I have a viewController, lets say blaVC, which calls another view controller blubbVC through a button press. As there are 4 buttons, all calling blubbVC with the same nib, but the content should vary according to which button was pressed in blaVC (content will be loaded from a plist), I'd need blubbVC to know "I've been called, because button A was pressed, so I'll load from the plist with objectForKey:#"button A"" (so to speak..).
I call blubbVC like that
- (IBAction) buttonA:(id)sender {
blubbVC *detailView = [[blubbVC alloc] initWithNibName:#"blubbNib" bundle:nil];
[self.navigationController pushViewController:detailView animated:YES];
[detailView release];
}
I tried to pass sender, but as I load the content in initWithNibName, sender comes to late, the content was already loaded (or tried to) and my view stays empty. How would I do that?
Thank you!
You should define a function that says takes the sender (or some value representing which button was pressed) that sets up all the state, after it's been initialized.
For example:
[detailView setupContent:(id)sender];
When you init the view controller, it's not yet displayed. Before you call pushViewController, call the new function, so you'd have:
- (IBAction) buttonA:(id)sender {
blubbVC *detailView = [[blubbVC alloc] initWithNibName:#"blubbNib" bundle:nil];
[detailView setupContent:sender];
[self.navigationController pushViewController:detailView animated:YES];
[detailView release];
}
If it's true that this is too late (you need the data in 'initWithNibName'), then either define your own -[initWithNibName: andSender:] or something similar, and calls [super initWithNibName:] before setting up the rest of the state.
You need to create a custom init method in your view controller. Something like:
+(id)initWithCaller:(NSString*)caller
{
if(self == [super initWithNibName:#"blubbNib" bundle:nil])
{
calledFrom = x;
}
return self;
}
That was just typing from memory so there may be some errors. You'd then use that new init method in your IBActions
Related
I'm trying to move an NSString between two View Controllers and after searching around all convoluted ways, the easiest and most straight-forward way I want to get used to was to write an initWithName function in the Receiving VC and calling it in the Sending VC. It does move it successfully but I want it to get executed before ViewDidLoad loads the textViewer so that it shows right after the tab button is pressed. Here's the code from the sending VC:
- (void)textViewDidEndEditing:(UITextView *)textView
{
if ([textView.text isEqualToString: #""]) {
textView.text = #"*Paste the machine code in question here*";
}
SecondViewController *theVCMover = [[SecondViewController alloc] initWithName: textView.text];
[self.navigationController pushViewController:theVCMover animated:YES]; //Is this really necessary if I'm not going to segue it directly, I'm just waiting for the user to press the next tab
gotItLabel.text = #"Got it! Ready for action...";
}
And here's the code on the receiving VC:
- (id)initWithName:(NSString *)theVCMovee {
self = [super initWithNibName:#"SecondViewController" bundle:nil];
if (self) {
rawUserInput = theVCMovee;
CleanerText.text = rawUserInput;
}
return self;
}
- (void)viewDidLoad {
[super viewDidLoad];
CleanerText.text = rawUserInput;
NSLog(#"Got the other tab's text and it's %# ", rawUserInput);
}
Your code is mostly fine, but you'll find that as you have more complex view controllers that you won't necessarily want to write custom initializers to do every bit of property setting. Note that if CleanerText is a UI element that you're loading from your nib, it doesn't help to set CleanerText.text in your init method—it's not loaded until -viewDidLoad is called.
You don't have to do everything in init, though, if you declare properties for rawUserInput or other variables you want to set. You can then just go:
SecondViewController *theVCMover = [[SecondViewController alloc] initWithNibName:#"SecondViewController" bundle:nil];
theVCMover.rawUserInput = textView.text;
theVCMover.otherProperty = otherValue;
....
And the rest of your code works the same.
You can't (reliably) call methods on an instance until init has finished executing, so this pattern is "safe" and is how it's supposed to work.
I'm searching a way to be able to display one modal view controller after another one, and make the second appear while the first is disapearing.
