Superview is Nil after Second Launch of View Controller - objective-c

I've spent hours and I cant figure this out. I have a detail view controller (UITableView) which is launched here:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
EventLocationDetailController *newDetailViewController = [[EventLocationDetailController alloc] initWithNibName:#"EventLocationDetailController" bundle:nil];
self.eventDetailController = newDetailViewController;
[self.navigationController pushViewController:self.eventDetailController animated:YES];
[newDetailViewController release];
}
In the detail view controller there is a button method which calls the below method to display a slide-in-slide-out animation confirming the users choice:
-(void)confirmLastActionWithMessage:(NSString *)message {
ConfirmActionViewController *newConfirmActionViewController = [[ConfirmActionViewController alloc] initWithNibName:#"ConfirmActionViewController" bundle:nil];
self.confirmActionViewController = newConfirmActionViewController;
[newConfirmActionViewController release];
[[self.view superview] addSubview:self.confirmActionViewController.view];
}
Protocol method called by the ConfirmActionViewController indicating that the animation is finished.
-(void)didFinishConfirmDisplay:(UIView *)viewToRemoveFromSuperview {
[viewToRemoveFromSuperview removeFromSuperview];
}
This works perfect the first time I press the button. If I pop the detail controller and push it back on to the stack and press the button again, nothing happens and the detail controller's superview is nil every time I invoke the method after that. Superview is not nil in the viewWillAppear method for the detail view, only when It gets to the confirmLastActionWithMessage method. No other user interaction happens in between. How do I get the superview back? I have a similar code that works without animation.
I've also noticed that the detail view controller hasn't called dealloc when popped off the stack. Not sure where the problem is.
Thanks.
EDIT 1
OK. I replaced the addSubview line with this one:
[self.view insertSubview:self.confirmActionViewController.view atIndex:0];
and the animation view appeared underneath one of the table cells. Could one of the table cells steal the superview?

Well I don't really understand why you should add the subview to the superview. Why not add it just to self.view
I may not be able to explain why there is no superview but try either adding the controller view to self.view or
[[[[UIApplication sharedApplication] delegate] window] addSubview:yourview];
This will render the view on top of everything.

Related

iOS7 - popToRootViewControllerAnimated not doing anything

I have looked around but haven't found a satisfying answer. My problem is that whenever I call popToRootViewControllerAnimated:(BOOL) it is not doing anything. When I NSLog it, it logs (null).
Let me back up a bit here. I have a table view controller that has a list of things, at the navigation bar up top there is an option to add and that takes me to a new view controller with a segue "Present as PopOver" which gets rid of the principal or main navigation bar. So I made one manually and added 2 bar button items "Cancel" and "Add". When "Cancel" is tapped, it should take the user back to the table view controller and discard changes, when "Add" button is tapped, it should also take user back to the previous table view controller with the changes. But it's not doing anything.
Here is my code.
- (IBAction)cancelButton:(UIBarButtonItem *)sender {
UINavigationController * navigationController = self.navigationController;
NSLog(#"%#", navigationController);
NSLog(#"cancel tapped though");
ListingTableViewController *rootController = [[ListingTableViewController alloc] init];
[navigationController popToRootViewControllerAnimated:NO];
[navigationController pushViewController:rootController animated:YES];
}
As far as the segue, this view controller is not connected to anything, or should I connect it? This is a noobish question indeed. Here is my xcode screenshot.
Check this link for the screenshot of the storyboard
http://i.stack.imgur.com/lqnCF.png
You must call
- (IBAction)cancelButton:(UIBarButtonItem *)sender {
NSLog(#"cancel tapped though");
[self dismissViewControllerAnimated:YES completion:nil];
}
instead of popToRootViewControllerAnimated because your VC presented and not pushed!
When presenting a view, you are not pushing it in your navigation controller, but having it presented. To dismiss it, try using [self.presentingViewController dismissViewControllerAnimated:NO completion:nil].

