After searching online I found that, if we declare a property inside a custom view as #IBInspectable, that property can be altered in the IB attribute inspector.
But my question is what is the use of #IBDesignable. Even if I don't declare a class as # IBDesignable, Im able to see the live rendering of the #IBInspectable properties
IBDesignable is user defined run time. Mean that if any IBDesignable view is rendered on the storyboard, you will find the view and change the value of the IBInspectable property, this will directly reflect on the storyboard without running the app.
IBInspectable is run time property, this works as key coding value. You can't find the change in storyboard, it will be applied in the run time.
The live rendering of a custom view should stop once you remove #IBDesignable. But sometimes this does not happen immediately.
If you remove #IBDesignable, then, close and reopen Xcode.
You should not see any live rendering the custom view directly in the canvas.
Related
I have created a custom view (Quantity View) with nib file in Swift. I have created some IBOutlets & IBActions (for buttons, labels etc.) in my custom view.
I tried to use this custom view (Quantity View) by assigning class name to a UIView in my storyboard.
It's showing me all the IBOutlets & IBActions in the Connections Inspector, as shown in this screenshot: .
I just want to show only delegate for the Custom view.
Possible Answer:
I thought I can use the -viewWithTag to get the views instead of Outlets.
But, I want to know if it's possible with having Outlets also or if there is much better way to do this?
What are the other possible ways (optimum) to handle this situation?
You can also consider the following solution:
You can take the subviews of your QuantityViews(custom view) and you can identify the specific views by its frame origin.
Note : you should know the customview subviews frame
Its not possible to hide IBOutlets from storyboard if you declare the class members as IBs (IBOutlets or IBActions).
The IBOutlets or the IBActions are just indicators to the interface builder so that it can show the names on it when you try to bind them it actually calls the setValue: forKey: method to set the view's reference to the IBOutlet property.
Now if you try to access an subview from the file's owner class without any IBoutlets you need to have a pointer to point it, so for that either you can get the reference using ObjectID which is assigned to the subview by the interface builder or you can get it using the viewWithTag: method.
The ObjectID you need to find all time when you add or replace a subview from the view, so better and convenient approach is to use tag property of UIView class.
So my conclusion to this problem is to access the views using the viewWithTag method you mentioned earlier.
I think your way is correct. But sometimes Xcode doesn't work correctly.
The following makes the IBOutlets and IBActions reappear and work properly:
Clean project your project in Xcode.
Quit Xcode completely.
Delete all contents of ~/Library/Developer/Xcode/DerivedData/.
Restart MacOS just in case.
I hope you will resolve that :)
Where should I customise my IBOutlets?
Say I have created a button with interface builder, created an IBOutlet for it and I would want to change a property during runtime (ex: background color or localized title).
I would think of adding it to the viewDidLoad method, but outlets aren't yet created.
I remember having nil outlets in viewDidLoad, but I might be wrong.
If I move it viewWillAppear, the code will be executed every time the view controller's view appears.
Is there any better place for my IBOutlet related code, so it's only executed once?
Obviously I can do just about any customization using only the interface builder and making use of the User defined runtime attributes or localized stroryboards, but I don't like that since it's much more tedious to change later.
From the Doc
Its clearly says about the Views loaded into the memory in the -viewDidLoad() delegate itself.
I would think of adding it to the viewDidLoad method, but outlets
aren't yet created.
It is a false statement, Because you only get the viewDidLoad: message after IBOutlets are created. So you can safely do any customization in viewDidLoad:
Let’s say you have a Button you want to customise. You put the button at the place where you want it to be and then open the “Identity Inspector” on the right.
There is a textfield for “Custom Class”:
I usually create a subclass of UIButton / NSButton (depending on iOS or OSX) and edit the behaviour, drawing methods and functionality in this class file. Then just add the name of this class in this textfield. Voila!
I've recently started developing an iOS app, which I've never done before, so it's been going a bit slow, but I'm learning, so that's understandable.
I want to make a custom interface, so I've been making subclasses of the default view classes (like UIButton) so that I can define custom drawing. I've been told this is the best way to define custom interface elements that can be reusable. It definitely seems to be working that way. However, I haven't been able to make elements completely reusable by just using a subclass.
For example, in order to prevent a button's text from changing color when it is clicked, I have to manually go into the interface builder and set the button type to "Custom." After that, code that I enter into the subclass's constructor to change attributes seems to work. But I have to do this for every button I add, and in code the "buttonType" attribute is read only. Is there a way for me to define (just once) certain attributes for every instance of my button subclass that I add to the interface?
My goal is to be able to have a button subclass or template that defines all attribute values that I want my buttons to have, and every instance that I add automatically reflects those properties without me having to change anything. More so, I want to be able to modify that subclass/template and have those changes reflected in every existing instance. I have to imagine that this is possible in iOS. There is simply no way to build sophisticated interfaces without this capability.
Define a custom Button class (inherited from UIButton) in your project and in the init set the properties which you wanted to be set across.
In the interface builder go to the the class inspector and enter the button to be of the previously declared button.
buttonType needs to be set for all the button as this is defined at initialization time and exposed as read only property. If you want absolute reusability for your case, create a view, with an embedded button in code. when you create a button, create using the static method buttonWithType.
Wherever you need, drag and drop a UIView and set the view type to be the custom view.
I have an iOS app with multiple ViewControllers. Each view has numerous IB generated UIButtons, each set to custom. I need to change the color of the background in normal and highlighted states. Further, I need to vary the colors to an RGB value based on user interaction. Thus, I can't use image files.
I found an example of a custom class derived from UIButton that implements the color change and click methods to change the colors as I desired. I created a test button and changed its IB custom class to my new class.
I have an outlet property for my IB created button.
The problem I am having is in the viewcontroller.m file when I attempt to access the custom method in my class, xcode can't see the methods.
Use IBAction as a return type for that method
Declare that particular method in .h file
I have a nib file where I have a view that contains a background image, a button and another image that covers the full screen (a shadow) that needs to be moved to the front.
On the view, I'm creating child views, and after creating those and adding them using [self addView] I need to move to the front the shadow image.
I'm currently using the tag attribute to find that view, but I'm thinking there's probably a better way, by means of identifying the subviews I add in Interface Builder by some name.
I tries adding a IBOutlet to connect the subview with its parent, but it didn't work (and made no sense, since the subview is already connected to its parent in some way).
The IBOutlets way should work, and is probably the best way to do it. Make sure you made the proper connection in Interface Builder after you declared them in the .h file.
The iPhone does a lazy loading of view controllers. The nib might not have been loaded in initWithCoder or any init method for that matter as Kendall specified.
viewDidLoad is the preferred place to access anything from the nib if you want to access them before the view is displayed.
Hope that helps.
At what point are you trying to access the subviews? If you try within init of a ViewController, the IBOutlets will be nil. The first method you can get at them is probably viewDidLoad.
The reason it does make sense to do things this way is that IBOutlets are just direct pointers to some component, even if they are already subviews of something else. Just saves a lot of hunting.
Using the Tag is a perfectly valid way to locate specific views, so long as you're using the viewWithTag: method. If you're already using tags, there's no need to change to IBOutlets unless you just don't like calling viewWithTag:.