| // 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 "core/layout/LayoutFlowThread.h" |
| |
| namespace blink { |
| |
| 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 |