| /** |
| * Copyright (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org> |
| * |
| * 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_FONTS) |
| #include "Font.h" |
| |
| #include "CSSFontSelector.h" |
| #include "GraphicsContext.h" |
| #include "RenderObject.h" |
| #include "SimpleFontData.h" |
| #include "SVGFontData.h" |
| #include "SVGGlyphElement.h" |
| #include "SVGFontElement.h" |
| #include "SVGFontFaceElement.h" |
| #include "SVGMissingGlyphElement.h" |
| #include "SVGPaintServer.h" |
| #include "SVGPaintServerSolid.h" |
| #include "XMLNames.h" |
| |
| using namespace WTF::Unicode; |
| |
| namespace WebCore { |
| |
| static inline float convertEmUnitToPixel(float fontSize, float unitsPerEm, float value) |
| { |
| if (unitsPerEm == 0.0f) |
| return 0.0f; |
| |
| return value * fontSize / unitsPerEm; |
| } |
| |
| static inline bool isVerticalWritingMode(const SVGRenderStyle* style) |
| { |
| return style->writingMode() == WM_TBRL || style->writingMode() == WM_TB; |
| } |
| |
| // Helper functions to determine the arabic character forms (initial, medial, terminal, isolated) |
| enum ArabicCharShapingMode { |
| SNone = 0, |
| SRight = 1, |
| SDual = 2 |
| }; |
| |
| static const ArabicCharShapingMode s_arabicCharShapingMode[222] = { |
| SRight, SRight, SRight, SRight, SDual , SRight, SDual , SRight, SDual , SDual , SDual , SDual , SDual , SRight, /* 0x0622 - 0x062F */ |
| SRight, SRight, SRight, SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SNone , SNone , SNone , SNone , SNone , /* 0x0630 - 0x063F */ |
| SNone , SDual , SDual , SDual , SDual , SDual , SDual , SRight, SDual , SDual , SNone , SNone , SNone , SNone , SNone , SNone , /* 0x0640 - 0x064F */ |
| SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , /* 0x0650 - 0x065F */ |
| SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , /* 0x0660 - 0x066F */ |
| SNone , SRight, SRight, SRight, SNone , SRight, SRight, SRight, SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , /* 0x0670 - 0x067F */ |
| SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SRight, SRight, SRight, SRight, SRight, SRight, SRight, SRight, /* 0x0680 - 0x068F */ |
| SRight, SRight, SRight, SRight, SRight, SRight, SRight, SRight, SRight, SRight, SDual , SDual , SDual , SDual , SDual , SDual , /* 0x0690 - 0x069F */ |
| SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , /* 0x06A0 - 0x06AF */ |
| SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , SDual , /* 0x06B0 - 0x06BF */ |
| SRight, SDual , SRight, SRight, SRight, SRight, SRight, SRight, SRight, SRight, SRight, SRight, SDual , SRight, SDual , SRight, /* 0x06C0 - 0x06CF */ |
| SDual , SDual , SRight, SRight, SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , /* 0x06D0 - 0x06DF */ |
| SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , /* 0x06E0 - 0x06EF */ |
| SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SNone , SDual , SDual , SDual , SNone , SNone , SNone /* 0x06F0 - 0x06FF */ |
| }; |
| |
| static inline SVGGlyphIdentifier::ArabicForm processArabicFormDetection(const UChar& curChar, bool& lastCharShapesRight, SVGGlyphIdentifier::ArabicForm* prevForm) |
| { |
| SVGGlyphIdentifier::ArabicForm curForm; |
| |
| ArabicCharShapingMode shapingMode = SNone; |
| if (curChar >= 0x0622 && curChar <= 0x06FF) |
| shapingMode = s_arabicCharShapingMode[curChar - 0x0622]; |
| |
| // Use a simple state machine to identify the actual arabic form |
| // It depends on the order of the arabic form enum: |
| // enum ArabicForm { None = 0, Isolated, Terminal, Initial, Medial }; |
| |
| if (lastCharShapesRight && shapingMode == SDual) { |
| if (prevForm) { |
| int correctedForm = (int) *prevForm + 1; |
| ASSERT(correctedForm >= SVGGlyphIdentifier::None && correctedForm <= SVGGlyphIdentifier::Medial); |
| *prevForm = static_cast<SVGGlyphIdentifier::ArabicForm>(correctedForm); |
| } |
| |
| curForm = SVGGlyphIdentifier::Initial; |
| } else |
