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 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
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package com.sun.star.comp.connections;

import com.sun.star.bridge.XInstanceProvider;

import com.sun.star.lang.XMultiServiceFactory;
import com.sun.star.lang.XSingleServiceFactory;

import com.sun.star.registry.XRegistryKey;

import com.sun.star.comp.loader.FactoryHelper;


/**
 * The <code>ConstantInstanceProvider</code> is a component 
 * that implements the <code>XInstanceProvider</code> Interface.
 * <p>
 * @version 	$Revision: 1.3 $ $ $Date$
 * @author 	    Kay Ramme
 * @see         com.sun.star.bridge.XBridge
 * @see         com.sun.star.bridge.XBridgeFactory
 * @see         com.sun.star.bridge.XInstanceProvider
 * @see         com.sun.star.comp.loader.JavaLoader
 * @since       UDK1.0
 */
public class ConstantInstanceProvider implements XInstanceProvider {
	/**
	 * When set to true, enables various debugging output.
	 */
	static public final boolean DEBUG = false;

	/**
	 * The name of the service, the <code>JavaLoader</code> acceses this through reflection.
	 */
    static private final String __serviceName = "com.sun.star.comp.connection.InstanceProvider";

	/**
	 * Gives a factory for creating the service.
	 * This method is called by the <code>JavaLoader</code>
	 * <p>
	 * @return  returns a <code>XSingleServiceFactory</code> for creating the component
	 * @param   implName     the name of the implementation for which a service is desired
	 * @param   multiFactory the service manager to be uses if needed
	 * @param   regKey       the registryKey
	 * @see                  com.sun.star.comp.loader.JavaLoader
	 */
	public static XSingleServiceFactory __getServiceFactory(String implName, 
															XMultiServiceFactory multiFactory, 
															XRegistryKey regKey)
	{
		XSingleServiceFactory xSingleServiceFactory = null;

	    if (implName.equals(ConstantInstanceProvider.class.getName()) )
	        xSingleServiceFactory = FactoryHelper.getServiceFactory(ConstantInstanceProvider.class,
																	__serviceName,
																	multiFactory, 
																	regKey);
	    
	    return xSingleServiceFactory;
	}

	protected XMultiServiceFactory _serviceManager;
	protected String _serviceName;
	protected Object _instance;


	public void setInstance(String serviceName) throws com.sun.star.uno.Exception {
		_instance = _serviceManager.createInstance(serviceName);
		_serviceName = serviceName;
	}

	/**
	 * Constructs a new <code>ConstantInstanceProvider</code>.
	 * Uses the provided ServiceManager as the provided instance.
	 * <p>
	 * @param    serviceName   the provided service manager
	 */
	public ConstantInstanceProvider(XMultiServiceFactory serviceManager) {
		_serviceManager = serviceManager;

		_serviceName = "SERVICEMANAGER";
		_instance    = serviceManager;
	}

	/**
	 * Gives an object for the passed instance name.
	 * <p>
	 * @return  the desired instance
	 * @param   sInstanceName   the name of the desired instance
	 */
    public Object getInstance(String sInstanceName) throws com.sun.star.container.NoSuchElementException, com.sun.star.uno.RuntimeException {
		Object result = sInstanceName.equals(_serviceName) ? _instance : null;

		if(DEBUG) System.err.println("##### " + getClass().getName() + ".getInstance(" + sInstanceName + "):" + result);

		return result;
	}
}

