third_party/WebKit/Source/core/svg/SVGUseElement.h

/*
 * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann
 * <zimmermann@kde.org>
 * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#ifndef SVGUseElement_h
#define SVGUseElement_h

#include "core/fetch/DocumentResource.h"
#include "core/svg/SVGAnimatedLength.h"
#include "core/svg/SVGGeometryElement.h"
#include "core/svg/SVGGraphicsElement.h"
#include "core/svg/SVGURIReference.h"
#include "platform/heap/Handle.h"

namespace blink {

class SVGUseElement final : public SVGGraphicsElement,
                            public SVGURIReference,
                            public DocumentResourceClient {
  DEFINE_WRAPPERTYPEINFO();
  USING_GARBAGE_COLLECTED_MIXIN(SVGUseElement);
  USING_PRE_FINALIZER(SVGUseElement, dispose);

 public:
  static SVGUseElement* create(Document&);
  ~SVGUseElement() override;

  void invalidateShadowTree();

  // Return the element that should be used for clipping,
  // or null if a valid clip element is not directly referenced.
  SVGGraphicsElement* visibleTargetGraphicsElementForClipping() const;

  SVGAnimatedLength* x() const { return m_x.get(); }
  SVGAnimatedLength* y() const { return m_y.get(); }
  SVGAnimatedLength* width() const { return m_width.get(); }
  SVGAnimatedLength* height() const { return m_height.get(); }

  void buildPendingResource() override;

  void dispatchPendingEvent();
  void toClipPath(Path&) const;

  DECLARE_VIRTUAL_TRACE();

 private:
  explicit SVGUseElement(Document&);

  void dispose();

  FloatRect getBBox() override;

  bool isPresentationAttribute(const QualifiedName&) const override;
  void collectStyleForPresentationAttribute(const QualifiedName&,
                                            const AtomicString&,
                                            MutableStylePropertySet*) override;
  bool isPresentationAttributeWithSVGDOM(const QualifiedName&) const override;

  bool isStructurallyExternal() const override;

  InsertionNotificationRequest insertedInto(ContainerNode*) override;
  void removedFrom(ContainerNode*) override;

  void svgAttributeChanged(const QualifiedName&) override;

  LayoutObject* createLayoutObject(const ComputedStyle&) override;

  void scheduleShadowTreeRecreation();
  void cancelShadowTreeRecreation();
  bool haveLoadedRequiredResources() override {
    return !isStructurallyExternal() || m_haveFiredLoadEvent;
  }

  bool selfHasRelativeLengths() const override;

  // Instance tree handling
  Element* resolveTargetElement();
  void buildShadowAndInstanceTree(SVGElement& target);
  void clearInstanceRoot();
  Element* createInstanceTree(SVGElement& targetRoot) const;
  void clearShadowTree();
  bool hasCycleUseReferencing(const SVGUseElement&,
                              const ContainerNode& targetInstance,
                              SVGElement*& newTarget) const;
  bool expandUseElementsInShadowTree();
  void addReferencesToFirstDegreeNestedUseElements(SVGElement& target);

  void invalidateDependentShadowTrees();

  bool resourceIsStillLoading() const;
  bool resourceIsValid() const;
  bool instanceTreeIsLoading() const;
  void notifyFinished(Resource*) override;
  String debugName() const override { return "SVGUseElement"; }
  void updateTargetReference();
  void setDocumentResource(DocumentResource*);

  Member<SVGAnimatedLength> m_x;
  Member<SVGAnimatedLength> m_y;
  Member<SVGAnimatedLength> m_width;
  Member<SVGAnimatedLength> m_height;

  AtomicString m_elementIdentifier;
  bool m_elementIdentifierIsLocal;
  bool m_haveFiredLoadEvent;
  bool m_needsShadowTreeRecreation;
  Member<SVGElement> m_targetElementInstance;
  Member<DocumentResource> m_resource;
};

}  // namespace blink

#endif  // SVGUseElement_h