third_party/WebKit/Source/core/svg/SVGFEDropShadowElement.cpp

/*
 * Copyright (C) Research In Motion Limited 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 "core/svg/SVGFEDropShadowElement.h"

#include "core/SVGNames.h"
#include "core/layout/LayoutObject.h"
#include "core/style/ComputedStyle.h"
#include "core/style/SVGComputedStyle.h"
#include "core/svg/graphics/filters/SVGFilterBuilder.h"
#include "platform/graphics/filters/FEDropShadow.h"

namespace blink {

inline SVGFEDropShadowElement::SVGFEDropShadowElement(Document& document)
    : SVGFilterPrimitiveStandardAttributes(SVGNames::feDropShadowTag, document)
    , m_dx(SVGAnimatedNumber::create(this, SVGNames::dxAttr, SVGNumber::create(2)))
    , m_dy(SVGAnimatedNumber::create(this, SVGNames::dyAttr, SVGNumber::create(2)))
    , m_stdDeviation(SVGAnimatedNumberOptionalNumber::create(this, SVGNames::stdDeviationAttr, 2, 2))
    , m_in1(SVGAnimatedString::create(this, SVGNames::inAttr, SVGString::create()))
{
    addToPropertyMap(m_dx);
    addToPropertyMap(m_dy);
    addToPropertyMap(m_stdDeviation);
    addToPropertyMap(m_in1);
}

DEFINE_TRACE(SVGFEDropShadowElement)
{
    visitor->trace(m_dx);
    visitor->trace(m_dy);
    visitor->trace(m_stdDeviation);
    visitor->trace(m_in1);
    SVGFilterPrimitiveStandardAttributes::trace(visitor);
}

DEFINE_NODE_FACTORY(SVGFEDropShadowElement)

void SVGFEDropShadowElement::setStdDeviation(float x, float y)
{
    stdDeviationX()->baseValue()->setValue(x);
    stdDeviationY()->baseValue()->setValue(y);
    invalidate();
}

bool SVGFEDropShadowElement::setFilterEffectAttribute(FilterEffect* effect, const QualifiedName& attrName)
{
    DCHECK(layoutObject());
    FEDropShadow* dropShadow = static_cast<FEDropShadow*>(effect);

    const SVGComputedStyle& svgStyle = layoutObject()->styleRef().svgStyle();
    if (attrName == SVGNames::flood_colorAttr) {
        dropShadow->setShadowColor(svgStyle.floodColor());
        return true;
    }
    if (attrName == SVGNames::flood_opacityAttr) {
        dropShadow->setShadowOpacity(svgStyle.floodOpacity());
        return true;
    }
    return SVGFilterPrimitiveStandardAttributes::setFilterEffectAttribute(effect, attrName);
}

void SVGFEDropShadowElement::svgAttributeChanged(const QualifiedName& attrName)
{
    if (attrName == SVGNames::inAttr
        || attrName == SVGNames::stdDeviationAttr
        || attrName == SVGNames::dxAttr
        || attrName == SVGNames::dyAttr) {
        SVGElement::InvalidationGuard invalidationGuard(this);
        invalidate();
        return;
    }

    SVGFilterPrimitiveStandardAttributes::svgAttributeChanged(attrName);
}

FilterEffect* SVGFEDropShadowElement::build(SVGFilterBuilder* filterBuilder, Filter* filter)
{
    LayoutObject* layoutObject = this->layoutObject();
    if (!layoutObject)
        return nullptr;

    ASSERT(layoutObject->style());
    const SVGComputedStyle& svgStyle = layoutObject->style()->svgStyle();

    Color color = svgStyle.floodColor();
    float opacity = svgStyle.floodOpacity();

    FilterEffect* input1 = filterBuilder->getEffectById(AtomicString(m_in1->currentValue()->value()));
    ASSERT(input1);

    // Clamp std.dev. to non-negative. (See SVGFEGaussianBlurElement::build)
    float stdDevX = std::max(0.0f, stdDeviationX()->currentValue()->value());
    float stdDevY = std::max(0.0f, stdDeviationY()->currentValue()->value());
    FilterEffect* effect = FEDropShadow::create(filter, stdDevX, stdDevY, m_dx->currentValue()->value(), m_dy->currentValue()->value(), color, opacity);
    effect->inputEffects().append(input1);
    return effect;
}

} // namespace blink