Move SVGTextMetricsCalculator to LayoutSVGInlineText.cpp

third_party/WebKit/Source/core/layout/svg/SVGTextMetricsBuilder.cpp

Index: third_party/WebKit/Source/core/layout/svg/SVGTextMetricsBuilder.cpp
diff --git a/third_party/WebKit/Source/core/layout/svg/SVGTextMetricsBuilder.cpp b/third_party/WebKit/Source/core/layout/svg/SVGTextMetricsBuilder.cpp
deleted file mode 100644
index fc03d131ed0f8b8629ff03de1ff1bd293fd27bde..0000000000000000000000000000000000000000
--- a/third_party/WebKit/Source/core/layout/svg/SVGTextMetricsBuilder.cpp
+++ /dev/null
@@ -1,263 +0,0 @@
-/*
- * Copyright (C) Research In Motion Limited 2010-2012. All rights reserved.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Library General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public License
- * along with this library; see the file COPYING.LIB.  If not, write to
- * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
- * Boston, MA 02110-1301, USA.
- */
-
-#include "core/layout/svg/SVGTextMetricsBuilder.h"
-
-#include "core/layout/api/LineLayoutSVGInlineText.h"
-#include "core/layout/svg/LayoutSVGInlineText.h"
-#include "core/layout/svg/SVGTextMetrics.h"
-#include "platform/fonts/CharacterRange.h"
-#include "platform/text/BidiCharacterRun.h"
-#include "platform/text/BidiResolver.h"
-#include "platform/text/TextDirection.h"
-#include "platform/text/TextRun.h"
-#include "platform/text/TextRunIterator.h"
-#include "wtf/Vector.h"
-
-namespace blink {
-
-namespace {
-
-inline bool characterStartsSurrogatePair(const TextRun& run, unsigned index)
-{
-    if (!U16_IS_LEAD(run[index]))
-        return false;
-    if (index + 1 >= static_cast<unsigned>(run.charactersLength()))
-        return false;
-    return U16_IS_TRAIL(run[index + 1]);
-}
-
-class SVGTextMetricsCalculator {
-public:
-    SVGTextMetricsCalculator(LayoutSVGInlineText&);
-    ~SVGTextMetricsCalculator();
-
-    bool advancePosition();
-    unsigned currentPosition() const { return m_currentPosition; }
-
-    SVGTextMetrics currentCharacterMetrics();
-
-    // TODO(pdr): Character-based iteration is ambiguous and error-prone. It
-    // should be unified under a single concept. See: https://crbug.com/593570
-    bool currentCharacterStartsSurrogatePair() const
-    {
-        return characterStartsSurrogatePair(m_run, m_currentPosition);
-    }
-    bool currentCharacterIsWhiteSpace() const
-    {
-        return m_run[m_currentPosition] == ' ';
-    }
-    unsigned characterCount() const
-    {
-        return static_cast<unsigned>(m_run.charactersLength());
-    }
-
-private:
-    void setupBidiRuns();
-
-    static TextRun constructTextRun(LayoutSVGInlineText&, unsigned position, unsigned length, TextDirection);
-
-    // Ensure |m_subrunRanges| is updated for the current bidi run, or the
-    // complete m_run if no bidi runs are present. Returns the current position
-    // in the subrun which can be used to index into |m_subrunRanges|.
-    unsigned updateSubrunRangesForCurrentPosition();
-
-    // Current character position in m_text.
-    unsigned m_currentPosition;
-
-    LayoutSVGInlineText& m_text;
-    float m_fontScalingFactor;
-    float m_cachedFontHeight;
-    TextRun m_run;
-
-    BidiCharacterRun* m_bidiRun;
-    BidiResolver<TextRunIterator, BidiCharacterRun> m_bidiResolver;
-
-    // Ranges for the current bidi run if present, or the entire run otherwise.
