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      1 /*
      2  * Copyright (C) 2007 Eric Seidel <eric (at) webkit.org>
      3  * Copyright (C) 2007, 2008 Nikolas Zimmermann <zimmermann (at) kde.org>
      4  * Copyright (C) 2008 Apple Inc. All rights reserved.
      5  *
      6  * This library is free software; you can redistribute it and/or
      7  * modify it under the terms of the GNU Library General Public
      8  * License as published by the Free Software Foundation; either
      9  * version 2 of the License, or (at your option) any later version.
     10  *
     11  * This library is distributed in the hope that it will be useful,
     12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14  * Library General Public License for more details.
     15  *
     16  * You should have received a copy of the GNU Library General Public License
     17  * along with this library; see the file COPYING.LIB.  If not, write to
     18  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     19  * Boston, MA 02110-1301, USA.
     20  */
     21 
     22 #include "config.h"
     23 
     24 #if ENABLE(SVG_FONTS)
     25 #include "core/svg/SVGFontFaceElement.h"
     26 
     27 #include "core/CSSPropertyNames.h"
     28 #include "core/CSSValueKeywords.h"
     29 #include "core/css/CSSFontFaceSrcValue.h"
     30 #include "core/css/CSSFontSelector.h"
     31 #include "core/css/CSSStyleSheet.h"
     32 #include "core/css/CSSValueList.h"
     33 #include "core/css/StylePropertySet.h"
     34 #include "core/css/StyleRule.h"
     35 #include "core/dom/Attribute.h"
     36 #include "core/dom/Document.h"
     37 #include "core/dom/StyleEngine.h"
     38 #include "core/svg/SVGDocumentExtensions.h"
     39 #include "core/svg/SVGFontElement.h"
     40 #include "core/svg/SVGFontFaceSrcElement.h"
     41 #include "core/svg/SVGGlyphElement.h"
     42 #include "platform/fonts/Font.h"
     43 #include <math.h>
     44 
     45 namespace blink {
     46 
     47 using namespace SVGNames;
     48 
     49 inline SVGFontFaceElement::SVGFontFaceElement(Document& document)
     50     : SVGElement(font_faceTag, document)
     51     , m_fontFaceRule(StyleRuleFontFace::create())
     52     , m_fontElement(nullptr)
     53     , m_weakFactory(this)
     54 {
     55     RefPtrWillBeRawPtr<MutableStylePropertySet> styleDeclaration = MutableStylePropertySet::create(HTMLStandardMode);
     56     m_fontFaceRule->setProperties(styleDeclaration.release());
     57 }
     58 
     59 DEFINE_NODE_FACTORY(SVGFontFaceElement)
     60 
     61 static CSSPropertyID cssPropertyIdForFontFaceAttributeName(const QualifiedName& attrName)
     62 {
     63     if (!attrName.namespaceURI().isNull())
     64         return CSSPropertyInvalid;
     65 
     66     static HashMap<StringImpl*, CSSPropertyID>* propertyNameToIdMap = 0;
     67     if (!propertyNameToIdMap) {
     68         propertyNameToIdMap = new HashMap<StringImpl*, CSSPropertyID>;
     69         // This is a list of all @font-face CSS properties which are exposed as SVG XML attributes
     70         // Those commented out are not yet supported by WebCore's style system
     71         // mapAttributeToCSSProperty(propertyNameToIdMap, accent_heightAttr);
     72         // mapAttributeToCSSProperty(propertyNameToIdMap, alphabeticAttr);
     73         // mapAttributeToCSSProperty(propertyNameToIdMap, ascentAttr);
     74         // mapAttributeToCSSProperty(propertyNameToIdMap, bboxAttr);
     75         // mapAttributeToCSSProperty(propertyNameToIdMap, cap_heightAttr);
     76         // mapAttributeToCSSProperty(propertyNameToIdMap, descentAttr);
     77         mapAttributeToCSSProperty(propertyNameToIdMap, font_familyAttr);
     78         mapAttributeToCSSProperty(propertyNameToIdMap, font_sizeAttr);
     79         mapAttributeToCSSProperty(propertyNameToIdMap, font_stretchAttr);
     80         mapAttributeToCSSProperty(propertyNameToIdMap, font_styleAttr);
     81         mapAttributeToCSSProperty(propertyNameToIdMap, font_variantAttr);
     82         mapAttributeToCSSProperty(propertyNameToIdMap, font_weightAttr);
     83         // mapAttributeToCSSProperty(propertyNameToIdMap, hangingAttr);
