third_party/WebKit/Source/core/css/resolver/FilterOperationResolver.cpp

/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
 * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
 * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
 * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
 * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
 * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
 * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
 * Copyright (C) Research In Motion Limited 2011. All rights reserved.
 * Copyright (C) 2012 Google 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"
#include "core/css/resolver/FilterOperationResolver.h"

#include "core/css/CSSFunctionValue.h"
#include "core/css/CSSPrimitiveValueMappings.h"
#include "core/css/CSSShadowValue.h"
#include "core/css/resolver/StyleResolverState.h"
#include "core/layout/svg/ReferenceFilterBuilder.h"
#include "core/svg/SVGElement.h"
#include "core/svg/SVGURIReference.h"

namespace blink {

static FilterOperation::OperationType filterOperationForType(CSSValueID type)
{
    switch (type) {
    case CSSValueUrl:
        return FilterOperation::REFERENCE;
    case CSSValueGrayscale:
        return FilterOperation::GRAYSCALE;
    case CSSValueSepia:
        return FilterOperation::SEPIA;
    case CSSValueSaturate:
        return FilterOperation::SATURATE;
    case CSSValueHueRotate:
        return FilterOperation::HUE_ROTATE;
    case CSSValueInvert:
        return FilterOperation::INVERT;
    case CSSValueOpacity:
        return FilterOperation::OPACITY;
    case CSSValueBrightness:
        return FilterOperation::BRIGHTNESS;
    case CSSValueContrast:
        return FilterOperation::CONTRAST;
    case CSSValueBlur:
        return FilterOperation::BLUR;
    case CSSValueDropShadow:
        return FilterOperation::DROP_SHADOW;
    default:
        ASSERT_NOT_REACHED();
        // FIXME: We shouldn't have a type None since we never create them
        return FilterOperation::NONE;
    }
}

FilterOperations FilterOperationResolver::createFilterOperations(StyleResolverState& state, const CSSValue& inValue)
{
    FilterOperations operations;

    if (inValue.isPrimitiveValue()) {
        ASSERT(toCSSPrimitiveValue(inValue).getValueID() == CSSValueNone);
        return operations;
    }

    const CSSToLengthConversionData& conversionData = state.cssToLengthConversionData();
    for (auto& currValue : toCSSValueList(inValue)) {
        CSSFunctionValue* filterValue = toCSSFunctionValue(currValue.get());
        FilterOperation::OperationType operationType = filterOperationForType(filterValue->functionType());
        ASSERT(filterValue->length() <= 1);

        if (operationType == FilterOperation::REFERENCE) {
            CSSSVGDocumentValue* svgDocumentValue = toCSSSVGDocumentValue(filterValue->item(0));
            KURL url = state.document().completeURL(svgDocumentValue->url());

            RefPtrWillBeRawPtr<ReferenceFilterOperation> operation = ReferenceFilterOperation::create(svgDocumentValue->url(), AtomicString(url.fragmentIdentifier()));
            if (SVGURIReference::isExternalURIReference(svgDocumentValue->url(), state.document())) {
                if (!svgDocumentValue->loadRequested())
                    state.elementStyleResources().addPendingSVGDocument(operation.get(), svgDocumentValue);
                else if (svgDocumentValue->cachedSVGDocument())
                    ReferenceFilterBuilder::setDocumentResourceReference(operation.get(), adoptPtr(new DocumentResourceReference(svgDocumentValue->cachedSVGDocument())));
            }
            operations.operations().append(operation);
            continue;
        }

        CSSPrimitiveValue* firstValue = filterValue->length() && filterValue->item(0)->isPrimitiveValue() ? toCSSPrimitiveValue(filterValue->item(0)) : nullptr;
        switch (filterValue->functionType()) {
        case CSSValueGrayscale:
        case CSSValueSepia:
        case CSSValueSaturate: {
            double amount = 1;
            if (filterValue->length() == 1) {
                amount = firstValue->getDoubleValue();
                if (firstValue->isPercentage())
                    amount /= 100;
            }

            operations.operations().append(BasicColorMatrixFilterOperation::create(amount, operationType));
            break;
        }
        case CSSValueHueRotate: {
            double angle = 0;
            if (filterValue->length() == 1)
                angle = firstValue->computeDegrees();

            operations.operations().append(BasicColorMatrixFilterOperation::create(angle, operationType));
            break;
        }
        case CSSValueInvert:
        case CSSValueBrightness:
        case CSSValueContrast:
        case CSSValueOpacity: {
            double amount = (filterValue->functionType() == CSSValueBrightness) ? 0 : 1;
            if (filterValue->length() == 1) {
                amount = firstValue->getDoubleValue();
                if (firstValue->isPercentage())
                    amount /= 100;
            }

            operations.operations().append(BasicComponentTransferFilterOperation::create(amount, operationType));
            break;
        }
        case CSSValueBlur: {
            Length stdDeviation = Length(0, Fixed);
            if (filterValue->length() >= 1)
                stdDeviation = firstValue->convertToLength(conversionData);
            operations.operations().append(BlurFilterOperation::create(stdDeviation));
            break;
        }
        case CSSValueDropShadow: {
            CSSShadowValue* item = toCSSShadowValue(filterValue->item(0));
            IntPoint location(item->x->computeLength<int>(conversionData), item->y->computeLength<int>(conversionData));
            int blur = item->blur ? item->blur->computeLength<int>(conversionData) : 0;
            Color shadowColor = Color::black;
            if (item->color)
                shadowColor = state.document().textLinkColors().colorFromCSSValue(*item->color, state.style()->color());

            operations.operations().append(DropShadowFilterOperation::create(location, blur, shadowColor));
            break;
        }
        default:
            ASSERT_NOT_REACHED();
            break;
        }
    }

    return operations;
}

} // namespace blink