root/Source/core/svg/SVGFontFaceElement.cpp

DEFINITIONS

1. m_fontElement
2. create
3. cssPropertyIdForFontFaceAttributeName
4. parseAttribute
5. unitsPerEm
6. xHeight
7. horizontalOriginX
8. horizontalOriginY
9. horizontalAdvanceX
10. verticalOriginX
11. verticalOriginY
12. verticalAdvanceY
13. ascent
14. descent
15. fontFamily
16. associatedFontElement
17. rebuildFontFace
18. insertedInto
19. removedFrom
20. childrenChanged

/*
 * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
 * Copyright (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
 * Copyright (C) 2008 Apple Inc. 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_FONTS)
#include "core/svg/SVGFontFaceElement.h"

#include <math.h>
#include "CSSPropertyNames.h"
#include "CSSValueKeywords.h"
#include "core/css/CSSFontFaceSrcValue.h"
#include "core/css/CSSFontSelector.h"
#include "core/css/CSSStyleSheet.h"
#include "core/css/CSSValueList.h"
#include "core/css/StylePropertySet.h"
#include "core/css/StyleRule.h"
#include "core/dom/Attribute.h"
#include "core/dom/Document.h"
#include "core/dom/StyleEngine.h"
#include "core/svg/SVGDocumentExtensions.h"
#include "core/svg/SVGFontElement.h"
#include "core/svg/SVGFontFaceSrcElement.h"
#include "core/svg/SVGGlyphElement.h"
#include "platform/fonts/Font.h"

namespace WebCore {

using namespace SVGNames;

inline SVGFontFaceElement::SVGFontFaceElement(Document& document)
    : SVGElement(font_faceTag, document)
    , m_fontFaceRule(StyleRuleFontFace::create())
    , m_fontElement(0)
{
    ScriptWrappable::init(this);
    RefPtrWillBeRawPtr<MutableStylePropertySet> styleDeclaration = MutableStylePropertySet::create(HTMLStandardMode);
    m_fontFaceRule->setProperties(styleDeclaration.release());
}

PassRefPtr<SVGFontFaceElement> SVGFontFaceElement::create(Document& document)
{
    return adoptRef(new SVGFontFaceElement(document));
}

static CSSPropertyID cssPropertyIdForFontFaceAttributeName(const QualifiedName& attrName)
{
    if (!attrName.namespaceURI().isNull())
        return CSSPropertyInvalid;

    static HashMap<StringImpl*, CSSPropertyID>* propertyNameToIdMap = 0;
    if (!propertyNameToIdMap) {
        propertyNameToIdMap = new HashMap<StringImpl*, CSSPropertyID>;
        // This is a list of all @font-face CSS properties which are exposed as SVG XML attributes
        // Those commented out are not yet supported by WebCore's style system
        // mapAttributeToCSSProperty(propertyNameToIdMap, accent_heightAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, alphabeticAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, ascentAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, bboxAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, cap_heightAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, descentAttr);
        mapAttributeToCSSProperty(propertyNameToIdMap, font_familyAttr);
        mapAttributeToCSSProperty(propertyNameToIdMap, font_sizeAttr);
        mapAttributeToCSSProperty(propertyNameToIdMap, font_stretchAttr);
        mapAttributeToCSSProperty(propertyNameToIdMap, font_styleAttr);
        mapAttributeToCSSProperty(propertyNameToIdMap, font_variantAttr);
        mapAttributeToCSSProperty(propertyNameToIdMap, font_weightAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, hangingAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, ideographicAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, mathematicalAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, overline_positionAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, overline_thicknessAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, panose_1Attr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, slopeAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, stemhAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, stemvAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, strikethrough_positionAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, strikethrough_thicknessAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, underline_positionAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, underline_thicknessAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, unicode_rangeAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, units_per_emAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, v_alphabeticAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, v_hangingAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, v_ideographicAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, v_mathematicalAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, widthsAttr);
        // mapAttributeToCSSProperty(propertyNameToIdMap, x_heightAttr);
    }

    return propertyNameToIdMap->get(attrName.localName().impl());
}

void SVGFontFaceElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
{
    CSSPropertyID propId = cssPropertyIdForFontFaceAttributeName(name);
    if (propId > 0) {
        m_fontFaceRule->mutableProperties().setProperty(propId, value, false);
        rebuildFontFace();
        return;
    }

