How to change the selection color in an NSTextView in SwiftUI?

Question

I'm using SwiftUI and NSViewRepresentable to create a custom NSTextView that can display selectable text. Here's my code:

struct SelectableText: NSViewRepresentable {
    let text: String
    let font: NSFont?
    
    init(text: String, font: NSFont? = nil) {
        self.text = text
        self.font = font
    }
    
    func makeNSView(context: Context) -> NSTextField {
        let textField = NSTextField(wrappingLabelWithString: text)
        textField.isBezeled = false
        textField.isEditable = false
        textField.isSelectable = true
        textField.backgroundColor = .clear
        textField.font = font ?? NSFont.systemFont(ofSize: NSFont.systemFontSize)
        return textField
    }
    
    func updateNSView(_ nsView: NSTextField, context: Context) {
        nsView.stringValue = text
        nsView.font = font ?? NSFont.systemFont(ofSize: NSFont.systemFontSize)
    }
}

I want to change the color of the selection highlight in the NSTextView. I tried setting the selectedTextAttributes property, but it didn't work as expected. The NSTextView is not receiving the events it needs to handle text selection correctly.

How can I change the selection color in an NSTextView in SwiftUI? Any help would be greatly appreciated.

Answer 1

If you meant NSTextView, here is a possible approach:

struct SelectableTextView: NSViewRepresentable {
    let text: String
    let font: NSFont?
    
    init(text: String, font: NSFont? = nil) {
        self.text = text
        self.font = font
    }
    
    func makeNSView(context: Context) -> NSTextView {
        let textView = NSTextView(frame: .zero)
        textView.isEditable = false
        textView.isSelectable = true
        textView.backgroundColor = .clear
        textView.font = font ?? NSFont.systemFont(ofSize: NSFont.systemFontSize)
        textView.string = text
        
        textView.selectedTextAttributes = [
            NSAttributedString.Key.foregroundColor : NSColor.systemGreen, // Change the text color
            NSAttributedString.Key.backgroundColor: NSColor.systemRed// Change the background color
        ]
        return textView
    }
    
    func updateNSView(_ nsView: NSTextView, context: Context) {
        nsView.string = text
        nsView.font = font ?? NSFont.systemFont(ofSize: NSFont.systemFontSize)
    }
}