void LayoutSVGInlineText::addMetricsFromRun(
const TextRun& run, bool& lastCharacterWasWhiteSpace)
{
Vector<CharacterRange> charRanges = scaledFont().individualCharacterRanges(run);
synthesizeGraphemeWidths(run, charRanges);
const float cachedFontHeight = scaledFont().getFontMetrics().floatHeight() / m_scalingFactor;
const bool preserveWhiteSpace = styleRef().whiteSpace() == PRE;
const unsigned runLength = static_cast<unsigned>(run.length());
// TODO(pdr): Character-based iteration is ambiguous and error-prone. It
// should be unified under a single concept. See: https://crbug.com/593570
unsigned characterIndex = 0;
while (characterIndex < runLength) {
bool currentCharacterIsWhiteSpace = run[characterIndex] == ' ';
if (!preserveWhiteSpace && lastCharacterWasWhiteSpace && currentCharacterIsWhiteSpace) {
m_metrics.append(SVGTextMetrics(SVGTextMetrics::SkippedSpaceMetrics));
characterIndex++;
continue;
}
unsigned length = isValidSurrogatePair(run, characterIndex) ? 2 : 1;
float width = charRanges[characterIndex].width() / m_scalingFactor;
m_metrics.append(SVGTextMetrics(length, width, cachedFontHeight));
lastCharacterWasWhiteSpace = currentCharacterIsWhiteSpace;
characterIndex += length;
}
}
void SVGTextMetricsBuilder::advanceSimpleText()
{
#if PLATFORM(QT) && !HAVE(QRAWFONT)
ASSERT_NOT_REACHED();
#else
GlyphBuffer glyphBuffer;
unsigned metricsLength = m_simpleWidthIterator->advance(m_textPosition + 1, &glyphBuffer);
if (!metricsLength) {
m_currentMetrics = SVGTextMetrics();
return;
}
if (currentCharacterStartsSurrogatePair())
ASSERT(metricsLength == 2);
float currentWidth = m_simpleWidthIterator->runWidthSoFar() - m_totalWidth;
m_totalWidth = m_simpleWidthIterator->runWidthSoFar();
#if ENABLE(SVG_FONTS)
m_currentMetrics = SVGTextMetrics(m_text, m_textPosition, metricsLength, currentWidth, m_simpleWidthIterator->lastGlyphName());
#else
m_currentMetrics = SVGTextMetrics(m_text, m_textPosition, metricsLength, currentWidth, emptyString());
#endif
#endif
}
SVGTextMetrics SVGTextMetricsCalculator::computeMetricsForCharacterSimple(unsigned textPosition)
{
GlyphBuffer glyphBuffer;
unsigned metricsLength = m_simpleShaper->advance(textPosition + 1, &glyphBuffer);
if (!metricsLength)
return SVGTextMetrics();
float currentWidth = m_simpleShaper->runWidthSoFar() - m_totalWidth;
m_totalWidth = m_simpleShaper->runWidthSoFar();
return SVGTextMetrics(m_text, textPosition, metricsLength, currentWidth);
}
void SVGTextMetricsBuilder::initializeMeasurementWithTextRenderer(RenderSVGInlineText* text)
{
m_text = text;
m_textPosition = 0;
m_currentMetrics = SVGTextMetrics();
m_complexStartToCurrentMetrics = SVGTextMetrics();
m_totalWidth = 0;
const Font& scaledFont = text->scaledFont();
m_run = SVGTextMetrics::constructTextRun(text, text->characters(), 0, text->textLength());
m_isComplexText = scaledFont.codePath(m_run) == Font::Complex;
if (m_isComplexText)
m_simpleWidthIterator.clear();
else
m_simpleWidthIterator = adoptPtr(new WidthIterator(&scaledFont, m_run));
}
void SVGTextMetricsBuilder::advanceSimpleText()
{
GlyphBuffer glyphBuffer;
unsigned metricsLength = m_simpleWidthIterator->advance(m_textPosition + 1, &glyphBuffer);
if (!metricsLength) {
m_currentMetrics = SVGTextMetrics();
return;
}
float currentWidth = m_simpleWidthIterator->runWidthSoFar() - m_totalWidth;
m_totalWidth = m_simpleWidthIterator->runWidthSoFar();
#if ENABLE(SVG_FONTS)
m_currentMetrics = SVGTextMetrics(m_text, m_textPosition, metricsLength, currentWidth, m_simpleWidthIterator->lastGlyphName());
#else
m_currentMetrics = SVGTextMetrics(m_text, m_textPosition, metricsLength, currentWidth, emptyString());
#endif
}
static void measureTextRenderer(RenderSVGInlineText* text, MeasureTextData* data, bool processRenderer)
