Getting Started with Swing

Java | Sunday, 1 January 2017

Swing is a GUI widget toolkit for Java. It is part of Oracle’s Java Foundation Classes (JFC) – an API for providing a graphical user interface (GUI) for Java programs.

Swing was developed to provide a more sophisticated set of GUI components than the earlier Abstract Window Toolkit (AWT). Swing provides a native look and feel that emulates the look and feel of several platforms, and also supports a pluggable look and feel that allows applications to have a look and feel unrelated to the underlying platform. It has more powerful and flexible components than AWT. In addition to familiar components such as buttons, check boxes and labels, Swing provides several advanced components such as tabbed panel, scroll panes, trees, tables, and lists.

Hello World

import javax.swing.JFrame;
import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				JFrame frame = new JFrame("Hello World");
				frame.setSize(600, 500);
				frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
				frame.setVisible(true);
			}
		});	
	}

}

Border Layout and Text Areas

import java.awt.BorderLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;

public class MainFrame extends JFrame {
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private JTextArea textArea;
	private JButton btn;
	
	public MainFrame() {
		super("Hello World");
		
		setLayout(new BorderLayout());
		
		textArea = new JTextArea();
		btn = new JButton("Click Me!");
		
		add(textArea, BorderLayout.CENTER);
		add(btn, BorderLayout.SOUTH);
		
		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

Button Clicks

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;


public class MainFrame extends JFrame {
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private JButton btn;
	private JTextArea textArea;
	
	public MainFrame() {
		super("Hello World");
		
		setLayout(new BorderLayout());
		
		btn = new JButton("Click me");
		textArea = new JTextArea();
		
		btn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				textArea.append("Hello\n");
			}
		});
		
		add(textArea, BorderLayout.CENTER);
		add(btn, BorderLayout.SOUTH);
		
		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

Custom Components

import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;


public class TextPanel extends JPanel {
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private JTextArea textArea;
	
	public TextPanel() {
		textArea = new JTextArea();
		
		setLayout(new BorderLayout());
		
		add(new JScrollPane(textArea), BorderLayout.CENTER);
	}
	
	public void appendText(String text) {
		textArea.append(text);
	}
}

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;

public class MainFrame extends JFrame {
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private JButton btn;
	private TextPanel textPanel;
	
	public MainFrame() {
		super("Hello World");
		
		setLayout(new BorderLayout());
		
		btn = new JButton("Click me");
		textPanel = new TextPanel();
		
		btn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				textPanel.appendText("Hello\n");
			}
		});
		
		add(textPanel, BorderLayout.CENTER);
		add(btn, BorderLayout.SOUTH);
		
		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

Simple Toolbars

import java.awt.FlowLayout;
import javax.swing.JButton;
import javax.swing.JPanel;


public class Toolbar extends JPanel {
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private JButton helloButton;
	private JButton goodbyeButton;
	
	public Toolbar() {
		helloButton = new JButton("Hello");
		goodbyeButton = new JButton("Goodbye");
		
		setLayout(new FlowLayout(FlowLayout.LEFT));
		
		add(helloButton);
		add(goodbyeButton);
	}
}

import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;


public class TextPanel extends JPanel {
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private JTextArea textArea;
	
	public TextPanel() {
		textArea = new JTextArea();
		
		setLayout(new BorderLayout());
		
		add(new JScrollPane(textArea), BorderLayout.CENTER);
	}
	
	public void appendText(String text) {
		textArea.append(text);
	}
}

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;

public class MainFrame extends JFrame {
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private JButton btn;
	private TextPanel textPanel;
	private Toolbar toolbar;
	
	public MainFrame() {
		super("Hello World");
		
		setLayout(new BorderLayout());
		
		toolbar = new Toolbar();
		btn = new JButton("Click me");
		textPanel = new TextPanel();
		
		btn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				textPanel.appendText("Hello\n");
			}
		});
		
		add(toolbar, BorderLayout.NORTH);
		add(textPanel, BorderLayout.CENTER);
		add(btn, BorderLayout.SOUTH);
		
		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

Communication

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JPanel;


public class Toolbar extends JPanel implements ActionListener {
	private static final long serialVersionUID = 1L;
	private JButton helloButton;
	private JButton goodbyeButton;
	
	private TextPanel textPanel;
	
	public Toolbar() {
		helloButton = new JButton("Hello");
		goodbyeButton = new JButton("Goodbye");
		
		helloButton.addActionListener(this);
		goodbyeButton.addActionListener(this);
		
		setLayout(new FlowLayout(FlowLayout.LEFT));
		
		add(helloButton);
		add(goodbyeButton);
	}
	
	public void setTextPanel(TextPanel textPanel) {
		this.textPanel = textPanel;
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		JButton clicked = (JButton)e.getSource();
		
		if(clicked == helloButton) {
			textPanel.appendText("Hello\n");
		}
		else if(clicked == goodbyeButton) {
			textPanel.appendText("Goodbye\n");
		}
		