     84         // mapAttributeToCSSProperty(propertyNameToIdMap, ideographicAttr);
     85         // mapAttributeToCSSProperty(propertyNameToIdMap, mathematicalAttr);
     86         // mapAttributeToCSSProperty(propertyNameToIdMap, overline_positionAttr);
     87         // mapAttributeToCSSProperty(propertyNameToIdMap, overline_thicknessAttr);
     88         // mapAttributeToCSSProperty(propertyNameToIdMap, panose_1Attr);
     89         // mapAttributeToCSSProperty(propertyNameToIdMap, slopeAttr);
     90         // mapAttributeToCSSProperty(propertyNameToIdMap, stemhAttr);
     91         // mapAttributeToCSSProperty(propertyNameToIdMap, stemvAttr);
     92         // mapAttributeToCSSProperty(propertyNameToIdMap, strikethrough_positionAttr);
     93         // mapAttributeToCSSProperty(propertyNameToIdMap, strikethrough_thicknessAttr);
     94         // mapAttributeToCSSProperty(propertyNameToIdMap, underline_positionAttr);
     95         // mapAttributeToCSSProperty(propertyNameToIdMap, underline_thicknessAttr);
     96         // mapAttributeToCSSProperty(propertyNameToIdMap, unicode_rangeAttr);
     97         // mapAttributeToCSSProperty(propertyNameToIdMap, units_per_emAttr);
     98         // mapAttributeToCSSProperty(propertyNameToIdMap, v_alphabeticAttr);
     99         // mapAttributeToCSSProperty(propertyNameToIdMap, v_hangingAttr);
    100         // mapAttributeToCSSProperty(propertyNameToIdMap, v_ideographicAttr);
    101         // mapAttributeToCSSProperty(propertyNameToIdMap, v_mathematicalAttr);
    102         // mapAttributeToCSSProperty(propertyNameToIdMap, widthsAttr);
    103         // mapAttributeToCSSProperty(propertyNameToIdMap, x_heightAttr);
    104     }
    105 
    106     return propertyNameToIdMap->get(attrName.localName().impl());
    107 }
    108 
    109 void SVGFontFaceElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
    110 {
    111     CSSPropertyID propId = cssPropertyIdForFontFaceAttributeName(name);
    112     if (propId > 0) {
    113         m_fontFaceRule->mutableProperties().setProperty(propId, value, false);
    114         rebuildFontFace();
    115         return;
    116     }
    117 
    118     SVGElement::parseAttribute(name, value);
    119 }
    120 
    121 unsigned SVGFontFaceElement::unitsPerEm() const
    122 {
    123     const AtomicString& value = fastGetAttribute(units_per_emAttr);
    124     if (value.isEmpty())
    125         return gDefaultUnitsPerEm;
    126 
    127     return static_cast<unsigned>(ceilf(value.toFloat()));
    128 }
    129 
    130 int SVGFontFaceElement::xHeight() const
    131 {
    132     return static_cast<int>(ceilf(fastGetAttribute(x_heightAttr).toFloat()));
    133 }
    134 
    135 float SVGFontFaceElement::horizontalOriginX() const
    136 {
    137     if (!m_fontElement)
    138         return 0.0f;
    139 
    140     // Spec: The X-coordinate in the font coordinate system of the origin of a glyph to be used when
    141     // drawing horizontally oriented text. (Note that the origin applies to all glyphs in the font.)
    142     // If the attribute is not specified, the effect is as if a value of "0" were specified.
    143     return m_fontElement->fastGetAttribute(horiz_origin_xAttr).toFloat();
    144 }
    145 
    146 float SVGFontFaceElement::horizontalOriginY() const
    147 {
    148     if (!m_fontElement)
    149         return 0.0f;
    150 
    151     // Spec: The Y-coordinate in the font coordinate system of the origin of a glyph to be used when
    152     // drawing horizontally oriented text. (Note that the origin applies to all glyphs in the font.)
    153     // If the attribute is not specified, the effect is as if a value of "0" were specified.
    154     return m_fontElement->fastGetAttribute(horiz_origin_yAttr).toFloat();
    155 }
    156 
    157 float SVGFontFaceElement::horizontalAdvanceX() const
    158 {
    159     if (!m_fontElement)
    160         return 0.0f;
    161 
    162     // Spec: The default horizontal advance after rendering a glyph in horizontal orientation. Glyph
    163     // widths are required to be non-negative, even if the glyph is typically rendered right-to-left,
    164     // as in Hebrew and Arabic scripts.
