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// Copyright 2014 The Cobalt Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef COBALT_CSSOM_CSS_PARSER_H_
#define COBALT_CSSOM_CSS_PARSER_H_
#include <string>
#include "base/memory/ref_counted.h"
#include "cobalt/base/source_location.h"
namespace cobalt {
namespace cssom {
class CSSDeclarationData;
class CSSFontFaceDeclarationData;
class CSSRule;
class CSSDeclaredStyleData;
class CSSStyleSheet;
class MediaList;
class MediaQuery;
class PropertyValue;
// An abstraction of CSS parser. The parser turns a string in UTF-8 encoding
// into one of CSSOM objects. Created CSSOM objects should be self-contained
// and should not depend on the input, so the arguments can be safely destroyed
// after one of the Parse...() methods returns. Similarly to Chromium, parser
// should always succeed. Errors, if any, should be reported to logs.
//
// This class is not a part of any specification.
class CSSParser {
public:
//
// Parser entry points
// (see http://dev.w3.org/csswg/css-syntax/#parser-entry-points):
//
// TODO: Revisit the return values of below methods in case of an error and
// match the behavior with appropriate specifications. Currently some
// methods return a default-constructed value even if an error occurred,
// others return NULL, and some call sites are known to make incorrect
// assumptions.
// Parses the entire stylesheet.
// Always returns non-NULL style sheet, even if an error occurred.
virtual scoped_refptr<CSSStyleSheet> ParseStyleSheet(
const std::string& input, const base::SourceLocation& input_location) = 0;
// Parses the style rule.
// Returns NULL if an error occurred.
virtual scoped_refptr<CSSRule> ParseRule(
const std::string& input, const base::SourceLocation& input_location) = 0;
// Parses the contents of a HTMLElement.style attribute.
// Always returns non-NULL declaration, even if an error occurred.
virtual scoped_refptr<CSSDeclaredStyleData> ParseStyleDeclarationList(
const std::string& input, const base::SourceLocation& input_location) = 0;
// Parses the contents of an @font-face rule.
// Always returns non-NULL declaration, even if an error occurred.
virtual scoped_refptr<CSSFontFaceDeclarationData>
ParseFontFaceDeclarationList(const std::string& input,
const base::SourceLocation& input_location) = 0;
// Parses the property value.
// |property_name| must be a valid CSS property name (see property_names.h).
// May return NULL which is considered a valid property value.
// This method is primarily for use by tests, since it is not able to
// handle parsing of shorthand properties.
virtual scoped_refptr<PropertyValue> ParsePropertyValue(
const std::string& property_name, const std::string& property_value,
const base::SourceLocation& property_location) = 0;
// Parses the specified property value assuming it is to be used for a
// property with property_name. The style_declaration parameter will have
// its specified property set to the resulting parsed value.
// This is Cobalt's equivalent of a "list of component values".
virtual void ParsePropertyIntoDeclarationData(
const std::string& property_name, const std::string& property_value,
const base::SourceLocation& property_location,
CSSDeclarationData* declaration_data) = 0;
// Parses the media list.
// Always returns non-NULL media list, even if an error occurred.
virtual scoped_refptr<MediaList> ParseMediaList(
const std::string& media_list,
const base::SourceLocation& input_location) = 0;
// Parses the media query.
// Always returns non-NULL media query, even if an error occurred.
virtual scoped_refptr<MediaQuery> ParseMediaQuery(
const std::string& media_query,
const base::SourceLocation& input_location) = 0;
protected:
virtual ~CSSParser() {}
};
} // namespace cssom
} // namespace cobalt
#endif // COBALT_CSSOM_CSS_PARSER_H_