001    package util.swing;
002    
003    import javax.swing.table.*;
004    
005    import java.util.Comparator;
006    
007    /**
008     * <i>Abstract</i> base implementation of {@link TableEntryDescriptor}.
009     *
010     * <p>This base implementations is useful when you want to define a TableEntryDescriptor that describes rows
011     * that are non-editable and use the default renderer for each cell, based on the cell value's class.
012     *
013     * @see util.swing.AbstractTableModel
014     *
015     * @author Steffen Zschaler
016     * @version 2.0 27/07/1999
017     * @since v2.0
018     */
019    public abstract class AbstractTableEntryDescriptor extends Object implements TableEntryDescriptor {
020    
021        /**
022         * Dummy constructor, does nothing but call <code>super()</code>.
023         */
024        public AbstractTableEntryDescriptor() {
025            super();
026        }
027    
028        /**
029         * Returns <code>null</code> to indicate that the default cell renderer is to be used based on the cell
030         * value's class.
031         *
032         * @override Sometimes Override this method if you want to define specialized cell renderers for certain
033         * columns.
034         */
035        public TableCellRenderer getCellRenderer(int nIdx) {
036            return null;
037        }
038    
039        /**
040         * Returns <code>null</code> to indicate that the default cell editor is to be used based on the cell
041         * value's class.
042         *
043         * @override Sometimes Override this method if you want to define specialized cell editors for certain
044         * columns. Note that you will also have to override {@link #isElementEditable} and {@link #setValueAt}
045         * for complete editing support.
046         */
047        public TableCellEditor getCellEditor(int nIdx) {
048            return null;
049        }
050    
051        /**
052         * Returns <code>false</code> to indicate that no cell is editable in the entire table.
053         *
054         * @override Sometimes Override this method if you want to allow editing for certain cells. The actual class
055         * of the record passed as <code>oRecord</code> depends on the {@link util.swing.AbstractTableModel TableModel}
056         * with which you work. See {@link util.swing.AbstractTableModel#getRecord} in the concrete TableModel for a
057         * description.
058         * Note that you will also have to override {@link #setValueAt} for complete editing support. It is also
059         * recommended that you override {@link #getCellEditor} if you override this method.
060         */
061        public boolean isElementEditable(Object oRecord, int nIdx) {
062            return false;
063        }
064    
065        /**
066         * Does nothing because AbstractTableEntryDescriptor does not allow editing by default.
067         *
068         * @override Sometimes Override this method if you want to allow editing for certain cells. The actual class
069         * of the record passed as <code>oRecord</code> depends on the {@link util.swing.AbstractTableModel TableModel}
070         * with which you work. See {@link util.swing.AbstractTableModel#getRecord} in the concrete TableModel for a
071         * description.
072         * Note that you will also have to override {@link #isElementEditable} for complete editing support. It is
073         * also recommended that you override {@link #getCellEditor} if you override this method.
074         */
075        public void setValueAt(Object oRecord, int nIdx, Object oValue) {}
076    
077        /**
078         * Returns false because AbstractTableEntryDescriptor does not allow sorting by column by default.
079         *
080         * @param nIdx the index of the column concerned.
081         *
082         * @return whether or not records can be sorted by the specified column.
083         *
084         * @override Sometimes Override this method if you want to support sorting by column
085         */
086        public boolean canSortByColumn(int nIdx) {
087            return false;
088        }
089    
090        /**
091         * Returns <code>null</code> because AbstractTableEntryDescriptor does not allow sorting by column by default.
092         *
093         * @param nIdx the index of the column concerned.
094         *
095         * @override Sometimes Override this method if you want to support sorting by column
096         */
097        public Comparator getColumnOrder(int nIdx) {
098            return null;
099        }
100    }