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/*
* Copyright (c) 2012, Google Inc. All rights reserved.
* Copyright (C) 2015, 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:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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 THE COPYRIGHT
* OWNER 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
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef WritingMode_h
#define WritingMode_h
namespace WebCore {
enum TextDirection { LTR, RTL };
inline bool isLeftToRightDirection(TextDirection direction)
{
return direction == LTR;
}
enum WritingMode {
TopToBottomWritingMode = 0, // horizontal-tb
BottomToTopWritingMode = 1, // horizontal-bt
LeftToRightWritingMode = 2, // vertical-lr
RightToLeftWritingMode = 3, // vertical-rl
};
#define MAKE_TEXT_FLOW(writingMode, direction) ((writingMode) << 1 | (direction))
// Define the text flow in terms of the writing mode and the text direction. The first
// part is the line growing direction and the second part is the block growing direction.
enum TextFlow {
InlineEastBlockSouth = MAKE_TEXT_FLOW(TopToBottomWritingMode, LTR),
InlineWestBlockSouth = MAKE_TEXT_FLOW(TopToBottomWritingMode, RTL),
InlineEastBlockNorth = MAKE_TEXT_FLOW(BottomToTopWritingMode, LTR),
InlineWestBlockNorth = MAKE_TEXT_FLOW(BottomToTopWritingMode, RTL),
InlineSouthBlockEast = MAKE_TEXT_FLOW(LeftToRightWritingMode, LTR),
InlineSouthBlockWest = MAKE_TEXT_FLOW(LeftToRightWritingMode, RTL),
InlineNorthBlockEast = MAKE_TEXT_FLOW(RightToLeftWritingMode, LTR),
InlineNorthBlockWest = MAKE_TEXT_FLOW(RightToLeftWritingMode, RTL)
};
inline TextFlow makeTextFlow(WritingMode writingMode, TextDirection direction)
{
return static_cast<TextFlow>(MAKE_TEXT_FLOW(writingMode, direction));
}
#undef MAKE_TEXT_FLOW
const unsigned TextFlowReversedMask = 1;
const unsigned TextFlowFlippedMask = 2;
const unsigned TextFlowVerticalMask = 4;
inline bool isReversedTextFlow(TextFlow textflow)
{
return textflow & TextFlowReversedMask;
}
inline bool isFlippedTextFlow(TextFlow textflow)
{
return textflow & TextFlowFlippedMask;
}
inline bool isVerticalTextFlow(TextFlow textflow)
{
return textflow & TextFlowVerticalMask;
}
// Lines have vertical orientation; modes vertical-lr or vertical-rl.
inline bool isVerticalWritingMode(WritingMode writingMode)
{
return isVerticalTextFlow(makeTextFlow(writingMode, LTR));
}
// Block progression increases in the opposite direction to normal; modes vertical-rl or horizontal-bt.
inline bool isFlippedWritingMode(WritingMode writingMode)
{
return isFlippedTextFlow(makeTextFlow(writingMode, LTR));
}
// Lines have horizontal orientation; modes horizontal-tb or horizontal-bt.
inline bool isHorizontalWritingMode(WritingMode writingMode)
{
return !isVerticalWritingMode(writingMode);
}
// Bottom of the line occurs earlier in the block; modes vertical-lr or horizontal-bt.
inline bool isFlippedLinesWritingMode(WritingMode writingMode)
{
return isVerticalWritingMode(writingMode) != isFlippedWritingMode(writingMode);
}
enum LogicalBoxSide {
BeforeSide,
EndSide,
AfterSide,
StartSide
};
enum PhysicalBoxSide {
NilSide = -1,
TopSide,
RightSide,
BottomSide,
LeftSide
};
inline bool isHorizontalPhysicalSide(PhysicalBoxSide physicalSide)
{
return physicalSide == LeftSide || physicalSide == RightSide;
}
inline PhysicalBoxSide mirrorPhysicalSide(PhysicalBoxSide physicalSide)
{
// top <-> bottom and left <-> right conversion
return static_cast<PhysicalBoxSide>((static_cast<int>(physicalSide) + 2) % 4);
}
inline PhysicalBoxSide rotatePhysicalSide(PhysicalBoxSide physicalSide)
{
// top <-> left and right <-> bottom conversion
bool horizontalSide = isHorizontalPhysicalSide(physicalSide);
return static_cast<PhysicalBoxSide>((static_cast<int>(physicalSide) + (horizontalSide ? 1 : 3)) % 4);
}
inline PhysicalBoxSide mapLogicalSideToPhysicalSide(TextFlow textflow, LogicalBoxSide logicalSide)
{
PhysicalBoxSide physicalSide = static_cast<PhysicalBoxSide>(logicalSide);
bool horizontalSide = isHorizontalPhysicalSide(physicalSide);
if (isVerticalTextFlow(textflow))
physicalSide = rotatePhysicalSide(physicalSide);
if ((horizontalSide && isReversedTextFlow(textflow)) || (!horizontalSide && isFlippedTextFlow(textflow)))
physicalSide = mirrorPhysicalSide(physicalSide);
return physicalSide;
}
inline PhysicalBoxSide mapLogicalSideToPhysicalSide(WritingMode writingMode, LogicalBoxSide logicalSide)
{
// Set the direction such that side is mirrored if isFlippedWritingMode() is true
TextDirection direction = isFlippedWritingMode(writingMode) ? RTL : LTR;
return mapLogicalSideToPhysicalSide(makeTextFlow(writingMode, direction), logicalSide);
}
} // namespace WebCore
#endif // WritingMode_h
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