UIKeyInput
is your friend:
protocol KeyboardInputControlDelegate: class {
func keyboardInputControl( keyboardInputControl:KeyboardInputControl, didPressKey key:Character)
}
class KeyboardInputControl: UIControl, UIKeyInput {
// MARK: - properties
weak var delegate: KeyboardInputControlDelegate?
// MARK: - init
override init(frame: CGRect) {
super.init(frame: frame)
addTarget(self, action: Selector("onTouchUpInside:"), forControlEvents: .TouchUpInside)
}
required init(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
// MARK: - UIView
override func canBecomeFirstResponder() -> Bool {
return true
}
// MARK: - methods
dynamic private func onTouchUpInside(sender: KeyboardInputControl) {
becomeFirstResponder()
}
// MARK: - UIKeyInput
var text:String = ""
func hasText() -> Bool {
return text.isEmpty
}
func insertText(text: String) {
self.text = text
for ch in text {
delegate?.keyboardInputControl(self, didPressKey: ch)
}
}
func deleteBackward() {
if !text.isEmpty {
let newText = text[text.startIndex..<text.endIndex.predecessor()]
text = newText
}
}
}
Example usage. Tap the red view and see the Xcode console output:
class ViewController: UIViewController, KeyboardInputControlDelegate {
override func viewDidLoad() {
super.viewDidLoad()
let kic = KeyboardInputControl(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
kic.delegate = self
kic.backgroundColor = UIColor.redColor()
view.addSubview(kic)
}
func keyboardInputControl(keyboardInputControl: KeyboardInputControl, didPressKey key: Character) {
println("Did press: \(key)")
}
}