base/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_PUMP_GTK_H_
   6 #define BASE_MESSAGE_PUMP_GTK_H_
   7
   8 #include "base/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 MessagePumpObserver {
  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 ~MessagePumpObserver() {}
  26 };
  27
  28 // The documentation for this class is in message_pump_glib.h
  29 //
  30 // The nested loop is exited by either posting a quit, or returning false
  31 // from Dispatch.
  32 class MessagePumpDispatcher {
  33  public:
  34   // Dispatches the event. If true is returned processing continues as
  35   // normal. If false is returned, the nested loop exits immediately.
  36   virtual bool Dispatch(GdkEvent* event) = 0;
  37
  38  protected:
  39   virtual ~MessagePumpDispatcher() {}
  40 };
  41
  42 // This class implements a message-pump for dispatching GTK events.
  43 class BASE_EXPORT MessagePumpGtk : public MessagePumpGlib {
  44  public:
  45   MessagePumpGtk();
  46
  47   // Dispatch an available GdkEvent. Essentially this allows a subclass to do
  48   // some task before/after calling the default handler (EventDispatcher).
  49   void DispatchEvents(GdkEvent* event);
  50
  51   // Returns default X Display.
  52   static Display* GetDefaultXDisplay();
  53
  54  protected:
  55   virtual ~MessagePumpGtk();
  56
  57  private:
  58   // Invoked from EventDispatcher. Notifies all observers we're about to
  59   // process an event.
  60   void WillProcessEvent(GdkEvent* event);
  61
  62   // Invoked from EventDispatcher. Notifies all observers we processed an
  63   // event.
  64   void DidProcessEvent(GdkEvent* event);
  65
  66   // Callback prior to gdk dispatching an event.
  67   static void EventDispatcher(GdkEvent* event, void* data);
  68
  69   DISALLOW_COPY_AND_ASSIGN(MessagePumpGtk);
  70 };
  71
  72 typedef MessagePumpGtk MessagePumpForUI;
  73
  74 }  // namespace base
  75
  76 #endif  // BASE_MESSAGE_PUMP_GTK_H_