The problem is that the dismiss call that is done inside the first modalviewcontroller applies to both and SecondController is never shown.
Putting the first dismiss before or after the parent call does not change anything.
If first dismiss is set wih animate= NO, everything works fine. But I need the animation.
I planned to do that this way, but the problem is that the dismiss call that is done inside the first modalviewcontroller applies to both and SecondController is never shown.
I don't understand why because each modal view has its own navigationcontrollers, so they shouldn't collide.
I tried another way by showing the second modal view with a NSTimer after 0.5 sec, but it's not satisfying : the second appears when the first has completely disapeared. Not smooth at all... If I set the delay less than 0.5 sec, the second modal view never shows up. And using such a timer to make this does not seem to be a good way of coding.
Main.m
- (void) entry {
FirstController *nextWindow = [[FirstController alloc] initWithNibName:#"theNIB" bundle:nil];
nextWindow.caller = self;
UINavigationController* navController = [[UINavigationController alloc] initWithRootViewController:nextWindow];
[self.navigationController presentModalViewController:navController animated:YES];
[nextWindow release];
[navController release];
}
- (void) thingsDoneInFirstModalController:(OBJECT)returnValue retval2:(OBJECT2)returnValue2 {
[self display2ndController];
}
- (void) display2ndController {
SecondController *nextWindow;
nextWindow = [[SecondController alloc] initWithNibName:#"NIB2" bundle:nil];
UINavigationController* navController = [[UINavigationController alloc] initWithRootViewController:nextWindow];
[self.navigationController presentModalViewController:navController animated:YES];
[navController release];
[nextWindow release];
}
1st ModalViewController.m
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[self.navigationController dismissModalViewControllerAnimated:YES];
[self.caller thingsDoneInFirstModalController:theResult retval2:someMoreResult];
}
Do you know a way to make this possible (make the second view appears while the first one is disappearing), with some code for example ?
Thank you.
Try creating some dummy ViewController, and present your second one using it.
I have a button inside the content of a UIPopoverController. This button runs a method called myAction.
MyAction has the form
- (void) myAction:(id)sender
so, myAction receives the id of the caller button.
Now, inside this method I would like to dismiss the UIPopoverController, but the only thing I have is the ID of the caller button. Remember that the button is inside the UIPopoverController.
Is there a way to discover the ID of the UIPopoverController, given the button ID I already have?
thanks.
Unfortunately no. At least, not within the standard practices. You might be able to travel up the responder stack to find it, but it's a hack, it's buggy, and it's really, really messy.
If you want to dismiss a popover by pushing a button, some place relevant should keep a reference to the popover. Usually that would be the owner of the popover (not the controller showed within the popover). When the button is pressed, it can send a message to the owner controller, which can then dismiss the popover.
You might be tempted to have the controller displayed inside of the popover be the owner of its own popover, but coding this way is brittle, can get messy (again), and may result in retain loops so that neither ever gets released.
You can access the presenting popoverController by accessing "popoverController" with KVC.
[[self valueForKey:#"popoverController"] dismissPopoverAnimated:YES]
I have this working, and I do not think it is a hack. I have a standard split view iPad app. I then added a method on my detail controller (the owner of the pop over) to handle the dismissal.
On the standard split view architechture, both the root and detail view controllers are available via the app delegate. So I bound a button click inside the pop over to call a method which gets the app delegate. From there I call the method on the detail controller to dismiss the pop over.
This is the code for the method on the View Controller that is displayed inside the popover:
- (void) exitView: (id)sender {
MyAppDelegate *appDelegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];
[appDelegate.detailViewController exitDrill];
}
Then the simple method to dismiss on the Detail View Controller:
- (void) exitDrill {
if(dtController != nil){
[dtController dismissPopoverAnimated: YES];
[dtController release];
}
}
I like the ability to do this because it give me a way to show a user how they can exit a pop over. This may not be necessary in future versions of the app; for right now, while this paradigm is still new to the platform, I prefer to let the users gexit a display in a couple fo different ways to make sure I minimize frustration.