-    Vector<CharacterRange> m_subrunRanges;
-};
-
-TextRun SVGTextMetricsCalculator::constructTextRun(LayoutSVGInlineText& text, unsigned position, unsigned length, TextDirection textDirection)
-{
-    const ComputedStyle& style = text.styleRef();
-
-    TextRun run(static_cast<const LChar*>(nullptr) // characters, will be set below if non-zero.
-        , 0 // length, will be set below if non-zero.
-        , 0 // xPos, only relevant with allowTabs=true
-        , 0 // padding, only relevant for justified text, not relevant for SVG
-        , TextRun::AllowTrailingExpansion
-        , textDirection
-        , isOverride(style.unicodeBidi()) /* directionalOverride */);
-
-    if (length) {
-        if (text.is8Bit())
-            run.setText(text.characters8() + position, length);
-        else
-            run.setText(text.characters16() + position, length);
-    }
-
-    // We handle letter & word spacing ourselves.
-    run.disableSpacing();
-
-    // Propagate the maximum length of the characters buffer to the TextRun, even when we're only processing a substring.
-    run.setCharactersLength(text.textLength() - position);
-    ASSERT(run.charactersLength() >= run.length());
-    return run;
-}
-
-SVGTextMetricsCalculator::SVGTextMetricsCalculator(LayoutSVGInlineText& text)
-    : m_currentPosition(0)
-    , m_text(text)
-    , m_fontScalingFactor(m_text.scalingFactor())
-    , m_cachedFontHeight(m_text.scaledFont().getFontMetrics().floatHeight() / m_fontScalingFactor)
-    , m_run(constructTextRun(m_text, 0, m_text.textLength(), m_text.styleRef().direction()))
-    , m_bidiRun(nullptr)
-{
-    setupBidiRuns();
-}
-
-SVGTextMetricsCalculator::~SVGTextMetricsCalculator()
-{
-    m_bidiResolver.runs().deleteRuns();
-}
-
-void SVGTextMetricsCalculator::setupBidiRuns()
-{
-    BidiRunList<BidiCharacterRun>& bidiRuns = m_bidiResolver.runs();
-    bool bidiOverride = isOverride(m_text.styleRef().unicodeBidi());
-    BidiStatus status(LTR, bidiOverride);
-    if (m_run.is8Bit() || bidiOverride) {
-        WTF::Unicode::CharDirection direction = WTF::Unicode::LeftToRight;
-        // If BiDi override is in effect, use the specified direction.
-        if (bidiOverride && !m_text.styleRef().isLeftToRightDirection())
-            direction = WTF::Unicode::RightToLeft;
-        bidiRuns.addRun(new BidiCharacterRun(0, m_run.charactersLength(), status.context.get(), direction));
-    } else {
-        status.last = status.lastStrong = WTF::Unicode::OtherNeutral;
-        m_bidiResolver.setStatus(status);
-        m_bidiResolver.setPositionIgnoringNestedIsolates(TextRunIterator(&m_run, 0));
-        const bool hardLineBreak = false;
-        const bool reorderRuns = false;
-        m_bidiResolver.createBidiRunsForLine(TextRunIterator(&m_run, m_run.length()), NoVisualOverride, hardLineBreak, reorderRuns);
-    }
-    m_bidiRun = bidiRuns.firstRun();
-}
-
-bool SVGTextMetricsCalculator::advancePosition()
-{
-    m_currentPosition += currentCharacterStartsSurrogatePair() ? 2 : 1;
-    return m_currentPosition < characterCount();
-}
-
-// TODO(pdr): We only have per-glyph data so we need to synthesize per-grapheme
-// data. E.g., if 'fi' is shaped into a single glyph, we do not know the 'i'
-// position. The code below synthesizes an average glyph width when characters
-// share a single position. This will incorrectly split combining diacritics.
-// See: https://crbug.com/473476.
-static void synthesizeGraphemeWidths(const TextRun& run, Vector<CharacterRange>& ranges)
-{
-    unsigned distributeCount = 0;
-    for (int rangeIndex = static_cast<int>(ranges.size()) - 1; rangeIndex >= 0; --rangeIndex) {
-        CharacterRange& currentRange = ranges[rangeIndex];
-        if (currentRange.width() == 0) {
-            distributeCount++;
-        } else if (distributeCount != 0) {
-            // Only count surrogate pairs as a single character.