Calling reloadData on same UITableView, but it seems like it's calling on a different one

This has been a headache for few hours now and I finally found out what is actually happening, but I don't know how to solve this issue.
I've got List.h with UITableView properly connected from storyboard:
#property (strong, nonatomic) IBOutlet UITableView *tableView;
Then there's List.m where I set delegates and datasource for my UITableView:
// Set tableview datasource and register class for cell reuse
self.tableView.dataSource = self;
[self.tableView registerClass:[TableViewCell class] forCellReuseIdentifier:#"cell"];
// Set tableview delegate
self.tableView.delegate = self;
// Set tableview cells style
self.tableView.separatorStyle = UITableViewCellSeparatorStyleNone;
self.tableView.backgroundColor = [UIColor colorWithWhite:0.1f alpha:1.0f];
// Set tableview frame
self.tableView.frame = CGRectMake(0.0, 35.0, self.tableView.frame.size.width, self.tableView.frame.size.height-35.0);
Then on NSNotification I'm trying to [self.tableView reloadData]:
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(doUpdateAppBefore:) name:UIApplicationWillEnterForegroundNotification object:nil];
Also I'm reloading data of tableView on every UIApplicationBecomeActive notification.
Before I close my app and open it up from background to find out if it's reloads the data, I'm moving to another UIViewController and going back, which causes that somehow identifier of my self.tableView changes. I'm checking it in:
NSLog(#"Calling reloadData on : %#");
and at the beginning it gives me:
Calling reloadData on <UITableView: 0x9b09400;....
but after I segue back from another UIViewController it gives me:
Calling reloadData on <UITableView: 0x9b4b000;
which causes that it doesn't actually reload the data after I open up the app from the background state.
I've been thinking... when I segue back from another viewcontroller, viewDidLoad fires again, is it possible that it somehow sets tableView.delegate again and changes something? Just thinking...
Thank you very much for your answers.
It sounds like you have a view controller, push a modal view on top of it, and then want to go back to the original view controller when you're done. So, you set up a modal segue in your storyboard, and then a second modal segue to go back. The problem is that your second modal segue doesn't return to the original view controller, but it creates a new instance of that view controller, and now your have the original view controller, the second view controller, and an unwanted third view controller. Instead of creating a segue, which creates the third view controller, you need to dismiss the second view controller, which then gets you back to your original view controller, and therefore also your original table view. So what you want to do is get rid of the second segue and replace it with an IBAction, put something like
- (IBAction)goBack:(id)sender;
in your .h file. Connect that to your button or whatever you're using to trigger the segue now. Then, in your implementation file, dismiss the modal view like so:
- (IBAction)goBack:(id)sender
{
[self dismissViewControllerAnimated:YES completion:nil];
}
That should get you what you want.
Alternately, and this is probably better, you can use an unwind segue as well. Go to List.h, and create this method:
- (IBAction)unwind:(UIStoryboardSegue *)segue;
Then just implement it, you can leave it blank for now. Then, drag from the button that currently triggers the segue to Exit, and select the Action Segue unwind. That will also get you back.

Navigating back to main ViewController dismissViewControllerAnimated dilemma

I have 2 ViewControllers directly connected with a push segue. I am navigating from first to second view controller by calling [self performSegueWithIdentifier:#"segueIdentifier" sender:sender]. On the second one I have an IBAction method that is bound to a "Done" button. Pressing that button should basically cause the first view controller to be displayed (sort of a back button). I managed to do that with:
NSArray *viewControllers = self.navigationController.viewControllers;
[self.navigationController popToViewController:[viewControllers
objectAtIndex:0] animated:YES];
I did try to achieve the same effect by using:
[self dismissViewControllerAnimated:YES completion:nil];
No matter what I tried though this didn't do the job. I am trying to understand what exactly am I missing but I can't figure it out. Does dismissViewControllerAnimated method work only with Modal segues ( this is the only thing that came to mind ).
Thank you
Yes,
- (void)dismissViewControllerAnimated:(BOOL)flag completion:(void (^)(void))completion
is when a UIViewController is displayed modally.
- (UIViewController *)popViewControllerAnimated:(BOOL)animated
should do what you are seeking.
So basically, in your second VC:
[self.navigationController popViewControllerAnimated:YES];
You will save you a lot of trouble if you read the UIViewController and UINavigationController references. Twice ;)

