问SwiftUI中的多行可编辑文本字段

EN

import SwiftUI
import os

let uiLog = OSLog(subsystem: "com.visual-science.CryptiK", category: "UI")

class  EditorCoordinator : NSObject, NSTextViewDelegate {
  let textView: NSTextView;
  let scrollView : NSScrollView
  let text : Binding<NSAttributedString>

  init(binding: Binding<NSAttributedString>) {
    text = binding

    textView = NSTextView(frame: .zero)
    textView.autoresizingMask = [.height, .width]
    textView.textStorage?.setAttributedString(text.wrappedValue)
    textView.textColor = NSColor.textColor

    scrollView = NSScrollView(frame: .zero)
    scrollView.hasVerticalScroller = true
    scrollView.autohidesScrollers = false
    scrollView.autoresizingMask = [.height, .width]
    scrollView.documentView = textView

    super.init()
    textView.delegate = self
  }

  func textDidChange(_ notification: Notification) {
    switch  notification.name {
    case NSText.didChangeNotification :
      text.wrappedValue = (notification.object as? NSTextView)?.textStorage ?? NSAttributedString(string: "")
    default:
      os_log(.error, log: uiLog, "Coordinator received unwanted notification")
    }
  }

}

struct DataTextEditorView: View, NSViewRepresentable {
  typealias Coordinator = EditorCoordinator
  typealias NSViewType = NSScrollView

  let text : Binding<NSAttributedString>

  func makeNSView(context: NSViewRepresentableContext<DataTextEditorView>) -> DataTextEditorView.NSViewType {
    os_log(.info, log: uiLog, "%@", context.coordinator.scrollView)
    return context.coordinator.scrollView
  }

  func updateNSView(_ nsView: NSScrollView, context: NSViewRepresentableContext<DataTextEditorView>) {
    os_log(.debug, log: uiLog, "%@", context.coordinator.self)
    os_log(.debug, log: uiLog, "%@", text.wrappedValue)
  }

  func makeCoordinator() -> EditorCoordinator {
    os_log(.info, log: uiLog, "makeCoordinator")
    let coordinator =  EditorCoordinator(binding: text)
    return coordinator
  }

}