third_party/WebKit/Source/core/layout/svg/LayoutSVGShape.h

/*
 * Copyright (C) 2004, 2005, 2007 Nikolas Zimmermann <zimmermann@kde.org>
 * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
 * Copyright (C) 2005 Eric Seidel <eric@webkit.org>
 * Copyright (C) 2006 Apple Computer, Inc
 * Copyright (C) 2009 Google, Inc.
 * Copyright (C) 2011 Renata Hodovan <reni@webkit.org>
 * Copyright (C) 2011 University of Szeged
 *
 * 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 LayoutSVGShape_h
#define LayoutSVGShape_h

#include "core/layout/svg/LayoutSVGModelObject.h"
#include "core/layout/svg/SVGMarkerData.h"
#include "platform/geometry/FloatRect.h"
#include "platform/transforms/AffineTransform.h"
#include "wtf/Vector.h"
#include <memory>

namespace blink {

class FloatPoint;
class PointerEventsHitRules;
class SVGGeometryElement;

enum ShapeGeometryCodePath {
  PathGeometry,
  RectGeometryFastPath,
  EllipseGeometryFastPath
};

struct LayoutSVGShapeRareData {
  WTF_MAKE_NONCOPYABLE(LayoutSVGShapeRareData);
  USING_FAST_MALLOC(LayoutSVGShapeRareData);

 public:
  LayoutSVGShapeRareData() {}
  Path m_cachedNonScalingStrokePath;
  AffineTransform m_cachedNonScalingStrokeTransform;
};

class LayoutSVGShape : public LayoutSVGModelObject {
 public:
  explicit LayoutSVGShape(SVGGeometryElement*);
  ~LayoutSVGShape() override;

  void setNeedsShapeUpdate() { m_needsShapeUpdate = true; }
  void setNeedsBoundariesUpdate() final { m_needsBoundariesUpdate = true; }
  void setNeedsTransformUpdate() final { m_needsTransformUpdate = true; }

  bool nodeAtFloatPointInternal(const HitTestRequest&,
                                const FloatPoint&,
                                PointerEventsHitRules);

  Path& path() const {
    DCHECK(m_path);
    return *m_path;
  }
  bool hasPath() const { return m_path.get(); }
  float dashScaleFactor() const;

  // This method is sometimes (rarely) called with a null path and crashes. The
  // code managing the path enforces the necessary invariants to ensure a valid
  // path but somehow that fails. The assert and check for hasPath() are
  // intended to detect and prevent crashes.
  virtual bool isShapeEmpty() const {
    DCHECK(m_path);
    return !hasPath() || path().isEmpty();
  }

  bool hasNonScalingStroke() const {
    return style()->svgStyle().vectorEffect() == VE_NON_SCALING_STROKE;
  }
  Path* nonScalingStrokePath(const Path*, const AffineTransform&) const;
  AffineTransform nonScalingStrokeTransform() const;
  AffineTransform localSVGTransform() const final { return m_localTransform; }

  virtual const Vector<MarkerPosition>* markerPositions() const {
    return nullptr;
  }

  float strokeWidth() const;

  virtual ShapeGeometryCodePath geometryCodePath() const {
    return PathGeometry;
  }

  FloatRect objectBoundingBox() const final { return m_fillBoundingBox; }

  const char* name() const override { return "LayoutSVGShape"; }

 protected:
  void clearPath() { m_path.reset(); }
  void createPath();

  virtual void updateShapeFromElement();
  // Calculates an inclusive bounding box of this shape as if this shape has
  // a stroke. If this shape has a stroke, then m_strokeBoundingBox is returned;
  // otherwise, estimates a bounding box (not necessarily tight) that would
  // include this shape's stroke bounding box if it had a stroke.
  virtual FloatRect hitTestStrokeBoundingBox() const;
  virtual bool shapeDependentStrokeContains(const FloatPoint&);
  virtual bool shapeDependentFillContains(const FloatPoint&,
                                          const WindRule) const;

  FloatRect m_fillBoundingBox;
  FloatRect m_strokeBoundingBox;
  LayoutSVGShapeRareData& ensureRareData() const;

 private:
  // Hit-detection separated for the fill and the stroke
  bool fillContains(const FloatPoint&,
                    bool requiresFill = true,
                    const WindRule fillRule = RULE_NONZERO);
  bool strokeContains(const FloatPoint&, bool requiresStroke = true);

  const AffineTransform& localToSVGParentTransform() const final {
    return m_localTransform;
  }

  bool isOfType(LayoutObjectType type) const override {
    return type == LayoutObjectSVGShape || LayoutSVGModelObject::isOfType(type);
  }
  void layout() final;
  void paint(const PaintInfo&, const LayoutPoint&) const final;
  void addOutlineRects(Vector<LayoutRect>&,
                       const LayoutPoint& additionalOffset,
                       IncludeBlockVisualOverflowOrNot) const final;

  bool nodeAtFloatPoint(HitTestResult&,
                        const FloatPoint& pointInParent,
                        HitTestAction) final;

  FloatRect strokeBoundingBox() const final { return m_strokeBoundingBox; }
  FloatRect calculateObjectBoundingBox() const;
  FloatRect calculateStrokeBoundingBox() const;
  void updateLocalTransform();

 private:
  AffineTransform m_localTransform;
  // TODO(fmalita): the Path is now cached in SVGPath; while this additional
  // cache is just a shallow copy, it certainly has a complexity/state
  // management cost (plus allocation & storage overhead) - so we should look
  // into removing it.
  std::unique_ptr<Path> m_path;
  mutable std::unique_ptr<LayoutSVGShapeRareData> m_rareData;

  bool m_needsBoundariesUpdate : 1;
  bool m_needsShapeUpdate : 1;
  bool m_needsTransformUpdate : 1;
};

DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutSVGShape, isSVGShape());

}  // namespace blink

#endif