EventHandler

public protocol EventHandler : AnyObject

Base event handler interface

  • Returns whether this event handler is the first responder in the responder chain.

    Declaration

    Swift

    var isFirstResponder: Bool { get }

  • Returns whether this event handler can become the first responder of targeted events.

    Declaration

    Swift

    var canBecomeFirstResponder: Bool { get }

  • If this event handler is the first responder, returns whether it can currently resign the state.

    Declaration

    Swift

    var canResignFirstResponder: Bool { get }

  • Next target to direct an event to, in case this handler has not handled the event.

    Declaration

    Swift

    var next: EventHandler? { get }

  • Asks this event handler to become the first responder on the event responder chain.

    Returns a value specifying whether this event handler successfully became the first responder. If another event handler in the hierarchy is the first responder and it denies resigning it, or this event handler returns canBecomeFirstResponder as false, false is returned and this event handler does not become the first responder.

    If this handler is already the first responder (see isFirstResponder), the method returns true immediately.

    Declaration

    Swift

    func becomeFirstResponder() -> Bool

  • Asks this event handler to dismiss its first responder status.

    Declaration

    Swift

    func resignFirstResponder()

  • Asks this event handler to convert a screen-coordinate space point into its own local coordinates when synthesizing location events (e.g. mouse events) into this event handler.

    Declaration

    Swift

    func convertFromScreen(_ point: UIVector) -> UIVector

  • Requests that this event handler analyze an event request, and potentially accept the event via EventRequest.accept(handler:), or forward to a next event handler in a responder chain or other custom sequence of potential event handlers.

    Event handlers are not required to interact with an event request and may simply ignore it, but they may not accept it more than once.

    Declaration

    Swift

    func handleOrPass(_ eventRequest: EventRequest)