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 without specific prior written permission.
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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/Deprecation.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), url_(url), loader_(loader), client_(nullptr) {
  DCHECK(loader);
}

HTMLImportChild::~HTMLImportChild() {}

void HTMLImportChild::OwnerInserted() {
  if (!loader_->IsDone())
    return;

  DCHECK(Root());
  DCHECK(Root()->GetDocument());
  Root()->GetDocument()->GetStyleEngine().HtmlImportAddedOrRemoved();
}

void HTMLImportChild::DidShareLoader() {
  CreateCustomElementMicrotaskStepIfNeeded();
  StateWillChange();
}

void HTMLImportChild::DidStartLoading() {
  CreateCustomElementMicrotaskStepIfNeeded();
}

void HTMLImportChild::DidFinish() {
  if (client_)
    client_->DidFinish();
}

void HTMLImportChild::DidFinishLoading() {
  StateWillChange();
  if (GetDocument() && GetDocument()->GetStyleEngine().HasStyleSheets()) {
    Deprecation::CountDeprecation(Root()->GetDocument(),
                                  WebFeature::kHTMLImportsHasStyleSheets);
  }
  V0CustomElement::DidFinishLoadingImport(*(Root()->GetDocument()));
}

void HTMLImportChild::DidFinishUpgradingCustomElements() {
  StateWillChange();
  custom_element_microtask_step_.Clear();
}

void HTMLImportChild::Dispose() {
  InvalidateCustomElementMicrotaskStep();
  if (Parent())
    Parent()->RemoveChild(this);

  DCHECK(loader_);
  loader_->RemoveImport(this);
  loader_ = nullptr;

  if (client_) {
    client_->ImportChildWasDisposed(this);
    client_ = nullptr;
  }
}

Document* HTMLImportChild::GetDocument() const {
  DCHECK(loader_);
  return loader_->GetDocument();
}

void HTMLImportChild::StateWillChange() {
  ToHTMLImportTreeRoot(Root())->ScheduleRecalcState();
}

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

  if (GetState().IsReady())
    DidFinish();
}

void HTMLImportChild::InvalidateCustomElementMicrotaskStep() {
  if (!custom_element_microtask_step_)
    return;
  custom_element_microtask_step_->Invalidate();
  custom_element_microtask_step_.Clear();
}

void HTMLImportChild::CreateCustomElementMicrotaskStepIfNeeded() {
  DCHECK(!custom_element_microtask_step_);

  if (!HasFinishedLoading() && !FormsCycle()) {
    custom_element_microtask_step_ = V0CustomElement::DidCreateImport(this);
  }
}

bool HTMLImportChild::HasFinishedLoading() const {
  DCHECK(loader_);

  return loader_->IsDone() && loader_->MicrotaskQueue()->IsEmpty() &&
         !custom_element_microtask_step_;
}

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

void HTMLImportChild::SetClient(HTMLImportChildClient* client) {
  DCHECK(client);
  DCHECK(!client_);
  client_ = client;
}

HTMLLinkElement* HTMLImportChild::Link() const {
  if (!client_)
    return nullptr;
  return 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* old_first = Loader()->FirstImport();
    Loader()->MoveToFirst(this);
    TakeChildrenFrom(old_first);
  }

  for (HTMLImportChild* child = ToHTMLImportChild(FirstChild()); child;
       child = ToHTMLImportChild(child->Next())) {
    if (child->FormsCycle())
      child->InvalidateCustomElementMicrotaskStep();
    child->Normalize();
  }
}

#if !defined(NDEBUG)
void HTMLImportChild::ShowThis() {
  bool is_first = Loader() ? Loader()->IsFirstImport(this) : false;
  HTMLImport::ShowThis();
  fprintf(stderr, " loader=%p first=%d, step=%p sync=%s url=%s", loader_.Get(),
          is_first, custom_element_microtask_step_.Get(), IsSync() ? "Y" : "N",
          Url().GetString().Utf8().data());
}
#endif

DEFINE_TRACE(HTMLImportChild) {
  visitor->Trace(custom_element_microtask_step_);
  visitor->Trace(loader_);
  visitor->Trace(client_);
  HTMLImport::Trace(visitor);
}

}  // namespace blink