	}
}

import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;


public class TextPanel extends JPanel {

	private static final long serialVersionUID = 1L;
	private JTextArea textArea;
	
	public TextPanel() {
		textArea = new JTextArea();
		
		setLayout(new BorderLayout());
		
		add(new JScrollPane(textArea), BorderLayout.CENTER);
	}
	
	public void appendText(String text) {
		textArea.append(text);
	}
}

import java.awt.BorderLayout;
import javax.swing.JFrame;

public class MainFrame extends JFrame {
	
	private static final long serialVersionUID = 1L;
	private TextPanel textPanel;
	private Toolbar toolbar;
	
	public MainFrame() {
		super("Hello World");
		
		setLayout(new BorderLayout());
		
		toolbar = new Toolbar();
		textPanel = new TextPanel();
		
		toolbar.setTextPanel(textPanel);
		
		add(toolbar, BorderLayout.NORTH);
		add(textPanel, BorderLayout.CENTER);
		
		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

Listeners

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JPanel;


public class Toolbar extends JPanel implements ActionListener {
	private static final long serialVersionUID = 1L;
	private JButton helloButton;
	private JButton goodbyeButton;
	
	private StringListener textListener;
	
	public Toolbar() {
		helloButton = new JButton("Hello");
		goodbyeButton = new JButton("Goodbye");
		
		helloButton.addActionListener(this);
		goodbyeButton.addActionListener(this);
		
		setLayout(new FlowLayout(FlowLayout.LEFT));
		
		add(helloButton);
		add(goodbyeButton);
	}
	
	public void setStringListener(StringListener listener) {
		this.textListener = listener;
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		JButton clicked = (JButton)e.getSource();
		
		if(clicked == helloButton) {
			if(textListener != null) {
				textListener.textEmitted("Hello\n");
			}
		}
		else if(clicked == goodbyeButton) {
			if(textListener != null) {
				textListener.textEmitted("Goodbye\n");
			}
		}
		
	}
}

import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;


public class TextPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JTextArea textArea;
	
	public TextPanel() {
		textArea = new JTextArea();
		
		setLayout(new BorderLayout());
		
		add(new JScrollPane(textArea), BorderLayout.CENTER);
	}
	
	public void appendText(String text) {
		textArea.append(text);
	}
}

public interface StringListener {
	public void textEmitted(String text);
}

import java.awt.BorderLayout;
import javax.swing.JFrame;

public class MainFrame extends JFrame {
	private static final long serialVersionUID = 1L;
	private TextPanel textPanel;
	private Toolbar toolbar;
	
	public MainFrame() {
		super("Hello World");
		
		setLayout(new BorderLayout());
		
		toolbar = new Toolbar();
		textPanel = new TextPanel();
		
		toolbar.setStringListener(new StringListener() {
			public void textEmitted(String text) {
				textPanel.appendText(text);
			}
		});
		
		add(toolbar, BorderLayout.NORTH);
		add(textPanel, BorderLayout.CENTER);
		
		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

Size

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JPanel;

public class Toolbar extends JPanel implements ActionListener {
	private static final long serialVersionUID = 1L;
	private JButton helloButton;
	private JButton goodbyeButton;
	
	private StringListener textListener;
	
	public Toolbar() {
		helloButton = new JButton("Hello");
		goodbyeButton = new JButton("Goodbye");
		
		helloButton.addActionListener(this);
		goodbyeButton.addActionListener(this);
		
		setLayout(new FlowLayout(FlowLayout.LEFT));
		
		add(helloButton);
		add(goodbyeButton);
	}
	
	public void setStringListener(StringListener listener) {
		this.textListener = listener;
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		JButton clicked = (JButton)e.getSource();
		
		if(clicked == helloButton) {
			if(textListener != null) {
				textListener.textEmitted("Hello\n");
			}
		}
		else if(clicked == goodbyeButton) {
			if(textListener != null) {
				textListener.textEmitted("Goodbye\n");
			}
		}
		
	}
}

import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;

public class TextPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JTextArea textArea;
	
	public TextPanel() {
		textArea = new JTextArea();
		
		setLayout(new BorderLayout());
		
		add(new JScrollPane(textArea), BorderLayout.CENTER);
	}
	
	public void appendText(String text) {
		textArea.append(text);
	}
}

public interface StringListener {
	public void textEmitted(String text);
}

import java.awt.BorderLayout;
import javax.swing.JFrame;

public class MainFrame extends JFrame {
	private static final long serialVersionUID = 1L;
	private TextPanel textPanel;
	private Toolbar toolbar;
	private FormPanel formPanel;
	
	public MainFrame() {
		super("Hello World");
		
		setLayout(new BorderLayout());
		
		toolbar = new Toolbar();
		textPanel = new TextPanel();
		formPanel = new FormPanel();
		
		toolbar.setStringListener(new StringListener() {
			public void textEmitted(String text) {
				textPanel.appendText(text);
			}
		});
		
		add(formPanel, BorderLayout.WEST);
		add(toolbar, BorderLayout.NORTH);
		add(textPanel, BorderLayout.CENTER);
		
