scummvm/common/error.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#ifndef COMMON_ERROR_H
#define COMMON_ERROR_H

#include "common/str.h"

namespace Common {

/**
 * This file contains an enum with commonly used error codes.
 */



/**
 * Error codes which may be reported by plugins under various circumstances.
 *
 * @note Error names should follow the pattern k-NOUN/ACTION-CONDITION-Error.
 *       So kPathInvalidError would be correct, but these would not be:
 *       kInvalidPath, kPathInvalid, kPathIsInvalid, kInvalidPathError.
 * @todo Adjust all error codes to comply with these conventions.
 */
enum ErrorCode {
	kNoError = 0,				///< No error occurred
	kNoGameDataFoundError,		///< Engine initialization: No game data was found in the specified location
	kUnsupportedGameidError,	///< Engine initialization: Gameid not supported by this (Meta)Engine
	kUnsupportedColorMode,		///< Engine initialization: Engine does not support backend's color mode
	kAudioDeviceInitFailed,		///< Engine initialization: Audio device initialization failed

	kReadPermissionDenied,		///< Unable to read data due to missing read permission
	kWritePermissionDenied,		///< Unable to write data due to missing write permission

	kPathDoesNotExist,			///< The specified path does not exist
	kPathNotDirectory,			///< The specified path does not point to a directory
	kPathNotFile,				///< The specified path does not point to a file

	kCreatingFileFailed,		///< Failed creating a (savestate) file
	kReadingFailed,				///< Failed to read a file (permission denied?)
	kWritingFailed,				///< Failure to write data -- disk full?

	// The following are used by --list-saves
	kEnginePluginNotFound,		///< Failed to find plugin to handle target
	kEnginePluginNotSupportSaves,	///< Failed if plugin does not support listing save states

	kUserCanceled,			///< User has canceled the launching of the game

	kUnknownError				///< Catch-all error, used if no other error code matches
};

/**
 * An Error instance pairs an error code with string description providing more
 * details about the error. For every error code, a default description is
 * provided, but it is possible to optionally augment that description with
 * extra information when creating a new Error instance.
 */
class Error {
protected:
	ErrorCode _code;
	String _desc;
public:
	/**
	 * Construct a new Error with the specified error code and the default
	 * error message.
	 */
	Error(ErrorCode code = kUnknownError);

	/**
	 * Construct a new Error with the specified error code and an augmented
	 * error message. Specifically, the provided extra text is suitably
	 * appended to the default message.
	 */
	Error(ErrorCode code, const String &extra);

	/**
	 * Get the description of this error.
	 */
	const String &getDesc() const { return _desc; }

	/**
	 * Get the error code of this error.
	 */
	ErrorCode getCode() const { return _code; }
};

} // End of namespace Common

#endif //COMMON_ERROR_H