001    // Copyright 2004, 2005 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.tapestry.contrib.table.model.simple;
016    
017    import org.apache.tapestry.IRender;
018    import org.apache.tapestry.IRequestCycle;
019    import org.apache.tapestry.contrib.table.model.ITableColumn;
020    import org.apache.tapestry.contrib.table.model.ITableModelSource;
021    import org.apache.tapestry.contrib.table.model.ITableRendererSource;
022    import org.apache.tapestry.contrib.table.model.common.ComponentTableRendererSource;
023    import org.apache.tapestry.util.ComponentAddress;
024    
025    /**
026     * This is a simple implementation of 
027     * {@link org.apache.tapestry.contrib.table.model.ITableRendererSource} 
028     * that returns a standard renderer of a column header. <p>
029     * 
030     * This implementation requires that the column passed is of type SimpleTableColumn
031     * 
032     * @see org.apache.tapestry.contrib.table.model.common.AbstractTableColumn
033     * @author mindbridge
034     * @since 2.3
035     */
036    public class SimpleTableColumnRendererSource implements ITableRendererSource
037    {
038            private static final long serialVersionUID = 1L;
039            
040            private ComponentTableRendererSource m_objComponentRenderer;
041    
042            public SimpleTableColumnRendererSource()
043            {
044                    m_objComponentRenderer = null;
045            }
046    
047            /**
048             * @see org.apache.tapestry.contrib.table.model.ITableRendererSource#getRenderer(IRequestCycle, ITableModelSource, ITableColumn, Object)
049             */
050            public IRender getRenderer(
051                    IRequestCycle objCycle,
052                    ITableModelSource objSource,
053                    ITableColumn objColumn,
054                    Object objRow)
055            {
056                    if (m_objComponentRenderer == null)
057                    {
058                            synchronized (this)
059                            {
060                                    if (m_objComponentRenderer == null)
061                                    {
062                                            ComponentAddress objAddress =
063                                                    new ComponentAddress(
064                                                            objSource.getNamespace(),
065                                                            "SimpleTableColumnPage",
066                                                            "tableColumnComponent");
067                                            m_objComponentRenderer =
068                                                    new ComponentTableRendererSource(objAddress);
069                                    }
070                            }
071                    }
072    
073                    return m_objComponentRenderer.getRenderer(
074                            objCycle,
075                            objSource,
076                            objColumn,
077                            objRow);
078            }
079    }