Plugin.h

/*
 * 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 Library 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.
 *
 * Plugin.h
 * Header file for plugin class - plugins inherit from this.
 * Copyright (C) 2005 Simon Newton
 */

#ifndef INCLUDE_OLAD_PLUGIN_H_
#define INCLUDE_OLAD_PLUGIN_H_

#include <ola/base/Macro.h>
#include <ola/plugin_id.h>

#include <set>
#include <string>
#include <functional>

namespace ola {

class PluginAdaptor;

class AbstractPlugin {
 public :
 AbstractPlugin() {}
 virtual ~AbstractPlugin() {}

 virtual bool LoadPreferences() = 0;

 virtual std::string PreferenceSource() const = 0;

 virtual bool IsEnabled() const = 0;

 virtual bool Start() = 0;

 virtual bool Stop() = 0;

 virtual ola_plugin_id Id() const = 0;

 virtual std::string Name() const = 0;

 virtual std::string Description() const = 0;

 virtual void ConflictsWith(std::set<ola_plugin_id> *conflict_set) = 0;

 // used to sort plugins
 virtual bool operator<(const AbstractPlugin &other) const = 0;
};


struct PluginLessThan: public std::binary_function<AbstractPlugin*,
 AbstractPlugin*, bool> {
 bool operator()(AbstractPlugin *x, AbstractPlugin *y) {
 return x->Id() < y->Id();
 }
};


class Plugin: public AbstractPlugin {
 public :
 explicit Plugin(PluginAdaptor *plugin_adaptor):
 AbstractPlugin(),
 m_plugin_adaptor(plugin_adaptor),
 m_preferences(NULL),
 m_enabled(false) {
 }
 virtual ~Plugin() {}

 bool LoadPreferences();
 std::string PreferenceSource() const;
 bool IsEnabled() const;
 virtual bool Start();
 virtual bool Stop();
 // return true if this plugin is enabled by default
 virtual bool DefaultMode() const { return true; }
 virtual ola_plugin_id Id() const = 0;

 virtual std::string PluginPrefix() const = 0;

 // by default we don't conflict with any other plugins
 virtual void ConflictsWith(std::set<ola_plugin_id>*) {}

 bool operator<(const AbstractPlugin &other) const {
 return Id() < other.Id();
 }

 protected:
 virtual bool StartHook() { return 0; }
 virtual bool StopHook() { return 0; }

 virtual bool SetDefaultPreferences() { return true; }

 PluginAdaptor *m_plugin_adaptor;
 class Preferences *m_preferences; // preferences container
 static const char ENABLED_KEY[];

 private:
 bool m_enabled; // are we running

 DISALLOW_COPY_AND_ASSIGN(Plugin);
};
} // namespace ola

// interface functions
typedef ola::AbstractPlugin* create_t(ola::PluginAdaptor *plugin_adaptor);

#endif // INCLUDE_OLAD_PLUGIN_H_