-            bool surrogatePair = characterStartsSurrogatePair(run, rangeIndex);
-            if (!surrogatePair)
-                distributeCount++;
-
-            float newWidth = currentRange.width() / distributeCount;
-            currentRange.end = currentRange.start + newWidth;
-            float lastEndPosition = currentRange.end;
-            for (unsigned distribute = 1; distribute < distributeCount; distribute++) {
-                // This surrogate pair check will skip processing of the second
-                // character forming the surrogate pair.
-                unsigned distributeIndex = rangeIndex + distribute + (surrogatePair ? 1 : 0);
-                ranges[distributeIndex].start = lastEndPosition;
-                ranges[distributeIndex].end = lastEndPosition + newWidth;
-                lastEndPosition = ranges[distributeIndex].end;
-            }
-
-            distributeCount = 0;
-        }
-    }
-}
-
-unsigned SVGTextMetricsCalculator::updateSubrunRangesForCurrentPosition()
-{
-    ASSERT(m_bidiRun);
-    if (m_currentPosition >= static_cast<unsigned>(m_bidiRun->stop())) {
-        m_bidiRun = m_bidiRun->next();
-        // Ensure new subrange ranges are computed below.
-        m_subrunRanges.clear();
-    }
-    ASSERT(m_bidiRun);
-    ASSERT(static_cast<int>(m_currentPosition) < m_bidiRun->stop());
-
-    unsigned positionInRun = m_currentPosition - m_bidiRun->start();
-    if (positionInRun >= m_subrunRanges.size()) {
-        TextRun subRun = constructTextRun(m_text, m_bidiRun->start(),
-            m_bidiRun->stop() - m_bidiRun->start(), m_bidiRun->direction());
-        m_subrunRanges = m_text.scaledFont().individualCharacterRanges(subRun);
-        synthesizeGraphemeWidths(subRun, m_subrunRanges);
-    }
-
-    ASSERT(m_subrunRanges.size() && positionInRun < m_subrunRanges.size());
-    return positionInRun;
-}
-
-SVGTextMetrics SVGTextMetricsCalculator::currentCharacterMetrics()
-{
-    unsigned currentSubrunPosition = updateSubrunRangesForCurrentPosition();
-    unsigned length = currentCharacterStartsSurrogatePair() ? 2 : 1;
-    float width = m_subrunRanges[currentSubrunPosition].width();
-    return SVGTextMetrics(length, width / m_fontScalingFactor, m_cachedFontHeight);
-}
-
-} // namespace
-
-void SVGTextMetricsBuilder::updateTextMetrics(LayoutSVGInlineText& text, bool& lastCharacterWasWhiteSpace)
-{
-    Vector<SVGTextMetrics>& metricsList = text.metricsList();
-    metricsList.clear();
-
-    if (!text.textLength())
-        return;
-
-    // TODO(pdr): This loop is too tightly coupled to SVGTextMetricsCalculator.
-    // We should refactor SVGTextMetricsCalculator to be a simple bidi run
-    // iterator and move all subrun logic to a single function.
-    SVGTextMetricsCalculator calculator(text);
-    bool preserveWhiteSpace = text.styleRef().whiteSpace() == PRE;
-    do {
-        bool currentCharacterIsWhiteSpace = calculator.currentCharacterIsWhiteSpace();
-        if (!preserveWhiteSpace && lastCharacterWasWhiteSpace && currentCharacterIsWhiteSpace) {
-            metricsList.append(SVGTextMetrics(SVGTextMetrics::SkippedSpaceMetrics));
-            ASSERT(calculator.currentCharacterMetrics().length() == 1);
-            continue;
-        }
-
-        metricsList.append(calculator.currentCharacterMetrics());
-
-        lastCharacterWasWhiteSpace = currentCharacterIsWhiteSpace;
-    } while (calculator.advancePosition());
-}
-
-} // namespace blink