not an answer,
but see whats happens, with JPanel as renderers JComponents for JComboBox
are you sure that JPanel with String value is proper way, please whats goal,
is there the same effect with default JLabel, (J)Component instead of JPanel
from code
import java.awt.*;
import java.awt.event.*;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.*;
public class TextDemo extends JPanel implements ActionListener {
private static JFrame frame;
public TextDemo() {
super(new GridBagLayout());
JComboBox correct = new JComboBox(new String[]{"One", "Two", "Three"});
JComboBox alsoCorrect = new JComboBox(new String[]{"One", "Two", "Three"});
alsoCorrect.setRenderer(new MyRenderer());
JComboBox incorrect = new JComboBox(new String[]{"One", "Two", "Three"});
incorrect.setRenderer(new NotWorkingRenderer());
JButton button = new JButton("Change LnF");
button.addActionListener(this);
add(incorrect, getConstraints(0));
add(correct, getConstraints(1));
add(alsoCorrect, getConstraints(2));
add(button, getConstraints(3));
}
private GridBagConstraints getConstraints(int y) {
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.gridy = y;
c.insets = new Insets(4, 8, 4, 8);
c.weightx = 1.0;
c.weighty = 1.0;
c.fill = GridBagConstraints.HORIZONTAL;
c.anchor = GridBagConstraints.FIRST_LINE_START;
return c;
}
@Override
public void actionPerformed(ActionEvent ev) {
try {
UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
SwingUtilities.updateComponentTreeUI(frame);
} catch (Exception ex) {
ex.printStackTrace();
}
}
private static void createAndShowGUI() {
frame = new JFrame("TextDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TextDemo());
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.motif.MotifLookAndFeel");
//SwingUtilities.updateComponentTreeUI(frame);
} catch (Exception ex) {
ex.printStackTrace();
}
javax.swing.SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
createAndShowGUI();
}
});
}
}
class MyRenderer implements ListCellRenderer {
protected static ListCellRenderer delegate;
static {
refreshRenderers();
UIManager.addPropertyChangeListener(new PropertyChangeListener() {
@Override
public void propertyChange(PropertyChangeEvent evt) {
if (evt.getPropertyName().equals("lookAndFeel")) {
refreshRenderers();
}
}
});
}
protected static void refreshRenderers() {
delegate = new JComboBox().getRenderer();
}
@Override
public Component getListCellRendererComponent(JList list, Object value,
int index, boolean isSelected, boolean cellHasFocus) {
return delegate.getListCellRendererComponent(list, value,
index, isSelected, cellHasFocus);
}
}
class NotWorkingRenderer extends MyRenderer {
private JPanel panel = new JPanel();
public NotWorkingRenderer() {
panel.setLayout(new BoxLayout(panel, BoxLayout.X_AXIS));
}
@Override
public Component getListCellRendererComponent(JList list, Object value,
int index, boolean isSelected, boolean cellHasFocus) {
Component c = super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
c.setMaximumSize(new Dimension(Short.MAX_VALUE, Short.MAX_VALUE));
panel.add(c);
return panel;
}
}
EDIT_1st.
all Standard L&F excluding ModifL&F showing that properly
one step forward ???, code line
incorrect.setEditable(true);
generating
- I'm don't know proper way for ModifL&F and non_editable JComboBox
EDIT_2nd.
I'm blind
class NotWorkingRenderer extends MyRenderer {
, pip... pip... pip...phaaa I'm participated on never ever to
add
/remove
/modify
aJComponent
inXxx(Xxx)Renderer
, but is about if is possible or not,
class NotWorkingRenderer extends BasicComboBoxRenderer {
private JPanel panel = new JPanel();
public NotWorkingRenderer() {
panel.setLayout(new BoxLayout(panel, BoxLayout.X_AXIS));
//panel.setOpaque(false);
}
@Override
public Component getListCellRendererComponent(JList list, Object value,
int index, boolean isSelected, boolean cellHasFocus) {
JLabel c = (JLabel) super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
c.setMaximumSize(new Dimension(Short.MAX_VALUE, Short.MAX_VALUE));
panel.removeAll();
panel.add(c);
panel.revalidate();
panel.repaint();
return panel;
}
}