NAME

       PDL::Graphics::TriD::ButtonControl - default event handler subroutines

FUNCTIONS

   new()
       Bless an oject into the class ButtonControl, expects the associated Window object to be
       supplied as an argument.

       The ButtonControl class is a base class which all TriD event controllers should inherit
       from.  By itself it does not do much.  It defines ButtonPress and ButtonRelease functions
       which are expected by the Event loop.

   mouse_moved
       A do-nothing function to prevent errors if not defined in a subclass

   ButtonRelease
       A do nothing function to prevent errors if not defined in a subclass

   ButtonPress
       Activates the viewport the mouse is inside when pressed

   set_wh
       Define the width and Height of the window for button control