As Ed Marty already wrote
If you want to dismiss a popover by pushing a button, some place relevant should keep a reference to the popover
This is very true; however, when showing a UIPopoverController, the class opening the popovercontroller keeps this resource already. So, what you could do is to use this class as the delegate class for your Popover Controller.
To do so, you could do the following, which I use in my code.
In the class opening the popover, this is my code:
- (void)showInformationForView:(Booking*)booking frame:(CGRect)rect
{
BookingDetailsViewController *bookingView = [[BookingDetailsViewController alloc] initWithStyle:UITableViewStyleGrouped booking:booking];
[bookingView setDelegate:self];
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:bookingView];
self.popController = [[UIPopoverController alloc] initWithContentViewController:navController];
[self.popController setDelegate:self];
[self.popController setPopoverContentSize:CGSizeMake(320, 320)];
rect.size.width = 0;
[self.popController presentPopoverFromRect:rect inView:self.view permittedArrowDirections:UIPopoverArrowDirectionLeft animated:YES];
}
- (void)dismissPopoverAnimated:(BOOL)animated
{
[self.popController dismissPopoverAnimated:animated];
}
So what I am doing here is creating a UINavigationController and setting a BookingDetailsViewController as its rootViewController. Then I am also adding the current class as delegate to this BookingDetailsViewController.
The second thing I added is a dismissal method called dismissPopoverAnimated:animated.
In my BookingDetailsViewController.h I added the following code:
[...]
#property (nonatomic, strong) id delegate;
[...]
And in my BookingDetailsViewController.m I added this code:
[...]
#synthesize delegate = _delegate;
- (void)viewDidLoad
{
UIBarButtonItem *closeButton = [[UIBarButtonItem alloc] initWithTitle:#"Close" style:UIBarButtonItemStylePlain target:self action:#selector(closeView)];
[self.navigationItem setRightBarButtonItem:closeButton];
[super viewDidLoad];
}
- (void)closeView
{
if ([self.delegate respondsToSelector:#selector(dismissPopoverAnimated:)]) {
[self.delegate dismissPopoverAnimated:YES];
}
else {
NSLog(#"Cannot close the view, nu such dismiss method");
}
}
[...]
What happens is that when the "Close" button in the UINavigationController is pressed, the method closeView is called. This method check if the delegate responds to dismissPopoverAnimated:animated and if so, it calls it. If it does not respond to this method it will show a log message and do nothing more (so it wont crash).
I have written my code using ARC, hence there is no memory management.
I hope this helped you.
I am a newbie iPhone Programmer and have a question regarding how to access methods of a Parent View Controller.
In my program when the program first loads (applicationDidFinishLaunching) I do the following code:
[window addSubview:rootViewController.view];
[window makeKeyAndVisible];
which basically calls this
- (void)viewDidLoad {
HomeViewController *homeController=[[HomeViewController alloc] initWithNibName:#"HomeView" bundle:nil];
self.homeViewController=homeController;
[self.view insertSubview:homeController.view atIndex:0];
[homeController release];
[super viewDidLoad];
}
Now, I have an IBAction call on HomeViewController that I want to have it call a method in root View Controller
I want to call this method
- (void)loadNewGame
{
self.questionViewController = [[QuestionViewController alloc] initWithNibName:#"QuestionView" bundle:nil];
//[homeViewController.view removeFromSuperview];
[self.view insertSubview:questionViewController.view atIndex:0];
}
So my question is how do I call a method from the Parent View controller?
I've tried
[self.view removeFromSuperview];
[self.parentViewController loadNewGame];
but that doesn't seem to work. Could someone please ploint me in the right direction.
Thanks in advance
Scott
First off, typically you call [super viewDidLoad] first in your viewDidLoad.
You will have to have an instance variable in your homeController class for your rootViewController. Then you could have a method in homeController:
- (void) loadNewGame
{
[self.rootViewController loadNewGame];
}
This is one of many different ways to accomplish this. You may want to move the method to homeController completely. Or you may wish to have IB use the rootViewControllers' methods directly...
