aboutsummaryrefslogtreecommitdiff
path: root/base/plugins.h
blob: 817ec79f857ed41b52341eac4c337d0d4e21e530 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
/* ScummVM - Scumm Interpreter
 * Copyright (C) 2001  Ludvig Strigeus
 * Copyright (C) 2001-2003 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header$
 *
 */

#ifndef COMMON_PLUGINS_H
#define COMMON_PLUGINS_H

#include "common/list.h"
#include "common/singleton.h"

class Engine;
class GameDetector;
class OSystem;
struct GameSettings;

/**
 * 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()		{ return true; }
	virtual void unloadPlugin()		{}

	virtual const char *getName() const = 0;
	virtual int getVersion() const	{ return 0; }	// TODO!
	
	virtual int countTargets() const;
	virtual const GameSettings *getTargets() const = 0;
	virtual const GameSettings *findGame(const char *gameName) const;

	virtual Engine *createInstance(GameDetector *detector, OSystem *syst) const = 0;
};


/**
 * The 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.
 *
 * @todo	add some means to query the plugin API version etc.
 * @todo	on Windows, we might need __declspec(dllexport) ?
 */
#ifndef DYNAMIC_MODULES
#define REGISTER_PLUGIN(name,targetListFactory,engineFactory)
#else
#define REGISTER_PLUGIN(name,targetListFactory,engineFactory) \
	extern "C" { \
		const char *PLUGIN_name() { return name; } \
		const GameSettings *PLUGIN_getTargetList() { return targetListFactory(); } \
		Engine *PLUGIN_createEngine(GameDetector *detector, OSystem *syst) { return engineFactory(detector, syst); } \
	}
#endif


/** List of plugins. */
typedef Common::List<Plugin *> PluginList;


/**
 * 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> {
private:
	PluginList _plugins;
	
	bool tryLoadPlugin(Plugin *plugin);
	
	friend class Common::Singleton<PluginManager>;
	PluginManager();

public:
	~PluginManager();

	void loadPlugins();
	void unloadPlugins();
	
	const PluginList &getPlugins()	{ return _plugins; }
};

#endif