GUI.Quit - OpenTuring Documentation

Syntax

GUI.Quit

Description

This procedure causes GUI.ProcessEvent to return true. If the program is structured properly with a

        loop
            exit when GUI.ProcessEvent
        end loop

at the end of the program, then the program will exit the loop after finishing the current action procedure. This procedure is usually called from the action procedure of a Quit button or Exit menu item.

Example

Here is program that does nothing but wait for the user to press the quit button or type the letter 'Q', 'q', 'X', or 'x'.

        import GUI
        
        procedure KeyHandler (ch : char)
            if ch = 'Q' or ch = 'q' or ch = 'X' or ch = 'x' then
                GUI.Quit
            end if
        end KeyHandler
        
        var quitButton : int := GUI.CreateButton (10, 10, 0, "Quit", GUI.Quit)
        GUI.SetKeyEventHandler (KeyHandler)
        
        loop
            exit when GUI.ProcessEvent
        end loop
        
        put "Done!"

Status

Exported qualified.

This means that you can only call the procedures by calling GUI.Quit, not by calling Quit.

See also

GUI.ProcessEvent. See also GUI.ResetQuit for resetting the "quit" flag, so that a second event loop can be used in the same program.