| /* |
| * Copyright 2015 Google Inc. All Rights Reserved. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef COBALT_DOM_EVENT_QUEUE_H_ |
| #define COBALT_DOM_EVENT_QUEUE_H_ |
| |
| #include <vector> |
| |
| #include "base/memory/ref_counted.h" |
| #include "base/memory/weak_ptr.h" |
| #include "base/message_loop.h" |
| #include "cobalt/dom/event.h" |
| #include "cobalt/dom/event_target.h" |
| |
| namespace cobalt { |
| namespace dom { |
| |
| // Maintains an event queue that fires events asynchronously. The events in the |
| // queue are not guaranteed to be fired if the EventQueue is destroyed before |
| // it gets a chance to fire the events. However it does guarantee that the |
| // events will be fired asynchronous and in the order of appending. |
| // |
| // This is used where the spec requires certain events to be fired |
| // asynchronously and can be cancelled. For example, most of the events on the |
| // media element work in this way. |
| // Note: After putting an event to the queue, the caller should no longer modify |
| // the content of the event until it is fired or cancelled. |
| class EventQueue : public base::SupportsWeakPtr<EventQueue> { |
| public: |
| // The EventTarget is guaranteed to be valid during the life time and should |
| // usually be the owner. |
| explicit EventQueue(EventTarget* event_target); |
| void Enqueue(const scoped_refptr<Event>& event); |
| void CancelAllEvents(); |
| |
| private: |
| typedef std::vector<scoped_refptr<Event> > Events; |
| void DispatchEvents(); |
| |
| EventTarget* event_target_; |
| scoped_refptr<base::MessageLoopProxy> message_loop_; |
| Events events_; |
| }; |
| |
| } // namespace dom |
| } // namespace cobalt |
| |
| #endif // COBALT_DOM_EVENT_QUEUE_H_ |