third_party/WebKit/Source/core/html/imports/HTMLImportChild.cpp

/*
 * Copyright (C) 2013 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
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 * in the documentation and/or other materials provided with the
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#include "core/html/imports/HTMLImportChild.h"

#include "core/css/StyleSheetList.h"
#include "core/dom/Document.h"
#include "core/dom/StyleEngine.h"
#include "core/dom/custom/V0CustomElement.h"
#include "core/dom/custom/V0CustomElementMicrotaskImportStep.h"
#include "core/dom/custom/V0CustomElementSyncMicrotaskQueue.h"
#include "core/frame/UseCounter.h"
#include "core/html/imports/HTMLImportChildClient.h"
#include "core/html/imports/HTMLImportLoader.h"
#include "core/html/imports/HTMLImportTreeRoot.h"
#include "core/html/imports/HTMLImportsController.h"

namespace blink {

HTMLImportChild::HTMLImportChild(const KURL& url,
                                 HTMLImportLoader* loader,
                                 SyncMode sync)
    : HTMLImport(sync), m_url(url), m_loader(loader), m_client(nullptr) {}

HTMLImportChild::~HTMLImportChild() {}

void HTMLImportChild::ownerInserted() {
  if (!m_loader->isDone())
    return;
  root()->document()->styleEngine().resolverChanged(FullStyleUpdate);
}

void HTMLImportChild::didShareLoader() {
  createCustomElementMicrotaskStepIfNeeded();
  stateWillChange();
}

void HTMLImportChild::didStartLoading() {
  createCustomElementMicrotaskStepIfNeeded();
}

void HTMLImportChild::didFinish() {
  if (m_client)
    m_client->didFinish();
}

void HTMLImportChild::didFinishLoading() {
  stateWillChange();
  if (document() && document()->styleSheets().length() > 0)
    UseCounter::count(root()->document(),
                      UseCounter::HTMLImportsHasStyleSheets);
  V0CustomElement::didFinishLoadingImport(*(root()->document()));
}

void HTMLImportChild::didFinishUpgradingCustomElements() {
  stateWillChange();
  m_customElementMicrotaskStep.clear();
}

void HTMLImportChild::dispose() {
  invalidateCustomElementMicrotaskStep();
  if (parent())
    parent()->removeChild(this);

  DCHECK(m_loader);
  m_loader->removeImport(this);
  m_loader = nullptr;

  if (m_client) {
    m_client->importChildWasDisposed(this);
    m_client = nullptr;
  }
}

Document* HTMLImportChild::document() const {
  DCHECK(m_loader);
  return m_loader->document();
}

void HTMLImportChild::stateWillChange() {
  toHTMLImportTreeRoot(root())->scheduleRecalcState();
}

void HTMLImportChild::stateDidChange() {
  HTMLImport::stateDidChange();

  if (state().isReady())
    didFinish();
}

void HTMLImportChild::invalidateCustomElementMicrotaskStep() {
  if (!m_customElementMicrotaskStep)
    return;
  m_customElementMicrotaskStep->invalidate();
  m_customElementMicrotaskStep.clear();
}

void HTMLImportChild::createCustomElementMicrotaskStepIfNeeded() {
  DCHECK(!m_customElementMicrotaskStep);

  if (!hasFinishedLoading() && !formsCycle()) {
    m_customElementMicrotaskStep = V0CustomElement::didCreateImport(this);
  }
}

bool HTMLImportChild::hasFinishedLoading() const {
  DCHECK(m_loader);

  return m_loader->isDone() && m_loader->microtaskQueue()->isEmpty() &&
         !m_customElementMicrotaskStep;
}

HTMLImportLoader* HTMLImportChild::loader() const {
  // This should never be called after dispose().
  DCHECK(m_loader);
  return m_loader;
}

void HTMLImportChild::setClient(HTMLImportChildClient* client) {
  DCHECK(client);
  DCHECK(!m_client);
  m_client = client;
}

HTMLLinkElement* HTMLImportChild::link() const {
  if (!m_client)
    return nullptr;
  return m_client->link();
}

// Ensuring following invariants against the import tree:
// - HTMLImportChild::firstImport() is the "first import" of the DFS order of
//   the import tree.
// - The "first import" manages all the children that is loaded by the document.
void HTMLImportChild::normalize() {
  if (!loader()->isFirstImport(this) &&
      this->precedes(loader()->firstImport())) {
    HTMLImportChild* oldFirst = loader()->firstImport();
    loader()->moveToFirst(this);
    takeChildrenFrom(oldFirst);
  }

  for (HTMLImportChild* child = toHTMLImportChild(firstChild()); child;
       child = toHTMLImportChild(child->next())) {
    if (child->formsCycle())
      child->invalidateCustomElementMicrotaskStep();
    child->normalize();
  }
}

#if !defined(NDEBUG)
void HTMLImportChild::showThis() {
  bool isFirst = loader() ? loader()->isFirstImport(this) : false;
  HTMLImport::showThis();
  fprintf(stderr, " loader=%p first=%d, step=%p sync=%s url=%s", m_loader.get(),
          isFirst, m_customElementMicrotaskStep.get(), isSync() ? "Y" : "N",
          url().getString().utf8().data());
}
#endif

DEFINE_TRACE(HTMLImportChild) {
  visitor->trace(m_customElementMicrotaskStep);
  visitor->trace(m_loader);
  visitor->trace(m_client);
  HTMLImport::trace(visitor);
}

}  // namespace blink