In my application window I have two NSViews. On the left the NSView ("Menu") contains a few buttons. When one of the buttons is clicked it should change the contents of the right NSView ("Content").
For each of the views on the right I have a separate NSViewControllers that get loaded and their views gets added as a subview. When a further button gets pressed on the left the added subviews on the right should be removed and the new view should be loaded as a subview.
To accomplish this I load my Menu in AppDelegate with the following:
MenuVC *menuSubView = [[MenuVC alloc] initWithNibName:#"MenuVC" bundle: nil];
menuSubView.contentView = (NSView*)[self contentView];
[[self menuView] addSubview:[menuSubView view]];
This works fine. As you can see I have a NSView pointer in the Menu VC which points to the contentView so that I can populate it with the subviews.
Now as a method for one of the button presses I do the following:
SomeContentVC *subView = [[SomeContentVC alloc] initWithNibName:#"SomeContentVC" bundle:nil];
[self.contentView addSubview:[subView view]];
This does not work.
If I however add a subview from the awakeFromNib method of the MenuViewController implementation (in the case of default content when the app opens) it works. However when I try to remove that subview using
[[self.contentView setSubviews:[NSArray array]];
I can't. Interesting is also that if I try to count the number of subviews (even after having added one in the awakeFromNib method) it returns 0 subviews for self.contentView. Why? How can I get it to work properly?
Thanks
The fact that messaging self.contentView achieves nothing except, for some things, returning 0 probably means that self.contentView is nil.
Do you perhaps have two instances of MenuVC by accident? Perhaps one instantiated in a NIB and one instantiated in code?
When in doubt, log everything. Log self in various methods. Log menuSubView just after you create it. Log menuSubView.contentView just after you assign it. Etc. Eventually, you'll probably see that you're interacting with different objects than you thought you were.
Related
I have a Swift application view adding some component written in ObjC.
I'm adding the ObjC UIViewController class to Swift view in this way, which works anyway (I don't want the view to be a popup one):
view.addSubview(myObjcViewController.view)
Although, the ObjC ViewController's view populated properly without any problem, different gesture recogniser written in that viewController is not working anymore:
UISwipeGestureRecognizer *upSwipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(upButtonTapped)];
upSwipe.numberOfTouchesRequired = 1;
upSwipe.direction = UISwipeGestureRecognizerDirectionUp;
[self.view addGestureRecognizer:upSwipe];
I tried to change the gestureRecognizer addition in following ways, but none worked:
[self.parentViewController.view addGestureRecognizer:upSwipe];
// or
[[[[UIApplication sharedApplication] delegate] window] addGestureRecognizer:upSwipe];
Please, help.
The problem is that you cannot simply grab a view controller's view and stuff it into the interface like this:
view.addSubview(myObjcViewController.view)
Instead, there is an elaborate dance that you must do in order to ensure that the two view controllers (the one that owns view and the one that owns myObjcViewController.view) both persist in a coherent parent-child relationship.
You are not doing that dance. Therefore the "child" view controller just goes out of existence, and there is nothing containing any code for the gesture recognizer to talk to.
I have a UIViewController with an UIScrollView in it.
Then I created a new UIView subclass with some properties that I want to programmatically add in this UIScrollView until my data ends.
Something that should look like this picture:
I have read other topics that does that by creating a view and setting its class to the custom view subclass, but I want to do it programmatically and its not working.
how would I do that?
From your image it looks like you're looking to load views from a nib and add them as subviews of your UIScrollView. To do this have a look at the UINib documentation.
You want to create your nib and set it's main view to be an instance of your UIView subclass then load the nib in viewDidLoad of your viewController, and add the nib's views as subivews of your scrollview (which I'm assuming is a subview of your viewController's view).
You can instantiate a nib with instantiateWithOwner:options:.
This method unarchives each object, initializes it, sets its
properties to their configured values, and reestablishes any
connections to other objects
To get the array of views from a nib you do something similar to:
UINib *myNib = [UINib nibWithNibName:#"myNib" bundle:[NSBundle mainBundle]];
NSArray *viewsFromNib = [myNib instantiateWithOwner:nil options:nil];
I'll assume we're inside a UIViewController and we're somewhere in (or after) viewDidLoad. You would then use the array from above and add the views as subviews of your scrollview. You may need to set the frames of these views to place them properly, but that should be trivial.
UIView *aView = [viewsFromNib objectAtIndex:0];
[self.scrollView addSubview:aView];
I hope that sets you in the right direction.
Edit:
If you want more information you may need to read deeper into how nibs work to manage your expectation. Linked with the UINib documentation is the 'Resource Programming Guide' in particular the nib section
André, this can be done with relative ease. make sure to import the class that you want to embed. then to create them with your normal
ClassName *subview=[[ClassName alloc]init];
[subview.view setFrame:CGRectMake(x,y,width,height)];
[self.view addSubview:subview.view];
which will add it to the x,y coordinates you specify with the size specified by your width, height. you can do this in the viewDidLoad or whenever you need them to be created.
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
Just because I am unable to find a secure way (in a sense that it can be rejected by Apple guys) to customize UITabbar, in particular UITabBarItem I am trying some workaround.
I have a main view on which I recreate a kind of UITabBar, a normal view with two buttons inside. This is (roughly) the current hierarchy:
-MainView
--placeholder(UIView)
--fakeTab (UIView)
What I want to do is, after tapping a button in fakeTab, build a UINavigationController and add it to "placeholder" view so that the fakeTab remain on top and the whole navigation happens on the placeholder level.
I already tried with this piece of code in the method that it's intercepting tap button, and it works, I can see the ipvc.view added to placeholder.
IPPlantsViewController *ipvc = [[IPPlantsViewController alloc] initWithNibName:#"IPPlantsView" bundle:[NSBundle mainBundle]];
UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:ipvc];
UIView *placeholder = [self.view viewWithTag:200];
[placeholder addSubview:ipvc.view];
But later when I call from inside ipvc, then nothing happens:
IPAttributes *ipas = [[IPFactory findPlantByIndex:indexPath.row] attrs];
[self.navigationController pushViewController:ipa animated:YES];
I find the solution myself. What I was doing wrong is to attach the ipvc controller view to placeholder. Instead of doing this:
[placeholder addSubview:nav.view];
and everything works as expected, with my fake tabbar fully customized :-)
But, as a side note, the viewWillAppear seems to be never called.
It would be interesting to know why. I partially solved by making IPPlantsViewController the delegate of the UINavigationController.
I am trying to create a reusable "picker". It is basically like a keypad of a phone. Since I will be using this a lot in my iPhone app, I have been frustrated with trying to make it appear.
It is in its own XIB file and has its own UIViewController subclass as the FileOwner.
However, when I instantiate this with:
MonthPickerViewController *mpvc
= [[MonthPickerViewController alloc] initWithNibName:#"MonthPicker"
bundle:nil];
Nothing happens on the screen. Yet is does fire the -viewWillAppear methods, etc.
So, what am I doing wrong either in code or in InterfaceBuilder that is preventing my view to appear?
Are you pushing the view controller?
[[self navigationController] pushViewController:mpvc animated:YES];
Or are you adding the view controller's view as a subView of your current view?
First, make sure you've hooked everything up right inside Interface Builder. An easy gotcha is to forget to connect the View object up to the view outlet of your UIViewController subclass.
Then, as Adam says, you need to actually display the view. Assuming you're doing this inside the code of another view controller, you'd need something like the following if you just wanted the new view to appear ontop of your current view:
[self.view addSubview:mpvc.view];
Of if you are using a navigation controller to stack views:-
[[self navigationController] pushViewController:mpvc animated:YES];