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/* ScummVM - Scumm Interpreter
* Copyright (C) 2001 Ludvig Strigeus
* Copyright (C) 2001-2006 The ScummVM project
*
* 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.
*
* $URL$
* $Id$
*
*/
#ifndef BASE_PLUGINS_H
#define BASE_PLUGINS_H
#include "common/stdafx.h"
#include "common/array.h"
#include "common/list.h"
#include "common/singleton.h"
#include "common/util.h"
#include "base/game.h"
class Engine;
class FSList;
class OSystem;
/**
* Error codes which mayb be reported by plugins under various circumstances.
* @todo Turn this into a global 'ErrorCode' enum used by all of ScummVM ?
*/
enum PluginError {
kNoError = 0, // No error occured
kInvalidPathError,
kNoGameDataFoundError,
kUnsupportedGameidError,
kUnknownError // Catch-all error, used if no other error code matches
};
/**
* Abstract base class for the plugin system.
* Subclasses for this can be used to wrap both static and dynamic
* plugins.
*/
class Plugin {
public:
virtual ~Plugin() {}
virtual bool loadPlugin() = 0;
virtual void unloadPlugin() = 0;
virtual const char *getName() const = 0;
virtual const char *getCopyright() const = 0;
// virtual int getVersion() const { return 0; } // TODO!
virtual GameList getSupportedGames() const = 0;
virtual GameDescriptor findGame(const char *gameid) const = 0;
virtual GameList detectGames(const FSList &fslist) const = 0;
virtual PluginError createInstance(OSystem *syst, Engine **engine) const = 0;
};
/**
* REGISTER_PLUGIN is a convenience macro meant to ease writing
* the plugin interface for our modules. In particular, using it
* makes it possible to compile the very same code in a module
* both as a static and a dynamic plugin.
*
* Each plugin has to define the following functions:
* - GameList Engine_##ID##_gameIDList()
* -> returns a list of gameid/desc pairs. Only used to implement '--list-games'.
* - GameDescriptor Engine_##ID##_findGameID(const char *gameid)
* -> asks the Engine for a GameDescriptor matching the gameid. If that is not
* possible, the engine MUST set the gameid of the returned value to 0.
* Note: This MUST succeed for every gameID on the list returned by
* gameIDList(), but MAY also work for additional gameids (e.g. to support
* obsolete targets).
* - DetectedGameList Engine_##ID##_detectGames(const FSList &fslist)
* -> scans through the given file list (usually the contents of a directory),
* and attempts to detects games present in that location.
* - PluginError Engine_##ID##_create(OSystem *syst, Engine **engine)
* -> factory function, create an instance of the Engine class.
*
* @todo add some means to query the plugin API version etc.
*/
#ifndef DYNAMIC_MODULES
#define REGISTER_PLUGIN(ID,name,copyright) \
PluginRegistrator *g_##ID##_PluginReg; \
void g_##ID##_PluginReg_alloc() { \
g_##ID##_PluginReg = new PluginRegistrator(name, copyright, \
Engine_##ID##_gameIDList(), \
Engine_##ID##_findGameID, \
Engine_##ID##_create, \
Engine_##ID##_detectGames \
);\
} \
void dummyFuncToAllowTrailingSemicolon()
#else
#define REGISTER_PLUGIN(ID,name,copyright) \
extern "C" { \
PLUGIN_EXPORT const char *PLUGIN_name() { return name; } \
PLUGIN_EXPORT const char *PLUGIN_copyright() { return copyright; } \
PLUGIN_EXPORT GameList PLUGIN_gameIDList() { return Engine_##ID##_gameIDList(); } \
PLUGIN_EXPORT GameDescriptor PLUGIN_findGameID(const char *gameid) { return Engine_##ID##_findGameID(gameid); } \
PLUGIN_EXPORT PluginError PLUGIN_createEngine(OSystem *syst, Engine **engine) { return Engine_##ID##_create(syst, engine); } \
PLUGIN_EXPORT GameList PLUGIN_detectGames(const FSList &fslist) { return Engine_##ID##_detectGames(fslist); } \
} \
void dummyFuncToAllowTrailingSemicolon()
#endif
#ifndef DYNAMIC_MODULES
/**
* The PluginRegistrator class is used by the static version of REGISTER_PLUGIN
* to allow static 'plugins' to register with the PluginManager.
*/
class PluginRegistrator {
friend class StaticPlugin;
public:
typedef GameDescriptor (*GameIDQueryFunc)(const char *gameid);
typedef PluginError (*EngineFactory)(OSystem *syst, Engine **engine);
typedef GameList (*DetectFunc)(const FSList &fslist);
protected:
const char *_name;
const char *_copyright;
GameIDQueryFunc _qf;
EngineFactory _ef;
DetectFunc _df;
GameList _games;
public:
PluginRegistrator(const char *name, const char *copyright, GameList games, GameIDQueryFunc qf, EngineFactory ef, DetectFunc df)
: _name(name), _copyright(copyright), _qf(qf), _ef(ef), _df(df), _games(games) {}
};
#endif
/** List of plugins. */
typedef Common::Array<Plugin *> PluginList;
class PluginProvider {
public:
virtual ~PluginProvider() {}
/**
* Return a list of Plugin objects. The caller is responsible for actually
* loading/unloading them (by invoking the appropriate methods).
* Furthermore, the caller is responsible for deleting these objects
* eventually.
*/
virtual PluginList getPlugins() = 0;
};
//class PluginManager;
/**
* Instances of this class manage all plugins, including loading them,
* making wrapper objects of class Plugin available, and unloading them.
*
* @todo Add support for dynamic plugins (this may need additional API, e.g. for a plugin path)
*/
class PluginManager : public Common::Singleton<PluginManager> {
typedef Common::List<PluginProvider *> ProviderList;
private:
PluginList _plugins;
ProviderList _providers;
bool tryLoadPlugin(Plugin *plugin);
friend class Common::Singleton<SingletonBaseType>;
PluginManager();
public:
~PluginManager();
void addPluginProvider(PluginProvider *pp);
void loadPlugins();
void unloadPlugins();
void unloadPluginsExcept(const Plugin *plugin);
const PluginList &getPlugins() { return _plugins; }
GameList detectGames(const FSList &fslist) const;
};
#endif
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