base/message_pump_gtk.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef BASE_MESSAGE_PUMP_GTK_H_
   6 #define BASE_MESSAGE_PUMP_GTK_H_
   7 #pragma once
   8
   9 #include "base/message_pump_glib.h"
  10
  11 typedef union _GdkEvent GdkEvent;
  12 typedef struct _XDisplay Display;
  13
  14 namespace base {
  15
  16 // The documentation for this class is in message_pump_glib.h
  17 class MessagePumpObserver {
  18  public:
  19   // This method is called before processing a message.
  20   virtual void WillProcessEvent(GdkEvent* event) = 0;
  21
  22   // This method is called after processing a message.
  23   virtual void DidProcessEvent(GdkEvent* event) = 0;
  24
  25  protected:
  26   virtual ~MessagePumpObserver() {}
  27 };
  28
  29 // The documentation for this class is in message_pump_glib.h
  30 //
  31 // The nested loop is exited by either posting a quit, or returning false
  32 // from Dispatch.
  33 class MessagePumpDispatcher {
  34  public:
  35   // Dispatches the event. If true is returned processing continues as
  36   // normal. If false is returned, the nested loop exits immediately.
  37   virtual bool Dispatch(GdkEvent* event) = 0;
  38
  39  protected:
  40   virtual ~MessagePumpDispatcher() {}
  41 };
  42
  43 // This class implements a message-pump for dispatching GTK events.
  44 class BASE_EXPORT MessagePumpGtk : public MessagePumpGlib {
  45  public:
  46   MessagePumpGtk();
  47   virtual ~MessagePumpGtk();
  48
  49   // Dispatch an available GdkEvent. Essentially this allows a subclass to do
  50   // some task before/after calling the default handler (EventDispatcher).
  51   void DispatchEvents(GdkEvent* event);
  52
  53   // Returns default X Display.
  54   static Display* GetDefaultXDisplay();
  55
  56  private:
  57   // Invoked from EventDispatcher. Notifies all observers we're about to
  58   // process an event.
  59   void WillProcessEvent(GdkEvent* event);
  60
  61   // Invoked from EventDispatcher. Notifies all observers we processed an
  62   // event.
  63   void DidProcessEvent(GdkEvent* event);
  64
  65   // Callback prior to gdk dispatching an event.
  66   static void EventDispatcher(GdkEvent* event, void* data);
  67
  68   DISALLOW_COPY_AND_ASSIGN(MessagePumpGtk);
  69 };
  70
  71 typedef MessagePumpGtk MessagePumpForUI;
  72
  73 }  // namespace base
  74
  75 #endif  // BASE_MESSAGE_PUMP_GTK_H_