Sorry if this has an obvious answer, I can't seem to find anything describing this situation. How can I set up a nib file which directly implements a custom UIView? In other words, the top-level view in the nib file becomes an instance of my custom UIView class? The closest I've been able to find so far is to create a custom UIView which loads the nib and sets it's top-level view to a UIView* property (and all it's subviews to the appropriate outlets by loading with owner:self). This works, but as I understand the top-level View does nothing except act as a container for all the other views - which is what my custom UIView is supposed to do. Any suggestions?
Edit: I got this in the end: the issue is my custom view class was set as the File's Owner class, when it should have been set as the top-level View's class. I didn't know it was possible to set outlets on elements in the IB as well as the Owner. Setting the Owner to the class of the ViewController that will hold it and the top-level view to my custom view has it all working.
If you create a project using the single view template, you will get an empty view. If you add a class that is a subclass of UIView, you can change the class of that view in IB to your class (in the identity inspector).
If I have understood your question correctly, then this should help -
In the IB, on the right-pane. select the "custom class" dropdown & fill in your custom UIView class. The image shows UITableViewCell instead of that put your custom UIView class name.
Correct me if I have not understood your question correctly.
Related
I've made a view in my storyboard which I've now decided I'd rather display its data via static table cells.
I can't use static table views in a UIViewController (Static table views are only valid when embedded in UITableViewController instances). So, I need to convert my existing UIViewController to a UITableViewController somehow. I've changed the .h file's parent, but that hasn't done it.
Is there another way to get this going? I'd really rather not have to make a new VC in the storyboard and move everything over, it's a big hassle.
I'll add to this, since the question is about how to change a UIViewController into a UITableViewController, and given that this question is over a year old and the original answer, while valid and may or may not have been the only solution at the time, doesn't actually answer the question and is not the only solution.
It IS possible to do this, you just have to set up the table view delegate and datasource outlets in IB, and manually edit the storyboard XML, which sounds scary but is actually very easy.
First, change your class's parent to be a UITableViewController. UITableViewController already adopts the UITableViewDatasource and UITableViewDelegate protocols, so if your class does too you can remove them:
#implementation MyTableViewController : UITableViewController
...
#end
Next, create new referencing outlets on your UITableView for its dataSource and delegate. The easiest way to do this is to control-drag from the UITableView to itself. The popup will give you the dataSource and delegate options.
Lastly, you need to change the storyboard XML. The storyboard file can get pretty big pretty fast. The easiest way to find the scene you are looking for is by setting Storyboard Identifier in the Identity Inspector. To view the XML directly, right click on the storyboard file in the project navigator and select "Open As -> Source Code". Now just search for whatever you set the reuse identifier to earlier. You'll see something similar to this:
<!-- My Table View Controller -->
<scene sceneID="EuE-XX-cCb">
<objects>
<viewController storyboardIdentifier="MY_TABLE_VIEW_IDENTIFIER" ... >
// Lots of other stuff
</viewController>
</objects>
</scene>
All you need to do is change the opening and closing view controller tags
<viewController>
</viewController>
to be tableViewController instead
<tableViewController>
</tableViewController>
That's it! No need to create a new UITableViewController scene or embed a UITableViewController in a container view.
EDIT:
I should also add that the UITableView MUST be the root view. It cannot be embedded inside another UIView.
If you want your static cell table view not to take up the entire screen, then using a container view is the easiest way to go. Start with a regular UIViewController and drag a container view (next to normal UIView in the object list) into its view. Resize it however you want -- the storyboard will automatically provide a view controller connected to this container view with an embed segue. Delete that controller, drag out a table view controller and right-drag from the container view to this table view controller to make a new embed segue. This table view controller can be accessed from the UIViewController with its childViewControllers property (and conversely, you can access the UIViewController from the table view controller with parentViewController if you need to).
What I did, is creating a UITableViewController in IB, open the Storyboard with a text editor, and copy all the nodes inside from the UIViewController to the UITableViewController.
I think that with this way there's less risk of deleting something important.
Before copying the sections objects, make sure that both tableviews (UIViewController and UITableViewController) have the same properties set like: static or dynamic cells, style (plain or grouped), etc.
In my application I have a single nib file. The File's Owner is a NSViewController and insider there is just a vertical slider that I want to bind to a property in one of my classes. (I don't have any other nib files since it is a status bar application, so I don't have a window). The nib is loaded runtime to create a custom view for a NSMenuItem.
The problem is that I want to use an object controller to do the binding but I'm not sure what is the content of the object controller. How can I access from the nib to an arbitrary class in my project?
In the examples I have seen, usually the object controller uses the File's Owner to access the class (and the property for the binding) setting the Content Object binding to the File's Owner. But in my case from the File's Owner I do not have access to the class.
Any pointer?
Ok this works for me. It is enough subclassing NSViewController and sets the new subclass as the File's Owner. Now it is possible to use a Controller Object to bind through the File's Owner.
If you use XCode 4 you can Control-drag from the slider to the .h file (AppController.h?), and you will get the option to generate an outlet or an action. If you want to create an action, caused by sliding the slider, you should select action. The generated method will be called whenever the slider is changed. If you want the slider value to react to an event (or a changed instance variable in your program), set it to 'outlet'.
Hope that helps, let me know if you were really looking for something else :-)
I am just trying to get my head around MVC in Objective C and IOS but am having a problem I'm hoping someone can help me with.
I have created a custom view (created as a child UIView in a XIB) that uses a simple delegate protocol for requesting information from its delegate in drawRect. I have a view Controller that implementes the protocol and is connected to the view through interface builder.
