问题
I have a JTable with a custom cell renderer. The cell is a JPanel that contains a JTextField and a JButton. The JTextField contains an integer, and when the user clicks on the JButton the integer should be increased.
The problem is that the JButton can't be clicked when I have it in a JTable cell. How can I make it click-able?
Here is my test code:
public class ActiveTable extends JFrame {
public ActiveTable() {
RecordModel model = new RecordModel();
model.addRecord(new Record());
JTable table = new JTable(model);
EditorAndRenderer editorAndRenderer = new EditorAndRenderer();
table.setDefaultRenderer(Object.class, editorAndRenderer);
table.setDefaultEditor(Object.class, editorAndRenderer);
table.setRowHeight(38);
add(new JScrollPane(table));
setPreferredSize(new Dimension(600, 400));
pack();
setDefaultCloseOperation(EXIT_ON_CLOSE);
setTitle("Active Table");
setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new ActiveTable();
}
});
}
class RecordModel extends AbstractTableModel {
private final List<Record> records = new ArrayList<Record>();
@Override
public int getColumnCount() {
return 1;
}
@Override
public int getRowCount() {
return records.size();
}
@Override
public Object getValueAt(int rowIndex, int columnIndex) {
return records.get(rowIndex);
}
public void addRecord(Record r) {
records.add(r);
fireTableRowsInserted(records.size()-1, records.size()-1);
}
}
class Record {
private int count = 1;
public int getCount() { return count; }
public void increase() { count = count + 1; }
}
class CellPanel extends JPanel {
private Record record;
private final JTextField field = new JTextField(8);
private final Action increaseAction = new AbstractAction("+") {
public void actionPerformed(ActionEvent e) {
record.increase();
field.setText(record.getCount()+"");
JTable table = (JTable) SwingUtilities.getAncestorOfClass(JTable.class, (Component) e.getSource());
table.getCellEditor().stopCellEditing();
}
};
private final JButton button = new JButton(increaseAction);
public CellPanel() {
add(field);
add(button);
}
public void setRecord(Record r) {
record = r;
field.setText(record.getCount()+"");
}
public Record getRecord() {
return record;
}
}
class EditorAndRenderer extends AbstractCellEditor implements TableCellEditor, TableCellRenderer {
private final CellPanel renderer = new CellPanel();
private final CellPanel editor = new CellPanel();
@Override
public Component getTableCellRendererComponent(JTable table, Object value,
boolean isSelected, boolean hasFocus, int row, int column) {
renderer.setRecord((Record) value);
return renderer;
}
@Override
public Component getTableCellEditorComponent(JTable table, Object value,
boolean isSelected, int row, int column) {
editor.setRecord((Record) value);
return editor;
}
@Override
public Object getCellEditorValue() {
return editor.getRecord();
}
@Override
public boolean isCellEditable(EventObject ev) {
return true;
}
@Override
public boolean shouldSelectCell(EventObject ev) {
return false;
}
}
}
回答1:
Here's one way to use ButtonColumn.
public class TableTest extends JFrame {
public TableTest() {
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTable table = new JTable(new TestModel());
table.getColumnModel().getColumn(1).setPreferredWidth(3);
table.getColumnModel().getColumn(2).setPreferredWidth(3);
this.add(new JScrollPane(table));
Action increase = new AbstractAction("+") {
@Override
public void actionPerformed(ActionEvent e) {
JTable table = (JTable) e.getSource();
int row = Integer.valueOf(e.getActionCommand());
TestModel model = (TestModel) table.getModel();
model.increment(row, 0);
}
};
ButtonColumn inc = new ButtonColumn(table, increase, 1);
Action decrease = new AbstractAction("-") {
@Override
public void actionPerformed(ActionEvent e) {
JTable table = (JTable) e.getSource();
int row = Integer.valueOf(e.getActionCommand());
TestModel model = (TestModel) table.getModel();
model.decrement(row, 0);
}
};
ButtonColumn dec = new ButtonColumn(table, decrease, 2);
pack();
}
public static void main(String[] args) {
new TableTest().setVisible(true);
}
}
class TestModel extends AbstractTableModel {
List<TestRecord> records = new LinkedList<TestRecord>();
private static class TestRecord {
private int val = 0;
}
public void increment(int row, int col) {
records.get(row).val++;
fireTableCellUpdated(row, 0);
}
public void decrement(int row, int col) {
records.get(row).val--;
fireTableCellUpdated(row, 0);
}
public TestModel() {
records.add(new TestRecord());
records.add(new TestRecord());
}
@Override
public Class<?> getColumnClass(int col) {
if (col == 0) {
return Integer.class;
} else {
return ButtonColumn.class;
}
}
@Override
public boolean isCellEditable(int row, int col) {
return true;
}
@Override
public int getColumnCount() {
return 3;
}
@Override
public int getRowCount() {
return records.size();
}
@Override
public Object getValueAt(int row, int col) {
if (col == 0) {
return records.get(row).val;
} else if (col == 1) {
return "+";
} else {
return "-";
}
}
}
回答2:
I based my last example on the code provided by mKrobels answer to How to implement dynamic GUI in swing
The main difference between his and my example in the question is that he use DefaultTableModel and I use AbstractTableModel. His example does work, but not mine.
The solution I found was that I had to implement isCellEditable() in the TableModel, so with this method added, my example works:
@Override
public boolean isCellEditable(int rowIndex, int columnIndex) {
return true;
}
回答3:
The renderer is just a display for painting the cells. You need an editor component that allows you to make changes.
Take a look at:
http://download.oracle.com/javase/6/docs/api/javax/swing/table/TableCellEditor.html
来源：https://stackoverflow.com/questions/5555938/how-to-make-a-jbutton-in-a-jtable-cell-click-able