Here is another discussion of this.
First off your code doesn't really make sense. Why are you adding your HomeViewController in a -viewDidLoad call. If you want to load the HomeViewController as the initial view, you should set that in Interface Builder instead of RootViewController. When you want to display a new view controller, you should be using a navigation controller stack and pushing the new view controller onto it with [[self navigationController] pushViewController:newViewController animated:YES].
Assuming you get that sorted, you should create a delegate (id) field for your child view controller that you can set when you instantiate the new view controller. So your code might look something like this:
HomeViewController *homeController=[[HomeViewController alloc]
initWithNibName:#"HomeView" bundle:nil];
[homeController setDelegate:self];
[[self navigationController] pushViewController:homeController animated:YES];
[homeController release];
Then, when your action gets fired in the HomeViewController, you can check to see if the delegate is set and if so, call the selector in question, like this:
- (IBAction)action:(id)sender;
{
if (delegate && [delegate respondsToSelector:#selector(loadNewGame)])
[delegate performSelector:#selector(loadNewGame)];
}
You might want to read Apple's docs on how to use the navigation controller stack. This might help clarify some things.
I'd like to use a modal UITableView at startup to ask users for password, etc. if they are not already configured. However, the command to call the uitableview doesn't seem to work inside viewDidLoad.
startup code:
- (void)viewDidLoad {
rootViewController = [[SettingsController alloc]
initWithStyle:UITableViewStyleGrouped];
navigationController = [[UINavigationController alloc]
initWithRootViewController:rootViewController];
// place where code doesn't work
//[self presentModalViewController:navigationController animated:YES];
}
However, the same code works fine when called later by a button:
- (IBAction)settingsPressed:(id)sender{
[self presentModalViewController:navigationController animated:YES];
}
Related question: how do I sense (at the upper level) when the UITableView has used the command to quit?
[self.parentViewController dismissModalViewControllerAnimated:YES];
You can place the presentModalViewController:animated: call elsewhere in code - it should work in the viewWillAppear method of the view controller, or in the applicationDidFinishLaunching method in the app delegate (this is where I place my on-launch modal controllers).
As for knowing when the view controller disappears, you can define a method on the parent view controller and override the implementation of dismissModalViewControllerAnimated on the child controller to call the method. Something like this:
// Parent view controller, of class ParentController
- (void)modalViewControllerWasDismissed {
NSLog(#"dismissed!");
}
// Modal (child) view controller
- (void)dismissModalViewControllerAnimated:(BOOL)animated {
ParentController *parent = (ParentController *)(self.parentViewController);
[parent modalViewControllerWasDismissed];
[super dismissModalViewControllerAnimated:animated];
}
I had quite the same problem. I know the topic is old but maybe my solution could help someone else...
You just have to move your modal definition in a method:
// ModalViewController initialization
- (void) presentStartUpModal
{
ModalStartupViewController *startUpModal = [[ModalStartupViewController alloc] initWithNibName:#"StartUpModalView" bundle:nil];
startUpModal.delegate = self;
[self presentModalViewController:startUpModal animated:YES];
[startUpModal release];
}
Next, in viewDidLoad, call your modal definition method in a performSelector:withObject:afterDelay: with 0 as delay value. Like this:
- (void)viewDidLoad
{
[super viewDidLoad];
//[self presentStartUpModal]; // <== This line don't seems to work but the next one is fine.
[self performSelector:#selector(presentStartUpModal) withObject:nil afterDelay:0.0];
}
I still don't understand why the 'standard' way doesn't work.
If you are going to do it like that then you are going to have to declare your own protocol to be able to tell when the UITableView dismissed the parentViewController, so you declare a protocol that has a method like
-(void)MyTableViewDidDismiss
then in your parent class you can implement this protocol and after you dismissModalView in tableView you can call MyTableViewDidDismiss on the delegate (whihc is the parent view controller).