{
ASSERT(text);
SVGTextLayoutAttributes* attributes = text->layoutAttributes();
Vector<SVGTextMetrics>* textMetricsValues = &attributes->textMetricsValues();
if (processRenderer) {
if (data->allCharactersMap)
attributes->clear();
else
textMetricsValues->clear();
}
SVGTextMetricsCalculator calculator(text);
bool preserveWhiteSpace = text->style()->whiteSpace() == PRE;
unsigned surrogatePairCharacters = 0;
unsigned skippedCharacters = 0;
unsigned textPosition = 0;
unsigned textLength = calculator.textLength();
SVGTextMetrics currentMetrics;
for (; textPosition < textLength; textPosition += currentMetrics.length()) {
currentMetrics = calculator.computeMetricsForCharacter(textPosition);
if (!currentMetrics.length())
break;
bool characterIsWhiteSpace = calculator.characterIsWhiteSpace(textPosition);
if (characterIsWhiteSpace && !preserveWhiteSpace && data->lastCharacterWasWhiteSpace) {
if (processRenderer)
textMetricsValues->append(SVGTextMetrics(SVGTextMetrics::SkippedSpaceMetrics));
if (data->allCharactersMap)
skippedCharacters += currentMetrics.length();
continue;
}
if (processRenderer) {
if (data->allCharactersMap) {
const SVGCharacterDataMap::const_iterator it = data->allCharactersMap->find(data->valueListPosition + textPosition - skippedCharacters - surrogatePairCharacters + 1);
if (it != data->allCharactersMap->end())
attributes->characterDataMap().set(textPosition + 1, it->value);
}
textMetricsValues->append(currentMetrics);
}
if (data->allCharactersMap && calculator.characterStartsSurrogatePair(textPosition))
surrogatePairCharacters++;
data->lastCharacterWasWhiteSpace = characterIsWhiteSpace;
}
if (!data->allCharactersMap)
return;
data->valueListPosition += textPosition - skippedCharacters;
}
void SVGTextMetricsBuilder::measureTextRenderer(RenderSVGInlineText* text, MeasureTextData* data)
{
ASSERT(text);
SVGTextLayoutAttributes* attributes = text->layoutAttributes();
Vector<SVGTextMetrics>* textMetricsValues = &attributes->textMetricsValues();
if (data->processRenderer) {
if (data->allCharactersMap)
attributes->clear();
else
textMetricsValues->clear();
}
initializeMeasurementWithTextRenderer(text);
bool preserveWhiteSpace = text->style()->whiteSpace() == PRE;
int surrogatePairCharacters = 0;
while (advance()) {
const UChar* currentCharacter = m_run.data16(m_textPosition);
if (*currentCharacter == ' ' && !preserveWhiteSpace && (!data->lastCharacter || *data->lastCharacter == ' ')) {
if (data->processRenderer)
textMetricsValues->append(SVGTextMetrics(SVGTextMetrics::SkippedSpaceMetrics));
if (data->allCharactersMap)
data->skippedCharacters += m_currentMetrics.length();
continue;
}
if (data->processRenderer) {
if (data->allCharactersMap) {
const SVGCharacterDataMap::const_iterator it = data->allCharactersMap->find(data->valueListPosition + m_textPosition - data->skippedCharacters - surrogatePairCharacters + 1);
if (it != data->allCharactersMap->end())
attributes->characterDataMap().set(m_textPosition + 1, it->value);
}
textMetricsValues->append(m_currentMetrics);
}
if (data->allCharactersMap && currentCharacterStartsSurrogatePair())
surrogatePairCharacters++;
data->lastCharacter = currentCharacter;
}
if (!data->allCharactersMap)
return;
data->valueListPosition += m_textPosition - data->skippedCharacters;
data->skippedCharacters = 0;
}
SVGTextMetrics SVGTextMetrics::measureCharacterRange(RenderSVGInlineText* text, unsigned position, unsigned length)
{
ASSERT(text);
return SVGTextMetrics(text, constructTextRun(text, position, length));
}
SVGTextMetrics SVGTextMetrics::measureCharacterRange(LineLayoutSVGInlineText textLayoutItem, unsigned position, unsigned length, TextDirection textDirection)
{
ASSERT(textLayoutItem);
