Okay so I feel like there's something obvious I'm missing in this question. I've used makeFirstResponder throughout my code to move from textField 1 to 2, 2 to 3, etc. That seems to work as I want it to, yet when the new view is loaded, I want the cursor to be in textField1, and yet the following code does not place the cursor in textField1 upon load.
- (void) awakeFromNib{
[[[self view] window] makeFirstResponder:textField1];
}
I also tried setInitialFirstResponder, and that didn't have any effect either (I don't even think that would be right.) So, is it because it is in the awakeFromNib method? Can anyone tell me what I'm missing? Thanks in advance.
EDIT - My solution was differed slightly from the accepted answer so I thought I'd post my implementation. Because the view I wanted to set the first responder for was a subview added later (think the second screen of an application wizard), I simply added a setCursorToFirstTextField method:
- (void) setCursorToFirstTextField {
[[[self view] window] makeFirstResponder:textField1];
}
And made sure to call it after I had added the subview to the custom view on the original window.
Yes, you're right about the problem being the location of the method in awakeFromNib. If you log [self.view window] in your awakeFromNib, you'll see that it's NULL. I don't know how exactly you have things set up, but I'm guessing (if this relates to your WizardController question) that you're doing an alloc initWithNibName:bundle: in another class to create your view controller and then adding that controller's view to the view hierarchy. If you throw some logs in there, it will show you that awakeFromNib in the controller class is called after the alloc init, but before the view is added as a subview, so there is no window at that time. The way I got around this problem was to create a setup method in the view controller class (with the makeFirstResponder code in it), and call it from the class where you create the controller after you add it as a subview.
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
self.wizard = [[WizardController alloc] initWithNibName:#"WizardController" bundle:nil];
[self.window.contentView addSubview:wizard.view];
[self.wizard doSetup];
}
Related
I perform a segue which is defined in the Storyboard to open a new view controller. I need to configure the destination view controller of the segue in a special state where some of it's buttons does not needed to be displayed.
I know that I can do this by setting a variable on this controller in my source view controller's -prepareForSegue:sender:. The problem with this is, that firstly it instantiates the controller, so it's -viewDidLoad: will run, then only after can I set anything on it.
I can't create the controller entirely from code, because it's user interface is in Storyboard. -instantiateViewControllerWithIdentifier: also calls -viewDidLoad first obviously.
I could probably use a semaphore and add the initialization code into my destination controller's -viewWillAppear, but that's ugly, it has to be some more elegant way to do this than doing a check every time the view appears. (My settings need to be done only once.)
Is there some way to pass variables into the controller before it's -viewDidLoad runs?
EDIT: It looks like this happens only if I trigger the segue from code using -performSegueWithIdentifier:.
On my machine and on iOS 8.0 and iOS 9.0, viewDidLoad is called after prepareForSegue. So, something like the following worked for my test case of your answer.
In your source controller:
- (void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
TimViewController * controller = segue.destinationViewController;
if( [controller isKindOfClass:[TimViewController class]] )
controller.name = #"tim";
}
In your destination controller (TimViewController):
- (void)viewDidLoad
{
[super viewDidLoad];
// Do view setup here.
NSLog( #"view did load %#", self.name );
}
Add a segue (a show segue) from your source control to the destination view controller.
Output:
2015-09-17 19:09:04.351 Test[51471:7984717] view did load tim
I think there is some confusion here. -prepareForSegue:sender: gets called before -viewDidLoad gets called. Please double check your implementation.
Edit:
May be this thread will help you understand this and one of the mentioned cases fall in your case.
I am developing an app that is a single NSWindow and clicking a button inside the window will present a NSViewController, and a button exists in that controller that will present a different NSViewController. I know how to swap out views in the window, but I ran into an issue trying to do this with the multiple view controllers. I have resolved the issue, but I don't believe I am accomplishing this behavior in an appropriate way.
