michael@0: // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: // This file defines the type used to provide sources for NotificationService
michael@0: // notifications.
michael@0: 
michael@0: #ifndef CHROME_COMMON_NOTIFICATION_SOURCE_H__
michael@0: #define CHROME_COMMON_NOTIFICATION_SOURCE_H__
michael@0: 
michael@0: #include "base/basictypes.h"
michael@0: 
michael@0: // Do not declare a NotificationSource directly--use either
michael@0: // "Source<sourceclassname>(sourceclasspointer)" or
michael@0: // NotificationService::AllSources().
michael@0: class NotificationSource {
michael@0:  public:
michael@0:   NotificationSource(const NotificationSource& other) : ptr_(other.ptr_) { }
michael@0:   ~NotificationSource() {}
michael@0: 
michael@0:   // NotificationSource can be used as the index for a map; this method
michael@0:   // returns the pointer to the current source as an identifier, for use as a
michael@0:   // map index.
michael@0:   uintptr_t map_key() const { return reinterpret_cast<uintptr_t>(ptr_); }
michael@0: 
michael@0:   bool operator!=(const NotificationSource& other) const {
michael@0:     return ptr_ != other.ptr_;
michael@0:   }
michael@0:   bool operator==(const NotificationSource& other) const {
michael@0:     return ptr_ == other.ptr_;
michael@0:   }
michael@0: 
michael@0:  protected:
michael@0:   NotificationSource(void* ptr) : ptr_(ptr) {}
michael@0: 
michael@0:   void* ptr_;
michael@0: };
michael@0: 
michael@0: template <class T>
michael@0: class Source : public NotificationSource {
michael@0:  public:
michael@0:   Source(T* ptr) : NotificationSource(ptr) {}
michael@0: 
michael@0:   Source(const NotificationSource& other)
michael@0:     : NotificationSource(other) {}
michael@0: 
michael@0:   T* operator->() const { return ptr(); }
michael@0:   T* ptr() const { return static_cast<T*>(ptr_); }
michael@0: };
michael@0: 
michael@0: #endif  // CHROME_COMMON_NOTIFICATION_SOURCE_H__