headers/os/app/MessageFilter.h

   1 /*
   2  * Copyright 2001-2014 Haiku, Inc. All rights reserved.
   3  * Distributed under the terms of the MIT License.
   4  *
   5  * Authors:
   6  *              Erik Jaesler, erik@cgsoftware.com
   7  */
   8 #ifndef _MESSAGE_FILTER_H
   9 #define _MESSAGE_FILTER_H
  10
  11
  12 #include <Handler.h>
  13
  14
  15 class BMessage;
  16
  17
  18 // filter_hook Return Codes and Protocol
  19 enum filter_result {
  20         B_SKIP_MESSAGE,
  21         B_DISPATCH_MESSAGE
  22 };
  23
  24
  25 typedef filter_result (*filter_hook)
  26         (BMessage* message, BHandler** target, BMessageFilter* filter);
  27
  28
  29 // BMessageFilter invocation criteria
  30 enum message_delivery {
  31         B_ANY_DELIVERY,
  32         B_DROPPED_DELIVERY,
  33         B_PROGRAMMED_DELIVERY
  34 };
  35
  36 enum message_source {
  37         B_ANY_SOURCE,
  38         B_REMOTE_SOURCE,
  39         B_LOCAL_SOURCE
  40 };
  41
  42
  43 class BMessageFilter {
  44 public:
  45                                                                 BMessageFilter(uint32 what,
  46                                                                         filter_hook func = NULL);
  47                                                                 BMessageFilter(message_delivery delivery,
  48                                                                         message_source source, filter_hook func = NULL);
  49                                                                 BMessageFilter(message_delivery delivery,
  50                                                                         message_source source, uint32 what,
  51                                                                         filter_hook func = NULL);
  52                                                                 BMessageFilter(const BMessageFilter& filter);
  53                                                                 BMessageFilter(const BMessageFilter* filter);
  54         virtual                                         ~BMessageFilter();
  55
  56                         BMessageFilter&         operator=(const BMessageFilter& from);
  57
  58                         // Hook function; ignored if filter_hook is non-NULL
  59         virtual filter_result           Filter(BMessage* message, BHandler** _target);
  60
  61                         message_delivery        MessageDelivery() const;
  62                         message_source          MessageSource() const;
  63                         uint32                          Command() const;
  64                         bool                            FiltersAnyCommand() const;
  65                         BLooper*                        Looper() const;
  66
  67 private:
  68         friend class BLooper;
  69         friend class BHandler;
  70
  71         virtual void                            _ReservedMessageFilter1();
  72         virtual void                            _ReservedMessageFilter2();
  73
  74                         void                            SetLooper(BLooper* owner);
  75                         filter_hook                     FilterFunction() const;
  76
  77                         bool                            fFiltersAny;
  78                         uint32                          fWhat;
  79                         message_delivery        fDelivery;
  80                         message_source          fSource;
  81                         BLooper*                        fLooper;
  82                         filter_hook                     fFilterFunction;
  83
  84                         uint32                          _reserved[3];
  85 };
  86
  87
  88 #endif  // _MESSAGE_FILTER_H