dependencymanager/core/src/main/java/org/apache/felix/dm/ServiceDependency.java

/*
 * 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
 * under the License.
 */
package org.apache.felix.dm;

import org.osgi.framework.ServiceReference;

/**
 * Service dependency that can track an OSGi service.
 * 
 * @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
 */
public interface ServiceDependency extends Dependency, ComponentDependencyDeclaration {
    /**
     * Sets the name of the service that should be tracked. 
     * 
     * @param serviceName the name of the service
     * @return this service dependency
     */
	public ServiceDependency setService(Class serviceName);
    
    /**
     * Sets the name of the service that should be tracked. You can either specify
     * only the name, or the name and a filter. In the latter case, the filter is used
     * to track the service and should only return services of the type that was specified
     * in the name. To make sure of this, the filter is actually extended internally to
     * filter on the correct name.
     * 
     * @param serviceName the name of the service
     * @param serviceFilter the filter condition
     * @return this service dependency
     */
	public ServiceDependency setService(Class serviceName, String serviceFilter);
    
    /**
     * Sets the filter for the services that should be tracked. Any service object
     * matching the filter will be returned, without any additional filter on the
     * class.
     * 
     * @param serviceFilter the filter condition
     * @return this service dependency
     */
	public ServiceDependency setService(String serviceFilter);

    /**
     * Sets the name of the service that should be tracked. You can either specify
     * only the name, or the name and a reference. In the latter case, the service reference
     * is used to track the service and should only return services of the type that was 
     * specified in the name.
     * 
     * @param serviceName the name of the service
     * @param serviceReference the service reference to track
     * @return this service dependency
     */
	public ServiceDependency setService(Class serviceName, ServiceReference serviceReference);
    
    /**
     * Sets the default implementation for this service dependency. You can use this to supply
     * your own implementation that will be used instead of a Null Object when the dependency is
     * not available. This is also convenient if the service dependency is not an interface
     * (which would cause the Null Object creation to fail) but a class.
     * 
     * @param implementation the instance to use or the class to instantiate if you want to lazily
     *     instantiate this implementation
     * @return this service dependency
     */
	public ServiceDependency setDefaultImplementation(Object implementation);

    /**
     * Sets the required flag which determines if this service is required or not.
     * 
     * @param required the required flag
     * @return this service dependency
     */
	public ServiceDependency setRequired(boolean required);
    
    /**
     * Sets auto configuration for this service. Auto configuration allows the
     * dependency to fill in any attributes in the service implementation that
     * are of the same type as this dependency. Default is on.
     * 
     * @param autoConfig the value of auto config
     * @return this service dependency
     */
	public ServiceDependency setAutoConfig(boolean autoConfig);
    
    /**
     * Sets auto configuration for this service. Auto configuration allows the
     * dependency to fill in the attribute in the service implementation that
     * has the same type and instance name.
     * 
     * @param instanceName the name of attribute to auto config
     * @return this service dependency
     */
	public ServiceDependency setAutoConfig(String instanceName);
    
    /**
     * Sets the callbacks for this service. These callbacks can be used as hooks whenever a
     * dependency is added or removed. When you specify callbacks, the auto configuration 
     * feature is automatically turned off, because we're assuming you don't need it in this 
     * case.
     * 
     * @param added the method to call when a service was added
     * @param removed the method to call when a service was removed
     * @return this service dependency
     */
	public ServiceDependency setCallbacks(String added, String removed);
    
    /**
     * Sets the callbacks for this service. These callbacks can be used as hooks whenever a
     * dependency is added, changed or removed. When you specify callbacks, the auto 
     * configuration feature is automatically turned off, because we're assuming you don't 
     * need it in this case.
     * 
     * @param added the method to call when a service was added
     * @param changed the method to call when a service was changed
     * @param removed the method to call when a service was removed
     * @return this service dependency
     */
	public ServiceDependency setCallbacks(String added, String changed, String removed);

    /**
     * Sets the callbacks for this service. These callbacks can be used as hooks whenever a
     * dependency is added, changed or removed. When you specify callbacks, the auto 
     * configuration feature is automatically turned off, because we're assuming you don't 
     * need it in this case.
     * @param added the method to call when a service was added
     * @param changed the method to call when a service was changed
     * @param removed the method to call when a service was removed
     * @param swapped the method to call when the service was swapped due to addition or 
     * removal of an aspect
     * @return this service dependency
     */
    public ServiceDependency setCallbacks(String added, String changed, String removed, String swapped);
    
    /**
     * Sets the callbacks for this service. These callbacks can be used as hooks whenever a
     * dependency is added or removed. They are called on the instance you provide. When you
     * specify callbacks, the auto configuration feature is automatically turned off, because
     * we're assuming you don't need it in this case.
     * 
     * @param instance the instance to call the callbacks on
     * @param added the method to call when a service was added
     * @param removed the method to call when a service was removed
     * @return this service dependency
     */
	public ServiceDependency setCallbacks(Object instance, String added, String removed);
    
    /**
     * Sets the callbacks for this service. These callbacks can be used as hooks whenever a
     * dependency is added, changed or removed. They are called on the instance you provide. When you
     * specify callbacks, the auto configuration feature is automatically turned off, because
     * we're assuming you don't need it in this case.
     * 
     * @param instance the instance to call the callbacks on
     * @param added the method to call when a service was added
     * @param changed the method to call when a service was changed
     * @param removed the method to call when a service was removed
     * @return this service dependency
     */
	public ServiceDependency setCallbacks(Object instance, String added, String changed, String removed);
    
    /**
     * Sets the callbacks for this service. These callbacks can be used as hooks whenever a
     * dependency is added, changed or removed. When you specify callbacks, the auto 
     * configuration feature is automatically turned off, because we're assuming you don't 
     * need it in this case.
     * @param instance the instance to call the callbacks on
     * @param added the method to call when a service was added
     * @param changed the method to call when a service was changed
     * @param removed the method to call when a service was removed
     * @param swapped the method to call when the service was swapped due to addition or 
     * removal of an aspect
     * @return this service dependency
     */    
    public ServiceDependency setCallbacks(Object instance, String added, String changed, String removed, String swapped);
	
    /**
     * Sets propagation of the service dependency properties to the provided service properties. Any additional
     * service properties specified directly are merged with these.
     */
    public ServiceDependency setPropagate(boolean propagate);
    
    /**
     * Sets an Object instance and a callback method used to propagate some properties to the provided service properties.
     * The method will be invoked on the specified object instance and must have one of the following signatures:<p>
     * <ul><li>Dictionary callback(ServiceReference, Object service) 
     * <li>Dictionary callback(ServiceReference)
     * </ul>
     * @param instance the Object instance which is used to retrieve propagated service properties 
     * @param method the method to invoke for retrieving the properties to be propagated to the service properties.
     * @return this service dependency.
     */
    public ServiceDependency setPropagate(Object instance, String method);

	/**
	 * Sets this dependency to be instance bound or not.
	 * 
	 * @param isInstanceBound <code>true</code> if this dependency should be instance bound
	 */
    public ServiceDependency setInstanceBound(boolean isInstanceBound);    
}