Input gestures - iOS

On iOS, the UIGestureRecognizer and UIGestureRecognizerDelegate objects are a common way to detect gestures.

A gesture should not be the only way to trigger actions. Make sure to provide a second way, such as a button, to trigger the same action.

let gesture = UIPinchGestureRecognizer(
    target: self, 
    action: #selector(onPinch(_:))
)
addGestureRecognizer(gesture)

@objc private func onPinch(_ sender: UIPinchGestureRecognizer) {
  // Provide alternative
}