I'm using a GridBagLayout
and have a JList
of my custom class. The JList
itself is shown as I expect, but the scroll bar doesn't appear. (My size of data is also larger than the size of my JList
.) I checked many of related links and all of them mentioned these 2 lines to do so, but it didn't work for me.
JScrollPane scrollPane = new JScrollPane(list);
add(scrollPane);
Full code:
import java.awt.Button;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Label;
import javax.swing.*;
public class UserPart extends JFrame {
Label messageL = new Label("Confirm an item for more options.");
Button confirmB = new Button("Confirm");
Button backB = new Button("Back");
DefaultListModel<User2> model;
public UserPart() {
JList<User2> list = new JList<User2>();
model = new DefaultListModel<User2>();
for (int i = 0; i < MainActivity2.arr.size(); i++) {
User2 u = new User2();
u.setForShow(i);
model.addElement(u);
}
// SETTING THE APPEARANCE OF THE JLIST
list.setModel(model);
list.setCellRenderer(new MyListCellRenderer());
list.setLayoutOrientation(JList.VERTICAL);
list.setPreferredSize(new Dimension(500, 750));
//////////////////////////////////////////////
GridBagLayout grid = new GridBagLayout();
GridBagConstraints gbc = new GridBagConstraints();
setLayout(grid);
setTitle("List of users");
GridBagLayout layout = new GridBagLayout();
this.setLayout(layout);
gbc.gridx = 0;
gbc.gridy = 0;
this.add(messageL, gbc);
gbc.gridx = 0;
gbc.gridy = 1;
this.add(list, gbc); //ADDED JLIST TO LAYOUT HERE
JScrollPane scrollPane = new JScrollPane(list); // DEFINED SCROLL BAR HERE
add(scrollPane); // ADDED SCROLL BAR TO LAYOUT HERE
setSize(1000, 1500);
setPreferredSize(getSize());
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
}
Set the constraints weight (weightx
, weighty
) to a value greater than zero - to use all the layout - also set fill
to BOTH
. Do not add the list directly to the frame, just add the scroll pane with the constraints set as explained above. Do not mix AWT components (Label
) with Swing ones, use JLabel
instead. Here the summary:
JLabel label = new JLabel("Confirm an item for more options.");
JScrollPane scroll = new JScrollPane(list);
GridBagConstraints gbc = new GridBagConstraints();
JFrame frame = new JFrame();
frame.setLayout(new GridBagLayout());
gbc.gridx = 0;
gbc.gridy = 0;
frame.add(label, gbc);
gbc.gridx = 0;
gbc.gridy = 1;
gbc.weightx = 1;
gbc.weighty = 1;
gbc.fill = GridBagConstraints.BOTH;
frame.add(scroll, gbc);