
Navigation Controller stack do not
receive
willAnimateRotationToInterfaceOrientation:duration:
messages when a Tab Bar Controller's
'More Navigation Controller' is in
use.
This problem does not occur when the tab bar item view controllers are basic view controllers. Only when they are navigation controllers and only when the "More" navigation hierarchy is in use.
The console message (regarding two-stage rotation animation) suggests that something within the framework (the More Navigation Controller?) is still using a two-stage animation, even though single stage is now recommended as of iPhone OS 3.0.
That could explain why willAnimateRotationToInterfaceOrientation: is not called in that particular case. Per Apple's view controler documentation, this message will NOT be invoked when two-stage, first/second-half orientation messages are being responded to instead.
A slightly modified version of Victorb's answer which allows every single view controller to decide if it allows rotation.
Here as a gist for easier copying & forking
AppDelegate.h
#interface UITabBarController (MyApp)
#end
#interface UINavigationController (MyApp)
#end
AppDelegate.m
#implementation UITabBarController (MyApp)
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation {
UIViewController *selectedVC = [self selectedViewController];
if ([selectedVC respondsToSelector:#selector(shouldAutorotateToInterfaceOrientation:)]) {
return [selectedVC shouldAutorotateToInterfaceOrientation:toInterfaceOrientation];
}
//optimistic return - if you want no rotation, you have to specifically tell me!
return YES;
}
#end
#implementation UINavigationController (MyApp)
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation {
UIViewController *visibleVC = [self visibleViewController];
if ([visibleVC respondsToSelector:#selector(shouldAutorotateToInterfaceOrientation:)]) {
return [visibleVC shouldAutorotateToInterfaceOrientation:toInterfaceOrientation];
}
//optimistic return - if you want no rotation, you have to specifically tell me!
return YES;
}
#end