TOnUserInputEvent procedure type
Specifies an event handler signalled to respond to user input messages in an application.
Declaration
TOnUserInputEvent = procedure(Sender: TObject; var Msg: TLMessage)
of objectArguments
Sender | TObject instance for the event notification. |
Msg | Message structure with the message code, parameters, and result for the user input event. |
Description
TOnUserInputEvent is an object procedure type which defines an
event handler signalled to respond to user input messages in an application.
It is used as a callback which forwards input messages from widgetset classes
to the current application.
TOnUserInputEvent is the type used for the
OnUserInput
event handler in
TApplication and
TApplicationProperties. It is also passed as an argument to methods
like
AddOnUserInputHandler and
RemoveOnUserInputHandler
in TApplication.
An application must implement and assign a handler routine using the signature for the object procedure type to respond to the notification. Some components (like TCustomIdleTimer) provide an implementation for the event handler which is assigned to the application.
Modified in LCL version 5.0 to use TLMessage in the Msg argument instead of the cardinal value for the notification message.
See also
An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.