return SVGTextMetrics(textLayoutItem, constructTextRun(textLayoutItem, position, length, textDirection));
}
void SVGTextLayoutAttributesBuilder::propagateLayoutAttributes(RenderObject* start, Vector<SVGTextLayoutAttributes>& allAttributes, unsigned& atCharacter, UChar& lastCharacter) const
{
for (RenderObject* child = start->firstChild(); child; child = child->nextSibling()) {
if (child->isSVGInlineText()) {
RenderSVGInlineText* text = toRenderSVGInlineText(child);
const UChar* characters = text->characters();
unsigned textLength = text->textLength();
bool preserveWhiteSpace = shouldPreserveAllWhiteSpace(text->style());
SVGTextLayoutAttributes attributes(text);
attributes.reserveCapacity(textLength);
unsigned valueListPosition = atCharacter;
unsigned metricsLength = 1;
SVGTextMetrics lastMetrics(SVGTextMetrics::SkippedSpaceMetrics);
for (unsigned textPosition = 0; textPosition < textLength; textPosition += metricsLength) {
const UChar& currentCharacter = characters[textPosition];
SVGTextMetrics startToCurrentMetrics;
SVGTextMetrics currentMetrics;
unsigned valueListAdvance = 0;
if (U16_IS_LEAD(currentCharacter) && (textPosition + 1) < textLength && U16_IS_TRAIL(characters[textPosition + 1])) {
// Handle surrogate pairs.
startToCurrentMetrics = SVGTextMetrics::measureCharacterRange(text, 0, textPosition + 2);
currentMetrics = SVGTextMetrics::measureCharacterRange(text, textPosition, 2);
metricsLength = currentMetrics.length();
valueListAdvance = 1;
} else {
// Handle BMP characters.
startToCurrentMetrics = SVGTextMetrics::measureCharacterRange(text, 0, textPosition + 1);
currentMetrics = SVGTextMetrics::measureCharacterRange(text, textPosition, 1);
metricsLength = currentMetrics.length();
valueListAdvance = metricsLength;
}
if (!metricsLength)
break;
// Frequent case for Arabic text: when measuring a single character the arabic isolated form is taken
// when rendering the glyph "in context" (with it's surrounding characters) it changes due to shaping.
// So whenever runWidthAdvance != currentMetrics.width(), we are processing a text run whose length is
// not equal to the sum of the individual lengths of the glyphs, when measuring them isolated.
float runWidthAdvance = startToCurrentMetrics.width() - lastMetrics.width();
if (runWidthAdvance != currentMetrics.width())
currentMetrics.setWidth(runWidthAdvance);
lastMetrics = startToCurrentMetrics;
if (!preserveWhiteSpace && characterIsSpace(currentCharacter) && characterIsSpaceOrNull(lastCharacter)) {
attributes.positioningLists().appendEmptyValues();
attributes.textMetricsValues().append(SVGTextMetrics(SVGTextMetrics::SkippedSpaceMetrics));
continue;
}
SVGTextLayoutAttributes::PositioningLists& positioningLists = attributes.positioningLists();
positioningLists.appendValuesFromPosition(m_positioningLists, valueListPosition);
attributes.textMetricsValues().append(currentMetrics);
// Pad x/y/dx/dy/rotate value lists with empty values, if the metrics span more than one character.
if (metricsLength > 1) {
for (unsigned i = 0; i < metricsLength - 1; ++i)
positioningLists.appendEmptyValues();
}
lastCharacter = currentCharacter;
valueListPosition += valueListAdvance;
}
#if DUMP_TEXT_LAYOUT_ATTRIBUTES > 0
fprintf(stderr, "\nDumping layout attributes for RenderSVGInlineText, renderer=%p, node=%p (atCharacter: %i)\n", text, text->node(), atCharacter);
fprintf(stderr, "BiDi properties: unicode-bidi=%i, block direction=%i\n", text->style()->unicodeBidi(), text->style()->direction());
attributes.dump();
#endif
text->storeLayoutAttributes(attributes);
allAttributes.append(attributes);
atCharacter = valueListPosition;
continue;
}
if (!child->isSVGInline())
continue;
propagateLayoutAttributes(child, allAttributes, atCharacter, lastCharacter);
}
}
