i'm currently building a little JTable, and want to highlight the column header (and row headers - the row-header part is actually working) when a cell is selected to make it easier to find the associated names with this cell. Here is a picture:
I already tried switching out the renderer for the header with this:
table.getTableHeader().setDefaultRenderer(new ColumnHeaderRenderer());
But it's only called when i click on the header and always says isSelected is false.
This is the code i use for the row-names, including the highlight inside the renderer - code is not by me, i just modified it a little:
/*
* Use a JTable as a renderer for row numbers of a given main table.
* This table must be added to the row header of the scrollpane that
* contains the main table.
*/
public class RowNameTable extends JTable
implements ChangeListener, PropertyChangeListener {
private JTable main;
public RowNameTable(JTable table) {
main = table;
main.addPropertyChangeListener(this);
setFocusable(false);
setAutoCreateColumnsFromModel(false);
setModel(main.getModel());
setSelectionModel(main.getSelectionModel());
TableColumn column = new TableColumn();
column.setHeaderValue(" ");
addColumn(column);
column.setCellRenderer(new RowNameRenderer(main));
getColumnModel().getColumn(0).setPreferredWidth(table.getColumnModel().getColumn(0).getPreferredWidth());
setPreferredScrollableViewportSize(getPreferredSize());
}
@Override
public void addNotify() {
super.addNotify();
Component c = getParent();
// Keep scrolling of the row table in sync with the main table.
if (c instanceof JViewport) {
JViewport viewport = (JViewport) c;
viewport.addChangeListener(this);
}
}
/*
* Delegate method to main table
*/
@Override
public int getRowCount() {
return main.getRowCount();
}
@Override
public int getRowHeight(int row) {
return main.getRowHeight(row);
}
/*
* This table does not use any data from the main TableModel,
* so just return a value based on the row parameter.
*/
@Override
public Object getValueAt(int row, int column) {
return Integer.toString(row + 1);
}
/*
* Don't edit data in the main TableModel by mistake
*/
@Override
public boolean isCellEditable(int row, int column) {
return false;
}
//
// Implement the ChangeListener
//
public void stateChanged(ChangeEvent e) {
// Keep the scrolling of the row table in sync with main table
JViewport viewport = (JViewport) e.getSource();
JScrollPane scrollPane = (JScrollPane) viewport.getParent();
scrollPane.getVerticalScrollBar().setValue(viewport.getViewPosition().y);
}
//
// Implement the PropertyChangeListener
//
public void propertyChange(PropertyChangeEvent e) {
// Keep the row table in sync with the main table
if ("selectionModel".equals(e.getPropertyName())) {
setSelectionModel(main.getSelectionModel());
}
if ("model".equals(e.getPropertyName())) {
setModel(main.getModel());
}
}
/*
* Borrow the renderer from JDK1.4.2 table header
*/
private static class RowNameRenderer extends DefaultTableCellRenderer {
private JTable main;
public RowNameRenderer(JTable main) {
this.main = main;
setHorizontalAlignment(JLabel.CENTER);
}
@Override
public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
if (table != null) {
JTableHeader header = table.getTableHeader();
if (header != null) {
setForeground(header.getForeground());
setBackground(header.getBackground());
setFont(header.getFont());
}
}
if (isSelected) {
setFont(getFont().deriveFont(Font.BOLD));
}
setText((value == null) ? "" : main.getColumnName(row));
setBorder(UIManager.getBorder("TableHeader.cellBorder"));
return this;
}
}
}
And here we have the relevant part to create the table:
costTableModel = new CostTableModel(costCalc);
table = new JTable(costTableModel);
table.setPreferredScrollableViewportSize(table.getPreferredSize());
table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
table.setCellSelectionEnabled(true);
scrollPane = new JScrollPane(table);
RowNameTable nameTable = new RowNameTable(table);
scrollPane.setRowHeaderView(nameTable);
And the class costTableModel, just for completeness sake:
public class CostTableModel extends AbstractTableModel {
private CostCalculator costCalc;
public CostTableModel(CostCalculator costCalc) {
this.costCalc = costCalc;
}
@Override
public int getRowCount() {
return costCalc.getPersonsList().size();
}
@Override
public int getColumnCount() {
return costCalc.getPersonsList().size();
}
@Override
public String getColumnName(int col) {
return costCalc.getPersonsList().get(col).getName();
}
@Override
public Object getValueAt(int rowIndex, int columnIndex) {
Person debtor = costCalc.getPersonsList().get(rowIndex);
Person debtee = costCalc.getPersonsList().get(columnIndex);
return costCalc.getAmountOwed(debtor, debtee);
}
@Override
public Class getColumnClass(int c) {
return getValueAt(0, c).getClass();
}
}
Thank you for your help in advance!
The basic issue I had was there was no connection between the table header and the selection change. In fact, the header is really clever with it's repaints...
I ended up providing my own header, which attached a listener to the table's selection model and repainted the header on the selection changed.
A slight variant: as I read the question, the main problem is the header not updating on column selection change. Having a custom header listen to row selection changes doesn't help much for that scenario.
In fact, a JTableHeader already is listening to the ColumnModel and the model's change notification includes selection changes. Only the columnSelectionChange method is intentionally implemented to do nothing:
A custom header can simply implement to repaint (here lazy me does it in the table's factory method just to spare me the wiring to the table, you can easily make it a stand-alone class :-).
Also tweaked Mad's renderer a bit, using table api:
As to the observation:
The reason is a slight quirk in BasicTableHeaderUI:
uiSelected is the column which will be accessible to keybindings - if the laf supports it and the header is focusOwner. Doesn't really make sense to me, but fully defining the semantics of ui and columnModel selection fell into the excitement about the new babe fx, that is got forgotten ;-)