Question

The JTableHaeder has no ‘pressed’ highlighting by default. (Nimbus)

NimbusDefaults says it has a default [Pressed] background painter.

What should I do, to see this when i click on the TableHeader?

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UPDATE 1

The NimbusStyle.getExtendedState returns the PRESSED on mouseDown correctly. But the NimbusStyle.getBackgroundPainter(SynthContext) returns null cause there is an null in the NimbusStyle.Values cache for the CacheKey “backgroundPainter$$instance” with this state.

What is wrong there?

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UPDATE 2

My example shows a JTableHeader and a JScrollBar with an ‘Pressed Behavior’.

For the JScrollBar my putClientProperty( "Nimbus.State" ) works with a repaint problem.

public class Header extends JPanel{

    public Header() {
        super(new BorderLayout());
        JTableHeader header = new JTable(5, 3).getTableHeader();
        JScrollBar   scroll = new JScrollBar(JScrollBar.HORIZONTAL);
        add(header, BorderLayout.NORTH);
        add(scroll, BorderLayout.SOUTH);
        scroll.addMouseListener( new PressedBehavior() );
        header.addMouseListener( new PressedBehavior() );
    }

    static public void main( String[] s ) {
        try {
            UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
            SwingUtilities.invokeLater( new Runnable() {
                @Override
                public void run() {
                    JFrame f = new JFrame("Nimbus Pressed Example");
                    f.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
                    f.setBounds( 150, 150, 300, 200 );
                    f.getContentPane().add( new Header() );
                    f.setVisible( true );
                }
            });
        } catch( Exception fail ) { /*ignore*/ }
    }
    private class PressedBehavior extends MouseAdapter {
        @Override
        public void mouseReleased( MouseEvent e ) {
            JComponent source = (JComponent)e.getComponent();
            source.putClientProperty( "Nimbus.State", null );
        }
        @Override
        public void mousePressed( MouseEvent e ) {
            JComponent source = (JComponent)e.getComponent();
            source.putClientProperty( "Nimbus.State", "Pressed" );
            //source.invalidate();
            //source.repaint();
        }
    }
}

Answer 1

technically, you need that state on the rendering component, not on the JTableHeader itself:

    @Override
    public void mousePressed( MouseEvent e ) {
        JComponent source = (JComponent)e.getComponent();
        source.putClientProperty( "Nimbus.State", "Pressed" );
        if (source instanceof JTableHeader) {
            ((JComponent) ((JTableHeader) source).getDefaultRenderer())
                .putClientProperty("Nimbus.State", "Pressed");
        }
    }

Problem then is that the same instance (of rendering component) is used for all columns, so if you drag a column all appear pressed …

Edit: couldn’t resist to dig a bit … Nimbus is soooo … lacking, to put it mildly 😉

Turns out that the defaults indeed have the styles for pressed, what’s missing is the logic to set it. Probably not entirely trivial, because the logic (aka: MouseListener) resides in BasicTableHeaderUI which doesn’t know about subclass’ painter states. The only thingy the logic is supporting (hot needle fix) is rollover-awareness, but not pressed-ness.

While we can’t hook into the logic (well, we could … but that’s another trick 🙂 we can look for secondary state changes like draggingColumn/resizingColumn (not-bound) properties in JTableHeader and let a custom renderer update itself as appropriate. Here’s a line-out of how-to:

public static class WrappingRenderer implements TableCellRenderer {

    private DefaultTableCellHeaderRenderer delegate;
    private JTableHeader header;

    public WrappingRenderer(JTableHeader header) {
        this.header = header;
        this.delegate = (DefaultTableCellHeaderRenderer) header.getDefaultRenderer();
        header.setDefaultRenderer(this);
    }

    @Override
    public Component getTableCellRendererComponent(JTable table,
            Object value, boolean isSelected, boolean hasFocus, int row,
            int column) {
        Component comp = delegate.getTableCellRendererComponent(table, 
                value, isSelected, hasFocus, row, column);
        TableColumn draggedColumn = table.getTableHeader().getDraggedColumn();
        if (draggedColumn != null) {
            if (table.convertColumnIndexToModel(column) == draggedColumn.getModelIndex()) {
                setNimbusState("Pressed");
            } else {
                setNimbusState(null);
            }

        } else {
            setNimbusState(null);
        }
        // do similar for resizing column
        return comp;
    }

    public void setNimbusState(String state) {
        delegate.putClientProperty("Nimbus.State", state);
    }
}