I'm trying to refactor one of my ViewControllers, by splitting it up.
This is for an app which will do card manipulations. I had a controller which could edit multiple types of shuffles but now I'm splitting it into separate controllers for each individual shuffle type.
There is another story board which allows you to pick moves, it is set up to have segues from hidden buttons. The segues point to storyboard references. Originally I made the scenes for the segues in the dispatch story board, and then refactored them using Xcode's Editor>Refactor to Storyboard menu item.
I then made a new storyboard for the FaroEditor view controller. Then I tried to figure out how to add a reference to this storyboard. I finally found the 'Storyboard reference' in the object gallery.
I put this in the dispatch storyboard, and set it to point to the FaroEditor storyboard:
I did a bit of photoshopping to put the storyboard, the storyboard reference attributes, and the segue attributes in a single image.
When I run and trigger the segue, I get an exception thrown with no info as to what it is:
Again, I used photoshop to copy and paste the three top stack frames into a single image.
I'm at a bit of a loss about how to diagnose and fix this. Any ideas?
You need to add a 'storyboard ID' on the view you are referencing and then add that same ID to the Referenced ID in the Attributes Inspector
UI operations should be done in main thread
DispatchQueue.main.async {
self.performSegue(withIdentifier: "someSegue", sender: self)
}
Important
Use UIKit classes only from your app’s main thread or main dispatch queue, unless otherwise indicated. This restriction particularly applies to classes derived from UIResponder or that involve manipulating your app’s user interface in any way.
developer.apple.com/documentation/uikit
Related
In a view-based single-column NSTableView containing a default NSTextField in its Table Cell View, I'm trying to listen to confirmed user edits by connecting the NSTextField's action, within an Interface Builder view of the .xib, to a method in my ViewController for the window. But at run time (during window initialization) I get "Could not connect action, target class NSObject does not respond to -textCellChanged". I don't understand which NSObject is being incorrectly targeted, and I have many other NSViews in the window correctly connected to other outlets and actions in the same WindowController.
I see various other posts with a similar symptom, often also in the context of NSTableView, and have explored the solutions or partial solutions to those other problems in my context without success. Is there any particular magic about wiring Table View Cells in Interface Builder that I am overlooking? Or perhaps phrased differently: how is the target object actually determined at runtime, when the action is simply a class method in the File's Owner (and when does this vary for different controls all wired to the same owner of a common superview)?
Here are some particulars of context:
File Owner is set to a subclass of NSWindowController and Module there correctly inherited to my app target.
Probably relevant: I am not using Storyboards, and the top-level object in my XIB's outline view hierarchy is a Window (NSPanel), rather than an View or View Controller. The NSWindowController only appears within the XIB as the File Owner (not as its own object in Outline View).
In any of the various wiring scenarios I've tried (following), Interface Builder "looks like" the wiring op has succeeded. After wiring, the File Owner's Connections inspector lists the intended connection under Received Actions ("textCellChanged: ... [x] Table View Cell"), along with many other actions connecting components in the NSTableView's superview to other methods in the NSViewController.
Likewise, connecting the NSTextField as an OUTLET in the same NSViewController works with no problem. It's only the action (or target/action?? in IB one only sets "action") that fails.
The File Owner is also the data source and delegate of the NSTableView, and the NSTextField is set to Action:Send on End of Editing and Behavior:Editable. I don't think any of these are relevant to the particular symptom, which is just a failure to connect an action.
The NSWindowController is Swift; I have tried implementing the appropriate action within both the main NSWindowController implementation or in an extension that implements NSTableViewDelegate to no noticeably different effect.
Other posts suggest Xcode bugs in wiring, though in older versions of Xcode (I'm in 10.2). Here are various approaches I've tried, all with similar results:
Ctrl+Drag from Table View Cell icon in IB Outline View to NSWindowController source module, targeting there either an existing #IBAction or permitting Xcode to generate a new Connection (type Action, Object: File's Owner) and with it a new method in the ViewController
Reverse Drag from Source Code "left-column radio circle" next to an #IBAction to the Table View Cell in Outline View of my .xib
Ctrl+Drag from Table View Cell icon (in Outline View) to Placeholder/File's Owner icon, then choosing an appropriate action method from the pop-up list of methods implemented in the view controller.