    SVGElement::parseAttribute(name, value);
}

unsigned SVGFontFaceElement::unitsPerEm() const
{
    const AtomicString& value = fastGetAttribute(units_per_emAttr);
    if (value.isEmpty())
        return gDefaultUnitsPerEm;

    return static_cast<unsigned>(ceilf(value.toFloat()));
}

int SVGFontFaceElement::xHeight() const
{
    return static_cast<int>(ceilf(fastGetAttribute(x_heightAttr).toFloat()));
}

float SVGFontFaceElement::horizontalOriginX() const
{
    if (!m_fontElement)
        return 0.0f;

    // Spec: The X-coordinate in the font coordinate system of the origin of a glyph to be used when
    // drawing horizontally oriented text. (Note that the origin applies to all glyphs in the font.)
    // If the attribute is not specified, the effect is as if a value of "0" were specified.
    return m_fontElement->fastGetAttribute(horiz_origin_xAttr).toFloat();
}

float SVGFontFaceElement::horizontalOriginY() const
{
    if (!m_fontElement)
        return 0.0f;

    // Spec: The Y-coordinate in the font coordinate system of the origin of a glyph to be used when
    // drawing horizontally oriented text. (Note that the origin applies to all glyphs in the font.)
    // If the attribute is not specified, the effect is as if a value of "0" were specified.
    return m_fontElement->fastGetAttribute(horiz_origin_yAttr).toFloat();
}

float SVGFontFaceElement::horizontalAdvanceX() const
{
    if (!m_fontElement)
        return 0.0f;

    // Spec: The default horizontal advance after rendering a glyph in horizontal orientation. Glyph
    // widths are required to be non-negative, even if the glyph is typically rendered right-to-left,
    // as in Hebrew and Arabic scripts.
    return m_fontElement->fastGetAttribute(horiz_adv_xAttr).toFloat();
}

float SVGFontFaceElement::verticalOriginX() const
{
    if (!m_fontElement)
        return 0.0f;

    // Spec: The default X-coordinate in the font coordinate system of the origin of a glyph to be used when
    // drawing vertically oriented text. If the attribute is not specified, the effect is as if the attribute
    // were set to half of the effective value of attribute horiz-adv-x.
    const AtomicString& value = m_fontElement->fastGetAttribute(vert_origin_xAttr);
    if (value.isEmpty())
        return horizontalAdvanceX() / 2.0f;

    return value.toFloat();
}

float SVGFontFaceElement::verticalOriginY() const
{
    if (!m_fontElement)
        return 0.0f;

    // Spec: The default Y-coordinate in the font coordinate system of the origin of a glyph to be used when
    // drawing vertically oriented text. If the attribute is not specified, the effect is as if the attribute
    // were set to the position specified by the font's ascent attribute.
    const AtomicString& value = m_fontElement->fastGetAttribute(vert_origin_yAttr);
    if (value.isEmpty())
        return ascent();

    return value.toFloat();
}

float SVGFontFaceElement::verticalAdvanceY() const
{
    if (!m_fontElement)
        return 0.0f;

    // Spec: The default vertical advance after rendering a glyph in vertical orientation. If the attribute is
    // not specified, the effect is as if a value equivalent of one em were specified (see units-per-em).
    const AtomicString& value = m_fontElement->fastGetAttribute(vert_adv_yAttr);
       if (value.isEmpty())
        return 1.0f;

    return value.toFloat();
}

int SVGFontFaceElement::ascent() const
{
    // Spec: Same syntax and semantics as the 'ascent' descriptor within an @font-face rule. The maximum
    // unaccented height of the font within the font coordinate system. If the attribute is not specified,
    // the effect is as if the attribute were set to the difference between the units-per-em value and the
    // vert-origin-y value for the corresponding font.
    const AtomicString& ascentValue = fastGetAttribute(ascentAttr);
    if (!ascentValue.isEmpty())
        return static_cast<int>(ceilf(ascentValue.toFloat()));

    if (m_fontElement) {
        const AtomicString& vertOriginY = m_fontElement->fastGetAttribute(vert_origin_yAttr);
        if (!vertOriginY.isEmpty())
            return static_cast<int>(unitsPerEm()) - static_cast<int>(ceilf(vertOriginY.toFloat()));
    }