popToRootViewControllerAnimated does not display root view controller

I need a little help on a problem with navigation controllers.
I have a navigationController with 4 ViewControllers pushed. The last vc I push presents a further ViewController modally. The modal ViewController presents an ActionSheet. Depending on the user's answer I either dismiss the modal ViewController only or I want to go back to the root ViewController.
In the ViewController presented modally I have:
- (void) dismissGameReport
{
[[self delegate] GameReportModalWillBeDismissed:modalToPopToRoot];
}
In the last ViewController pushed onto the navigationController stack I have:
- (void)GameReportModalWillBeDismissed: (BOOL)popToRoot;
{
if (popToRoot)
{
[self.navigationController popToRootViewControllerAnimated:NO];
}
else
{
[self dismissModalViewControllerAnimated:YES];
}
}
Dismissing the modal view controller works fine.
However,
[self.navigationController popToRootViewControllerAnimated:NO];
does not cause the root ViewController to display its views. Adding some log info I see that after the message to self.navigationController the stack is correctly popped but execution continues sequentially. The screen still shows the view of the modal ViewController.
As a workaround I tried always dismissing the modal view controller and in the ViewWillAppear method have the popToRootAnimated message. No difference. Still the stack of controllers is popped but the screen continues showing my modal view controller's view and execution continues sequentially.
Could someone help me please?
I like these deceptive questions. It seems very simple, until you try to do it.
What I found was that basically you do need to dismiss that modal view controller, but if you try to pop from the navigation controller on the next line things get mixed up. You must ensure the dismiss is complete before attempting the pop. In iOS 5 you can use dismissViewControllerAnimated:completion: like so.
-(void)GameReportModalWillBeDismissed:(BOOL)popToRoot{
if (popToRoot){
[self dismissViewControllerAnimated:YES completion:^{
[self.navigationController popToRootViewControllerAnimated:YES];
}];
}
else{
[self dismissModalViewControllerAnimated:YES];
}
}
But I see you have 4.0 in your question tags. The solution I found for <iOS 5 is far less pretty but should still work, and it sounds like you were already on the trail. You want viewDidAppear: not viewWillAppear:. My solution here involves an ivar, lets say:
BOOL shouldPopToRootOnAppear;
And then your GameReportModalWillBeDismissed: would look something like this:
-(void)GameReportModalWillBeDismissed:(BOOL)popToRoot{
shouldPopToRootOnAppear = popToRoot;
[self dismissModalViewControllerAnimated:YES];
}
And your viewDidAppear: would look like this...
-(void)viewDidAppear:(BOOL)animated{
[super viewDidAppear:animated];
if (shouldPopToRootOnAppear){
[self.navigationController popToRootViewControllerAnimated:YES];
return;
}
// Normal viewDidAppear: stuff here
}

UIViewController to know if it got pushed or popped?

I have a main UITableView, when cell is pressed it goes to another UITableView and when a cell is pressed there it goes to a DetailView of that cell.
I want the middle UITableView to behave differently depending on if the detailView got popped or the UITableView itself got pushed. If the view got pushed on from the main table I want to scroll to the top, if it is shown after a DetailView got popped I want it to stay at the same position.
Any suggestions?
you could call a scrollToTop method on the DetailViewController after you have pushed it to the navigationController.
Something like that:
if (!detailViewController) {
detailViewController = [[DetailViewController alloc] initWithNibName:nil bundle:nil];
}
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController scrollToTop];
// or use the tableView directly:
// [detailViewController.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0] atScrollPosition:UITableViewScrollPositionTop animated:YES];
In your Middle View Controller, examine which view is next-to-display directly from the UINavigationController stack:
- (void)viewWillDisappear:(BOOL)animated
{
if ([self.navigationController.topViewController isEqual:(UITableViewController *)tvcDetailView]) {
// Detail view has been pushed onto the UINavigationController stack
}
else {
// Middle view has been popped from the UINavigationController stack
}
}
Create a BOOL #property on your middle UIViewController property called wasPushed or something similar, and when you initialise it from UIViewController 1, set the property on the new instance, push it onto the nav stack and you can then use your property in your middle view controller's loadView, viewDidLoad, viewWill/DidAppear methods.
As soon as you've used it, set it back to FALSE or NO (or whatever) and when you end up coming back to it due to popping off your 3rd view controller you'll have it as FALSE/NO in your loadView, viewDidLoad etc.. methods.