The custom view also has a few properties that I want to set on startup.
The problem I have is working out how the controller is supposed to access the view to set these properties as it doesn't appear to have direct access to it. Also the properties don't seem to be visible in interface builder inspector as I would expect unlike the delegate property I added.
Initially I thought I could do something like
[self.view setViewIntProperty:10]
But that would be calling the main XIB view and my custom view is actually a child of this view so I need someway to get that specific child view to I can initialise it from the controller in viewDidLoad.
Hopefully that is clear. I'm sure this should be easy and I've missed something simple but can't see how this should normally work.
You can just create another property on your view controller of type MyCustomView*.
Declare that property as an IBOutlet and you wire that up in IB.
Then in your view controller you can use that property to access that custom view.
Your custom view's properties (as opposed to its outlets) can only be set in code unless you create an IB plugin for it.
Your other subviews can be accessed easily if you create an outlet for each of them in your controller. The view outlet is there as the primary view of that view controller. There is nothing preventing you creating additional outlets to other views/controls. Yu would just need to subclass the view controller and add the outlets as needed. Just remember to set the class name of the controller (in Interface Builder) to that of your custom subclass. That will expose the available outlets for you to connect.
You'd still need to create an Interface Builder plugin if you want to make your control's custom properties available in IB's inspector palette. Unless you plan to reuse it frequently in other applications or make it available to others, it's probably easiest just to set the properties in your source code.
Example for setting corner radius of your custom subview (subclass of UIButton in my case) from xib.
Create a property like this
#property (nonatomic, assign) IBInspectable CGFloat cornerRadius;
Override setter in your custom view's implementation file.
-(void)setCornerRadius:(CGFloat)cornerRadius
{
self.layer.cornerRadius = cornerRadius;
}
Drag your view in xib and change its class to your custom class.
Magic... You will see the custom properties appearing in attribute inspector like this.
I'm trying to understand how these two are connected. Every time you make a UIViewController does it also automatically come with its own UIView?
Also are these from Cocoa or Objective-C?
UIViewController is a Cocoa Touch class built for the purpose of managing UIViews. It expects to have a view hierarchy, but you don't "automatically" get a view (this is slightly inaccurate; see edit below). Usually you will obtain views by calling initWithNibName on your view controller.
There is some built-in magic in Interface Builder which knows that if File's Owner is a UIViewController (or subclass), there is a property called view. That's about it.
Once you have linked a view controller and a view, the view controller does a fair amount of work for you: it registers as a responder for view touch events, registers for device rotation notifications (and handles them automatically, if you wish), helps you take care of some of the details of animation, and handles low-memory conditions semi-automatically.
Edit: correction—if you don't call initWithNibName or set the view property manually, the view property getter will invoke loadView if view is nil. The default implementation of loadView will see if you've set nibBundle and nibName and attempt to load the view from there (which is why you don't have to call initWithNibName, most of the time), but if those properties aren't set, it will instantiate a UIView object with default values. So technically, yes, it does automatically come with its own UIView, but most of the time that's of little value.
UIViewController doesn't automatically come with a view. You have to make a view in the -loadView method. By default, this loads the view from the nib file you've specified. You can also override this method to make a custom view if you prefer not to use a nib.
Also, the view is not created right when the UIViewController is created. UIViewController uses a technique known as lazy-loading to defer the creation of a view until the view is actually accessed for the first time.
I've created a ChildViewController class, and then a nib that uses that class.
Then I created a BaseView, that includes some buttons, and some text that I'll be changing programmatically.
Then I created two more views (Boy and Girl), that I want to be able to lay behind the baseview so that the background color is different along with some graphics in an ImageView. I've named the views that I created in IB 'Boy' and 'Girl'...
But when I go back to my code where I'm calling ChildViewController, I'm not sure how to access the views I created so I can call insertSubView. Do I need to instantiate them in code? (in ViewDidLoad perhaps?) Does the nib create the instances when it loads?
I'm confused about how to handle multiple views for a single ViewController
edit =================
#Pablo Santa Cruz
Your answer assumes that i have two nibs and two view controllers (one for each view). I want to know if I can use one nib and one controller, and load in UIViews. It seems silly to create another nib and controller, when all want to do is change the background color and some graphics. Can't I programatically load in UIViews into a UIViewController?
Add IBOutlets in your App Controller class in Xcode then link them in IB (ctrl-click or right-click) from the connections tab in the Inspector to the object.
Then you will be able to send method calls to the objects.
The code in Xcode should look like this:
#interface AppController : NSObject
{
IBOutlet Girl girlIvarName1;
IBOutlet Boy boyIvarName2;
}
#end
You can access a UIView programatically by assigning a value to its tag property, which can be set in IB on the first tab of the inspector (Command 1)
The tag value defaults to zero, so if you want to access it specifically, make it non zero and unique. e.g. 100, which I will use in the example code below
Once the tag is set you can access the view using the following code in your UIViewController that was initWithNibName for the NIB containing the tagged view
UIView *aView = [self.view viewWithTag:100];
You can get instances for your IBuilder views with this piece of code:
boyViewController = [[BoyViewController alloc] initWithNibName:#"BoyViewController" bundle:nil];
girlViewController = [[GirlViewController alloc] initWithNibName:#"GirlViewController" bundle:nil];
Assuming your NIB file names are BoyViewController and GirlViewController. With those instances, you can do whatever you need to. I.E., adding them to a parent view (with addSubView message on the parent).