Source/WebCore/css/DOMCSSRegisterCustomProperty.cpp

/*
 * Copyright (C) 2018 Apple Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
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#include "config.h"
#include "DOMCSSRegisterCustomProperty.h"

#include "CSSCustomPropertyValue.h"
#include "CSSPropertyNames.h"
#include "CSSPropertyParser.h"
#include "CSSRegisteredCustomProperty.h"
#include "CSSTokenizer.h"
#include "DOMCSSNamespace.h"
#include "Document.h"
#include "ExceptionOr.h"
#include "StyleBuilder.h"
#include "StyleCustomPropertyRegistry.h"
#include "StyleResolver.h"
#include "StyleScope.h"
#include <wtf/text/WTFString.h>

namespace WebCore {
DEFINE_ALLOCATOR_WITH_HEAP_IDENTIFIER(DOMCSSRegisterCustomProperty);

using namespace Style;

ExceptionOr<void> DOMCSSRegisterCustomProperty::registerProperty(Document& document, const DOMCSSCustomPropertyDescriptor& descriptor)
{
    if (!isCustomPropertyName(descriptor.name))
        return Exception { ExceptionCode::SyntaxError, "The name of this property is not a custom property name."_s };

    auto syntax = CSSCustomPropertySyntax::parse(descriptor.syntax);
    if (!syntax)
        return Exception { ExceptionCode::SyntaxError, "Invalid property syntax definition."_s };

    if (!syntax->isUniversal() && descriptor.initialValue.isNull())
        return Exception { ExceptionCode::SyntaxError, "An initial value is mandatory except for the '*' syntax."_s };

    RefPtr<const Style::CustomProperty> initialValue;
    RefPtr<CSSVariableData> initialValueTokensForViewportUnits;

    if (!descriptor.initialValue.isNull()) {
        CSSTokenizer tokenizer(descriptor.initialValue);

        auto parsedInitialValue = CustomPropertyRegistry::parseInitialValue(document, descriptor.name, *syntax, tokenizer.tokenRange());

        if (!parsedInitialValue) {
            if (parsedInitialValue.error() == CustomPropertyRegistry::ParseInitialValueError::NotComputationallyIndependent)
                return Exception { ExceptionCode::SyntaxError, "The given initial value must be computationally independent."_s };

            ASSERT(parsedInitialValue.error() == CustomPropertyRegistry::ParseInitialValueError::DidNotParse);
            return Exception { ExceptionCode::SyntaxError, "The given initial value does not parse for the given syntax."_s };
        }

        initialValue = parsedInitialValue->first;
        if (parsedInitialValue->second == CustomPropertyRegistry::ViewportUnitDependency::Yes) {
            initialValueTokensForViewportUnits = CSSVariableData::create(tokenizer.tokenRange());
            document.setHasStyleWithViewportUnits();
        }
    }

    auto property = CSSRegisteredCustomProperty {
        descriptor.name,
        *syntax,
        descriptor.inherits,
        WTF::move(initialValue),
        WTF::move(initialValueTokensForViewportUnits)
    };

    auto& registry = document.styleScope().customPropertyRegistry();
    if (!registry.registerFromAPI(WTF::move(property)))
        return Exception { ExceptionCode::InvalidModificationError, "This property has already been registered."_s };

    return { };
}

DOMCSSRegisterCustomProperty* DOMCSSRegisterCustomProperty::from(DOMCSSNamespace& css)
{
    auto* supplement = downcast<DOMCSSRegisterCustomProperty>(Supplement<DOMCSSNamespace>::from(&css, supplementName()));
    if (!supplement) {
        auto newSupplement = makeUnique<DOMCSSRegisterCustomProperty>(css);
        supplement = newSupplement.get();
        provideTo(&css, supplementName(), WTF::move(newSupplement));
    }
    return supplement;
}

} // namespace WebCore