		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import java.awt.Dimension;
import javax.swing.JPanel;


public class FormPanel extends JPanel {
	private static final long serialVersionUID = 1L;

	public FormPanel() {
		Dimension dim = getPreferredSize();
		dim.width = 250;
		setPreferredSize(dim);
	}
}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

Borders

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JPanel;


public class Toolbar extends JPanel implements ActionListener {
	private static final long serialVersionUID = 1L;
	private JButton helloButton;
	private JButton goodbyeButton;
	
	private StringListener textListener;
	
	public Toolbar() {
		setBorder(BorderFactory.createEtchedBorder());
		
		helloButton = new JButton("Hello");
		goodbyeButton = new JButton("Goodbye");
		
		helloButton.addActionListener(this);
		goodbyeButton.addActionListener(this);
		
		setLayout(new FlowLayout(FlowLayout.LEFT));
		
		add(helloButton);
		add(goodbyeButton);
	}
	
	public void setStringListener(StringListener listener) {
		this.textListener = listener;
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		JButton clicked = (JButton)e.getSource();
		
		if(clicked == helloButton) {
			if(textListener != null) {
				textListener.textEmitted("Hello\n");
			}
		}
		else if(clicked == goodbyeButton) {
			if(textListener != null) {
				textListener.textEmitted("Goodbye\n");
			}
		}
		
	}
}

import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;


public class TextPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JTextArea textArea;
	
	public TextPanel() {
		textArea = new JTextArea();
		
		setLayout(new BorderLayout());
		
		add(new JScrollPane(textArea), BorderLayout.CENTER);
	}
	
	public void appendText(String text) {
		textArea.append(text);
	}
}

public interface StringListener {
	public void textEmitted(String text);
}

import java.awt.BorderLayout;
import javax.swing.JFrame;


public class MainFrame extends JFrame {
	private static final long serialVersionUID = 1L;
	private TextPanel textPanel;
	private Toolbar toolbar;
	private FormPanel formPanel;
	
	public MainFrame() {
		super("Hello World");
		
		setLayout(new BorderLayout());
		
		toolbar = new Toolbar();
		textPanel = new TextPanel();
		formPanel = new FormPanel();
		
		toolbar.setStringListener(new StringListener() {
			public void textEmitted(String text) {
				textPanel.appendText(text);
			}
		});
		
		add(formPanel, BorderLayout.WEST);
		add(toolbar, BorderLayout.NORTH);
		add(textPanel, BorderLayout.CENTER);
		
		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import java.awt.Dimension;
import javax.swing.BorderFactory;
import javax.swing.JPanel;
import javax.swing.border.Border;


public class FormPanel extends JPanel {
	private static final long serialVersionUID = 1L;

	public FormPanel() {
		Dimension dim = getPreferredSize();
		dim.width = 250;
		setPreferredSize(dim);
		
		Border innerBorder = BorderFactory.createTitledBorder("Add Person");
		Border outerBorder = BorderFactory.createEmptyBorder(5, 5, 5, 5);
		setBorder(BorderFactory.createCompoundBorder(outerBorder, innerBorder));
	}
}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

Text Fields and Labels

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JPanel;

public class Toolbar extends JPanel implements ActionListener {
	private static final long serialVersionUID = 1L;
	private JButton helloButton;
	private JButton goodbyeButton;
	
	private StringListener textListener;
	
	public Toolbar() {
		setBorder(BorderFactory.createEtchedBorder());
		
		helloButton = new JButton("Hello");
		goodbyeButton = new JButton("Goodbye");
		
		helloButton.addActionListener(this);
		goodbyeButton.addActionListener(this);
		
		setLayout(new FlowLayout(FlowLayout.LEFT));
		
		add(helloButton);
		add(goodbyeButton);
	}
	
	public void setStringListener(StringListener listener) {
		this.textListener = listener;
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		JButton clicked = (JButton)e.getSource();
		
		if(clicked == helloButton) {
			if(textListener != null) {
				textListener.textEmitted("Hello\n");
			}
		}
		else if(clicked == goodbyeButton) {
			if(textListener != null) {
				textListener.textEmitted("Goodbye\n");
			}
		}
		
	}
}

import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;

public class TextPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JTextArea textArea;
	
	public TextPanel() {
		textArea = new JTextArea();
		
		setLayout(new BorderLayout());
		
		add(new JScrollPane(textArea), BorderLayout.CENTER);
	}
	
	public void appendText(String text) {
		textArea.append(text);
	}
}

public interface StringListener {
	public void textEmitted(String text);
}

import java.awt.BorderLayout;
import javax.swing.JFrame;

public class MainFrame extends JFrame {
	private static final long serialVersionUID = 1L;
	private TextPanel textPanel;
	private Toolbar toolbar;
	private FormPanel formPanel;
	
	public MainFrame() {
		super("Hello World");
		
		setLayout(new BorderLayout());
		
		toolbar = new Toolbar();
		textPanel = new TextPanel();
		formPanel = new FormPanel();
		
		toolbar.setStringListener(new StringListener() {
			public void textEmitted(String text) {
				textPanel.appendText(text);
			}
		});
		
		add(formPanel, BorderLayout.WEST);
		add(toolbar, BorderLayout.NORTH);
		add(textPanel, BorderLayout.CENTER);
		