| curForm = shapingMode == SNone ? SVGGlyphIdentifier::None : SVGGlyphIdentifier::Isolated; |
| |
| lastCharShapesRight = shapingMode != SNone; |
| return curForm; |
| } |
| |
| static Vector<SVGGlyphIdentifier::ArabicForm> charactersWithArabicForm(const String& input, bool rtl) |
| { |
| Vector<SVGGlyphIdentifier::ArabicForm> forms; |
| unsigned int length = input.length(); |
| |
| bool containsArabic = false; |
| for (unsigned int i = 0; i < length; ++i) { |
| if (isArabicChar(input[i])) { |
| containsArabic = true; |
| break; |
| } |
| } |
| |
| if (!containsArabic) |
| return forms; |
| |
| bool lastCharShapesRight = false; |
| |
| // Start identifying arabic forms |
| if (rtl) |
| for (int i = length - 1; i >= 0; --i) |
| forms.prepend(processArabicFormDetection(input[i], lastCharShapesRight, forms.isEmpty() ? 0 : &forms.first())); |
| else |
| for (unsigned int i = 0; i < length; ++i) |
| forms.append(processArabicFormDetection(input[i], lastCharShapesRight, forms.isEmpty() ? 0 : &forms.last())); |
| |
| return forms; |
| } |
| |
| static inline bool isCompatibleArabicForm(const SVGGlyphIdentifier& identifier, const Vector<SVGGlyphIdentifier::ArabicForm>& chars, unsigned int startPosition, unsigned int endPosition) |
| { |
| if (chars.isEmpty()) |
| return true; |
| |
| Vector<SVGGlyphIdentifier::ArabicForm>::const_iterator it = chars.begin() + startPosition; |
| Vector<SVGGlyphIdentifier::ArabicForm>::const_iterator end = chars.begin() + endPosition; |
| |
| ASSERT(end <= chars.end()); |
| for (; it != end; ++it) { |
| if ((*it) != identifier.arabicForm && (*it) != SVGGlyphIdentifier::None) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static inline bool isCompatibleGlyph(const SVGGlyphIdentifier& identifier, bool isVerticalText, const String& language, |
| const Vector<SVGGlyphIdentifier::ArabicForm>& chars, unsigned int startPosition, unsigned int endPosition) |
| { |
| bool valid = true; |
| |
| // Check wheter orientation if glyph fits within the request |
| switch (identifier.orientation) { |
| case SVGGlyphIdentifier::Vertical: |
| valid = isVerticalText; |
| break; |
| case SVGGlyphIdentifier::Horizontal: |
| valid = !isVerticalText; |
| break; |
| case SVGGlyphIdentifier::Both: |
| break; |
| } |
| |
| if (!valid) |
| return false; |
| |
| // Check wheter languages are compatible |
| if (!identifier.languages.isEmpty()) { |
| // This glyph exists only in certain languages, if we're not specifying a |
| // language on the referencing element we're unable to use this glyph. |
| if (language.isEmpty()) |
| return false; |
| |
| // Split subcode from language, if existant. |
| String languagePrefix; |
| |
| int subCodeSeparator = language.find('-'); |
| if (subCodeSeparator != -1) |
| languagePrefix = language.left(subCodeSeparator); |
| |
| Vector<String>::const_iterator it = identifier.languages.begin(); |
| Vector<String>::const_iterator end = identifier.languages.end(); |
| |
| bool found = false; |
| for (; it != end; ++it) { |
| String cur = (*it); |
| |
| if (cur == language || cur == languagePrefix) { |
| found = true; |
| break; |
| } |
| } |
| |
| if (!found) |
| return false; |
| } |
| |
| // Check wheter arabic form is compatible |
| return isCompatibleArabicForm(identifier, chars, startPosition, endPosition); |
| } |
| |
| static inline const SVGFontData* svgFontAndFontFaceElementForFontData(const SimpleFontData* fontData, SVGFontFaceElement*& fontFace, SVGFontElement*& font) |
| { |
| ASSERT(fontData->isCustomFont()); |
| ASSERT(fontData->isSVGFont()); |
| |
| const SVGFontData* svgFontData = static_cast<const SVGFontData*>(fontData->svgFontData()); |
| |
| fontFace = svgFontData->svgFontFaceElement(); |
| ASSERT(fontFace); |
| |
| font = fontFace->associatedFontElement(); |
| return svgFontData; |
| } |
| |
| // Helper class to walk a text run. Lookup a SVGGlyphIdentifier for each character |
| // - also respecting possibly defined ligatures - and invoke a callback for each found glyph. |
| template<typename SVGTextRunData> |
