| // Copyright 2015 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. |
| |
| #include "ui/events/scoped_target_handler.h" |
| |
| #include "ui/events/event.h" |
| #include "ui/events/event_handler.h" |
| #include "ui/events/event_target.h" |
| |
| namespace ui { |
| |
| ScopedTargetHandler::ScopedTargetHandler(EventTarget* target, |
| EventHandler* handler) |
| : destroyed_flag_(NULL), target_(target), new_handler_(handler) { |
| original_handler_ = target_->SetTargetHandler(this); |
| } |
| |
| ScopedTargetHandler::~ScopedTargetHandler() { |
| EventHandler* handler = target_->SetTargetHandler(original_handler_); |
| DCHECK_EQ(this, handler); |
| if (destroyed_flag_) |
| *destroyed_flag_ = true; |
| } |
| |
| void ScopedTargetHandler::OnEvent(Event* event) { |
| if (original_handler_) { |
| bool destroyed = false; |
| bool* old_destroyed_flag = destroyed_flag_; |
| destroyed_flag_ = &destroyed; |
| |
| original_handler_->OnEvent(event); |
| |
| if (destroyed) { |
| if (old_destroyed_flag) |
| *old_destroyed_flag = true; |
| return; |
| } |
| destroyed_flag_ = old_destroyed_flag; |
| } |
| |
| // This check is needed due to nested event loops when starting DragDrop. |
| if (event->stopped_propagation()) |
| return; |
| |
| new_handler_->OnEvent(event); |
| } |
| |
| } // namespace ui |