chromium/ui/message_center/public/cpp/notification_delegate.h

// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_MESSAGE_CENTER_PUBLIC_CPP_NOTIFICATION_DELEGATE_H_
#define UI_MESSAGE_CENTER_PUBLIC_CPP_NOTIFICATION_DELEGATE_H_

#include <memory>
#include <optional>
#include <string>

#include "base/functional/callback.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "ui/message_center/public/cpp/message_center_public_export.h"

namespace message_center {

// Handles actions performed on a notification.
class MESSAGE_CENTER_PUBLIC_EXPORT NotificationObserver { … };

// Ref counted version of NotificationObserver, required to satisfy
// message_center::Notification::delegate_.
class MESSAGE_CENTER_PUBLIC_EXPORT NotificationDelegate
    : public NotificationObserver,
      public base::RefCountedThreadSafe<NotificationDelegate> { … };

// A pass-through which converts the RefCounted requirement to a WeakPtr
// requirement. This class replaces the need for individual delegates that pass
// through to an actual controller class, and which only exist because the
// actual controller has a strong ownership model.
class MESSAGE_CENTER_PUBLIC_EXPORT ThunkNotificationDelegate
    : public NotificationDelegate { … };

// A simple notification delegate which invokes the passed closure when the body
// or a button is clicked.
class MESSAGE_CENTER_PUBLIC_EXPORT HandleNotificationClickDelegate
    : public NotificationDelegate { … };

}  //  namespace message_center

#endif  // UI_MESSAGE_CENTER_PUBLIC_CPP_NOTIFICATION_DELEGATE_H_