Main Class
public class Main {
public static void main(String[] args) {
new CredentialManager();
}
}
Main Window Class
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class CredentialManager extends JFrame implements ActionListener {
public CredentialManager() {
View.credentialManager.setSize(1200, 800);
View.credentialManager.setResizable(false);
View.credentialManager.setLayout(null);
View.credentialManager.setLocationRelativeTo(null);
View.credentialManager.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
View.credentialManager.setVisible(true);
View.btnCredentialManagerManageUser.setBounds(550, 50, 120, 30);
View.btnCredentialManagerSignOut.setBounds(50, 50, 95, 30);
View.listCredentials.setBounds(100,100, 75,75);
View.btnCredentialManagerManageUser.addActionListener(this);
View.btnCredentialManagerSignOut.addActionListener(this);
View.credentialManager.add(View.btnCredentialManagerManageUser);
View.credentialManager.add(View.btnCredentialManagerSignOut);
View.credentialManager.add(View.scrollPaneCredentials);
View.scrollPaneCredentials.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
View.listModelCredentials.addElement("Credential1");
View.listModelCredentials.addElement("Credential2");
View.listModelCredentials.addElement("Credential3");
View.listModelCredentials.addElement("Credential4");
View.listModelCredentials.addElement("Credential5");
View.listModelCredentials.addElement("Credential6");
}
@Override
public void actionPerformed(ActionEvent actionEvent) {
if (actionEvent.getSource().equals(View.btnCredentialManagerManageUser)) {
System.out.println("Manager");
} else if (actionEvent.getSource().equals(View.btnCredentialManagerSignOut)) {
System.out.println("Sign Out");
}
}
}
View Class with the Swing elements
import javax.swing.*;
public class View {
static JFrame credentialManager = new JFrame("Credential Manager");
static JButton btnCredentialManagerManageUser = new JButton("Manage User");
static JButton btnCredentialManagerSignOut = new JButton("Sign Out");
static DefaultListModel<String> listModelCredentials = new DefaultListModel<>();
static JList<String> listCredentials = new JList(listModelCredentials);
static JScrollPane scrollPaneCredentials = new JScrollPane(listCredentials);
}
When I execute the main class the list does not appear. I expect the main frame to contain the two button(which appears) and the list with the scrollbar but it does not appear. I have tried many things but any of them work.
A necessary premise, I don't understand the need of absolute positioning elements in Swing instead of using layout managers.
Said that, you try to position listCredentials, that is inside a scroll pane, instead of the scroll pane itself, so replace:
View.listCredentials.setBounds(100,100, 75,75);
with
View.scrollPaneCredentials.setBounds(100,100, 75,75);