base/message_loop/message_pump_gtk.h

   1 // Copyright (c) 2012 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_LOOP_MESSAGE_PUMP_GTK_H_
   6 #define BASE_MESSAGE_LOOP_MESSAGE_PUMP_GTK_H_
   7
   8 #include "base/message_loop/message_pump_glib.h"
   9
  10 typedef union _GdkEvent GdkEvent;
  11 typedef struct _XDisplay Display;
  12
  13 namespace base {
  14
  15 // The documentation for this class is in message_pump_glib.h
  16 class MessagePumpGdkObserver {
  17  public:
  18   // This method is called before processing a message.
  19   virtual void WillProcessEvent(GdkEvent* event) = 0;
  20
  21   // This method is called after processing a message.
  22   virtual void DidProcessEvent(GdkEvent* event) = 0;
  23
  24  protected:
  25   virtual ~MessagePumpGdkObserver() {}
  26 };
  27
  28 // This class implements a message-pump for dispatching GTK events.
  29 class BASE_EXPORT MessagePumpGtk : public MessagePumpGlib {
  30  public:
  31   MessagePumpGtk();
  32   virtual ~MessagePumpGtk();
  33
  34   // Dispatch an available GdkEvent. Essentially this allows a subclass to do
  35   // some task before/after calling the default handler (EventDispatcher).
  36   void DispatchEvents(GdkEvent* event);
  37
  38   // Returns default X Display.
  39   static Display* GetDefaultXDisplay();
  40
  41   // Adds an Observer, which will start receiving notifications immediately.
  42   void AddObserver(MessagePumpGdkObserver* observer);
  43
  44   // Removes an Observer.  It is safe to call this method while an Observer is
  45   // receiving a notification callback.
  46   void RemoveObserver(MessagePumpGdkObserver* observer);
  47
  48  private:
  49   // Invoked from EventDispatcher. Notifies all observers we're about to
  50   // process an event.
  51   void WillProcessEvent(GdkEvent* event);
  52
  53   // Invoked from EventDispatcher. Notifies all observers we processed an
  54   // event.
  55   void DidProcessEvent(GdkEvent* event);
  56
  57   // Callback prior to gdk dispatching an event.
  58   static void EventDispatcher(GdkEvent* event, void* data);
  59
  60   // List of observers.
  61   ObserverList<MessagePumpGdkObserver> observers_;
  62
  63   DISALLOW_COPY_AND_ASSIGN(MessagePumpGtk);
  64 };
  65
  66 typedef MessagePumpGtk MessagePumpForUI;
  67
  68 }  // namespace base
  69
  70 #endif  // BASE_MESSAGE_LOOP_MESSAGE_PUMP_GTK_H_