core/vgui/vgui_event_server.h

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// This is core/vgui/vgui_event_server.h
#ifndef vgui_event_server_h_
#define vgui_event_server_h_
#ifdef VCL_NEEDS_PRAGMA_INTERFACE
#pragma interface
#endif
//:
// \file
// \brief  Procedural event grabbing from a tableau
// \author Philip C. Pritchett, Robotics Research Group, University of Oxford
// \date   11 Sep 99
//
//  Contains class  vgui_event_server
//
// \verbatim
//  Modifications
//   11-SEP-1999 P.Pritchett - Initial version.
//   26-APR-2002 K.Y.McGaul - Converted to and added doxygen style comments.
// \endverbatim

#include <vgui/vgui_event.h>
#include <vgui/vgui_menu.h>
#include <vgui/vgui_tableau.h>
#include <vgui/vgui_tableau_sptr.h>
class vgui_event_server_interpose_tableau;

//: Procedural event grabbing from a tableau
//
//  vgui_event_server allows you to grab events intended for a tableau in a
//  procedural way, (i.e. in a "for" loop), in order to temporarily take control
//  of a tableau's event stream.  This is useful for modal operations such as
//  picking (- or maybe not, see below).
//
//  WARNING: This class is not as useful as it first appears!!
//   If we look at events outside the handle function of a tableau (e.g. by
//   using a vgui_event_server) then the gl state associated with those events
//   will have changed.  This means for a draw_overlay event we would end up
//   drawing into the wrong buffer. For a mouse event we may not be able to get
//   the position in the image using the projection_inspector (if e.g. the image
//   was zoomed) since all the gl matrices would have been reset.  I guess
//   you could use it to get key presses! - kym
class vgui_event_server
{
 public:
  //: Constructor - collects events from the given tableau.
  vgui_event_server(vgui_tableau_sptr const&);

  void reset();

  //: Move on to the next event in the event queue.
  bool next();

  void set_popup(const vgui_menu&);

  //: Returns the last event.
  vgui_event last_event() { return last_event_; }

 protected:
 ~vgui_event_server();

 private:
  friend class vgui_event_server_interpose_tableau;
  vgui_event_server_interpose_tableau* grabber_;
  vgui_tableau_sptr grabber_reference_;
  vgui_event last_event_;
  bool use_event_;
  vgui_menu menu;
};

#endif // vgui_event_server_h_