		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import java.awt.Dimension;
import javax.swing.BorderFactory;
import javax.swing.JPanel;
import javax.swing.border.Border;

public class FormPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	
	public FormPanel() {
		Dimension dim = getPreferredSize();
		dim.width = 250;
		setPreferredSize(dim);
		
		Border innerBorder = BorderFactory.createTitledBorder("Add Person");
		Border outerBorder = BorderFactory.createEmptyBorder(5, 5, 5, 5);
		setBorder(BorderFactory.createCompoundBorder(outerBorder, innerBorder));
	}
}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

GridBagLayout

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JPanel;


public class Toolbar extends JPanel implements ActionListener {
	private static final long serialVersionUID = 1L;
	private JButton helloButton;
	private JButton goodbyeButton;
	
	private StringListener textListener;
	
	public Toolbar() {
		setBorder(BorderFactory.createEtchedBorder());
		
		helloButton = new JButton("Hello");
		goodbyeButton = new JButton("Goodbye");
		
		helloButton.addActionListener(this);
		goodbyeButton.addActionListener(this);
		
		setLayout(new FlowLayout(FlowLayout.LEFT));
		
		add(helloButton);
		add(goodbyeButton);
	}
	
	public void setStringListener(StringListener listener) {
		this.textListener = listener;
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		JButton clicked = (JButton)e.getSource();
		
		if(clicked == helloButton) {
			if(textListener != null) {
				textListener.textEmitted("Hello\n");
			}
		}
		else if(clicked == goodbyeButton) {
			if(textListener != null) {
				textListener.textEmitted("Goodbye\n");
			}
		}
		
	}
}

import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;


public class TextPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JTextArea textArea;
	
	public TextPanel() {
		textArea = new JTextArea();
		
		setLayout(new BorderLayout());
		
		add(new JScrollPane(textArea), BorderLayout.CENTER);
	}
	
	public void appendText(String text) {
		textArea.append(text);
	}
}

public interface StringListener {
	public void textEmitted(String text);
}

import java.awt.BorderLayout;
import javax.swing.JFrame;


public class MainFrame extends JFrame {
	private static final long serialVersionUID = 1L;
	private TextPanel textPanel;
	private Toolbar toolbar;
	private FormPanel formPanel;
	
	public MainFrame() {
		super("Hello World");
		
		setLayout(new BorderLayout());
		
		toolbar = new Toolbar();
		textPanel = new TextPanel();
		formPanel = new FormPanel();
		
		toolbar.setStringListener(new StringListener() {
			public void textEmitted(String text) {
				textPanel.appendText(text);
			}
		});
		
		add(formPanel, BorderLayout.WEST);
		add(toolbar, BorderLayout.NORTH);
		add(textPanel, BorderLayout.CENTER);
		
		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.Border;


public class FormPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JLabel nameLabel;
	private JLabel occupationLabel;
	private JTextField nameField;
	private JTextField occupationField;
	private JButton okBtn;
	
	public FormPanel() {
		Dimension dim = getPreferredSize();
		dim.width = 250;
		setPreferredSize(dim);
		
		nameLabel = new JLabel("Name: ");
		occupationLabel = new JLabel("Occupation: ");
		nameField = new JTextField(10);
		occupationField = new JTextField(10);
		
		okBtn = new JButton("OK");
		
		Border innerBorder = BorderFactory.createTitledBorder("Add Person");
		Border outerBorder = BorderFactory.createEmptyBorder(5, 5, 5, 5);
		setBorder(BorderFactory.createCompoundBorder(outerBorder, innerBorder));
		
		setLayout(new GridBagLayout());
		
		GridBagConstraints gc = new GridBagConstraints();
		
		
		//////////// First row ///////////////////////////////////
		
		gc.weightx = 1;
		gc.weighty = 0.1;
		
		gc.gridx = 0;
		gc.gridy = 0;
		gc.fill = GridBagConstraints.NONE;
		gc.anchor = GridBagConstraints.LINE_END;
		gc.insets = new Insets(0, 0, 0, 5);
		add(nameLabel, gc);
		
		gc.gridx = 1;
		gc.gridy = 0;
		gc.insets = new Insets(0, 0, 0, 0);
		gc.anchor = GridBagConstraints.LINE_START;
		add(nameField, gc);
		
		////////////Second row ///////////////////////////////////
		
		gc.weightx = 1;
		gc.weighty = 0.1;
		
		gc.gridy = 1;
		gc.gridx = 0;
		gc.insets = new Insets(0, 0, 0, 5);
		gc.anchor = GridBagConstraints.LINE_END;
		add(occupationLabel, gc);
		
		gc.gridy = 1;
		gc.gridx = 1;
		gc.insets = new Insets(0, 0, 0, 0);
		gc.anchor = GridBagConstraints.LINE_START;
		add(occupationField, gc);
		
