I have to create 5 Jlists in succession to make their backgrounds look in different colors. My existing code creates these 5 lists without the colors (the default JList). I understand that I can only customize the inside/border of a jlist and not the margin/padding around it? Or Am I wrong and is there a way to it?
Btw, The space above the list is a Jlabel (not shown in the pic above) and the layout managers in use are GroupLayout and GridBagLayout.
UPDATE
AT, as per your suggestion, here is a comparison to how the lists look like when surrounded by a jpanel. The lists in the back are the ones with the Jpanel surrounded with a minimal empty border of size 1.
The issue with creating a JPanel with preferredsize overridden is that the jlists are in horizontal jpanel and above them is another jpanel with labels. So, wrapping jlist in a jpanel is not going to do it.
Please do have a look at this code example. Is it closer to what you wanted, else you define the changes that needs to be done. I be on them as soon as I get the reply from your side :-)
Here is the outcome :
import java.awt.*;
import javax.swing.*;
public class JListExample
{
private JList<String> list1;
private JList<String> list2;
private JList<String> list3;
private JList<String> list4;
private JList<String> list5;
private CustomPanel panel1;
private CustomPanel panel2;
private CustomPanel panel3;
private CustomPanel panel4;
private CustomPanel panel5;
private String[] data = {"one", "two", "three", "four"};
private int width = 110;
private int height = 300;
private void displayGUI()
{
JFrame frame = new JFrame("JList Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel contentPane = new JPanel();
contentPane.setLayout(new GridLayout(0, 5, 2, 2));
GridBagConstraints gbc = new GridBagConstraints();
gbc.fill = GridBagConstraints.BOTH;
gbc.gridx = 0;
gbc.gridy = 1;
gbc.weightx = 1.0;
gbc.weighty = 0.9;
panel1 = new CustomPanel(width, height, Color.GRAY, "List 1");
list1 = new JList<String>(data);
panel1.add(list1, gbc);
panel2 = new CustomPanel(width, height,
Color.GREEN.brighter().brighter(), "List 2");
list2 = new JList<String>(data);
panel2.add(list2, gbc);
panel3 = new CustomPanel(width, height,
Color.ORANGE.brighter(), "List 3");
list3 = new JList<String>(data);
panel3.add(list3, gbc);
panel4 = new CustomPanel(width, height,
Color.BLUE.brighter(), "List 4");
list4 = new JList<String>(data);
panel4.add(list4, gbc);
panel5 = new CustomPanel(width, height, Color.RED, "List 5");
list5 = new JList<String>(data);
panel5.add(list5, gbc);
contentPane.add(panel1);
contentPane.add(panel2);
contentPane.add(panel3);
contentPane.add(panel4);
contentPane.add(panel5);
frame.setContentPane(contentPane);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new JListExample().displayGUI();
}
});
}
}
class CustomPanel extends JPanel
{
private final int GAP = 5;
private int width;
private int height;
private Color backgroundColour;
private JLabel titleLabel;
public CustomPanel(int w, int h, Color c, String title)
{
width = w;
height = h;
backgroundColour = c;
titleLabel = new JLabel(title, JLabel.CENTER);
setBackground(backgroundColour);
setBorder(
BorderFactory.createEmptyBorder(
GAP, GAP, GAP, GAP));
setLayout(new GridBagLayout());
titleLabel.setAlignmentX(JLabel.CENTER_ALIGNMENT);
GridBagConstraints gbc = new GridBagConstraints();
gbc.fill = GridBagConstraints.NONE;
gbc.gridx = 0;
gbc.gridy = 0;
gbc.weightx = 1.0;
gbc.weighty = 0.1;
add(titleLabel, gbc);
}
@Override
public Dimension getPreferredSize()
{
return (new Dimension(width, height));
}
}
**LATEST EDIT : **
As rightly pointed by @kleopatra (not something that is new for me :-)), too good judgement call. Done the edit related to that below :
import java.awt.*;
import javax.swing.*;
public class JListExample
{
private final int GAP = 5;
private JList<String> list1;
private JList<String> list2;
private JList<String> list3;
private JList<String> list4;
private JList<String> list5;
private JPanel panel1;
private JPanel panel2;
private JPanel panel3;
private JPanel panel4;
private JPanel panel5;
private String[] data = {"one", "two", "three", "four"};
private int width = 110;
private int height = 300;
private GridBagConstraints gbc = new GridBagConstraints();
private void displayGUI()
{
JFrame frame = new JFrame("JList Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel contentPane = new JPanel();
contentPane.setLayout(new GridLayout(0, 5, 2, 2));
panel1 = getPanel(Color.GRAY, "List 1");
list1 = new JList<String>(data);
panel2 = getPanel(Color.GREEN.brighter().brighter(), "List 2");
list2 = new JList<String>(data);
panel3 = getPanel(Color.ORANGE.brighter(), "List 3");
list3 = new JList<String>(data);
panel4 = getPanel(Color.BLUE.brighter(), "List 4");
list4 = new JList<String>(data);
panel5 = getPanel(Color.RED, "List 5");
list5 = new JList<String>(data);
gbc.fill = GridBagConstraints.BOTH;
gbc.gridx = 0;
gbc.gridy = 1;
gbc.weightx = 1.0;
gbc.weighty = 0.9;
panel1.add(list1, gbc);
panel2.add(list2, gbc);
panel3.add(list3, gbc);
panel4.add(list4, gbc);
panel5.add(list5, gbc);
contentPane.add(panel1);
contentPane.add(panel2);
contentPane.add(panel3);
contentPane.add(panel4);
contentPane.add(panel5);
frame.setContentPane(contentPane);
frame.setSize(610, 300);
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
private JPanel getPanel(Color c, String title)
{
JPanel panel = new JPanel();
panel.setOpaque(true);
panel.setBorder(
BorderFactory.createEmptyBorder(
GAP, GAP, GAP, GAP));
panel.setBackground(c);
panel.setLayout(new GridBagLayout());
JLabel label = new JLabel(title, JLabel.CENTER);
label.setAlignmentX(JLabel.CENTER_ALIGNMENT);
gbc.fill = GridBagConstraints.NONE;
gbc.gridx = 0;
gbc.gridy = 0;
gbc.weightx = 1.0;
gbc.weighty = 0.1;
panel.add(label, gbc);
return panel;
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new JListExample().displayGUI();
}
});
}
}
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