transui/macos/Sources/Transui/HotkeyRecorder.swift

import AppKit
import SwiftUI

struct HotkeyRecorder: NSViewRepresentable {
  @Binding var shortcut: HotkeyShortcut

  func makeNSView(context: Context) -> HotkeyCaptureView {
    let view = HotkeyCaptureView()
    view.onShortcut = { shortcut = $0 }
    view.stringValue = shortcut.displayName
    return view
  }

  func updateNSView(_ view: HotkeyCaptureView, context: Context) {
    view.onShortcut = { shortcut = $0 }
    if view.window?.firstResponder !== view {
      view.stringValue = shortcut.displayName
    }
  }
}

final class HotkeyCaptureView: NSTextField {
  var onShortcut: ((HotkeyShortcut) -> Void)?

  override init(frame frameRect: NSRect) {
    super.init(frame: frameRect)
    isEditable = false
    isSelectable = false
    isBezeled = true
    bezelStyle = .roundedBezel
    alignment = .center
    font = .monospacedSystemFont(ofSize: NSFont.systemFontSize, weight: .medium)
    toolTip = "Click, then press a shortcut"
  }

  required init?(coder: NSCoder) { nil }

  override var acceptsFirstResponder: Bool { true }

  override func mouseDown(with event: NSEvent) {
    window?.makeFirstResponder(self)
    stringValue = "Type shortcut"
  }

  override func keyDown(with event: NSEvent) {
    guard let shortcut = HotkeyShortcut(event: event) else {
      NSSound.beep()
      return
    }
    stringValue = shortcut.displayName
    onShortcut?(shortcut)
    window?.makeFirstResponder(nil)
  }

  override func resignFirstResponder() -> Bool {
    needsDisplay = true
    return super.resignFirstResponder()
  }
}