gecko-dev/dom/svg/SVGSwitchElement.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "mozilla/dom/SVGSwitchElement.h"

#include "nsLayoutUtils.h"
#include "nsSVGUtils.h"
#include "mozilla/Preferences.h"
#include "mozilla/dom/SVGSwitchElementBinding.h"

class nsIFrame;

NS_IMPL_NS_NEW_SVG_ELEMENT(Switch)

namespace mozilla {
namespace dom {

JSObject* SVGSwitchElement::WrapNode(JSContext* aCx,
                                     JS::Handle<JSObject*> aGivenProto) {
  return SVGSwitchElement_Binding::Wrap(aCx, this, aGivenProto);
}

//----------------------------------------------------------------------
// nsISupports methods

NS_IMPL_CYCLE_COLLECTION_INHERITED(SVGSwitchElement, SVGSwitchElementBase,
                                   mActiveChild)

NS_IMPL_ADDREF_INHERITED(SVGSwitchElement, SVGSwitchElementBase)
NS_IMPL_RELEASE_INHERITED(SVGSwitchElement, SVGSwitchElementBase)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(SVGSwitchElement)
NS_INTERFACE_MAP_END_INHERITING(SVGSwitchElementBase)

//----------------------------------------------------------------------
// Implementation

SVGSwitchElement::SVGSwitchElement(
    already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo)
    : SVGSwitchElementBase(std::move(aNodeInfo)) {}

void SVGSwitchElement::MaybeInvalidate() {
  // We must not change mActiveChild until after
  // InvalidateAndScheduleBoundsUpdate has been called, otherwise
  // it will not correctly invalidate the old mActiveChild area.

  nsIContent* newActiveChild = FindActiveChild();

  if (newActiveChild == mActiveChild) {
    return;
  }

  nsIFrame* frame = GetPrimaryFrame();
  if (frame) {
    nsLayoutUtils::PostRestyleEvent(this, RestyleHint{0},
                                    nsChangeHint_InvalidateRenderingObservers);
    nsSVGUtils::ScheduleReflowSVG(frame);
  }

  mActiveChild = newActiveChild;
}

//----------------------------------------------------------------------
// nsINode methods

NS_IMPL_ELEMENT_CLONE_WITH_INIT(SVGSwitchElement)

//----------------------------------------------------------------------
// nsINode methods

nsresult SVGSwitchElement::InsertChildBefore(nsIContent* aKid,
                                             nsIContent* aBeforeThis,
                                             bool aNotify) {
  nsresult rv =
      SVGSwitchElementBase::InsertChildBefore(aKid, aBeforeThis, aNotify);
  if (NS_SUCCEEDED(rv)) {
    MaybeInvalidate();
  }
  return rv;
}

void SVGSwitchElement::RemoveChildNode(nsIContent* aKid, bool aNotify) {
  SVGSwitchElementBase::RemoveChildNode(aKid, aNotify);
  MaybeInvalidate();
}

//----------------------------------------------------------------------
// nsIContent methods

NS_IMETHODIMP_(bool)
SVGSwitchElement::IsAttributeMapped(const nsAtom* name) const {
  static const MappedAttributeEntry* const map[] = {sFEFloodMap,
                                                    sFiltersMap,
                                                    sFontSpecificationMap,
                                                    sGradientStopMap,
                                                    sLightingEffectsMap,
                                                    sMarkersMap,
                                                    sTextContentElementsMap,
                                                    sViewportsMap};

  return FindAttributeDependence(name, map) ||
         SVGSwitchElementBase::IsAttributeMapped(name);
}

//----------------------------------------------------------------------
// Implementation Helpers:

nsIContent* SVGSwitchElement::FindActiveChild() const {
  nsAutoString acceptLangs;
  Preferences::GetLocalizedString("intl.accept_languages", acceptLangs);

  if (!acceptLangs.IsEmpty()) {
    int32_t bestLanguagePreferenceRank = -1;
    nsIContent* bestChild = nullptr;
    nsIContent* defaultChild = nullptr;
    for (nsIContent* child = nsINode::GetFirstChild(); child;
         child = child->GetNextSibling()) {
      if (!child->IsElement()) {
        continue;
      }
      nsCOMPtr<SVGTests> tests(do_QueryInterface(child));
      if (tests) {
        if (tests->PassesConditionalProcessingTests(
                SVGTests::kIgnoreSystemLanguage)) {
          int32_t languagePreferenceRank =
              tests->GetBestLanguagePreferenceRank(acceptLangs);
          switch (languagePreferenceRank) {
            case 0:
              // best possible match
              return child;
            case -1:
              // no match
              break;
            case -2:
              // no systemLanguage attribute. If there's nothing better
              // we'll use the first such child.
              if (!defaultChild) {
                defaultChild = child;
              }
              break;
            default:
              if (bestLanguagePreferenceRank == -1 ||
                  languagePreferenceRank < bestLanguagePreferenceRank) {
                bestLanguagePreferenceRank = languagePreferenceRank;
                bestChild = child;
              }
              break;
          }
        }
      } else if (!bestChild) {
        bestChild = child;
      }
    }
    return bestChild ? bestChild : defaultChild;
  }

  for (nsIContent* child = nsINode::GetFirstChild(); child;
       child = child->GetNextSibling()) {
    if (!child->IsElement()) {
      continue;
    }
    nsCOMPtr<SVGTests> tests(do_QueryInterface(child));
    if (!tests || tests->PassesConditionalProcessingTests(&acceptLangs)) {
      return child;
    }
  }
  return nullptr;
}

}  // namespace dom
}  // namespace mozilla