Possibly some others
Finally, here are some related posts and how they differ:
This sounds like an identical symptom, but in comments OP claims to have fixed the issue by a combination of setting File Owner to the View Controller (done) and by working around blocking XCode bugs (not visible in my context).
This suggests I'm linking to a stale (deleted) method; definitely not the case when I allow Xcode to create the method for me.
This unanswered post suggests the user gave up on the situation as an IB bug and gave up in preference for a non-target/action workaround. I suppose I could pursue listening to notifications on the NSTextField as a similar workaround.
Finally, the accepted answer to a similar symptom here is that the connection to File Owner is incorrect in that case, where File Owner was the NSApplication object rather than the View Controller. In my case, File Owner is the View Controller object that defines these methods, so feels like the correct target.
Any stone unturned here? Thanks in advance for your help.
The file's owner in a xib file is a placeholder object representing the owner of the nib and representing the owner object passed to makeView(withIdentifier:owner:). Pass the owner of the nib (usually the view controller or window controller) to makeView(withIdentifier:owner:).
I'm getting an error connecting to my storyboard. I have a navigation controller connected to my view controller as a root. Everytime I play the application, it crashes. I get this error:
Unknown class ViewController in Interface Builder file.
(lldb)
scene is unreachable due to lack of entry points and does not have an identifier for runtime access via -instantiateViewControllerWithIdentifier-
What's this even mean?
My view controller is defined right under the normal code.
import UIKit
class ViewController: UIViewController {
//some code here
It sounds like one of the scenes in your Storyboard is (a) referencing a class, AboutMeViewController, which you haven't defined.
It further sounds like this scene also doesn't have any segues pointing to it, nor does it have a unique identifier. Thus there's no way to load it.
Select each scene in your storyboard in turn, select the outermost view controller object, and use the identity inspector to see the class of that view controller.
Since I transferred the storyboard from another project, it was linked to another project. I refreshed the "Custom Class"/"File Owner". Usually it's hidden and it confuses people but it's there. To locate it find the newspaper looking like icon and press on it. It'll be the first option all the way at the top.
I have a document based application. I have just created menu items in the storyboard and IBActions in my view controller. However the usual way I connect an action to a target doesn't work
-(IBAction) markAsHidden:(id)sender;
-(IBAction) markAsVisible:(id)sender;
-(IBAction) toggleHidden:(id)sender;
Here is what I see when from my menu item I press Ctrl and mouse click from menu to View Controller. It does not show my IBActions.
Any idea ? My 2 cents guess is that it has to do with the app being document based but... not really sure
Connect the menu items to the application scene's First Responder. When you connect to the application scene's First Responder, your view controller's IBActions should appear in the HUD's list of available actions instead of the action segues shown in your screenshot's HUD.
Why can't I connect my menu to my view controller IBAction?
Because your menu items and view controller are in different scenes in the storyboard. You can think of a scene as an independent graph of objects that are instantiated when the scene is loaded from the storyboard. Objects in different scenes can't be connected together in the storyboard because they're not loaded at the same time.
Just for fun, try creating an instance of your view controller in the Application Scene in your storyboard. To do that, you'll probably need to drag a plain old NSObject instance into the scene and then set its type. Once you do that, you'll find that you can drag a connection from a menu item to that view controller just as you'd expect, but you can't drag a connection to a different object of the very same type in a different scene.
Note: Once you've played around enough to convince yourself that it works, remember to delete the view controller that you added. A view controller without a view is like a duck without a quack, and a view controller and its view hierarchy should be in their own scene.
My 2 cents guess is that it has to do with the app being document based
No, it doesn't have anything to do with that. You'd have the same problem in an app that's not document-based. You'd also have the same problem if your app were .xib-based instead of using storyboards, since the controller you'd be trying to connect to would be in a completely different .xib file.
The easy solution, as Mark already described, is to use the responder chain. The First Responder proxy object is part of every scene, so you can always make connections to it. When you connect a menu item to First Responder its target will be nil, which tells NSMenu to walk the responder chain until it finds an object that responds to the menu item's action message. It then sends the message to that object.
