Replace PeekMessage for TSF awareness

base/message_pump_win.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_MESSAGE_PUMP_WIN_H_
 #define BASE_MESSAGE_PUMP_WIN_H_
 
 #include <windows.h>
 
 #include <list>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/message_pump.h"
 #include "base/message_pump_dispatcher.h"
 #include "base/message_pump_observer.h"
 #include "base/observer_list.h"
 #include "base/time.h"
 #include "base/win/scoped_handle.h"
 
 namespace base {
 
 // MessagePumpWin serves as the base for specialized versions of the MessagePump
@@ skipping 95 matching lines @@
 // is peeked, and before a replacement kMsgHaveWork is posted).
 //
 // NOTE: Although it may seem odd that messages are used to start and stop this
 // flow (as opposed to signaling objects, etc.), it should be understood that
 // the native message pump will *only* respond to messages.  As a result, it is
 // an excellent choice.  It is also helpful that the starter messages that are
 // placed in the queue when new task arrive also awakens DoRunLoop.
 //
 class BASE_EXPORT MessagePumpForUI : public MessagePumpWin {
  public:
+  // A MessageFilter implements the common Peek/Translate/Dispatch code to deal
+  // with windows messages.
+  class BASE_EXPORT MessageFilter {
+   public:
+    virtual ~MessageFilter() {}
+    virtual bool Init() = 0;
+    // Implements the functionality exposed by the OS through PeekMessage.
+    virtual BOOL DoPeekMessage(MSG* messge,
+                               HWND window_handle,
+                               UINT msg_filter_min,
+                               UINT msg_filter_max,
+                               UINT remove_msg) = 0;
+    // Returns true if |message| was consumed by the filter and no extra
+    // processing is required. If this method returns false, the normal message
+    // processing will take place.
+    // The priority to consume messages is the following:
+    // - Native Windows' message filter (CallMsgFilter).
+    // - MessageFilter::ProcessMessage.
+    // - MessagePumpDispatcher.
+    // - TranslateMessage / DispatchMessage.
+    virtual bool ProcessMessage(const MSG& message) = 0;
+  };
   // The application-defined code passed to the hook procedure.
   static const int kMessageFilterCode = 0x5001;
 
   MessagePumpForUI();
   virtual ~MessagePumpForUI();
 
+  // Sets a new MessageFilter. MessagePumpForUI has ownership of

[rvargas (doing something else), 2012/08/31 21:39:49]

nit: has -> takes

[yoichio, 2012/09/03 04:45:08]

Done.

+  // |message_filter|.
+  void SetMessageFilter(MessageFilter* message_filter);

[rvargas (doing something else), 2012/08/31 21:39:49]

There has to be documentation somewhere that states what happens when
SetMessageFilter is called multiple times.

This looks like the right place to do that... but then you should instruct
readers to refer to this file instead of relying on the description from
message_loop.h. See how RegisterIOHandler declaration forwards the
documentation.

[yoichio, 2012/09/03 04:45:08]

Done.

+
   // MessagePump methods:
   virtual void ScheduleWork();
   virtual void ScheduleDelayedWork(const TimeTicks& delayed_work_time);
 
   // Applications can call this to encourage us to process all pending WM_PAINT
   // messages.  This method will process all paint messages the Windows Message
   // queue can provide, up to some fixed number (to avoid any infinite loops).
   void PumpOutPendingPaintMessages();
 
- private:
-  static LRESULT CALLBACK WndProcThunk(
-      HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam);
+private:

[rvargas (doing something else), 2012/08/31 21:39:49]

nit: don't remove the space

[yoichio, 2012/09/03 04:45:08]

Done.

+  static LRESULT CALLBACK WndProcThunk(HWND window_handle,
+                                       UINT message,
+                                       WPARAM wparam,
+                                       LPARAM lparam);
   virtual void DoRunLoop();
   void InitMessageWnd();
   void WaitForWork();
   void HandleWorkMessage();
   void HandleTimerMessage();
   bool ProcessNextWindowsMessage();
-  bool ProcessMessageHelper(const MSG& msg);
+  bool ProcessMessageHelper(const MSG& message);
   bool ProcessPumpReplacementMessage();
 
   // Instance of the module containing the window procedure.
   HMODULE instance_;
 
   // A hidden message-only window.
   HWND message_hwnd_;
+
+  scoped_ptr<MessageFilter> message_filter_;
 };
 
 //-----------------------------------------------------------------------------
 // MessagePumpForIO extends MessagePumpWin with methods that are particular to a
 // MessageLoop instantiated with TYPE_IO. This version of MessagePump does not
 // deal with Windows mesagges, and instead has a Run loop based on Completion
 // Ports so it is better suited for IO operations.
 //
 class BASE_EXPORT MessagePumpForIO : public MessagePumpWin {
  public:
@@ skipping 179 matching lines @@
   // This list will be empty almost always. It stores IO completions that have
   // not been delivered yet because somebody was doing cleanup.
   std::list<IOItem> completed_io_;
 
   ObserverList<IOObserver> io_observers_;
 };
 
 }  // namespace base
 
 #endif  // BASE_MESSAGE_PUMP_WIN_H_