| struct SVGTextRunWalker { |
| typedef bool (*SVGTextRunWalkerCallback)(const SVGGlyphIdentifier&, SVGTextRunData&); |
| typedef void (*SVGTextRunWalkerMissingGlyphCallback)(const TextRun&, SVGTextRunData&); |
| |
| SVGTextRunWalker(const SVGFontData* fontData, SVGFontElement* fontElement, SVGTextRunData& data, |
| SVGTextRunWalkerCallback callback, SVGTextRunWalkerMissingGlyphCallback missingGlyphCallback) |
| : m_fontData(fontData) |
| , m_fontElement(fontElement) |
| , m_walkerData(data) |
| , m_walkerCallback(callback) |
| , m_walkerMissingGlyphCallback(missingGlyphCallback) |
| { |
| } |
| |
| void walk(const TextRun& run, bool isVerticalText, const String& language, int from, int to) |
| { |
| // Should hold true for SVG text, otherwhise sth. is wrong |
| ASSERT(to - from == run.length()); |
| |
| int maximumHashKeyLength = m_fontElement->maximumHashKeyLength(); |
| ASSERT(maximumHashKeyLength >= 0); |
| |
| Vector<SVGGlyphIdentifier::ArabicForm> chars(charactersWithArabicForm(String(run.data(from), run.length()), run.rtl())); |
| |
| SVGGlyphIdentifier identifier; |
| bool foundGlyph = false; |
| int characterLookupRange; |
| |
| for (int i = from; i < to; ++i) { |
| // If characterLookupRange is > 0, then the font defined ligatures (length of unicode property value > 1). |
| // We have to check wheter the current character & the next character define a ligature. This needs to be |
| // extended to the n-th next character (where n is 'characterLookupRange'), to check for any possible ligature. |
| characterLookupRange = maximumHashKeyLength + i >= to ? to - i : maximumHashKeyLength; |
| |
| while (characterLookupRange > 0 && !foundGlyph) { |
| String lookupString(run.data(run.rtl() ? run.length() - (i + characterLookupRange) : i), characterLookupRange); |
| |
| Vector<SVGGlyphIdentifier> glyphs = m_fontElement->glyphIdentifiersForString(lookupString); |
| Vector<SVGGlyphIdentifier>::iterator it = glyphs.begin(); |
| Vector<SVGGlyphIdentifier>::iterator end = glyphs.end(); |
| |
| for (; it != end; ++it) { |
| identifier = *it; |
| |
| unsigned int startPosition = run.rtl() ? run.length() - (i + lookupString.length()) : i; |
| unsigned int endPosition = startPosition + lookupString.length(); |
| |
| if (identifier.isValid && isCompatibleGlyph(identifier, isVerticalText, language, chars, startPosition, endPosition)) { |
| ASSERT(characterLookupRange > 0); |
| i += characterLookupRange - 1; |
| |
| foundGlyph = true; |
| SVGGlyphElement::inheritUnspecifiedAttributes(identifier, m_fontData); |
| break; |
| } |
| } |
| |
| characterLookupRange--; |
| } |
| |
| if (!foundGlyph) { |
| if (SVGMissingGlyphElement* element = m_fontElement->firstMissingGlyphElement()) { |
| // <missing-glyph> element support |
| identifier = SVGGlyphElement::buildGenericGlyphIdentifier(element); |
| SVGGlyphElement::inheritUnspecifiedAttributes(identifier, m_fontData); |
| } else { |
| // Fallback to system font fallback |
| TextRun subRun(run); |
| subRun.setText(subRun.data(i), 1); |
| |
| (*m_walkerMissingGlyphCallback)(subRun, m_walkerData); |
| continue; |
| } |
| } |
| |
| if (!(*m_walkerCallback)(identifier, m_walkerData)) |
| break; |
| |
| foundGlyph = false; |
| } |
| } |
| |
| private: |
| const SVGFontData* m_fontData; |
| SVGFontElement* m_fontElement; |
| SVGTextRunData& m_walkerData; |
| SVGTextRunWalkerCallback m_walkerCallback; |
| SVGTextRunWalkerMissingGlyphCallback m_walkerMissingGlyphCallback; |
| }; |
| |
| // Callback & data structures to compute the width of text using SVG Fonts |
| struct SVGTextRunWalkerMeasuredLengthData { |
| int at; |
| int from; |
| int to; |
| |
| float scale; |
| float length; |
| const Font* font; |
| }; |
| |
| bool floatWidthUsingSVGFontCallback(const SVGGlyphIdentifier& identifier, SVGTextRunWalkerMeasuredLengthData& data) |
| { |
| if (data.at >= data.from && data.at < data.to) |
| data.length += identifier.horizontalAdvanceX * data.scale; |
| |
| data.at++; |
