Well, the title says it all. What is the difference (if any) between subview and subclass? Is a subview also a subclass? e.g. when the app launches, the main View is a subview of UIWindow, but UIWindow is a subclass of UIView.
The UIWindow is a subview of UIView becuase the UIWindow is a subclass of UIView. The same concept holds true in other object oriented languages. I can have a super class called Vehicle with subclasses car and motorcycle. The car and the motorcycle are 'subVehicles' of Vehicle...just like UIWindow is a subclass and therefore 'subView' of UIView.
Related
I have an XIB for my UIViewController. Above my ViewController I want to add a UIView Custom Class.
Now I need a dark view between the UIViewController and my Custom UIView.
I wanted to implement the Dark View inside the UIView custom class using
[self.superview addsubview: _darkView]
I tried to do this but it doesn't seem to work ...
You can tell me how to solve this thing programmatically by working only from my uiview custom class ? Sorry for the stupid question but I can't solve this thing
You can try to add subview on window
[self.window addSubview: _darkview];
Let me know if it works for you or not.
I have an MVC architecture of a certain view within my app. Now I want to create a subclass of the View and Controller part. The original UIViewController subclass is loaded with a UIView subclass from storyboard. How can I make my subclass of this UIViewController subclass use my subclass of the UIView subclass code when it loads its view?
EDIT
Here's some more details about what I want to do. I currently have these classes:
ControlView
ControlViewController
which are connected with storyboard. I load an instance of ControlViewController using:
self.storyboard!.instantiateViewControllerWithIdentifier("ControlViewController")! as! ControlViewController
Now what I want to do is subclass ControlView so that I can change some constraints and add a few extra subviews. Let's call this subclass ExpandedControlView. I also want to subclass ControlViewController because I want to add some extra actions from ExpandedControlView to the controller. This can be called ExpandedControlViewController.
Then I want to be able to instantiate ExpandedControlViewController and use ExpandedControlView like ControlViewController would with ControlView.
In storyboard, select the hierarchy view.
Then select your UIViewController's View in the hierarchy on the left, and select that view's class in the identity inspector on the right.
Or if you want to do it in code. Override viewDidLoad on ControlViewController, instantiate your custom view and set your ControlViewController's view property to your custom view.
-(void)loadView{
ControlView *myCustomView = [[ControlView alloc]initWithFrame:[UIScreen mainScreen].applicationFrame];
self.view = myCustomView;
}
One caveat when doing this is that the layout of any subviews might change from the time loadView is called. So if you have subviews in your custom view, you should also override layoutSubviews in your custom view and set all your view's subviews' frame property again there.
Implement loadView in your view controller subclass and set the view property with instance of your custom view subclass.
I have a UIViewController say viewControllerA which contains some view element like UIButton, UILabel etc. Now my question is should I create those view elements in a separate UIView class and then add in UIViewController, or should I create those view elements directly inside the UIViewController. Accordingly to MVC isn't it appropriate to create view elements inside a separate UIView class and then add this in UIViewController?
The standard place to build the view hierarchy in a UIViewController is in the -viewDidLoad method. That method gets called whenever the UIViewController's view is created. The view controller's view will be loaded from the NIB/Storyboard if applicable; your outlets will be wired up; and then -viewDidLoad is called for you to perform further customization:
- (void)viewDidLoad
{
[super viewDidLoad];
UILabel *aLabel = [[UILabel alloc] initWithFrame:CGRectMake(0.0,0.0,100.0,40.0)];
[self.view addSubView:aLabel];
}
In Cocoa/Cocoa Touch you don't always want to subclass everything the way you would in, say, Java. There are often other preferred means of extending the functionality in built-in classes such as Objective-C categories, delegation, and pre-defined properties.
It's certainly possible to do this sort of thing another way, but this is the most "Cocoa-like" way to do it. Actually, the most "Cocoa-like" way would be to create the view hierarchy in Interface Builder, but if you want to do it programmatically this is the usual way.
I am trying to draw to a UIView subview from another class.
MainViewController with a view that I have dragged a UIView into in IB.
I have created a DrawView class and changed the UIView's(the one I dragged onto the MainController's view in IB earlier) class to DrawView.
I can draw to that DrawView UIView subview by coding in DrawView so that works as expected.
I have a custom UITableViewController class and would like to draw in the "DrawView UIView" from the custom UITableViewController. How to do so?
I have tried creating a new instance of DrawView from the custom UITableViewController and creating functions in DrawView that I can call to draw. Doesn't work because my created instance of DrawView is a different instance than the "DrawView UIView" in IB that is created on launch. The newly created DrawView's bounds are zero, too, passing in bounds for initWithFrame doesn't work.
I don't understand how I can get the same instance of DrawView created in IB to use in the custom UITableViewController.
In case the above is too wordy, I want to call drawing methods to draw in a UIView subview in its class from another class.
How can I implement this? Thanks.
I have a .xib file for my viewController. It contains a TableView and a UIView. The UIView is backed by a custom class - CommentsBarView (trying to position a small bar with a comments field underneath my tableView).
So in my Document Outline list I have:
view
tableView
comments bar view
UITextView
UILabel
Custom class for "comments bar view" is CommentsBarView.
I have outlets connected from within CommentsBarView to the textfield and label.
(and from the ViewController to the tableView).
When I load my with controller with:
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
I can access the tableView property and change the appearance of the tableVIew, however, from my commentsBarView initWithCoder I can not set the text value on my textView and label:
- (id) initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];
if (self) {
[self.commentTextView setText:#"Helo, World!"];
[self.characterCountLabel setText:#"200"];
}
return self;
}
It seems as if these properties are not available at initWithCoder time.
If I manually, from my controllers initWithNibName, accesses self.commentsBar.label.text = 200, there is no problem.
Am I experiencing a timing issue where the views are not ready yet or can I not nest a view inside a viewControllers view and have it backed by a custom UIView subclass?
IB is confusing me a bit.
Thanks for any help given.
When loading from a XIB file, the IBOutlets are not ready in the init methods of the objects being unarchived.
You need to override awakeFromNib in your CommentsBarView to have access to the ready and connected IBOutlets.
Once you get used to IB it becomes better. Since Cocoa is a MVC (Model-View-Controller) you should probably not create a UIView subclass and set your UIView to it. You should probably put the UIView back to just a UIView. I generally subclass a UIView if I need to have a customized look. For example; a good time to subclass a UIView is if you want it to have a gradient. Then you can reuse your subclass for any UIView you wish to show the gradient.
In your case you are trying to "control" the UITextView and UILabel. You can instead wire-up outlets of your UITextView and UILabel directly to your UIViewController (File Owner). That is the "controller" of the MVC in this case. Think of your UIView as a container that is simply holding the two controls for this example. Now you can use the viewDidLoad method or some other method of you UIViewController to set the values of you UITextView and UILabel. It is generally the UIVeiwController that interprets the data from the Model in Cocoa and places the data where it needs to be. It is not a rock-solid rule, but a good one.