Making copy & paste work with NSTextField
·
Igor Kulman
When I started working on my open-source Localization Editor, which is a macOS application, I encountered some things that were a bit strange compared to iOS development. One of those things is that copy & paste does not automatically work on a NSTextField.
To be exact, copy & paste works on a NSTextField as long as you do not delete the Edit menu from the standard Main menu. If you do that for some reason, you have to implement all the copy & paste functionality yourself.
The key to the implementation is overriding the performKeyEquivalent method and manually checking for cmd + c/v/x/z/a
final class EditableNSTextField: NSTextField {
private let commandKey = NSEvent.ModifierFlags.command.rawValue
private let commandShiftKey = NSEvent.ModifierFlags.command.rawValue | NSEvent.ModifierFlags.shift.rawValue
override func performKeyEquivalent(with event: NSEvent) -> Bool {
if event.type == NSEvent.EventType.keyDown {
if (event.modifierFlags.rawValue & NSEvent.ModifierFlags.deviceIndependentFlagsMask.rawValue) == commandKey {
switch event.charactersIgnoringModifiers! {
case "x":
if NSApp.sendAction(#selector(NSText.cut(_:)), to: nil, from: self) { return true }
case "c":
if NSApp.sendAction(#selector(NSText.copy(_:)), to: nil, from: self) { return true }
case "v":
if NSApp.sendAction(#selector(NSText.paste(_:)), to: nil, from: self) { return true }
case "z":
if NSApp.sendAction(Selector(("undo:")), to: nil, from: self) { return true }
case "a":
if NSApp.sendAction(#selector(NSResponder.selectAll(_:)), to: nil, from: self) { return true }
default:
break
}
} else if (event.modifierFlags.rawValue & NSEvent.ModifierFlags.deviceIndependentFlagsMask.rawValue) == commandShiftKey {
if event.charactersIgnoringModifiers == "Z" {
if NSApp.sendAction(Selector(("redo:")), to: nil, from: self) { return true }
}
}
}
return super.performKeyEquivalent(with: event)
}
}