chromium/src/third_party/blink/renderer/core/layout/layout_geometry_map.h

/*
 * Copyright (C) 2012 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_LAYOUT_GEOMETRY_MAP_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_LAYOUT_GEOMETRY_MAP_H_

#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/layout/geometry/physical_rect.h"
#include "third_party/blink/renderer/core/layout/layout_geometry_map_step.h"
#include "third_party/blink/renderer/core/layout/map_coordinates_flags.h"
#include "third_party/blink/renderer/platform/geometry/float_quad.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/vector.h"

namespace blink {

class PaintLayer;
class LayoutBoxModelObject;
class LayoutObject;
class TransformationMatrix;
class TransformState;

// Can be used while walking the layout tree to cache data about offsets and
// transforms.
class CORE_EXPORT LayoutGeometryMap {
  DISALLOW_NEW();

 public:
  LayoutGeometryMap(MapCoordinatesFlags = 0);
  LayoutGeometryMap(const LayoutGeometryMap&) = delete;
  LayoutGeometryMap& operator=(const LayoutGeometryMap&) = delete;
  ~LayoutGeometryMap();

  MapCoordinatesFlags GetMapCoordinatesFlags() const {
    return map_coordinates_flags_;
  }

  PhysicalRect AbsoluteRect(const PhysicalRect& rect) const {
    return MapToAncestor(rect, nullptr);
  }
  FloatQuad AbsoluteQuad(const PhysicalRect& rect) const {
    return MapToAncestorQuad(rect, nullptr);
  }

  // Map to an ancestor. Will assert that the ancestor has been pushed onto this
  // map. A null ancestor maps through the LayoutView (including its scale
  // transform, if any). If the ancestor is the LayoutView, the scroll offset is
  // applied, but not the scale.
  PhysicalRect MapToAncestor(const PhysicalRect&,
                             const LayoutBoxModelObject*) const;
  FloatQuad MapToAncestorQuad(const PhysicalRect&,
                              const LayoutBoxModelObject*) const;

  // Called by code walking the layout or layer trees.
  void PushMappingsToAncestor(const PaintLayer*,
                              const PaintLayer* ancestor_layer);
  void PopMappingsToAncestor(const PaintLayer*);
  void PushMappingsToAncestor(
      const LayoutObject*,
      const LayoutBoxModelObject* ancestor_layout_object);

  // The following methods should only be called by layoutObjects inside a call
  // to pushMappingsToAncestor().

  // Push geometry info between this layoutObject and some ancestor. The
  // ancestor must be its container() or some stacking context between the
  // layoutObject and its container.
  void Push(const LayoutObject*,
            const PhysicalOffset&,
            GeometryInfoFlags = 0,
            PhysicalOffset offset_for_fixed_position = PhysicalOffset());
  void Push(const LayoutObject*,
            const TransformationMatrix&,
            GeometryInfoFlags = 0,
            PhysicalOffset offset_for_fixed_position = PhysicalOffset());

 private:
  bool CanUseAccumulatedOffset(const LayoutBoxModelObject*) const;
  void PopMappingsToAncestor(const LayoutBoxModelObject*);
  void MapToAncestor(TransformState&,
                     const LayoutBoxModelObject* ancestor = nullptr) const;

  void StepInserted(const LayoutGeometryMapStep&);
  void StepRemoved(const LayoutGeometryMapStep&);

  bool HasNonUniformStep() const { return non_uniform_steps_count_; }
  bool HasTransformStep() const { return transformed_steps_count_; }
  bool HasFixedPositionStep() const { return fixed_steps_count_; }

#ifndef NDEBUG
  void DumpSteps() const;
#endif

#if DCHECK_IS_ON()
  bool IsTopmostLayoutView(const LayoutObject*) const;
#endif

  typedef Vector<LayoutGeometryMapStep, 32> LayoutGeometryMapSteps;

  wtf_size_t insertion_position_;
  int non_uniform_steps_count_;
  int transformed_steps_count_;
  int fixed_steps_count_;
  LayoutGeometryMapSteps mapping_;
  PhysicalOffset accumulated_offset_;
  MapCoordinatesFlags map_coordinates_flags_;
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_LAYOUT_GEOMETRY_MAP_H_