| return data.at < data.to; |
| } |
| |
| void floatWidthMissingGlyphCallback(const TextRun& run, SVGTextRunWalkerMeasuredLengthData& data) |
| { |
| // Handle system font fallback |
| FontDescription fontDescription(data.font->fontDescription()); |
| fontDescription.setFamily(FontFamily()); |
| Font font(fontDescription, 0, 0); // spacing handled by SVG text code. |
| font.update(data.font->fontSelector()); |
| |
| data.length += font.floatWidth(run); |
| } |
| |
| static float floatWidthOfSubStringUsingSVGFont(const Font* font, const TextRun& run, int from, int to) |
| { |
| int newFrom = to > from ? from : to; |
| int newTo = to > from ? to : from; |
| |
| from = newFrom; |
| to = newTo; |
| |
| SVGFontElement* fontElement = 0; |
| SVGFontFaceElement* fontFaceElement = 0; |
| |
| if (const SVGFontData* fontData = svgFontAndFontFaceElementForFontData(font->primaryFont(), fontFaceElement, fontElement)) { |
| if (!fontElement) |
| return 0.0f; |
| |
| SVGTextRunWalkerMeasuredLengthData data; |
| |
| data.font = font; |
| data.at = from; |
| data.from = from; |
| data.to = to; |
| data.scale = convertEmUnitToPixel(font->size(), fontFaceElement->unitsPerEm(), 1.0f); |
| data.length = 0.0f; |
| |
| String language; |
| bool isVerticalText = false; // Holds true for HTML text |
| |
| // TODO: language matching & svg glyphs should be possible for HTML text, too. |
| if (RenderObject* renderObject = run.referencingRenderObject()) { |
| isVerticalText = isVerticalWritingMode(renderObject->style()->svgStyle()); |
| |
| if (SVGElement* element = static_cast<SVGElement*>(renderObject->element())) |
| language = element->getAttribute(XMLNames::langAttr); |
| } |
| |
| SVGTextRunWalker<SVGTextRunWalkerMeasuredLengthData> runWalker(fontData, fontElement, data, floatWidthUsingSVGFontCallback, floatWidthMissingGlyphCallback); |
| runWalker.walk(run, isVerticalText, language, 0, run.length()); |
| return data.length; |
| } |
| |
| return 0.0f; |
| } |
| |
| float Font::floatWidthUsingSVGFont(const TextRun& run) const |
| { |
| return floatWidthOfSubStringUsingSVGFont(this, run, 0, run.length()); |
| } |
| |
| // Callback & data structures to draw text using SVG Fonts |
| struct SVGTextRunWalkerDrawTextData { |
| float scale; |
| bool isVerticalText; |
| |
| float xStartOffset; |
| FloatPoint currentPoint; |
| FloatPoint glyphOrigin; |
| |
| GraphicsContext* context; |
| RenderObject* renderObject; |
| |
| SVGPaintServer* activePaintServer; |
| }; |
| |
| bool drawTextUsingSVGFontCallback(const SVGGlyphIdentifier& identifier, SVGTextRunWalkerDrawTextData& data) |
| { |
| // TODO: Support arbitary SVG content as glyph (currently limited to <glyph d="..."> situations) |
| if (!identifier.pathData.isEmpty()) { |
| data.context->save(); |
| |
| if (data.isVerticalText) { |
| data.glyphOrigin.setX(identifier.verticalOriginX * data.scale); |
| data.glyphOrigin.setY(identifier.verticalOriginY * data.scale); |
| } |
| |
| data.context->translate(data.xStartOffset + data.currentPoint.x() + data.glyphOrigin.x(), data.currentPoint.y() + data.glyphOrigin.y()); |
| data.context->scale(FloatSize(data.scale, -data.scale)); |
| |
| data.context->beginPath(); |
| data.context->addPath(identifier.pathData); |
| |
| SVGPaintTargetType targetType = data.context->textDrawingMode() == cTextStroke ? ApplyToStrokeTargetType : ApplyToFillTargetType; |
| if (data.activePaintServer->setup(data.context, data.renderObject, targetType)) { |
| // Spec: Any properties specified on a text elements which represents a length, such as the |
| // 'stroke-width' property, might produce surprising results since the length value will be |
| // processed in the coordinate system of the glyph. (TODO: What other lengths? miter-limit? dash-offset?) |
| if (targetType == ApplyToStrokeTargetType && data.scale != 0.0f) |
| data.context->setStrokeThickness(data.context->strokeThickness() / data.scale); |
| |
| data.activePaintServer->renderPath(data.context, data.renderObject, targetType); |