I originally defined a method in the AppDelegate:
- (void)displayViewcontroller:(NSViewController *)viewController {
BOOL ended = [self.window makeFirstResponder:self.window];
if (!ended) {
NSBeep();
return;
}
[self.box setContentView:viewController.view];
}
I set up a target/action for an NSButton to the AppDelegate, and here's where I call that method to show a new view controller:
- (IBAction)didTapContinue:(NSButton *)sender {
NewViewController *newVC = [[NewViewController alloc] init];
[self displayViewcontroller:newVC];
}
This does work - it presents the new view controller's view. However if I then click any button in that view that has a target/action set up that resides within its view controller class, the app instantly crashes.
To resolve this issue, I have to change didTapContinue: to the following:
- (IBAction)didTapContinue:(NSButton *)sender {
NewViewController *newVC = [[NewViewController alloc] init];
[self.viewControllers addObject:newVC];
[self displayViewcontroller:[self.viewControllers lastObject]];
}
First of all, can you explain why that resolves the issue? Seems to be related to the way the controller is "held onto" in memory but I'm not positive.
My question is, how do I set this up so that I can swap out views from within any view controller? I was planning on getting a reference to the AppDelegate and calling displayViewcontroller: with a new controller I just instantiated in that class, but this causes the crash. I need to first store it in the array then send that reference into the method. Is that a valid approach - make the viewControllers array public then call that method with the lastObject, or how should this be set up?
What is interesting in your code is that you alloc/init a new view controller every time that you call the IBAction. It can be that your view its totally new every time you call the IBAction method, but I would think that you only have a limited number of views you want to show. As far as my knowledge goes this makes your view only to live as long as your IBAction method is long. That the view still exists, is because you haven't refreshed it. However, calling a method inside a view controller that is not in the heap anymore (since you left the IBAction method and all local objects, such as your view controller are taken of the heap thans to ARC) makes the app crash, because you reference a memory space that is not in use or used by something else.
Why does the app work when you ad the view to the viewcontrollers array? I assume this array is an array that has been initiated in the AppDelegate and now you add the view controller with a strong reference count to the viewcontrollers array. When you leave the IBAction method, the view controller still has a strong reference and ARC will not deallocate the view controller.
Is this the proper way? Well, it works. I would not think it is considered very good programming, since you don't alloc/init an object in a method that needs to stay alive after leaving the method. It would be better practice to allocate and initialize your view controller(s) somewhere in an init, awakeFromNIB or a windowDidLoad method of your AppDelegate. The problem with your current solution is that you are creating an endless array of view controllers of which you only use the last. Somewhere your program will feel the burden of this enormously long array of pretty heavy objects (view controllers) and will run out of memory.
Hope this helps.
By the way, this is independent of whether you use Mavericks or Yosemite. I was thinking in a storyboard solution, but that wouldn't answer your question.
Kind regards,
MacUserT
-(void)Complete{
CM(#"complete");
[BNUtilitiesQuick UtilitiesQuick].startForm=0;
[self.view removeFromSuperview]; //This remove superView and the new view will be listNewController
[self setSearchLocationWhenChangeSearchBar];
if([self.searchListTemp isEqualToString:[cachedProperties singleton].searchList] && [self.searchLocationTemp isEqualToString:[cachedProperties singleton].searchLocation]){
CLog(#"Don't do anything");
}
else{
...
//Blablabla
//[Timer searchCriteriaChanged];
}
[[BNUtilitiesQuick ListController] viewWillAppear:true];//It's not called if I don't do this
}
Part of me feel that it should be called automatically. Somehow I must have done something wrong when it's not called.
Obviously I don't want things to get called twice either.
So I ended up calling them explicitly. Somehow it feels wrong. Am I wrong?
viewWillAppear is declared in UIViewController.h , it gets called automatically every time the view is about to appear. at some point you have to use super in your implementation.that could be the reason why its not called automatically, because your BNUtilitiesQuick is not a class of UIViewController
If you want some action to happen just before your view disappears, you can write your code in the viewWillDisappear method. This method notifies the view controller that its view is about to be removed from a view hierarchy.