		////////////Third row ///////////////////////////////////
		
		gc.weightx = 1;
		gc.weighty = 2.0;
		
		gc.gridy = 2;
		gc.gridx = 1;
		gc.anchor = GridBagConstraints.FIRST_LINE_START;
		gc.insets = new Insets(0, 0, 0, 0);
		add(okBtn, gc);
		
		
	}
}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

Events

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JPanel;


public class Toolbar extends JPanel implements ActionListener {
	private static final long serialVersionUID = 1L;
	private JButton helloButton;
	private JButton goodbyeButton;
	
	private StringListener textListener;
	
	public Toolbar() {
		setBorder(BorderFactory.createEtchedBorder());
		
		helloButton = new JButton("Hello");
		goodbyeButton = new JButton("Goodbye");
		
		helloButton.addActionListener(this);
		goodbyeButton.addActionListener(this);
		
		setLayout(new FlowLayout(FlowLayout.LEFT));
		
		add(helloButton);
		add(goodbyeButton);
	}
	
	public void setStringListener(StringListener listener) {
		this.textListener = listener;
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		JButton clicked = (JButton)e.getSource();
		
		if(clicked == helloButton) {
			if(textListener != null) {
				textListener.textEmitted("Hello\n");
			}
		}
		else if(clicked == goodbyeButton) {
			if(textListener != null) {
				textListener.textEmitted("Goodbye\n");
			}
		}
		
	}
}

import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;


public class TextPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JTextArea textArea;
	
	public TextPanel() {
		textArea = new JTextArea();
		
		setLayout(new BorderLayout());
		
		add(new JScrollPane(textArea), BorderLayout.CENTER);
	}
	
	public void appendText(String text) {
		textArea.append(text);
	}
}

public interface StringListener {
	public void textEmitted(String text);
}

import java.awt.BorderLayout;
import javax.swing.JFrame;

public class MainFrame extends JFrame {
	private static final long serialVersionUID = 1L;
	private TextPanel textPanel;
	private Toolbar toolbar;
	private FormPanel formPanel;
	
	public MainFrame() {
		super("Hello World");
		
		setLayout(new BorderLayout());
		
		toolbar = new Toolbar();
		textPanel = new TextPanel();
		formPanel = new FormPanel();
		
		toolbar.setStringListener(new StringListener() {
			public void textEmitted(String text) {
				textPanel.appendText(text);
			}
		});
		
		formPanel.setFormListener(new FormListener() {
			public void formEventOccurred(FormEvent e) {
				String name = e.getName();
				String occupation = e.getOccupation();
				
				textPanel.appendText(name + ": " + occupation + "\n");
			}
		});
		
		add(formPanel, BorderLayout.WEST);
		add(toolbar, BorderLayout.NORTH);
		add(textPanel, BorderLayout.CENTER);
		
		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.Border;


public class FormPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JLabel nameLabel;
	private JLabel occupationLabel;
	private JTextField nameField;
	private JTextField occupationField;
	private JButton okBtn;
	private FormListener formListener;
	
	public FormPanel() {
		Dimension dim = getPreferredSize();
		dim.width = 250;
		setPreferredSize(dim);
		
		nameLabel = new JLabel("Name: ");
		occupationLabel = new JLabel("Occupation: ");
		nameField = new JTextField(10);
		occupationField = new JTextField(10);
		
		okBtn = new JButton("OK");
		
		okBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				String name = nameField.getText();
				String occupation = occupationField.getText();
				
				FormEvent ev = new FormEvent(this, name, occupation);
				
				if(formListener != null) {
					formListener.formEventOccurred(ev);
				}
			}
		});
		
		Border innerBorder = BorderFactory.createTitledBorder("Add Person");
		Border outerBorder = BorderFactory.createEmptyBorder(5, 5, 5, 5);
		setBorder(BorderFactory.createCompoundBorder(outerBorder, innerBorder));
		
		setLayout(new GridBagLayout());
		
		GridBagConstraints gc = new GridBagConstraints();
		
		
		//////////// First row ///////////////////////////////////
		
		gc.weightx = 1;
		gc.weighty = 0.1;
		
		gc.gridx = 0;
		gc.gridy = 0;
		gc.fill = GridBagConstraints.NONE;
		gc.anchor = GridBagConstraints.LINE_END;
		gc.insets = new Insets(0, 0, 0, 5);
		add(nameLabel, gc);
		
		gc.gridx = 1;
		gc.gridy = 0;
		gc.insets = new Insets(0, 0, 0, 0);
		gc.anchor = GridBagConstraints.LINE_START;
		add(nameField, gc);
		
		////////////Second row ///////////////////////////////////
		
		gc.weightx = 1;
		gc.weighty = 0.1;
		
		gc.gridy = 1;
		gc.gridx = 0;
		gc.insets = new Insets(0, 0, 0, 5);
		gc.anchor = GridBagConstraints.LINE_END;
		add(occupationLabel, gc);
		
		gc.gridy = 1;
		gc.gridx = 1;
		gc.insets = new Insets(0, 0, 0, 0);
		gc.anchor = GridBagConstraints.LINE_START;
		add(occupationField, gc);
		
