void SVGCharacterLayoutInfo::addLayoutInformation(InlineFlowBox* flowBox, float textAnchorStartOffset)
{
bool wasInitialLayout = isInitialLayout();
RenderSVGTextPath* textPath = toRenderSVGTextPath(flowBox->renderer());
Path path = textPath->layoutPath();
float baselineShift = calculateBaselineShift(textPath);
layoutPath = path;
layoutPathLength = path.length();
if (layoutPathLength <= 0.0f)
return;
startOffset = textPath->startOffset();
if (textPath->startOffset() >= 0.0f && textPath->startOffset() <= 1.0f)
startOffset *= layoutPathLength;
startOffset += textAnchorStartOffset;
currentOffset = startOffset;
// Only baseline-shift is handled through the normal layout system
addStackContent(BaselineShiftStack, baselineShift);
if (wasInitialLayout) {
xStackChanged = false;
yStackChanged = false;
dxStackChanged = false;
dyStackChanged = false;
angleStackChanged = false;
baselineShiftStackChanged = false;
}
}
void SVGTextLayoutEngine::beginTextPathLayout(RenderObject* object, SVGTextLayoutEngine& lineLayout)
{
ASSERT(object);
m_inPathLayout = true;
RenderSVGTextPath* textPath = toRenderSVGTextPath(object);
Path path = textPath->layoutPath();
if (path.isEmpty())
return;
m_textPathCalculator = new Path::PositionCalculator(path);
m_textPathStartOffset = textPath->startOffset();
m_textPathLength = path.length();
if (m_textPathStartOffset > 0 && m_textPathStartOffset <= 1)
m_textPathStartOffset *= m_textPathLength;
float totalLength = 0;
unsigned totalCharacters = 0;
lineLayout.m_chunkLayoutBuilder.buildTextChunks(lineLayout.m_lineLayoutBoxes);
const Vector<SVGTextChunk>& textChunks = lineLayout.m_chunkLayoutBuilder.textChunks();
unsigned size = textChunks.size();
for (unsigned i = 0; i < size; ++i) {
const SVGTextChunk& chunk = textChunks.at(i);
float length = 0;
unsigned characters = 0;
chunk.calculateLength(length, characters);
// Handle text-anchor as additional start offset for text paths.
m_textPathStartOffset += chunk.calculateTextAnchorShift(length);
totalLength += length;
totalCharacters += characters;
}
m_textPathCurrentOffset = m_textPathStartOffset;
// Eventually handle textLength adjustments.
SVGLengthAdjustType lengthAdjust = SVGLengthAdjustUnknown;
float desiredTextLength = 0;
if (SVGTextContentElement* textContentElement = SVGTextContentElement::elementFromRenderer(textPath)) {
SVGLengthContext lengthContext(textContentElement);
lengthAdjust = textContentElement->lengthAdjust()->currentValue()->enumValue();
if (textContentElement->textLengthIsSpecifiedByUser())
desiredTextLength = textContentElement->textLength()->currentValue()->value(lengthContext);
else
desiredTextLength = 0;
}
if (!desiredTextLength)
return;
if (lengthAdjust == SVGLengthAdjustSpacing)
m_textPathSpacing = (desiredTextLength - totalLength) / totalCharacters;
else
m_textPathScaling = desiredTextLength / totalLength;
}