Consolidate message observer API for win and aura (and touch).

base/message_pump_win.h

 // Copyright (c) 2011 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_
 #pragma once
 
 #include <windows.h>
 
 #include <list>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
 #include "base/message_pump.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
 // for Windows. It provides basic functionality like handling of observers and
 // controlling the lifetime of the message pump.
 class BASE_EXPORT MessagePumpWin : public MessagePump {
  public:
-  // An Observer is an object that receives global notifications from the
-  // UI MessageLoop.
-  //
-  // NOTE: An Observer implementation should be extremely fast!
-  //
-  class BASE_EXPORT Observer {
-   public:
-    virtual ~Observer() {}
-
-    // This method is called before processing a message.
-    // The message may be undefined in which case msg.message is 0
-    virtual void WillProcessMessage(const MSG& msg) = 0;
-
-    // This method is called when control returns from processing a UI message.
-    // The message may be undefined in which case msg.message is 0
-    virtual void DidProcessMessage(const MSG& msg) = 0;
-  };
 
   // Dispatcher is used during a nested invocation of Run to dispatch events.
   // If Run is invoked with a non-NULL Dispatcher, MessageLoop does not
   // dispatch events (or invoke TranslateMessage), rather every message is
   // passed to Dispatcher's Dispatch method for dispatch. It is up to the
   // Dispatcher to dispatch, or not, the event.
   //
   // The nested loop is exited by either posting a quit, or returning false
   // from Dispatch.
   class BASE_EXPORT Dispatcher {
    public:
     virtual ~Dispatcher() {}
     // Dispatches the event. If true is returned processing continues as
     // normal. If false is returned, the nested loop exits immediately.
     virtual bool Dispatch(const MSG& msg) = 0;
   };
 
   MessagePumpWin() : have_work_(0), state_(NULL) {}
   virtual ~MessagePumpWin() {}
 
   // Add an Observer, which will start receiving notifications immediately.
-  void AddObserver(Observer* observer);
+  void AddObserver(MessagePumpObserver* observer);
 
   // Remove an Observer.  It is safe to call this method while an Observer is
   // receiving a notification callback.
-  void RemoveObserver(Observer* observer);
+  void RemoveObserver(MessagePumpObserver* observer);
 
   // Give a chance to code processing additional messages to notify the
   // message loop observers that another message has been processed.
   void WillProcessMessage(const MSG& msg);
   void DidProcessMessage(const MSG& msg);
 
   // Like MessagePump::Run, but MSG objects are routed through dispatcher.
   void RunWithDispatcher(Delegate* delegate, Dispatcher* dispatcher);
 
   // MessagePump methods:
   virtual void Run(Delegate* delegate) { RunWithDispatcher(delegate, NULL); }
   virtual void Quit();
 
  protected:
   struct RunState {
     Delegate* delegate;
     Dispatcher* dispatcher;
 
     // Used to flag that the current Run() invocation should return ASAP.
     bool should_quit;
 
     // Used to count how many Run() invocations are on the stack.
     int run_depth;
   };
 
   virtual void DoRunLoop() = 0;
   int GetCurrentDelay() const;
 
-  ObserverList<Observer> observers_;
+  ObserverList<MessagePumpObserver> observers_;
 
   // The time at which delayed work should run.
   TimeTicks delayed_work_time_;
 
   // A boolean value used to indicate if there is a kMsgDoWork message pending
   // in the Windows Message queue.  There is at most one such message, and it
   // can drive execution of tasks when a native message pump is running.
   LONG have_work_;
 
   // State for the current invocation of Run.
@@ skipping 252 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_