michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: package ch.boye.httpclientandroidlib.params;
michael@0: 
michael@0: /**
michael@0:  * {@link HttpParams} implementation that delegates resolution of a parameter
michael@0:  * to the given default {@link HttpParams} instance if the parameter is not
michael@0:  * present in the local one. The state of the local collection can be mutated,
michael@0:  * whereas the default collection is treated as read-only.
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public final class DefaultedHttpParams extends AbstractHttpParams {
michael@0: 
michael@0:     private final HttpParams local;
michael@0:     private final HttpParams defaults;
michael@0: 
michael@0:     /**
michael@0:      * Create the defaulted set of HttpParams.
michael@0:      *
michael@0:      * @param local the mutable set of HttpParams
michael@0:      * @param defaults the default set of HttpParams, not mutated by this class
michael@0:      */
michael@0:     public DefaultedHttpParams(final HttpParams local, final HttpParams defaults) {
michael@0:         super();
michael@0:         if (local == null) {
michael@0:             throw new IllegalArgumentException("HTTP parameters may not be null");
michael@0:         }
michael@0:         this.local = local;
michael@0:         this.defaults = defaults;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Creates a copy of the local collection with the same default
michael@0:      *
michael@0:      * @deprecated
michael@0:      */
michael@0:     public HttpParams copy() {
michael@0:         HttpParams clone = this.local.copy();
michael@0:         return new DefaultedHttpParams(clone, this.defaults);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Retrieves the value of the parameter from the local collection and, if the
michael@0:      * parameter is not set locally, delegates its resolution to the default
michael@0:      * collection.
michael@0:      */
michael@0:     public Object getParameter(final String name) {
michael@0:         Object obj = this.local.getParameter(name);
michael@0:         if (obj == null && this.defaults != null) {
michael@0:             obj = this.defaults.getParameter(name);
michael@0:         }
michael@0:         return obj;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Attempts to remove the parameter from the local collection. This method
michael@0:      * <i>does not</i> modify the default collection.
michael@0:      */
michael@0:     public boolean removeParameter(final String name) {
michael@0:         return this.local.removeParameter(name);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Sets the parameter in the local collection. This method <i>does not</i>
michael@0:      * modify the default collection.
michael@0:      */
michael@0:     public HttpParams setParameter(final String name, final Object value) {
michael@0:         return this.local.setParameter(name, value);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      *
michael@0:      * @return the default HttpParams collection
michael@0:      */
michael@0:     public HttpParams getDefaults() {
michael@0:         return this.defaults;
michael@0:     }
michael@0: 
michael@0: }