    165     return m_fontElement->fastGetAttribute(horiz_adv_xAttr).toFloat();
    166 }
    167 
    168 float SVGFontFaceElement::verticalOriginX() const
    169 {
    170     if (!m_fontElement)
    171         return 0.0f;
    172 
    173     // Spec: The default X-coordinate in the font coordinate system of the origin of a glyph to be used when
    174     // drawing vertically oriented text. If the attribute is not specified, the effect is as if the attribute
    175     // were set to half of the effective value of attribute horiz-adv-x.
    176     const AtomicString& value = m_fontElement->fastGetAttribute(vert_origin_xAttr);
    177     if (value.isEmpty())
    178         return horizontalAdvanceX() / 2.0f;
    179 
    180     return value.toFloat();
    181 }
    182 
    183 float SVGFontFaceElement::verticalOriginY() const
    184 {
    185     if (!m_fontElement)
    186         return 0.0f;
    187 
    188     // Spec: The default Y-coordinate in the font coordinate system of the origin of a glyph to be used when
    189     // drawing vertically oriented text. If the attribute is not specified, the effect is as if the attribute
    190     // were set to the position specified by the font's ascent attribute.
    191     const AtomicString& value = m_fontElement->fastGetAttribute(vert_origin_yAttr);
    192     if (value.isEmpty())
    193         return ascent();
    194 
    195     return value.toFloat();
    196 }
    197 
    198 float SVGFontFaceElement::verticalAdvanceY() const
    199 {
    200     if (!m_fontElement)
    201         return 0.0f;
    202 
    203     // Spec: The default vertical advance after rendering a glyph in vertical orientation. If the attribute is
    204     // not specified, the effect is as if a value equivalent of one em were specified (see units-per-em).
    205     const AtomicString& value = m_fontElement->fastGetAttribute(vert_adv_yAttr);
    206        if (value.isEmpty())
    207         return 1.0f;
    208 
    209     return value.toFloat();
    210 }
    211 
    212 int SVGFontFaceElement::ascent() const
    213 {
    214     // Spec: Same syntax and semantics as the 'ascent' descriptor within an @font-face rule. The maximum
    215     // unaccented height of the font within the font coordinate system. If the attribute is not specified,
    216     // the effect is as if the attribute were set to the difference between the units-per-em value and the
    217     // vert-origin-y value for the corresponding font.
    218     const AtomicString& ascentValue = fastGetAttribute(ascentAttr);
    219     if (!ascentValue.isEmpty())
    220         return static_cast<int>(ceilf(ascentValue.toFloat()));
    221 
    222     if (m_fontElement) {
    223         const AtomicString& vertOriginY = m_fontElement->fastGetAttribute(vert_origin_yAttr);
    224         if (!vertOriginY.isEmpty())
    225             return static_cast<int>(unitsPerEm()) - static_cast<int>(ceilf(vertOriginY.toFloat()));
    226     }
    227 
    228     // Match Batiks default value
    229     return static_cast<int>(ceilf(unitsPerEm() * 0.8f));
    230 }
    231 
    232 int SVGFontFaceElement::descent() const
    233 {
    234     // Spec: Same syntax and semantics as the 'descent' descriptor within an @font-face rule. The maximum
    235     // unaccented depth of the font within the font coordinate system. If the attribute is not specified,
    236     // the effect is as if the attribute were set to the vert-origin-y value for the corresponding font.