		////////////Third row ///////////////////////////////////
		
		gc.weightx = 1;
		gc.weighty = 2.0;
		
		gc.gridy = 2;
		gc.gridx = 1;
		gc.anchor = GridBagConstraints.FIRST_LINE_START;
		gc.insets = new Insets(0, 0, 0, 0);
		add(okBtn, gc);
	}
	
	public void setFormListener(FormListener listener) {
		this.formListener = listener;
	}
}

import java.util.EventListener;

public interface FormListener extends EventListener {
	public void formEventOccurred(FormEvent e);
}

import java.util.EventObject;

public class FormEvent extends EventObject {
	private static final long serialVersionUID = 1L;
	private String name;
	private String occupation;

	public FormEvent(Object source) {
		super(source);
	}
	
	public FormEvent(Object source, String name, String occupation) {
		super(source);
		
		this.name = name;
		this.occupation = occupation;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getOccupation() {
		return occupation;
	}

	public void setOccupation(String occupation) {
		this.occupation = occupation;
	}
}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

List Boxes

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JPanel;

public class Toolbar extends JPanel implements ActionListener {
	private static final long serialVersionUID = 1L;
	private JButton helloButton;
	private JButton goodbyeButton;
	
	private StringListener textListener;
	
	public Toolbar() {
		setBorder(BorderFactory.createEtchedBorder());
		
		helloButton = new JButton("Hello");
		goodbyeButton = new JButton("Goodbye");
		
		helloButton.addActionListener(this);
		goodbyeButton.addActionListener(this);
		
		setLayout(new FlowLayout(FlowLayout.LEFT));
		
		add(helloButton);
		add(goodbyeButton);
	}
	
	public void setStringListener(StringListener listener) {
		this.textListener = listener;
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		JButton clicked = (JButton)e.getSource();
		
		if(clicked == helloButton) {
			if(textListener != null) {
				textListener.textEmitted("Hello\n");
			}
		}
		else if(clicked == goodbyeButton) {
			if(textListener != null) {
				textListener.textEmitted("Goodbye\n");
			}
		}
		
	}
}

import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;


public class TextPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JTextArea textArea;
	
	public TextPanel() {
		textArea = new JTextArea();
		
		setLayout(new BorderLayout());
		
		add(new JScrollPane(textArea), BorderLayout.CENTER);
	}
	
	public void appendText(String text) {
		textArea.append(text);
	}
}

public interface StringListener {
	public void textEmitted(String text);
}

import java.awt.BorderLayout;
import javax.swing.JFrame;


public class MainFrame extends JFrame {
	private static final long serialVersionUID = 1L;
	private TextPanel textPanel;
	private Toolbar toolbar;
	private FormPanel formPanel;
	
	public MainFrame() {
		super("Hello World");
		
		setLayout(new BorderLayout());
		
		toolbar = new Toolbar();
		textPanel = new TextPanel();
		formPanel = new FormPanel();
		
		toolbar.setStringListener(new StringListener() {
			public void textEmitted(String text) {
				textPanel.appendText(text);
			}
		});
		
		formPanel.setFormListener(new FormListener() {
			public void formEventOccurred(FormEvent e) {
				String name = e.getName();
				String occupation = e.getOccupation();
				
				textPanel.appendText(name + ": " + occupation + "\n");
			}
		});
		
		add(formPanel, BorderLayout.WEST);
		add(toolbar, BorderLayout.NORTH);
		add(textPanel, BorderLayout.CENTER);
		
		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.Border;


public class FormPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JLabel nameLabel;
	private JLabel occupationLabel;
	private JTextField nameField;
	private JTextField occupationField;
	private JButton okBtn;
	private FormListener formListener;
	private JList ageList;
	
	public FormPanel() {
		Dimension dim = getPreferredSize();
		dim.width = 250;
		setPreferredSize(dim);
		
		nameLabel = new JLabel("Name: ");
		occupationLabel = new JLabel("Occupation: ");
		nameField = new JTextField(10);
		occupationField = new JTextField(10);
		ageList = new JList();
		
		DefaultListModel ageModel = new DefaultListModel();
		ageModel.addElement("Under 18");
		ageModel.addElement("18 to 65");
		ageModel.addElement("65 or over");
		ageList.setModel(ageModel);
		
		ageList.setPreferredSize(new Dimension(110, 70));
		ageList.setBorder(BorderFactory.createEtchedBorder());
		ageList.setSelectedIndex(1);
		
		okBtn = new JButton("OK");
		
		okBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				String name = nameField.getText();
				String occupation = occupationField.getText();
				String ageCat = (String)ageList.getSelectedValue();
				
				System.out.println(ageCat);
				
				FormEvent ev = new FormEvent(this, name, occupation);
				
				if(formListener != null) {
					formListener.formEventOccurred(ev);
				}
			}
		});
		
		Border innerBorder = BorderFactory.createTitledBorder("Add Person");
		Border outerBorder = BorderFactory.createEmptyBorder(5, 5, 5, 5);
		setBorder(BorderFactory.createCompoundBorder(outerBorder, innerBorder));
		
		setLayout(new GridBagLayout());
		
