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LibWeb: Introduce Mutation{Record,Observer} and observer microtasks

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Luke Wilde 2022-07-11 16:37:51 +01:00 committed by Andreas Kling
parent 116a7b74fe
commit c9ba5531e0
15 changed files with 531 additions and 0 deletions

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/*
* Copyright (c) 2022, Luke Wilde <lukew@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibWeb/Bindings/MainThreadVM.h>
#include <LibWeb/Bindings/WindowObject.h>
#include <LibWeb/DOM/MutationObserver.h>
#include <LibWeb/DOM/Node.h>
namespace Web::DOM {
// https://dom.spec.whatwg.org/#dom-mutationobserver-mutationobserver
MutationObserver::MutationObserver(Bindings::WindowObject& window_object, Bindings::CallbackType callback)
: m_callback(move(callback))
{
// 1. Set thiss callback to callback.
// 2. Append this to thiss relevant agents mutation observers.
auto* agent_custom_data = verify_cast<Bindings::WebEngineCustomData>(window_object.vm().custom_data());
agent_custom_data->mutation_observers.append(*this);
}
// https://dom.spec.whatwg.org/#dom-mutationobserver-observe
ExceptionOr<void> MutationObserver::observe(Node& target, MutationObserverInit options)
{
// 1. If either options["attributeOldValue"] or options["attributeFilter"] exists, and options["attributes"] does not exist, then set options["attributes"] to true.
if ((options.attribute_old_value.has_value() || options.attribute_filter.has_value()) && !options.attributes.has_value())
options.attributes = true;
// 2. If options["characterDataOldValue"] exists and options["characterData"] does not exist, then set options["characterData"] to true.
if (options.character_data_old_value.has_value() && !options.character_data.has_value())
options.character_data = true;
// 3. If none of options["childList"], options["attributes"], and options["characterData"] is true, then throw a TypeError.
if (!options.child_list && (!options.attributes.has_value() || !options.attributes.value()) && (!options.character_data.has_value() || !options.character_data.value()))
return SimpleException { SimpleExceptionType::TypeError, "Options must have one of childList, attributes or characterData set to true." };
// 4. If options["attributeOldValue"] is true and options["attributes"] is false, then throw a TypeError.
// NOTE: If attributeOldValue is present, attributes will be present because of step 1.
if (options.attribute_old_value.has_value() && options.attribute_old_value.value() && !options.attributes.value())
return SimpleException { SimpleExceptionType::TypeError, "attributes must be true if attributeOldValue is true." };
// 5. If options["attributeFilter"] is present and options["attributes"] is false, then throw a TypeError.
// NOTE: If attributeFilter is present, attributes will be present because of step 1.
if (options.attribute_filter.has_value() && !options.attributes.value())
return SimpleException { SimpleExceptionType::TypeError, "attributes must be true if attributeFilter is present." };
// 6. If options["characterDataOldValue"] is true and options["characterData"] is false, then throw a TypeError.
// NOTE: If characterDataOldValue is present, characterData will be present because of step 2.
if (options.character_data_old_value.has_value() && options.character_data_old_value.value() && !options.character_data.value())
return SimpleException { SimpleExceptionType::TypeError, "characterData must be true if characterDataOldValue is true." };
// 7. For each registered of targets registered observer list, if registereds observer is this:
bool updated_existing_observer = false;
for (auto& registered_observer : target.registered_observers_list()) {
if (registered_observer.observer.ptr() != this)
continue;
updated_existing_observer = true;
// 1. For each node of thiss node list, remove all transient registered observers whose source is registered from nodes registered observer list.
for (auto& node : m_node_list) {
// FIXME: Is this correct?
if (node.is_null())
continue;
node->registered_observers_list().remove_all_matching([&registered_observer](RegisteredObserver& observer) {
return is<TransientRegisteredObserver>(observer) && verify_cast<TransientRegisteredObserver>(observer).source.ptr() == &registered_observer;
});
}
// 2. Set registereds options to options.
registered_observer.options = options;
break;
}
// 8. Otherwise:
if (!updated_existing_observer) {
// 1. Append a new registered observer whose observer is this and options is options to targets registered observer list.
auto new_registered_observer = RegisteredObserver::create(*this, options);
target.add_registered_observer(new_registered_observer);
// 2. Append target to thiss node list.
m_node_list.append(target.make_weak_ptr());
}
return {};
}
// https://dom.spec.whatwg.org/#dom-mutationobserver-disconnect
void MutationObserver::disconnect()
{
// 1. For each node of thiss node list, remove any registered observer from nodes registered observer list for which this is the observer.
for (auto& node : m_node_list) {
// FIXME: Is this correct?
if (node.is_null())
continue;
node->registered_observers_list().remove_all_matching([this](RegisteredObserver& registered_observer) {
return registered_observer.observer.ptr() == this;
});
}
// 2. Empty thiss record queue.
m_record_queue.clear();
}
// https://dom.spec.whatwg.org/#dom-mutationobserver-takerecords
NonnullRefPtrVector<MutationRecord> MutationObserver::take_records()
{
// 1. Let records be a clone of thiss record queue.
auto records = m_record_queue;
// 2. Empty thiss record queue.
m_record_queue.clear();
// 3. Return records.
return records;
}
}