/* * TableRenderDemo.java is a 1.4 application that requires no other files. */import javax.swing.DefaultCellEditor;import javax.swing.JComboBox;import javax.swing.JFrame;import javax.swing.JPanel;import javax.swing.JScrollPane;import javax.swing.JTable;import javax.swing.table.AbstractTableModel;import javax.swing.table.DefaultTableCellRenderer;import javax.swing.table.TableCellRenderer;import javax.swing.table.TableColumn;import java.awt.Component;import java.awt.Dimension;import java.awt.GridLayout;/**  * TableRenderDemo is just like TableDemo, except that it * explicitly initializes column sizes and it uses a combo box * as an editor for the Sport column. */public class TableRenderDemo extends JPanel {    private boolean DEBUG = false;    public TableRenderDemo() {        super(new GridLayout(1,0));        JTable table = new JTable(new MyTableModel());        table.setPreferredScrollableViewportSize(new Dimension(500, 70));        //Create the scroll pane and add the table to it.        JScrollPane scrollPane = new JScrollPane(table);        //Set up column sizes.        initColumnSizes(table);        //Fiddle with the Sport column's cell editors/renderers.        setUpSportColumn(table, table.getColumnModel().getColumn(2));        //Add the scroll pane to this panel.        add(scrollPane);    }    /*     * This method picks good column sizes.     * If all column heads are wider than the column's cells'     * contents, then you can just use column.sizeWidthToFit().     */    private void initColumnSizes(JTable table) {        MyTableModel model = (MyTableModel)table.getModel();        TableColumn column = null;        Component comp = null;        int headerWidth = 0;        int cellWidth = 0;        Object[] longValues = model.longValues;        TableCellRenderer headerRenderer =            table.getTableHeader().getDefaultRenderer();        for (int i = 0; i < 5; i++) {            column = table.getColumnModel().getColumn(i);            comp = headerRenderer.getTableCellRendererComponent(                                 null, column.getHeaderValue(),                                 false, false, 0, 0);            headerWidth = comp.getPreferredSize().width;            comp = table.getDefaultRenderer(model.getColumnClass(i)).                             getTableCellRendererComponent(                                 table, longValues[i],                                 false, false, 0, i);            cellWidth = comp.getPreferredSize().width;            if (DEBUG) {                System.out.println("Initializing width of column "                                   + i + ". "                                   + "headerWidth = " + headerWidth                                   + "; cellWidth = " + cellWidth);            }            //XXX: Before Swing 1.1 Beta 2, use setMinWidth instead.            column.setPreferredWidth(Math.max(headerWidth, cellWidth));        }    }    public void setUpSportColumn(JTable table,                                 TableColumn sportColumn) {        //Set up the editor for the sport cells.        JComboBox comboBox = new JComboBox();        comboBox.addItem("Snowboarding");        comboBox.addItem("Rowing");        comboBox.addItem("Knitting");        comboBox.addItem("Speed reading");        comboBox.addItem("Pool");        comboBox.addItem("None of the above");        sportColumn.setCellEditor(new DefaultCellEditor(comboBox));        //Set up tool tips for the sport cells.        DefaultTableCellRenderer renderer =                new DefaultTableCellRenderer();        renderer.setToolTipText("Click for combo box");        sportColumn.setCellRenderer(renderer);    }    class MyTableModel extends AbstractTableModel {        private String[] columnNames = {"First Name",                                        "Last Name",                                        "Sport",                                        "# of Years",                                        "Vegetarian"};        private Object[][] data = {            {"Mary", "Campione",             "Snowboarding", new Integer(5), new Boolean(false)},            {"Alison", "Huml",             "Rowing", new Integer(3), new Boolean(true)},            {"Kathy", "Walrath",             "Knitting", new Integer(2), new Boolean(false)},            {"Sharon", "Zakhour",             "Speed reading", new Integer(20), new Boolean(true)},            {"Philip", "Milne",             "Pool", new Integer(10), new Boolean(false)}        };        public final Object[] longValues = {"Sharon", "Campione",                                            "None of the above",                                            new Integer(20), Boolean.TRUE};        public int getColumnCount() {            return columnNames.length;        }        public int getRowCount() {            return data.length;        }        public String getColumnName(int col) {            return columnNames[col];        }        public Object getValueAt(int row, int col) {            return data[row][col];        }        /*         * JTable uses this method to determine the default renderer/         * editor for each cell.  If we didn't implement this method,         * then the last column would contain text ("true"/"false"),         * rather than a check box.         */        public Class getColumnClass(int c) {            return getValueAt(0, c).getClass();        }        /*         * Don't need to implement this method unless your table's         * editable.         */        public boolean isCellEditable(int row, int col) {            //Note that the data/cell address is constant,            //no matter where the cell appears onscreen.            if (col < 2) {                return false;            } else {                return true;            }        }        /*         * Don't need to implement this method unless your table's         * data can change.         */        public void setValueAt(Object value, int row, int col) {            if (DEBUG) {                System.out.println("Setting value at " + row + "," + col                                   + " to " + value                                   + " (an instance of "                                   + value.getClass() + ")");            }            data[row][col] = value;            fireTableCellUpdated(row, col);            if (DEBUG) {                System.out.println("New value of data:");                printDebugData();            }        }        private void printDebugData() {            int numRows = getRowCount();            int numCols = getColumnCount();            for (int i=0; i < numRows; i++) {                System.out.print("    row " + i + ":");                for (int j=0; j < numCols; j++) {                    System.out.print("  " + data[i][j]);                }                System.out.println();            }            System.out.println("--------------------------");        }    }    /**     * Create the GUI and show it.  For thread safety,     * this method should be invoked from the     * event-dispatching thread.     */    private static void createAndShowGUI() {        //Make sure we have nice window decorations.        JFrame.setDefaultLookAndFeelDecorated(true);        //Create and set up the window.        JFrame frame = new JFrame("TableRenderDemo");        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        //Create and set up the content pane.        TableRenderDemo newContentPane = new TableRenderDemo();        newContentPane.setOpaque(true); //content panes must be opaque        frame.setContentPane(newContentPane);        //Display the window.        frame.pack();        frame.setVisible(true);    }    public static void main(String[] args) {        //Schedule a job for the event-dispatching thread:        //creating and showing this application's GUI.        javax.swing.SwingUtilities.invokeLater(new Runnable() {            public void run() {                createAndShowGUI();            }        });    }}