michael@0: /**
michael@0:  * Copyright (c) 2012, Ben Fortuna
michael@0:  * All rights reserved.
michael@0:  *
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  *
michael@0:  *  o Redistributions of source code must retain the above copyright
michael@0:  * notice, this list of conditions and the following disclaimer.
michael@0:  *
michael@0:  *  o Redistributions in binary form must reproduce the above copyright
michael@0:  * notice, this list of conditions and the following disclaimer in the
michael@0:  * documentation and/or other materials provided with the distribution.
michael@0:  *
michael@0:  *  o Neither the name of Ben Fortuna nor the names of any other contributors
michael@0:  * may be used to endorse or promote products derived from this software
michael@0:  * without specific prior written permission.
michael@0:  *
michael@0:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0:  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0:  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
michael@0:  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
michael@0:  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
michael@0:  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
michael@0:  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
michael@0:  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
michael@0:  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
michael@0:  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
michael@0:  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0:  */
michael@0: package net.fortuna.ical4j.model;
michael@0: 
michael@0: import java.util.Collections;
michael@0: import java.util.HashMap;
michael@0: import java.util.Iterator;
michael@0: import java.util.Map;
michael@0: 
michael@0: /**
michael@0:  * $Id$
michael@0:  *
michael@0:  * Created on 4/02/2006
michael@0:  *
michael@0:  * Provides indexing of components on a specific property.
michael@0:  * @author Ben Fortuna
michael@0:  */
michael@0: public class IndexedComponentList {
michael@0: 
michael@0:     private static final ComponentList EMPTY_LIST = new ComponentList();
michael@0:     
michael@0:     private Map index;
michael@0:     
michael@0:     /**
michael@0:      * Creates a new instance indexed on properties with the specified name.
michael@0:      * @param list a list of components
michael@0:      * @param propertyName the name of the properties to index on
michael@0:      */
michael@0:     public IndexedComponentList(final ComponentList list, final String propertyName) {
michael@0:         final Map indexedComponents = new HashMap();
michael@0:         for (final Iterator i = list.iterator(); i.hasNext();) {
michael@0:             final Component component = (Component) i.next();
michael@0:             for (final Iterator j = component.getProperties(propertyName).iterator(); j.hasNext();) {
michael@0:                 final Property property = (Property) j.next();
michael@0:                 ComponentList components = (ComponentList) indexedComponents.get(property.getValue());
michael@0:                 if (components == null) {
michael@0:                     components = new ComponentList();
michael@0:                     indexedComponents.put(property.getValue(), components);
michael@0:                 }
michael@0:                 components.add(component);
michael@0:             }
michael@0:         }
michael@0:         this.index = Collections.unmodifiableMap(indexedComponents);
michael@0:     }
michael@0:     
michael@0:     /**
michael@0:      * Returns a list of components containing a property with the
michael@0:      * specified value.
michael@0:      * @param propertyValue the value of the property contained in the
michael@0:      * returned components
michael@0:      * @return a component list
michael@0:      */
michael@0:     public ComponentList getComponents(final String propertyValue) {
michael@0:         ComponentList components = (ComponentList) index.get(propertyValue);
michael@0:         if (components == null) {
michael@0:             components = EMPTY_LIST;
michael@0:         }
michael@0:         return components;
michael@0:     }
michael@0:     
michael@0:     /**
michael@0:      * Returns the first component containing a property with the specified
michael@0:      * value.
michael@0:      * @param propertyValue the value of the property identified in the returned
michael@0:      * component
michael@0:      * @return a component or null if no component is found containing a property
michael@0:      * with the specified value
michael@0:      */
michael@0:     public Component getComponent(final String propertyValue) {
michael@0:         final ComponentList components = getComponents(propertyValue);
michael@0:         if (!components.isEmpty()) {
michael@0:             return (Component) components.iterator().next();
michael@0:         }
michael@0:         return null;
michael@0:     }
michael@0: }