| /* |
| * Copyright (C) Research In Motion Limited 2010-2011. 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 "config.h" |
| |
| #if ENABLE(SVG) |
| #include "SVGTextLayoutAttributesBuilder.h" |
| |
| #include "RenderSVGInlineText.h" |
| #include "RenderSVGText.h" |
| #include "SVGTextPositioningElement.h" |
| |
| // Set to a value > 0 to dump the text layout attributes |
| #define DUMP_TEXT_LAYOUT_ATTRIBUTES 0 |
| |
| namespace WebCore { |
| |
| SVGTextLayoutAttributesBuilder::SVGTextLayoutAttributesBuilder() |
| { |
| } |
| |
| void SVGTextLayoutAttributesBuilder::buildLayoutAttributesForTextSubtree(RenderSVGText* textRoot) |
| { |
| ASSERT(textRoot); |
| |
| // Build list of x/y/dx/dy/rotate values for each subtree element that may define these values (tspan/textPath etc). |
| unsigned atCharacter = 0; |
| UChar lastCharacter = '\0'; |
| collectTextPositioningElements(textRoot, atCharacter, lastCharacter); |
| |
| if (!atCharacter) |
| return; |
| |
| // Collect x/y/dx/dy/rotate values for each character, stored in the m_positioningLists.xValues()/etc. lists. |
| buildLayoutAttributesForAllCharacters(textRoot, atCharacter); |
| |
| // Propagate layout attributes to each RenderSVGInlineText object, and the whole list to the RenderSVGText root. |
| Vector<SVGTextLayoutAttributes>& allAttributes = textRoot->layoutAttributes(); |
| allAttributes.clear(); |
| atCharacter = 0; |
| lastCharacter = '\0'; |
| propagateLayoutAttributes(textRoot, allAttributes, atCharacter, lastCharacter); |
| } |
| |
| static inline void extractFloatValuesFromSVGLengthList(SVGElement* lengthContext, const SVGLengthList& list, Vector<float>& floatValues, unsigned textContentLength) |
| { |
| ASSERT(lengthContext); |
| |
| unsigned length = list.size(); |
| if (length > textContentLength) |
| length = textContentLength; |
| floatValues.reserveCapacity(length); |
| |
| for (unsigned i = 0; i < length; ++i) { |
| const SVGLength& length = list.at(i); |
| floatValues.append(length.value(lengthContext)); |
| } |
| } |
| |
| static inline void extractFloatValuesFromSVGNumberList(const SVGNumberList& list, Vector<float>& floatValues, unsigned textContentLength) |
| { |
| unsigned length = list.size(); |
| if (length > textContentLength) |
| length = textContentLength; |
| floatValues.reserveCapacity(length); |
| |
| for (unsigned i = 0; i < length; ++i) |
| floatValues.append(list.at(i)); |
| } |
| |
| |
| static inline bool characterIsSpace(const UChar& character) |
| { |
| return character == ' '; |
| } |
| |
| static inline bool characterIsSpaceOrNull(const UChar& character) |
| { |
| return character == ' ' || character == '\0'; |
| } |
| |
| static inline bool shouldPreserveAllWhiteSpace(RenderStyle* style) |
| { |
| ASSERT(style); |
| return style->whiteSpace() == PRE; |
| } |
| |
| static inline void processRenderSVGInlineText(RenderSVGInlineText* text, unsigned& atCharacter, UChar& lastCharacter) |
| { |
| if (shouldPreserveAllWhiteSpace(text->style())) { |
| atCharacter += text->textLength(); |
| return; |
| } |
| |
| const UChar* characters = text->characters(); |
| unsigned textLength = text->textLength(); |
| for (unsigned textPosition = 0; textPosition < textLength; ++textPosition) { |
| const UChar& currentCharacter = characters[textPosition]; |
| if (characterIsSpace(currentCharacter) && characterIsSpaceOrNull(lastCharacter)) |
| continue; |
| |
| lastCharacter = currentCharacter; |
| ++atCharacter; |
| } |
| } |
| |
| void SVGTextLayoutAttributesBuilder::collectTextPositioningElements(RenderObject* start, unsigned& atCharacter, UChar& lastCharacter) |
| { |
| ASSERT(!start->isSVGText() || m_textPositions.isEmpty()); |
| |
| for (RenderObject* child = start->firstChild(); child; child = child->nextSibling()) { |
| if (child->isSVGInlineText()) { |
| processRenderSVGInlineText(toRenderSVGInlineText(child), atCharacter, lastCharacter); |
| continue; |
| } |
| |
| if (!child->isSVGInline()) |
| continue; |
| |
| SVGTextPositioningElement* element = SVGTextPositioningElement::elementFromRenderer(child); |
| unsigned atPosition = m_textPositions.size(); |
| if (element) |
| m_textPositions.append(TextPosition(element, atCharacter)); |
| |
| collectTextPositioningElements(child, atCharacter, lastCharacter); |
