| // Copyright 2017 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. |
| |
| #include "cobalt/dom/mutation_observer_task_manager.h" |
| |
| #include "base/callback.h" |
| #include "base/message_loop.h" |
| #include "cobalt/dom/mutation_observer.h" |
| |
| namespace cobalt { |
| namespace dom { |
| |
| void MutationObserverTaskManager::OnMutationObserverCreated( |
| MutationObserver* observer) { |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| DCHECK(observers_.find(observer) == observers_.end()); |
| observers_.insert(observer); |
| } |
| |
| void MutationObserverTaskManager::OnMutationObserverDestroyed( |
| MutationObserver* observer) { |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| DCHECK(observers_.find(observer) != observers_.end()); |
| observers_.erase(observer); |
| } |
| |
| void MutationObserverTaskManager::QueueMutationObserverMicrotask() { |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| // https://www.w3.org/TR/dom/#queue-a-mutation-observer-compound-microtask |
| // To queue a mutation observer compound microtask, run these steps: |
| // 1. If mutation observer compound microtask queued flag is set, terminate |
| // these steps. |
| if (task_posted_) { |
| return; |
| } |
| // 2. Set mutation observer compound microtask queued flag. |
| task_posted_ = true; |
| // 3. Queue a compound microtask to notify mutation observers. |
| MessageLoop::current()->PostTask( |
| FROM_HERE, |
| base::Bind(&MutationObserverTaskManager::NotifyMutationObservers, |
| base::Unretained(this))); |
| } |
| |
| void MutationObserverTaskManager::TraceMembers(script::Tracer* tracer) { |
| tracer->TraceItems(observers_); |
| } |
| |
| void MutationObserverTaskManager::NotifyMutationObservers() { |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| DCHECK(task_posted_); |
| DCHECK(MessageLoop::current()); |
| // https://www.w3.org/TR/dom/#notify-mutation-observers |
| // To notify mutation observers, run these steps: |
| // 1. Unset mutation observer compound microtask queued flag. |
| task_posted_ = false; |
| |
| // 2. Let notify list be a copy of unit of related similar-origin browsing |
| // contexts's list of MutationObserver objects. |
| // 3. For each MutationObserver object mo in notify list, execute a compound |
| // microtask subtask to run these steps: [HTML] |
| // |
| // Subtask steps are implemented in MutationObserver::Notify. |
| |
| // Calling Notify could eventually add/remove observers from the set, so make |
| // a copy of it. |
| MutationObserverSet observers_copy = observers_; |
| while (!observers_copy.empty()) { |
| MutationObserver* observer = *observers_copy.begin(); |
| // Check that this observer was not removed as a side effect of Notify(). |
| if (observers_.find(observer) != observers_.end()) { |
| if (!observer->Notify()) { |
| DLOG(ERROR) << "Exception when notifying mutation observer."; |
| } |
| } |
| observers_copy.erase(observers_copy.begin()); |
| } |
| } |
| |
| } // namespace dom |
| } // namespace cobalt |