		GridBagConstraints gc = new GridBagConstraints();
		
		
		//////////// First row ///////////////////////////////////
		
		gc.weightx = 1;
		gc.weighty = 0.1;
		
		gc.gridx = 0;
		gc.gridy = 0;
		gc.fill = GridBagConstraints.NONE;
		gc.anchor = GridBagConstraints.LINE_END;
		gc.insets = new Insets(0, 0, 0, 5);
		add(nameLabel, gc);
		
		gc.gridx = 1;
		gc.gridy = 0;
		gc.insets = new Insets(0, 0, 0, 0);
		gc.anchor = GridBagConstraints.LINE_START;
		add(nameField, gc);
		
		////////////Second row ///////////////////////////////////
		
		gc.weightx = 1;
		gc.weighty = 0.1;
		
		gc.gridy = 1;
		gc.gridx = 0;
		gc.insets = new Insets(0, 0, 0, 5);
		gc.anchor = GridBagConstraints.LINE_END;
		add(occupationLabel, gc);
		
		gc.gridy = 1;
		gc.gridx = 1;
		gc.insets = new Insets(0, 0, 0, 0);
		gc.anchor = GridBagConstraints.LINE_START;
		add(occupationField, gc);
		
		////////////Third row ///////////////////////////////////
		
		gc.weightx = 1;
		gc.weighty = 0.2;
		
		gc.gridy = 2;
		gc.gridx = 1;
		gc.anchor = GridBagConstraints.FIRST_LINE_START;
		gc.insets = new Insets(0, 0, 0, 0);
		add(ageList, gc);
		
		////////////Fourth row ///////////////////////////////////
		
		gc.weightx = 1;
		gc.weighty = 2.0;
		
		gc.gridy = 3;
		gc.gridx = 1;
		gc.anchor = GridBagConstraints.FIRST_LINE_START;
		gc.insets = new Insets(0, 0, 0, 0);
		add(okBtn, gc);
	}
	
	public void setFormListener(FormListener listener) {
		this.formListener = listener;
	}
}

import java.util.EventListener;

public interface FormListener extends EventListener {
	public void formEventOccurred(FormEvent e);
}

import java.util.EventObject;

public class FormEvent extends EventObject {
	private static final long serialVersionUID = 1L;
	private String name;
	private String occupation;

	public FormEvent(Object source) {
		super(source);
	}
	
	public FormEvent(Object source, String name, String occupation) {
		super(source);
		
		this.name = name;
		this.occupation = occupation;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getOccupation() {
		return occupation;
	}

	public void setOccupation(String occupation) {
		this.occupation = occupation;
	}
}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

Working With List Data

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JPanel;


public class Toolbar extends JPanel implements ActionListener {
	private static final long serialVersionUID = 1L;
	private JButton helloButton;
	private JButton goodbyeButton;
	
	private StringListener textListener;
	
	public Toolbar() {
		setBorder(BorderFactory.createEtchedBorder());
		
		helloButton = new JButton("Hello");
		goodbyeButton = new JButton("Goodbye");
		
		helloButton.addActionListener(this);
		goodbyeButton.addActionListener(this);
		
		setLayout(new FlowLayout(FlowLayout.LEFT));
		
		add(helloButton);
		add(goodbyeButton);
	}
	
	public void setStringListener(StringListener listener) {
		this.textListener = listener;
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		JButton clicked = (JButton)e.getSource();
		
		if(clicked == helloButton) {
			if(textListener != null) {
				textListener.textEmitted("Hello\n");
			}
		}
		else if(clicked == goodbyeButton) {
			if(textListener != null) {
				textListener.textEmitted("Goodbye\n");
			}
		}
		
	}
}

import java.awt.BorderLayout;

import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;


public class TextPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JTextArea textArea;
	
	public TextPanel() {
		textArea = new JTextArea();
		
		setLayout(new BorderLayout());
		
		add(new JScrollPane(textArea), BorderLayout.CENTER);
	}
	
	public void appendText(String text) {
		textArea.append(text);
	}
}

public interface StringListener {
	public void textEmitted(String text);
}

import java.awt.BorderLayout;
import javax.swing.JFrame;

public class MainFrame extends JFrame {
	private static final long serialVersionUID = 1L;
	private TextPanel textPanel;
	private Toolbar toolbar;
	private FormPanel formPanel;

	public MainFrame() {
		super("Hello World");

		setLayout(new BorderLayout());

		toolbar = new Toolbar();
		textPanel = new TextPanel();
		formPanel = new FormPanel();

		toolbar.setStringListener(new StringListener() {
			public void textEmitted(String text) {
				textPanel.appendText(text);
			}
		});

		formPanel.setFormListener(new FormListener() {
			public void formEventOccurred(FormEvent e) {
				String name = e.getName();
				String occupation = e.getOccupation();
				int ageCat = e.getAgeCategory();

				textPanel.appendText(name + ": " + occupation + ": " + ageCat
						+ "\n");
			}
		});

		add(formPanel, BorderLayout.WEST);
		add(toolbar, BorderLayout.NORTH);
		add(textPanel, BorderLayout.CENTER);

