blob: 235db668a00f2c19cad69dea1b1cc6a6bf17a419 [file] [log] [blame]
// 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