| data.activePaintServer->teardown(data.context, data.renderObject, targetType); |
| } |
| |
| data.context->restore(); |
| } |
| |
| if (data.isVerticalText) |
| data.currentPoint.move(0.0f, identifier.verticalAdvanceY * data.scale); |
| else |
| data.currentPoint.move(identifier.horizontalAdvanceX * data.scale, 0.0f); |
| |
| return true; |
| } |
| |
| void drawTextMissingGlyphCallback(const TextRun& run, SVGTextRunWalkerDrawTextData& data) |
| { |
| // Handle system font fallback |
| FontDescription fontDescription(data.context->font().fontDescription()); |
| fontDescription.setFamily(FontFamily()); |
| Font font(fontDescription, 0, 0); // spacing handled by SVG text code. |
| font.update(data.context->font().fontSelector()); |
| |
| font.drawText(data.context, run, data.currentPoint); |
| |
| if (data.isVerticalText) |
| data.currentPoint.move(0.0f, font.floatWidth(run)); |
| else |
| data.currentPoint.move(font.floatWidth(run), 0.0f); |
| } |
| |
| void Font::drawTextUsingSVGFont(GraphicsContext* context, const TextRun& run, |
| const FloatPoint& point, int from, int to) const |
| { |
| SVGFontElement* fontElement = 0; |
| SVGFontFaceElement* fontFaceElement = 0; |
| |
| if (const SVGFontData* fontData = svgFontAndFontFaceElementForFontData(primaryFont(), fontFaceElement, fontElement)) { |
| if (!fontElement) |
| return; |
| |
| SVGTextRunWalkerDrawTextData data; |
| data.currentPoint = point; |
| data.scale = convertEmUnitToPixel(size(), fontFaceElement->unitsPerEm(), 1.0f); |
| |
| // Required to be valid for SVG text only. |
| data.renderObject = run.referencingRenderObject(); |
| data.activePaintServer = run.activePaintServer(); |
| |
| // If renderObject is not set, we're dealing for HTML text rendered using SVG Fonts. |
| if (!data.renderObject) { |
| ASSERT(!data.activePaintServer); |
| |
| // TODO: We're only supporting simple filled HTML text so far. |
| SVGPaintServerSolid* solidPaintServer = SVGPaintServer::sharedSolidPaintServer(); |
| solidPaintServer->setColor(context->fillColor()); |
| |
| data.activePaintServer = solidPaintServer; |
| } |
| |
| ASSERT(data.activePaintServer); |
| |
| data.isVerticalText = false; |
| data.xStartOffset = floatWidthOfSubStringUsingSVGFont(this, run, run.rtl() ? to : 0, run.rtl() ? run.length() : from); |
| data.glyphOrigin = FloatPoint(); |
| data.context = context; |
| |
| String language; |
| |
| // TODO: language matching & svg glyphs should be possible for HTML text, too. |
| if (data.renderObject) { |
| data.isVerticalText = isVerticalWritingMode(data.renderObject->style()->svgStyle()); |
| |
| if (SVGElement* element = static_cast<SVGElement*>(data.renderObject->element())) |
| language = element->getAttribute(XMLNames::langAttr); |
| } |
| |
| if (!data.isVerticalText) { |
| data.glyphOrigin.setX(fontData->horizontalOriginX() * data.scale); |
| data.glyphOrigin.setY(fontData->horizontalOriginY() * data.scale); |
| } |
| |
| SVGTextRunWalker<SVGTextRunWalkerDrawTextData> runWalker(fontData, fontElement, data, drawTextUsingSVGFontCallback, drawTextMissingGlyphCallback); |
| runWalker.walk(run, data.isVerticalText, language, from, to); |
| } |
| } |
| |
| FloatRect Font::selectionRectForTextUsingSVGFont(const TextRun& run, const IntPoint& point, int height, int from, int to) const |
| { |
| return FloatRect(point.x() + floatWidthOfSubStringUsingSVGFont(this, run, run.rtl() ? to : 0, run.rtl() ? run.length() : from), |
| point.y(), floatWidthOfSubStringUsingSVGFont(this, run, from, to), height); |
| } |
| |
| int Font::offsetForPositionForTextUsingSVGFont(const TextRun&, int position, bool includePartialGlyphs) const |
| { |
| // TODO: Fix text selection when HTML text is drawn using a SVG Font |
| // We need to integrate the SVG text selection code in the offsetForPosition() framework. |
| // This will also fix a major issue, that SVG Text code can't select arabic strings properly. |
| return 0; |
| } |
| |
| } |
| |
| #endif |