    // Match Batiks default value
    return static_cast<int>(ceilf(unitsPerEm() * 0.8f));
}

int SVGFontFaceElement::descent() const
{
    // Spec: Same syntax and semantics as the 'descent' descriptor within an @font-face rule. The maximum
    // unaccented depth of the font within the font coordinate system. If the attribute is not specified,
    // the effect is as if the attribute were set to the vert-origin-y value for the corresponding font.
    const AtomicString& descentValue = fastGetAttribute(descentAttr);
    if (!descentValue.isEmpty()) {
        // 14 different W3C SVG 1.1 testcases use a negative descent value,
        // where a positive was meant to be used  Including:
        // animate-elem-24-t.svg, fonts-elem-01-t.svg, fonts-elem-02-t.svg (and 11 others)
        int descent = static_cast<int>(ceilf(descentValue.toFloat()));
        return descent < 0 ? -descent : descent;
    }

    if (m_fontElement) {
        const AtomicString& vertOriginY = m_fontElement->fastGetAttribute(vert_origin_yAttr);
        if (!vertOriginY.isEmpty())
            return static_cast<int>(ceilf(vertOriginY.toFloat()));
    }

    // Match Batiks default value
    return static_cast<int>(ceilf(unitsPerEm() * 0.2f));
}

String SVGFontFaceElement::fontFamily() const
{
    return m_fontFaceRule->properties().getPropertyValue(CSSPropertyFontFamily);
}

SVGFontElement* SVGFontFaceElement::associatedFontElement() const
{
    ASSERT(parentNode() == m_fontElement);
    ASSERT(!parentNode() || isSVGFontElement(*parentNode()));
    return m_fontElement;
}

void SVGFontFaceElement::rebuildFontFace()
{
    if (!inDocument()) {
        ASSERT(!m_fontElement);
        return;
    }

    bool describesParentFont = isSVGFontElement(*parentNode());
    RefPtrWillBeRawPtr<CSSValueList> list = nullptr;

    if (describesParentFont) {
        m_fontElement = toSVGFontElement(parentNode());

        list = CSSValueList::createCommaSeparated();
        list->append(CSSFontFaceSrcValue::createLocal(fontFamily()));
    } else {
        m_fontElement = 0;
        // we currently ignore all but the last src element, alternatively we could concat them
        if (SVGFontFaceSrcElement* element = Traversal<SVGFontFaceSrcElement>::lastChild(*this))
            list = element->srcValue();
    }

    if (!list || !list->length())
        return;

    // Parse in-memory CSS rules
    m_fontFaceRule->mutableProperties().addParsedProperty(CSSProperty(CSSPropertySrc, list));

    if (describesParentFont) {
        // Traverse parsed CSS values and associate CSSFontFaceSrcValue elements with ourselves.
        RefPtrWillBeRawPtr<CSSValue> src = m_fontFaceRule->properties().getPropertyCSSValue(CSSPropertySrc);
        CSSValueList* srcList = toCSSValueList(src.get());

        unsigned srcLength = srcList ? srcList->length() : 0;
        for (unsigned i = 0; i < srcLength; i++) {
            if (CSSFontFaceSrcValue* item = toCSSFontFaceSrcValue(srcList->itemWithoutBoundsCheck(i)))
                item->setSVGFontFaceElement(this);
        }
    }

    document().styleResolverChanged(RecalcStyleDeferred);
}

Node::InsertionNotificationRequest SVGFontFaceElement::insertedInto(ContainerNode* rootParent)
{
    SVGElement::insertedInto(rootParent);
    if (!rootParent->inDocument()) {
        ASSERT(!m_fontElement);
        return InsertionDone;
    }
    document().accessSVGExtensions().registerSVGFontFaceElement(this);

    rebuildFontFace();
    return InsertionDone;
}

void SVGFontFaceElement::removedFrom(ContainerNode* rootParent)
{
    SVGElement::removedFrom(rootParent);

    if (rootParent->inDocument()) {
        m_fontElement = 0;
        document().accessSVGExtensions().unregisterSVGFontFaceElement(this);

        // FIXME: HTMLTemplateElement's document or imported  document can be active?
        // If so, we also need to check whether fontSelector() is nullptr or not.
        // Otherwise, we will use just document().isActive() here.
        if (document().isActive() && document().styleEngine()->fontSelector()) {
            document().styleEngine()->fontSelector()->fontFaceCache()->remove(m_fontFaceRule.get());
            document().accessSVGExtensions().registerPendingSVGFontFaceElementsForRemoval(this);
        }
        m_fontFaceRule->mutableProperties().clear();
        document().styleResolverChanged(RecalcStyleDeferred);
    } else
        ASSERT(!m_fontElement);
}

void SVGFontFaceElement::childrenChanged(bool changedByParser, Node* beforeChange, Node* afterChange, int childCountDelta)
{
    SVGElement::childrenChanged(changedByParser, beforeChange, afterChange, childCountDelta);
    rebuildFontFace();
}

} // namespace WebCore

#endif // ENABLE(SVG_FONTS)