    237     const AtomicString& descentValue = fastGetAttribute(descentAttr);
    238     if (!descentValue.isEmpty()) {
    239         // 14 different W3C SVG 1.1 testcases use a negative descent value,
    240         // where a positive was meant to be used  Including:
    241         // animate-elem-24-t.svg, fonts-elem-01-t.svg, fonts-elem-02-t.svg (and 11 others)
    242         int descent = static_cast<int>(ceilf(descentValue.toFloat()));
    243         return descent < 0 ? -descent : descent;
    244     }
    245 
    246     if (m_fontElement) {
    247         const AtomicString& vertOriginY = m_fontElement->fastGetAttribute(vert_origin_yAttr);
    248         if (!vertOriginY.isEmpty())
    249             return static_cast<int>(ceilf(vertOriginY.toFloat()));
    250     }
    251 
    252     // Match Batiks default value
    253     return static_cast<int>(ceilf(unitsPerEm() * 0.2f));
    254 }
    255 
    256 String SVGFontFaceElement::fontFamily() const
    257 {
    258     return m_fontFaceRule->properties().getPropertyValue(CSSPropertyFontFamily);
    259 }
    260 
    261 SVGFontElement* SVGFontFaceElement::associatedFontElement() const
    262 {
    263     ASSERT(parentNode() == m_fontElement);
    264     ASSERT(!parentNode() || isSVGFontElement(*parentNode()));
    265     return m_fontElement;
    266 }
    267 
    268 void SVGFontFaceElement::rebuildFontFace()
    269 {
    270     if (!inDocument()) {
    271         ASSERT(!m_fontElement);
    272         return;
    273     }
    274 
    275     bool describesParentFont = isSVGFontElement(*parentNode());
    276     RefPtrWillBeRawPtr<CSSValueList> list = nullptr;
    277 
    278     if (describesParentFont) {
    279         m_fontElement = toSVGFontElement(parentNode());
    280 
    281         list = CSSValueList::createCommaSeparated();
    282         list->append(CSSFontFaceSrcValue::createLocal(fontFamily()));
    283     } else {
    284         m_fontElement = nullptr;
    285         // we currently ignore all but the last src element, alternatively we could concat them
    286         if (SVGFontFaceSrcElement* element = Traversal<SVGFontFaceSrcElement>::lastChild(*this))
    287             list = element->srcValue();
    288     }
    289 
    290     if (!list || !list->length())
    291         return;
    292 
    293     // Parse in-memory CSS rules
    294     m_fontFaceRule->mutableProperties().addParsedProperty(CSSProperty(CSSPropertySrc, list));
    295 
    296     if (describesParentFont) {
    297         // Traverse parsed CSS values and associate CSSFontFaceSrcValue elements with ourselves.
    298         RefPtrWillBeRawPtr<CSSValue> src = m_fontFaceRule->properties().getPropertyCSSValue(CSSPropertySrc);
    299         CSSValueList* srcList = toCSSValueList(src.get());
    300 
    301         unsigned srcLength = srcList ? srcList->length() : 0;
    302         for (unsigned i = 0; i < srcLength; i++) {
    303             if (CSSFontFaceSrcValue* item = toCSSFontFaceSrcValue(srcList->item(i)))
    304                 item->setSVGFontFaceElement(this);
    305         }
    306     }
    307 
    308     document().styleResolverChanged();
    309 }
    310 
    311 Node::InsertionNotificationRequest SVGFontFaceElement::insertedInto(ContainerNode* rootParent)
    312 {
    313     SVGElement::insertedInto(rootParent);
    314     if (!rootParent->inDocument()) {
    315         ASSERT(!m_fontElement);
    316         return InsertionDone;
    317     }
    318     document().accessSVGExtensions().registerSVGFontFaceElement(this);
    319 
    320     rebuildFontFace();
    321     return InsertionDone;
    322 }
    323 
    324 void SVGFontFaceElement::removedFrom(ContainerNode* rootParent)
    325 {
    326     SVGElement::removedFrom(rootParent);
    327 
    328     if (rootParent->inDocument()) {
    329         m_fontElement = nullptr;
    330         document().accessSVGExtensions().unregisterSVGFontFaceElement(this);
    331 
    332         // FIXME: HTMLTemplateElement's document or imported  document can be active?
    333         // If so, we also need to check whether fontSelector() is nullptr or not.
    334         // Otherwise, we will use just document().isActive() here.
    335         if (document().isActive() && document().styleEngine()->fontSelector()) {
    336             document().styleEngine()->fontSelector()->fontFaceCache()->remove(m_fontFaceRule.get());
    337             document().accessSVGExtensions().registerPendingSVGFontFaceElementsForRemoval(this);
    338         }
    339         m_fontFaceRule->mutableProperties().clear();
    340         document().styleResolverChanged();
    341     } else
    342         ASSERT(!m_fontElement);
    343 }
    344 
    345 void SVGFontFaceElement::childrenChanged(const ChildrenChange& change)
    346 {
    347     SVGElement::childrenChanged(change);
    348     rebuildFontFace();
    349 }
    350 
    351 void SVGFontFaceElement::trace(Visitor* visitor)
    352 {
    353     visitor->trace(m_fontFaceRule);
    354     visitor->trace(m_fontElement);
    355     SVGElement::trace(visitor);
    356 }
    357 
    358 } // namespace blink
    359 
    360 #endif // ENABLE(SVG_FONTS)
    361