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/*
* Copyright (C) 2015-2016 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 INC. AND ITS 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 APPLE INC. OR ITS 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.
*/
#pragma once
#include "BreakLines.h"
#include "RenderLineBreak.h"
#include "SimpleLineLayoutFlowContents.h"
namespace WebCore {
class RenderBlockFlow;
class RenderStyle;
namespace SimpleLineLayout {
class TextFragmentIterator {
public:
TextFragmentIterator(const RenderBlockFlow&);
class TextFragment {
public:
enum Type { Invalid, ContentEnd, SoftLineBreak, HardLineBreak, Whitespace, NonWhitespace };
TextFragment() = default;
TextFragment(unsigned start, unsigned end, float width, Type type, bool isLastInRenderer = false, bool overlapsToNextRenderer = false, bool isCollapsed = false, bool isCollapsible = false)
: m_start(start)
, m_end(end)
, m_width(width)
, m_type(type)
, m_isLastInRenderer(isLastInRenderer)
, m_overlapsToNextRenderer(overlapsToNextRenderer)
, m_isCollapsed(isCollapsed)
, m_isCollapsible(isCollapsible)
{
}
bool isValid() const { return m_type != Invalid; }
unsigned start() const { return m_start; }
unsigned end() const { return m_end; }
unsigned length() const { ASSERT(m_end >= m_start); return m_end - m_start; }
float width() const { return m_width; }
Type type() const { return m_type; }
bool overlapsToNextRenderer() const { return m_overlapsToNextRenderer; }
bool isLastInRenderer() const { return m_isLastInRenderer; }
bool isLineBreak() const { return m_type == SoftLineBreak || m_type == HardLineBreak; }
bool isCollapsed() const { return m_isCollapsed; }
bool isCollapsible() const { return m_isCollapsible; }
bool hasHyphen() const { return m_hasHyphen; }
bool isEmpty() const { return start() == end() && !isLineBreak(); }
TextFragment split(unsigned splitPosition, float leftSideWidth, float rightSideWidth);
TextFragment splitWithHyphen(unsigned hyphenPosition, float hyphenStringWidth, float leftSideWidth, float rightSideWidth);
bool operator==(const TextFragment& other) const
{
return m_start == other.m_start
&& m_end == other.m_end
&& m_width == other.m_width
&& m_type == other.m_type
&& m_isLastInRenderer == other.m_isLastInRenderer
&& m_overlapsToNextRenderer == other.m_overlapsToNextRenderer
&& m_isCollapsed == other.m_isCollapsed
&& m_isCollapsible == other.m_isCollapsible
&& m_hasHyphen == other.m_hasHyphen;
}
private:
unsigned m_start { 0 };
unsigned m_end { 0 };
float m_width { 0 };
Type m_type { Invalid };
bool m_isLastInRenderer { false };
bool m_overlapsToNextRenderer { false };
bool m_isCollapsed { false };
bool m_isCollapsible { false };
bool m_hasHyphen { false };
};
TextFragment nextTextFragment(float xPosition = 0);
void revertToEndOfFragment(const TextFragment&);
// FIXME: These functions below should be decoupled from the text iterator.
float textWidth(unsigned startPosition, unsigned endPosition, float xPosition) const;
std::optional<unsigned> lastHyphenPosition(const TextFragmentIterator::TextFragment& run, unsigned beforeIndex) const;
struct Style {
explicit Style(const RenderStyle&, bool useSimplifiedTextMeasuring);
const FontCascade& font;
ETextAlign textAlign;
bool hasKerningOrLigatures;
bool collapseWhitespace;
bool preserveNewline;
bool wrapLines;
bool breakAnyWordOnOverflow;
bool breakFirstWordOnOverflow;
bool breakNBSP;
bool keepAllWordsForCJK;
float wordSpacing;
unsigned tabWidth;
bool shouldHyphenate;
float hyphenStringWidth;
unsigned hyphenLimitBefore;
unsigned hyphenLimitAfter;
AtomicString locale;
std::optional<unsigned> hyphenLimitLines;
};
const Style& style() const { return m_style; }
private:
TextFragment findNextTextFragment(float xPosition);
enum PositionType { Breakable, NonWhitespace };
unsigned skipToNextPosition(PositionType, unsigned startPosition, float& width, float xPosition, bool& overlappingFragment);
bool isSoftLineBreak(unsigned position) const;
bool isHardLineBreak(const FlowContents::Iterator& segment) const;
unsigned nextBreakablePosition(const FlowContents::Segment&, unsigned startPosition);
unsigned nextNonWhitespacePosition(const FlowContents::Segment&, unsigned startPosition);
FlowContents m_flowContents;
FlowContents::Iterator m_currentSegment;
LazyLineBreakIterator m_lineBreakIterator;
const Style m_style;
unsigned m_position { 0 };
bool m_atEndOfSegment { false };
};
inline TextFragmentIterator::TextFragment TextFragmentIterator::TextFragment::split(unsigned splitPosition, float leftSideWidth, float rightSideWidth)
{
auto updateFragmentProperties = [] (TextFragment& fragment, unsigned start, unsigned end, float width)
{
fragment.m_start = start;
fragment.m_end = end;
fragment.m_width = width;
if (fragment.start() + 1 > fragment.end())
return;
fragment.m_isCollapsed = false;
};
TextFragment rightSide(*this);
updateFragmentProperties(*this, start(), splitPosition, leftSideWidth);
updateFragmentProperties(rightSide, splitPosition, rightSide.end(), rightSideWidth);
return rightSide;
}
inline TextFragmentIterator::TextFragment TextFragmentIterator::TextFragment::splitWithHyphen(unsigned hyphenPosition, float hyphenStringWidth,
float leftSideWidth, float rightSideWidth)
{
auto rightSide = split(hyphenPosition, leftSideWidth, rightSideWidth);
m_hasHyphen = true;
m_width += hyphenStringWidth;
return rightSide;
}
inline bool TextFragmentIterator::isSoftLineBreak(unsigned position) const
{
const auto& segment = *m_currentSegment;
ASSERT(segment.start <= position && position < segment.end);
return m_style.preserveNewline && segment.text[position - segment.start] == '\n';
}
inline bool TextFragmentIterator::isHardLineBreak(const FlowContents::Iterator& segment) const
{
ASSERT(segment->start != segment->end || (segment->start == segment->end && is<RenderLineBreak>(segment->renderer)));
return segment->start == segment->end;
}
}
}
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