PluginFactory.cc

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/*
 * PluginFactory.cc
 *
 * Smalltalk like class library for C++
 * Helper class to access plug-ins in dynamic linkable libraries.
 *
 * Copyright (c) 2003 Milan Cermak
 */
/*
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <stlib/Iterator.h>
#include <stlib/Set.h>
#include <stlib/String.h>
#include <stlib/KeyNotFoundError.h>

#include <stlib/external/Plugin.h>
#include <stlib/external/PluginFactory.h>

using namespace External;

Set *PluginFactory::_plugins = nil;
String PluginFactory::defaultNewInstanceSelector("newPluginInstance");
String PluginFactory::defaultPluginNameSelector("pluginName");

PluginFactory::PluginFactory(String *pluginLibName)
  : ExternalInterface(pluginLibName)
{
    plugins()->add(this);
    name = nil;
    new_instance_selector = &defaultNewInstanceSelector;
    plugin_name_selector = &defaultPluginNameSelector;
}

PluginFactory::~PluginFactory(void)
{
    plugins()->remove(this);
    name = nil;
}

/* Class-accessing protocol */
Set *PluginFactory::plugins(void)
{
    if (_plugins == nil) _plugins = new Set;
    return _plugins;
}

/* Accessing protocol */
void PluginFactory::newInstanceSelector(String *selector)
{
    new_instance_selector = selector;
}

void PluginFactory::pluginNameSelector(String *selector)
{
    plugin_name_selector = selector;
}

/* Searching protocol */
PluginFactory *PluginFactory::pluginWithName(String *pluginName)
{
    for (Iterator *i = plugins()->iterator(); !i->finished(); i->next()) {
        PluginFactory *plug = (PluginFactory *) i->value();
        if (plug->pluginName()->isEqual(pluginName)) {
            delete i;
            return plug;
        }
    }
    (new KeyNotFoundError(__PRETTY_FUNCTION__, pluginName))->raise();
    return nil; // Unreachable, but keeps compiler happy
}

/* Procedure protocol */
Plugin *PluginFactory::newPluginInstance(void)
{
    Plugin *(*creator)(void);

    creator = (Plugin *(*)(void)) symbol(new_instance_selector);
    return(creator());
}

String *PluginFactory::pluginName(void)
{
    String *(*function)(void);

    if (name == nil) {
        function = (String *(*)(void)) symbol(plugin_name_selector);
        name = function();
    }
    return name;
}

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