How to get notified of clicks in a view-based NSTableView - macos

I have a view-based NSTableView containing a list of words. When the user double-clicks on a word, I would like to take an action. The words are not editable or selectable. How do I do this?
I have tried setting the target and action of the table view in IB, but it only calls the action method when the user clicks in the header of the table, not in one of the words.
I have tried setting the target and action of the NSTextField that the table cell view keeps in IB. This results in this error message being repeated in the console:
2018-01-02 14:14:32.080347-0800 WordExplorer[7089:21457459] Could not connect action, target class NSObject does not respond to -relatedWordClick:
However the target class does respond to the selector. (I connected it in IB directly, so clearly, it does!) It is also not a simple NSObject, so I'm guessing that something else is going wrong there.
I have tried manually calling -setTarget: and -setAction: on the NSTextField contained in the table cell view in my delegate's -tableView:viewForTableColumn:row: method. This has no effect, and the debugger shows that despite calling those methods, they do not set the text field's action or target method. (Though, given this is Xcode we're talking about, it's likely that's just a debugger display issue.) I get no errors in the console like when I make the connection in IB, but it also does not call the appropriate method.
Do I need to make custom view class and use that for the table cell view? Or is there a simpler way to get clicks (and preferably double-clicks) on words in my list?

Simply create an IBAction on the object you have as the NSTableView's target, and then set the NSTableView's doubleAction property to the selector for that IBAction, and you can handle double-click events easily.

Related

How to wire-connect NSTableView/Table View to avoid runtime error "Could not connect action, target class NSObject does not respond to")

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:).

NSResponder and multiple NSTableView - who sent message?

I've got two NSTableView in a single NSViewController, and each has their own NSArrayController to handle what exists. I'm now trying to wire up the Edit->Delete button. How do I know, when the delete method is called, 'who' sent that message?
Specifically I want to know whether I was clicked into the first table view or the second one when I then chose the Delete menu item. The 'sender' to the delete method is just the NSMenuItem so I can't back-track that to the table.
Get firstResponder of the window and follow nextResponder until you find a table view.

How to implement my own selectAll: for UITextView without subclass it?

How do I implement my own selectAll: for UITextView without subclassing it? I don't want to subclass UITextView because if I do I need to change every place in my codes (.m/.xib) that need to use this subclass.
I had thought (wrongly!) that maybe I can connect UITextView action like selectAll: to my code (I do declare - (IBAction)select:(id)sender in my h file) ? I drag the action to File's Owner or to .h/.m file, nothing happens.
Now I know they are received action so I can't do that. Then how to ?
You cannot connect it because there is no such action. You are reading the Connections inspector incorrectly. The things in your screen shot are not actions. selectAll: is not an action. It is a received action. It is not emitted by the text view. It is sent to the text view, as a nil targeted action passing up the responder chain. To change or add to the text view behavior when it receives this action, you subclass UITextView. It's easy to do.

NSTableView & CoreData: Delete Object at clicked row

I am pretty new to Core Data and am currently working on a small (OSX) app that uses an NSTableView to organise objects. I would now like to delete a row/object with the click of a button on that targeted row.
I access the managed object within the table controller by calling [NSApp managedObjectContext] (still trying to figure out that dependency injection thing) but I can't easily delete an objectAtIndex: like I used to with the array (which has now been replaced by the core data stack, right?).
How do I identify the object to be deleted? And consequently, how can I cleanly remove it from the stack?
This is probably a really basic question but I couldn't find any resources on it. Bindings obviously don't work because the row does not get selected before the click occurs.
Any help is much appreciated!
Bindings would work, in that you could have the button's IBAction query the objectValue for the parent NSTableCellView. Once you have that objectValue, you could call the bound arrayController to delete the object, and then the cell/row would disappear.
So, if you have a tableCellView that has a delete button with an IBAction, within that IBAction, you could get the sender's superview, ensure it's an NSTableCellView, get the objectValue, and call [myArrayController removeObject:...]
As it says in the NSTableCellView class reference:
The objectValue is automatically set by the table when using bindings or is the object returned by the NSTableViewDataSource protocol method tableView:objectValueForTableColumn:row:.
This is actually a typical pattern with views in cocoa. objectValue or often representedObject are properties on the views that refer to the data model objects they represent, so if you have a view pointer from sender on the IBAction, you can get the related data model object. And if you're using bindings and a controller, you can then just have the controller remove that object.
With bindings, you will often create buttons that need IBActions attached, rather than some direct binding. But those IBActions can most definitely interact with the controller and not the view.
And with core data, array controllers are really slick vs. assuming you have to do it all programmatically.

NSTableView not refreshing

I have a table view that gets refreshed two different ways. Both are through a button, and as a matter of fact, both are through the same IBAction in the same class!
Here's my problem:
The buttons are in two different .xib files, the button in the same xib as the table view works perfectly, while the one in the different xib does the method to get the new data, but it DOES NOT refresh the table. Same exact method, different results. To get the IBAction for the other button I simply dragged out an NSObject in IB and set its class to the class of my table view, which contains the IBAction, then hooked it up to my button.
How can I fix this?
Sounds like you're creating a second, parallel, object of your class in the second XIB. The button sends a message to that instance, which does some of the stuff you expect because it's an object of the right class, but it isn't actually the right object and isn't connected to your view.
What you need to do is ensure that both buttons talk to the same instance. This is easiest if the target is in the responder chain -- you should be able to set the button's target to First Responder and the message will find its way to the right place. Otherwise, you need to get a pointer to the target into the XIB, eg as an IBOutlet in the object that will be File's Owner.

Resources