Source/core/dom/custom/CustomElementScheduler.cpp

/*
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#include "config.h"
#include "core/dom/custom/CustomElementScheduler.h"

#include "core/dom/Document.h"
#include "core/dom/Element.h"
#include "core/dom/custom/CustomElementCallbackDispatcher.h"
#include "core/dom/custom/CustomElementCallbackInvocation.h"
#include "core/dom/custom/CustomElementLifecycleCallbacks.h"
#include "core/dom/custom/CustomElementMicrotaskDispatcher.h"
#include "core/dom/custom/CustomElementMicrotaskImportStep.h"
#include "core/dom/custom/CustomElementMicrotaskQueue.h"
#include "core/dom/custom/CustomElementMicrotaskResolutionStep.h"
#include "core/dom/custom/CustomElementRegistrationContext.h"
#include "core/html/imports/HTMLImportChild.h"

namespace WebCore {

class HTMLImport;

void CustomElementScheduler::scheduleCallback(PassRefPtr<CustomElementLifecycleCallbacks> callbacks, PassRefPtr<Element> element, CustomElementLifecycleCallbacks::CallbackType type)
{
    ASSERT(type != CustomElementLifecycleCallbacks::AttributeChanged);

    if (!callbacks->hasCallback(type))
        return;

    CustomElementCallbackQueue& queue = instance().schedule(element);
    queue.append(CustomElementCallbackInvocation::createInvocation(callbacks, type));
}

void CustomElementScheduler::scheduleAttributeChangedCallback(PassRefPtr<CustomElementLifecycleCallbacks> callbacks, PassRefPtr<Element> element, const AtomicString& name, const AtomicString& oldValue, const AtomicString& newValue)
{
    if (!callbacks->hasCallback(CustomElementLifecycleCallbacks::AttributeChanged))
        return;

    CustomElementCallbackQueue& queue = instance().schedule(element);
    queue.append(CustomElementCallbackInvocation::createAttributeChangedInvocation(callbacks, name, oldValue, newValue));
}

void CustomElementScheduler::resolveOrScheduleResolution(PassRefPtr<CustomElementRegistrationContext> context, PassRefPtr<Element> element, const CustomElementDescriptor& descriptor)
{
    if (CustomElementCallbackDispatcher::inCallbackDeliveryScope()) {
        context->resolve(element.get(), descriptor);
        return;
    }

    HTMLImportLoader* loader = element->document().importLoader();
    OwnPtr<CustomElementMicrotaskResolutionStep> step = CustomElementMicrotaskResolutionStep::create(context, element, descriptor);
    CustomElementMicrotaskDispatcher::instance().enqueue(loader, step.release());
}

CustomElementMicrotaskImportStep* CustomElementScheduler::scheduleImport(HTMLImportChild* import)
{
    ASSERT(!import->isDone());
    ASSERT(import->parent());

    OwnPtr<CustomElementMicrotaskImportStep> step = CustomElementMicrotaskImportStep::create(import);
    CustomElementMicrotaskImportStep* rawStep = step.get();

    // Ownership of the new step is transferred to the parent
    // processing step, or the base queue.
    CustomElementMicrotaskDispatcher::instance().enqueue(import->parent()->loader(), step.release());

    return rawStep;
}

CustomElementScheduler& CustomElementScheduler::instance()
{
    DEFINE_STATIC_LOCAL(CustomElementScheduler, instance, ());
    return instance;
}

CustomElementCallbackQueue& CustomElementScheduler::ensureCallbackQueue(PassRefPtr<Element> element)
{
    ElementCallbackQueueMap::ValueType* it = m_elementCallbackQueueMap.add(element.get(), nullptr).storedValue;
    if (!it->value)
        it->value = CustomElementCallbackQueue::create(element);
    return *it->value.get();
}

void CustomElementScheduler::callbackDispatcherDidFinish()
{
    if (CustomElementMicrotaskDispatcher::instance().elementQueueIsEmpty())
        instance().clearElementCallbackQueueMap();
}

void CustomElementScheduler::microtaskDispatcherDidFinish()
{
    ASSERT(!CustomElementCallbackDispatcher::inCallbackDeliveryScope());
    instance().clearElementCallbackQueueMap();
}

void CustomElementScheduler::clearElementCallbackQueueMap()
{
    ElementCallbackQueueMap emptyMap;
    m_elementCallbackQueueMap.swap(emptyMap);
}

// Finds or creates the callback queue for element.
CustomElementCallbackQueue& CustomElementScheduler::schedule(PassRefPtr<Element> passElement)
{
    RefPtr<Element> element(passElement);

    CustomElementCallbackQueue& callbackQueue = ensureCallbackQueue(element);
    if (callbackQueue.inCreatedCallback()) {
        // Don't move it. Authors use the createdCallback like a
        // constructor. By not moving it, the createdCallback
        // completes before any other callbacks are entered for this
        // element.
        return callbackQueue;
    }

    if (CustomElementCallbackDispatcher::inCallbackDeliveryScope()) {
        // The processing stack is active.
        CustomElementCallbackDispatcher::instance().enqueue(&callbackQueue);
        return callbackQueue;
    }

    CustomElementMicrotaskDispatcher::instance().enqueue(&callbackQueue);
    return callbackQueue;
}

} // namespace WebCore