Handle keyboard inputs in NSTextView embedded via NSViewRepresentable? (SwiftUI/MacOS)

Question

I'm new to SwiftUI and am utterly confused.. I managed to embed a NSTextView into my SwiftUI View and bind its text with the below code.

What I don't understand; is there a way to handle keyboard inputs to the NSTextView and change its text accordingly (e.g. CMD + R sets the text color of the selected text to red)? Is there even any way to interact with UI-Elements in SwiftUI?

"RichTextField"

struct RichTextField: NSViewRepresentable {
    typealias NSViewType = NSTextView
    
    @Binding var attributedString: NSAttributedString 

    func makeNSView(context: Context) -> NSTextView {...
    // [...]

}

View

struct EditWindow: View {
      
  @ObservedObject var model: EditEntryViewModel
  @Binding var isPresented: Bool
        
  var body: some View {    
     RichTextField(attributedString: self.$model.answer1, isEditable: true)
      // [...]
    }
}

Furthermore, I've managed to set up a menu command in the AppDelegate, but how could I use this to change the text (at a certain position) in a NSTextView of an arbitrary View?

@IBAction func setTagImportant(_ sender: Any) {
  print("setTagImportant")
}

Thanks a lot for shedding some light on this for me...

Answer 1

Ironically, immediately after finally posting this question, I found a solution; simply subclass the NSTextView and then override keyDown:

import SwiftUI

class RichTextFieldExtended: NSTextView {
    
    override func keyDown(with event: NSEvent) {
        
        if event.modifierFlags.contains(NSEvent.ModifierFlags.command) {
            
            switch event.keyCode {
                
            case 18: // 1
                
                print("1 PRESSED")                
                
            default:
                print("keyCode \(event.keyCode) wasn't handled")
                super.keyDown(with: event)
            }
            
        } else {
            super.keyDown(with: event)
        }
        
    }
    
}

Then include the subclassed NSTextView in the NSViewRepresentable, as follows

struct RichTextField: NSViewRepresentable {
    typealias NSViewType = RichTextFieldExtended
    
    @Binding var attributedString: NSAttributedString
    var isEditable: Bool
    
    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }

    func makeNSView(context: Context) -> RichTextFieldExtended {
        let textView = RichTextFieldExtended(frame: .zero)
        
        textView.textStorage?.setAttributedString(self.attributedString)
        textView.isEditable = isEditable
        textView.delegate = context.coordinator
        
        textView.translatesAutoresizingMaskIntoConstraints = false
        textView.autoresizingMask = [.width, .height] 

        return textView
    }

    func updateNSView(_ nsView: RichTextFieldExtended, context: Context) {
//        nsView.textStorage!.setAttributedString(self.attributedString)
    }

    // Source: https://medium.com/fantageek/use-xib-de9d8a295757
    class Coordinator: NSObject, NSTextViewDelegate {
        let parent: RichTextField
        
        init(_ RichTextField: RichTextField) {
            self.parent = RichTextField
        }

        func textDidChange(_ notification: Notification) {

            guard let textView = notification.object as? RichTextFieldExtended else { return }
            self.parent.attributedString = textView.attributedString()

        }

    }
    
}

Cheers