| // 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 UI_BASE_EVENTS_EVENT_TARGET_H_ |
| #define UI_BASE_EVENTS_EVENT_TARGET_H_ |
| |
| #include "base/basictypes.h" |
| #include "base/compiler_specific.h" |
| #include "ui/base/events/event_handler.h" |
| #include "ui/base/ui_export.h" |
| |
| namespace ui { |
| |
| class EventDispatcher; |
| |
| class UI_EXPORT EventTarget : public EventHandler { |
| public: |
| typedef std::vector<EventTarget*> EventTargets; |
| |
| class TestApi { |
| public: |
| explicit TestApi(EventTarget* target) : target_(target) {} |
| |
| const EventHandlerList& pre_target_handlers() { |
| return target_->pre_target_list_; |
| } |
| |
| private: |
| TestApi(); |
| EventTarget* target_; |
| |
| DISALLOW_COPY_AND_ASSIGN(TestApi); |
| }; |
| |
| class DispatcherApi { |
| public: |
| explicit DispatcherApi(EventTarget* target) : target_(target) {} |
| |
| const EventHandlerList& pre_target_list() const { |
| return target_->pre_target_list_; |
| } |
| |
| private: |
| DispatcherApi(); |
| EventTarget* target_; |
| |
| DISALLOW_COPY_AND_ASSIGN(DispatcherApi); |
| }; |
| |
| EventTarget(); |
| virtual ~EventTarget(); |
| |
| virtual bool CanAcceptEvent(const ui::Event& event) = 0; |
| virtual EventTarget* GetParentTarget() = 0; |
| |
| // Adds a handler to receive events before the target. The handler must be |
| // explicitly removed from the target before the handler is destroyed. The |
| // EventTarget does not take ownership of the handler. |
| void AddPreTargetHandler(EventHandler* handler); |
| |
| // Same as AddPreTargetHandler except that the |handler| is added to the front |
| // of the list so it is the first one to receive events. |
| void PrependPreTargetHandler(EventHandler* handler); |
| void RemovePreTargetHandler(EventHandler* handler); |
| |
| // Adds a handler to receive events after the target. The handler must be |
| // explicitly removed from the target before the handler is destroyed. The |
| // EventTarget does not take ownership of the handler. |
| void AddPostTargetHandler(EventHandler* handler); |
| void RemovePostTargetHandler(EventHandler* handler); |
| |
| protected: |
| void set_target_handler(EventHandler* handler) { |
| target_handler_ = handler; |
| } |
| |
| // Overridden from EventHandler: |
| virtual void OnEvent(Event* event) OVERRIDE; |
| virtual void OnKeyEvent(KeyEvent* event) OVERRIDE; |
| virtual void OnMouseEvent(MouseEvent* event) OVERRIDE; |
| virtual void OnScrollEvent(ScrollEvent* event) OVERRIDE; |
| virtual void OnTouchEvent(TouchEvent* event) OVERRIDE; |
| virtual void OnGestureEvent(GestureEvent* event) OVERRIDE; |
| |
| private: |
| friend class EventDispatcher; |
| |
| // Returns the list of handlers that should receive the event before the |
| // target. The handlers from the outermost target are first in the list, and |
| // the handlers on |this| are the last in the list. |
| void GetPreTargetHandlers(EventHandlerList* list); |
| |
| // Returns the list of handlers that should receive the event after the |
| // target. The handlers from the outermost target are last in the list, and |
| // the handlers on |this| are the first in the list. |
| void GetPostTargetHandlers(EventHandlerList* list); |
| |
| EventHandlerList pre_target_list_; |
| EventHandlerList post_target_list_; |
| EventHandler* target_handler_; |
| |
| DISALLOW_COPY_AND_ASSIGN(EventTarget); |
| }; |
| |
| } // namespace ui |
| |
| #endif // UI_BASE_EVENTS_EVENT_TARGET_H_ |