feed_reader/shared/qt-json/json.h

/**
 * \file json.h
 */

#ifndef JSON_H
#define JSON_H

#include <QVariant>
#include <QString>

/**
 * \enum JsonToken
 */
enum JsonToken
{
	JsonTokenNone = 0,
	JsonTokenCurlyOpen = 1,
	JsonTokenCurlyClose = 2,
	JsonTokenSquaredOpen = 3,
	JsonTokenSquaredClose = 4,
	JsonTokenColon = 5,
	JsonTokenComma = 6,
	JsonTokenString = 7,
	JsonTokenNumber = 8,
	JsonTokenTrue = 9,
	JsonTokenFalse = 10,
	JsonTokenNull = 11
};

/**
 * \class Json
 * \brief A JSON data parser
 *
 * Json parses a JSON data into a QVariant hierarchy.
 */
class Json
{
	public:
		/**
		 * Parse a JSON string
		 *
		 * \param json The JSON data
		 */
		static QVariant parse(const QString &json);

		/**
		 * Parse a JSON string
		 *
		 * \param json The JSON data
		 * \param success The success of the parsing
		 */
		static QVariant parse(const QString &json, bool &success);

		/**
		* This method generates a textual JSON representation
		*
		* \param data The JSON data generated by the parser.
		* \param success The success of the serialization
		*/
		static QByteArray serialize(const QVariant &data);

		/**
		* This method generates a textual JSON representation
		*
		* \param data The JSON data generated by the parser.
		* \param success The success of the serialization
		*
		* \return QByteArray Textual JSON representation
		*/
		static QByteArray serialize(const QVariant &data, bool &success);

	private:
		/**
		 * Parses a value starting from index
		 *
		 * \param json The JSON data
		 * \param index The start index
		 * \param success The success of the parse process
		 *
		 * \return QVariant The parsed value
		 */
		static QVariant parseValue(const QString &json, int &index,
								   bool &success);

		/**
		 * Parses an object starting from index
		 *
		 * \param json The JSON data
		 * \param index The start index
		 * \param success The success of the object parse
		 *
		 * \return QVariant The parsed object map
		 */
		static QVariant parseObject(const QString &json, int &index,
									   bool &success);

		/**
		 * Parses an array starting from index
		 *
		 * \param json The JSON data
		 * \param index The starting index
		 * \param success The success of the array parse
		 *
		 * \return QVariant The parsed variant array
		 */
		static QVariant parseArray(const QString &json, int &index,
									   bool &success);

		/**
		 * Parses a string starting from index
		 *
		 * \param json The JSON data
		 * \param index The starting index
		 * \param success The success of the string parse
		 *
		 * \return QVariant The parsed string
		 */
		static QVariant parseString(const QString &json, int &index,
									bool &success);

		/**
		 * Parses a number starting from index
		 *
		 * \param json The JSON data
		 * \param index The starting index
		 *
		 * \return QVariant The parsed number
		 */
		static QVariant parseNumber(const QString &json, int &index);

		/**
		 * Get the last index of a number starting from index
		 *
		 * \param json The JSON data
		 * \param index The starting index
		 *
		 * \return The last index of the number
		 */
		static int lastIndexOfNumber(const QString &json, int index);

		/**
		 * Skip unwanted whitespace symbols starting from index
		 *
		 * \param json The JSON data
		 * \param index The start index
		 */
		static void eatWhitespace(const QString &json, int &index);

		/**
		 * Check what token lies ahead
		 *
		 * \param json The JSON data
		 * \param index The starting index
		 *
		 * \return int The upcoming token
		 */
		static int lookAhead(const QString &json, int index);

		/**
		 * Get the next JSON token
		 *
		 * \param json The JSON data
		 * \param index The starting index
		 *
		 * \return int The next JSON token
		 */
		static int nextToken(const QString &json, int &index);
};

#endif //JSON_H