import javax.swing.JTable; import javax.swing.table.AbstractTableModel; import javax.swing.table.TableColumn; import javax.swing.DefaultCellEditor; import javax.swing.table.TableCellRenderer; import javax.swing.table.DefaultTableCellRenderer; import javax.swing.JScrollPane; import javax.swing.JComboBox; import javax.swing.JFrame; import javax.swing.SwingUtilities; import javax.swing.JOptionPane; import java.awt.*; import java.awt.event.*; public class TableRenderDemo extends JFrame { private boolean DEBUG = true; public TableRenderDemo() { super("TableRenderDemo"); MyTableModel myModel = new MyTableModel(); JTable table = new JTable(myModel); 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, myModel); //Fiddle with the Sport column's cell editors/renderers. setUpSportColumn(table.getColumnModel().getColumn(2)); //Add the scroll pane to this window. getContentPane().add(scrollPane, BorderLayout.CENTER); addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); } /* * 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) { TableColumn column = null; Component comp = null; int headerWidth = 0; int cellWidth = 0; Object[] longValues = model.longValues; for (int i = 0; i < 5; i++) { column = table.getColumnModel().getColumn(i); comp = column.getHeaderRenderer(). 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(TableColumn sportColumn) { //Set up the editor for the sport cells. JComboBox comboBox = new JComboBox(); comboBox.addItem("Snowboarding"); comboBox.addItem("Rowing"); comboBox.addItem("Chasing toddlers"); comboBox.addItem("Speed reading"); comboBox.addItem("Teaching high school"); comboBox.addItem("None"); 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); //Set up tool tip for the sport column header. TableCellRenderer headerRenderer = sportColumn.getHeaderRenderer(); if (headerRenderer instanceof DefaultTableCellRenderer) { ((DefaultTableCellRenderer)headerRenderer).setToolTipText( "Click the sport to see a list of choices"); } } class MyTableModel extends AbstractTableModel { final String[] columnNames = {"First Name", "Last Name", "Sport", "# of Years", "Vegetarian"}; final Object[][] data = { {"Mary", "Campione", "Snowboarding", new Integer(5), new Boolean(false)}, {"Alison", "Huml", "Rowing", new Integer(3), new Boolean(true)}, {"Kathy", "Walrath", "Chasing toddlers", new Integer(2), new Boolean(false)}, {"Mark", "Andrews", "Speed reading", new Integer(20), new Boolean(true)}, {"Angela", "Lih", "Teaching high school", new Integer(4), new Boolean(false)} }; public final Object[] longValues = {"Angela", "Andrews", "Teaching high school", 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() + ")"); } if (data[0][col] instanceof Integer) { //If we don't do something like this, the column //switches to contain Strings. try { data[row][col] = new Integer((String)value); fireTableCellUpdated(row, col); } catch (NumberFormatException e) { JOptionPane.showMessageDialog(TableRenderDemo.this, "The \"" + getColumnName(col) + "\" column accepts only integer values."); } } else { 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("--------------------------"); } } public static void main(String[] args) { TableRenderDemo frame = new TableRenderDemo(); frame.pack(); frame.setVisible(true); } }