If you are converting a project from objective C to Swift, do not make my mistake. When writing your IBAction write like this:
#IBAction func someAction(_ sender:AnyObject) {
// this will work
}
Do not omit the underscore before sender or the Interface Builder won't be able to connect to your action as in here:
#IBAction func someAction(sender:AnyObject) {
// this won't work and IB won't connect to this action
// because sender will be part of the symbol name
}
I'm fairly new to Mac development and am slightly confused by the new "storyboard" feature in Xcode 6. What I'm trying to do is segue from one view controller to another in the same window. As of right now, all the different NSViewControllerSegues present the view controller in a new window, be it a modal or just another window. What I'd like to do is just segue within the same window, much in the same way one would on iOS (though an animated transition is not crucial). How would this be achieved?
If you provide a custom segue (subclass of NSStoryboardSegue) you can get the result you are after. There are a few gotchas with this approach though:
the custom segue will use presentViewController:animator so you will need to provide an animator object
because the presented view is not backed by a separate Window object, you may need to provide it with a custom NSView just to catch out mouse events that you don't want to propagate to the underlying NSViewController's view
there's also a Swift-only glitch regarding the custom segue's identifier property you need to watch out for.
As there doesn't seem to be much documentation about this I have made a small demo project with custom segue examples in Swift and Objective-C.
I also have provided some more detail in answer to this question.
(Reviving this as it comes up as first relevant result on Google and I had the same problem but decided against a custom segue)
While custom segues work (at least, the code given in foundry's answer worked under Swift 3; it needs updating for Swift 4), the sheer amount of work involved in writing a custom animator suggests to me that their main use case is custom animations.
The simple solution to changing the content of a window is to create an NSWindowController for your window, and to set its contentViewController to the desired viewController. This is particularly useful if you are following the typical pattern of storyboards and instantiate a new ViewController instance every time you switch.
However.
The NSStoryboard documentation says, quite clearly in macOS, containment (rather than transition) is the more common notion for storyboards which led me to look again at the available tools.
You could use a container view for this task, which adds a NWViewController layer instead of the NSWindowController outlined above. The solution I've gone with is to use an NSTabViewController. In the attributes inspector, set the style to 'unspecified', then select the TabView and set its style to 'tabless'.
To change tabs programatically, you set the selectedTabViewItemIndexof your TabViewController.
This solution reuses the same instance of the ViewControllers for the tab content, so that any data entered in text fields is preserved when the user switches to the other 'tab'.
Simple way with no segues involved to replace the current view controller in the same window:
if let myViewController = self.storyboard?.instantiateController(withIdentifier: "MyViewController") as? MyViewController {
self.view.window?.contentViewController = myViewController
}
When I create a new UIViewController in xcode, it offers to make me an associated nib for the interface. However, when I create a UIView, it does not. If my understanding of MVC is correct, views should really be the parts that contain the interface elements (i.e. the nib) while view controllers are the parts that hook the functionality to the views they control.
I'm sure I'll be able to get it working together either way, so this is more of an exploratory question.
This seems like a case where I'm missing some fundamental understanding of how these two parts should be used. What am I missing?
Because UIView is usually not used in such way.
However How do I associate a nib (.xib) file with a UIView?
The answer I eventually got that satisfied my interest was roughly this:
The job of a view controller is to manage a view hierarchy. Interface Builder is an excellent tool for creating view hierarchies. Xcode offers to create a .xib when you create a new view controller because chances are high that you'll want to load the controllers' views from a .xib.
.xib files aren't necessarily meant to hold every UIView (or subclass) that goes into the view, just a general outline of views that don't change during the life of the view. The other UIViews are much easier to create programmatically since they change often.
I had a similar confusion. Basically (according to the MVC) the View is contained inside the Controller. In the iPhone this means that UIViewController has a property called 'view' which is a UIView instance.
A XIB file (and this is not mentioned often) is a serialised UIView instance. It is roughly an XML sub format which represents a UIView with all its subsequent views. So when you create a UIViewController, a UIView is created in the form of a XIB and bounded to that controller.
A new UIView therefore does not have a XIB because they are essentially the same thing...