- (void)viewWillDisappear:(BOOL)animated{}
I can't seem to figure this out for the life of me. I have a custom table view cell, in that cell I have a few buttons configured. Each button connects to other view controllers via a storyboard segue. I've recently removed these segues and put a pushViewController method in place. Transition back and forth across the various views works as expected however the destination view controller is not displaying anything! I have some code below as an example.
Buttons have this method set:
[cell.spotButton1 addTarget:self action:#selector(showSpotDetails:) forControlEvents:UIControlEventTouchUpInside];
// etc...
[cell.spotButton4 addTarget:self action:#selector(showSpotDetails:) forControlEvents:UIControlEventTouchUpInside];
// etc...
showSpotDetails Method contains this code:
- (void)showSpotDetails:(id)sender
{
// determine which button (spot) was selected, then use its tag parameter to determine the spot.
UIButton *selectedButton = (UIButton *)sender;
Spot *spot = (Spot *)[spotsArray_ objectAtIndex:selectedButton.tag];
SpotDetails *spotDetails = [[SpotDetails alloc] init];
[spotDetails setSpotDetailsObject:spot];
[self.navigationController pushViewController:spotDetails animated:YES];
}
The details VC does receive the object data.
- (void)viewDidLoad
{
[super viewDidLoad];
NSLog(#"spotDetailsObject %#", spotDetailsObject_.name);
}
The NSLog method below does output the passed object. Also, everything in the details view controller is as it was. Nothing has changed on the details VC. It just does not render anything ever since I removed the segue and added the pushViewController method. Perhaps I am missing something on the pushViewController method? I never really do things this way, I try to always use segues...
Any suggestions?
Welcome to the real world. Previously, the storyboard was a crutch; you were hiding from yourself the true facts about how view controllers work. Now you are trying to throw away that crutch. Good! But now you must learn to walk. :) The key here is this line:
SpotDetails *spotDetails = [[SpotDetails alloc] init];
SpotDetails is a UIViewController subclass. You are not doing anything here that would cause this UIViewController to have a view. Thus you are ending up a with blank generic view! If you want a UIViewController to have a view, you need to give it a view somehow. For example, you could draw the view in a nib called SpotDetails.xib where the File's Owner is an SpotDetails instance. Or you could construct the view's contents in code in your override of viewDidLoad. The details are in the UIViewController documentation, or, even better, read my book which tells you all about how a view controller gets its view:
http://www.apeth.com/iOSBook/ch19.html
The reason this problem didn't arise before is that you drew the view in the same nib as the view controller (i.e. the storyboard file). But when you alloc-init a SpotDetails, that is not the same instance as the one in the storyboard file, so you don't get that view. Thus, one solution could be to load the storyboard and fetch that SpotDetails instance, the one in the storyboard (by calling instantiateViewControllerWithIdentifier:). I explain how to do that here:
http://www.apeth.com/iOSBook/ch19.html#SECsivc
I might be confused here and asking the wrong question.
If I use a class like the UISplitViewController inside the appdelete.m, will the only message i will receive is the message the UISplitViewController calls and not any VIEW message? for example:
in my myappdelegate.m
....
UISplitViewController *mySplitViewController = [[UISplitViewController alloc] init];
mySplitViewController.viewControllers = [NSArray arrayWithObjects:leftside,rightside,nil];
...
mySplitViewController.delegate = self;
....
[windows addSubView:mySplitViewController.view];
....
-(void) viewWillAppear:(BOOL) animated {
}
in myappdelegate.h I included UISplitViewControllerDelegate
I expected viewWillAppear to fire but it is not. I assume if I had subclass UISplitViewControler it would have fire. right?
BTW: I am doing this without using IB. Do I need to set the target for the mySplitViewController?
What I want to do is setup the orientation of the splitviewcontroller when it rotates.
the viewWillAppear method and other view related methods will be called on the view or view controller themselves, not on the delegate.
That means that if you make a subclass of UISplitViewController called SplitViewControllerSubClass, the view... methods will be called on the instance of SplitViewControllerSubClass, not on the delegate object.
But considering you are creating the views and displaying them programmatically, you already know exactly when the view will appear (i.e., right before you add it to the window), so I believe you could do whatever setup you want at that point.