001    // Copyright 2008, 2010 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    // http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry5.internal;
016    
017    import org.apache.tapestry5.services.ContextValueEncoder;
018    
019    /**
020     * Implementation based on values extracted from the URL (an event context, or a page activation
021     * context) that uses a {@link org.apache.tapestry5.services.ContextValueEncoder} to convert from
022     * string values to the desired values.
023     */
024    public class URLEventContext extends AbstractEventContext
025    {
026        private final ContextValueEncoder valueEncoder;
027    
028        private final String[] values;
029    
030        public URLEventContext(ContextValueEncoder valueEncoder, String[] values)
031        {
032            this.valueEncoder = valueEncoder;
033            this.values = values;
034        }
035    
036        public int getCount()
037        {
038            return values == null ? 0 : values.length;
039        }
040    
041        public <T> T get(Class<T> desiredType, int index)
042        {
043            return valueEncoder.toValue(desiredType, values[index]);
044        }
045    }