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.components.inserted;
016    
017    import org.apache.tapestry.BaseComponent;
018    import org.apache.tapestry.IAsset;
019    import org.apache.tapestry.IRequestCycle;
020    import org.apache.tapestry.Tapestry;
021    import org.apache.tapestry.contrib.table.components.Table;
022    import org.apache.tapestry.contrib.table.components.TableColumns;
023    import org.apache.tapestry.contrib.table.model.ITableColumn;
024    import org.apache.tapestry.contrib.table.model.ITableModel;
025    import org.apache.tapestry.contrib.table.model.ITableModelSource;
026    import org.apache.tapestry.contrib.table.model.ITableRendererListener;
027    import org.apache.tapestry.contrib.table.model.ITableSortingState;
028    import org.apache.tapestry.event.PageDetachListener;
029    import org.apache.tapestry.event.PageEvent;
030    
031    /**
032     * A component that renders the proper sort image for the current column - to be 
033     * used with contrib:Table when customizing a column's header.
034     * 
035     * @author Andreas Andreou
036     */
037    public abstract class SimpleTableColumnSortImage extends BaseComponent
038            implements PageDetachListener, ITableRendererListener
039    {
040        // transient
041        private ITableModelSource m_objModelSource;
042        private ITableColumn m_objColumn;
043        
044        public SimpleTableColumnSortImage()
045        {
046            init();
047        }
048    
049        public abstract Table getTable();
050        
051        /**
052         * @see org.apache.tapestry.event.PageDetachListener#pageDetached(PageEvent)
053         */
054        public void pageDetached(PageEvent arg0)
055        {
056            init();
057        }
058    
059        private void init()
060        {
061            m_objModelSource = null;
062            m_objColumn = null;
063        }
064    
065        /**
066         * @see org.apache.tapestry.contrib.table.model.ITableRendererListener#initializeRenderer(IRequestCycle,
067         *      ITableModelSource, ITableColumn, Object)
068         */
069        public void initializeRenderer(IRequestCycle objCycle,
070                ITableModelSource objSource, ITableColumn objColumn, Object objRow)
071        {
072            m_objModelSource = objSource;
073            m_objColumn = objColumn;
074        }
075        
076         public void prepareForRender(IRequestCycle cycle)
077         {         
078             if (getTable()==null)
079                throw Tapestry.createRequiredParameterException(this, "table");
080             
081             m_objModelSource = getTable();
082             m_objColumn = getTable().getTableColumn();
083                      
084         }
085             
086    
087        public ITableModel getTableModel()
088        {
089            return m_objModelSource.getTableModel();
090        }
091    
092        public IAsset getSortImage()
093        {
094            IAsset objImageAsset;
095    
096            IRequestCycle objCycle = getPage().getRequestCycle();
097            ITableSortingState objSortingState = getTableModel().getSortingState();
098            if (objSortingState.getSortOrder() == ITableSortingState.SORT_ASCENDING)
099            {
100                objImageAsset = (IAsset) objCycle
101                        .getAttribute(TableColumns.TABLE_COLUMN_ARROW_UP_ATTRIBUTE);
102                if (objImageAsset == null) objImageAsset = getAsset("sortUp");
103            }
104            else
105            {
106                objImageAsset = (IAsset) objCycle
107                        .getAttribute(TableColumns.TABLE_COLUMN_ARROW_DOWN_ATTRIBUTE);
108                if (objImageAsset == null) objImageAsset = getAsset("sortDown");
109            }
110    
111            return objImageAsset;
112        }
113        
114        public boolean getIsSorted()
115        {
116            ITableSortingState objSortingState = getTableModel().getSortingState();
117            String strSortColumn = objSortingState.getSortColumn();
118            return m_objColumn.getColumnName().equals(strSortColumn);
119        }    
120    }