ConvertHTMLDialog.java

import javax.swing.*;
import java.awt.*; // FlowLayout

// not tested
public class ConvertHTMLDialog extends JDialog {

 // widgets
 JLabel fileLabel;
 JComboBox fileComboBox;
 JButton okButton;
 FlowLayout mainLayout;

 ConvertHTMLDialog () {
 super(); // invoke parent constructor

 // widgets
 this.fileLabel = new JLabel();
 this.fileLabel.setText("Select HTML file to convert");
 String[] cbItems = ConvertHTMLDialog.getCbItems();
 this.fileComboBox = new JComboBox(cbItems);
 this.okButton = new JButton();
 this.okButton.setText("OK");

 // layout
 this.mainLayout = new FlowLayout();
 this.setLayout(this.mainLayout);
 this.add(this.fileLabel);
 this.add(this.fileComboBox);
 this.add(this.okButton);

 // event listeners
 this.okButton.addActionListener((event) -> this.onOKButtonPressed());

 // frame
 ImageIcon logo = new ImageIcon("images/icon.png");
 this.setIconImage(logo.getImage());
 this.setTitle("Select HTML Bracket");
 this.setSize(400, 500);
 }

 void onOKButtonPressed () {
 // todo
 }

 static String[] getCbItems() {
 String[] cbItems = {"french_open.html", "rogers.html", "atp_finals.html"}; // todo: get proper items
 return cbItems;
 }
}