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// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef FragmentainerIterator_h
#define FragmentainerIterator_h
#include "platform/geometry/LayoutRect.h"
namespace blink {
class LayoutFlowThread;
class LayoutMultiColumnSet;
class MultiColumnFragmentainerGroup;
// Used to find the fragmentainers that intersect with a given portion of the
// flow thread. The portion typically corresponds to the bounds of some
// descendant layout object. The iterator walks in block direction order.
class FragmentainerIterator {
public:
// Initialize the iterator, and move to the first fragmentainer of interest.
// The clip rectangle is optional. If it's empty, it means that no clipping
// will be performed, and that the only thing that can limit the set of
// fragmentainers to visit is |physicalBoundingBox|.
FragmentainerIterator(
const LayoutFlowThread&,
const LayoutRect& physicalBoundingBoxInFlowThread,
const LayoutRect& clipRectInMulticolContainer = LayoutRect());
// Advance to the next fragmentainer. Not allowed to call this if atEnd() is
// true.
void advance();
// Return true if we have walked through all relevant fragmentainers.
bool atEnd() const { return !m_currentColumnSet; }
// The physical translation to apply to shift the box when converting from
// flowthread to visual coordinates.
LayoutSize paginationOffset() const;
// Return the physical content box of the current fragmentainer, relative to
// the flow thread.
LayoutRect fragmentainerInFlowThread() const;
// Return the physical clip rectangle of the current fragmentainer, relative
// to the flow thread.
LayoutRect clipRectInFlowThread() const;
private:
const LayoutFlowThread& m_flowThread;
const LayoutRect m_clipRectInMulticolContainer;
const LayoutMultiColumnSet* m_currentColumnSet;
unsigned m_currentFragmentainerGroupIndex;
unsigned m_currentFragmentainerIndex;
unsigned m_endFragmentainerIndex;
LayoutUnit m_logicalTopInFlowThread;
LayoutUnit m_logicalBottomInFlowThread;
const MultiColumnFragmentainerGroup& currentGroup() const;
void moveToNextFragmentainerGroup();
bool setFragmentainersOfInterest();
void setAtEnd() { m_currentColumnSet = nullptr; }
bool hasClipRect() const { return !m_clipRectInMulticolContainer.isEmpty(); }
};
} // namespace blink
#endif // FragmentainerIterator_h
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