| |
| if (!element) |
| continue; |
| |
| // Update text position, after we're back from recursion. |
| TextPosition& position = m_textPositions[atPosition]; |
| ASSERT(!position.length); |
| position.length = atCharacter - position.start; |
| } |
| } |
| |
| void SVGTextLayoutAttributesBuilder::buildLayoutAttributesForAllCharacters(RenderSVGText* textRoot, unsigned textLength) |
| { |
| ASSERT(textLength); |
| |
| SVGTextPositioningElement* outermostTextElement = SVGTextPositioningElement::elementFromRenderer(textRoot); |
| ASSERT(outermostTextElement); |
| |
| // Fill the lists with the special emptyValue marker. |
| m_positioningLists.fillWithEmptyValues(textLength); |
| |
| // Grab outermost <text> element value lists and insert them in the m_positioningLists. |
| TextPosition wholeTextPosition(outermostTextElement, 0, textLength); |
| fillAttributesAtPosition(wholeTextPosition); |
| |
| // Handle x/y default attributes. |
| float& xFirst = m_positioningLists.xValues.first(); |
| if (xFirst == SVGTextLayoutAttributes::emptyValue()) |
| xFirst = 0; |
| |
| float& yFirst = m_positioningLists.yValues.first(); |
| if (yFirst == SVGTextLayoutAttributes::emptyValue()) |
| yFirst = 0; |
| |
| // Fill m_positioningLists using child text positioning elements in top-down order. |
| unsigned size = m_textPositions.size(); |
| for (unsigned i = 0; i < size; ++i) |
| fillAttributesAtPosition(m_textPositions[i]); |
| |
| // Now m_positioningLists.contains a x/y/dx/dy/rotate value for each character in the <text> subtree. |
| } |
| |
| 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::emptyMetrics(); |
| |
| for (unsigned textPosition = 0; textPosition < textLength; textPosition += metricsLength) { |
| const UChar& currentCharacter = characters[textPosition]; |
| |
| SVGTextMetrics startToCurrentMetrics = SVGTextMetrics::measureCharacterRange(text, 0, textPosition + 1); |
| SVGTextMetrics currentMetrics = SVGTextMetrics::measureCharacterRange(text, textPosition, 1); |
| |
| // 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; |
| metricsLength = currentMetrics.length(); |
| |
| if (!preserveWhiteSpace && characterIsSpace(currentCharacter) && characterIsSpaceOrNull(lastCharacter)) { |
| attributes.positioningLists().appendEmptyValues(); |
| attributes.textMetricsValues().append(SVGTextMetrics::emptyMetrics()); |
| 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 += metricsLength; |
| } |
| |
| #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); |
| } |
| } |
| |
| static inline void fillListAtPosition(Vector<float>& allValues, Vector<float>& values, unsigned start) |
| { |
| unsigned valuesSize = values.size(); |
| for (unsigned i = 0; i < valuesSize; ++i) |
| allValues[start + i] = values[i]; |
| } |
| |
| void SVGTextLayoutAttributesBuilder::fillAttributesAtPosition(const TextPosition& position) |
| { |
| Vector<float> values; |
| extractFloatValuesFromSVGLengthList(position.element, position.element->x(), values, position.length); |
| fillListAtPosition(m_positioningLists.xValues, values, position.start); |
| |
| values.clear(); |
| extractFloatValuesFromSVGLengthList(position.element, position.element->y(), values, position.length); |
| fillListAtPosition(m_positioningLists.yValues, values, position.start); |
| |
| values.clear(); |
| extractFloatValuesFromSVGLengthList(position.element, position.element->dx(), values, position.length); |
| fillListAtPosition(m_positioningLists.dxValues, values, position.start); |
| |
| values.clear(); |
| extractFloatValuesFromSVGLengthList(position.element, position.element->dy(), values, position.length); |
| fillListAtPosition(m_positioningLists.dyValues, values, position.start); |
| |
| values.clear(); |
| extractFloatValuesFromSVGNumberList(position.element->rotate(), values, position.length); |
| fillListAtPosition(m_positioningLists.rotateValues, values, position.start); |
| |
| // The last rotation value always spans the whole scope. |
| if (values.isEmpty()) |
| return; |
| |
| float lastValue = values.last(); |
| for (unsigned i = values.size(); i < position.length; ++i) |
| m_positioningLists.rotateValues[position.start + i] = lastValue; |
| } |
| |
| } |
| |
| #endif // ENABLE(SVG) |