		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.BorderFactory;
import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.Border;


public class FormPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JLabel nameLabel;
	private JLabel occupationLabel;
	private JTextField nameField;
	private JTextField occupationField;
	private JButton okBtn;
	private FormListener formListener;
	private JList ageList;
	
	public FormPanel() {
		Dimension dim = getPreferredSize();
		dim.width = 250;
		setPreferredSize(dim);
		
		nameLabel = new JLabel("Name: ");
		occupationLabel = new JLabel("Occupation: ");
		nameField = new JTextField(10);
		occupationField = new JTextField(10);
		ageList = new JList();
		
		DefaultListModel ageModel = new DefaultListModel();
		ageModel.addElement(new AgeCategory(0, "Under 18"));
		ageModel.addElement(new AgeCategory(1, "18 to 65"));
		ageModel.addElement(new AgeCategory(2, "65 or over"));
		ageList.setModel(ageModel);
		
		ageList.setPreferredSize(new Dimension(110, 70));
		ageList.setBorder(BorderFactory.createEtchedBorder());
		ageList.setSelectedIndex(1);
		
		okBtn = new JButton("OK");
		
		okBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				String name = nameField.getText();
				String occupation = occupationField.getText();
				AgeCategory ageCat = (AgeCategory)ageList.getSelectedValue();
				
				System.out.println(ageCat.getId());
				
				FormEvent ev = new FormEvent(this, name, occupation, ageCat.getId());
				
				if(formListener != null) {
					formListener.formEventOccurred(ev);
				}
			}
		});
		
		Border innerBorder = BorderFactory.createTitledBorder("Add Person");
		Border outerBorder = BorderFactory.createEmptyBorder(5, 5, 5, 5);
		setBorder(BorderFactory.createCompoundBorder(outerBorder, innerBorder));
		
		setLayout(new GridBagLayout());
		
		GridBagConstraints gc = new GridBagConstraints();
		
		
		//////////// First row ///////////////////////////////////
		
		gc.weightx = 1;
		gc.weighty = 0.1;
		
		gc.gridx = 0;
		gc.gridy = 0;
		gc.fill = GridBagConstraints.NONE;
		gc.anchor = GridBagConstraints.LINE_END;
		gc.insets = new Insets(0, 0, 0, 5);
		add(nameLabel, gc);
		
		gc.gridx = 1;
		gc.gridy = 0;
		gc.insets = new Insets(0, 0, 0, 0);
		gc.anchor = GridBagConstraints.LINE_START;
		add(nameField, gc);
		
		////////////Second row ///////////////////////////////////
		
		gc.weightx = 1;
		gc.weighty = 0.1;
		
		gc.gridy = 1;
		gc.gridx = 0;
		gc.insets = new Insets(0, 0, 0, 5);
		gc.anchor = GridBagConstraints.LINE_END;
		add(occupationLabel, gc);
		
		gc.gridy = 1;
		gc.gridx = 1;
		gc.insets = new Insets(0, 0, 0, 0);
		gc.anchor = GridBagConstraints.LINE_START;
		add(occupationField, gc);
		
		////////////Third row ///////////////////////////////////
		
		gc.weightx = 1;
		gc.weighty = 0.2;
		
		gc.gridy = 2;
		gc.gridx = 1;
		gc.anchor = GridBagConstraints.FIRST_LINE_START;
		gc.insets = new Insets(0, 0, 0, 0);
		add(ageList, gc);
		
		////////////Fourth row ///////////////////////////////////
		
		gc.weightx = 1;
		gc.weighty = 2.0;
		
		gc.gridy = 3;
		gc.gridx = 1;
		gc.anchor = GridBagConstraints.FIRST_LINE_START;
		gc.insets = new Insets(0, 0, 0, 0);
		add(okBtn, gc);
	}
	
	public void setFormListener(FormListener listener) {
		this.formListener = listener;
	}
}

class AgeCategory {
	private int id;
	private String text;
	
	public AgeCategory(int id, String text) {
		this.id = id;
		this.text = text;
	}
	
	public String toString() {
		return text;
	}
	
	public int getId() {
		return id;
	}
}

import java.util.EventListener;

public interface FormListener extends EventListener {
	public void formEventOccurred(FormEvent e);
}

import java.util.EventObject;

public class FormEvent extends EventObject {
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private String name;
	private String occupation;
	private int ageCategory;

	public FormEvent(Object source) {
		super(source);
	}
	
	public FormEvent(Object source, String name, String occupation, int ageCat) {
		super(source);
		
		this.name = name;
		this.occupation = occupation;
		this.ageCategory = ageCat;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getOccupation() {
		return occupation;
	}

	public void setOccupation(String occupation) {
		this.occupation = occupation;
	}
	
	public int getAgeCategory() {
		return ageCategory;
	}
	

}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

Combo Boxes

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JPanel;


public class Toolbar extends JPanel implements ActionListener {
	private static final long serialVersionUID = 1L;
	private JButton helloButton;
	private JButton goodbyeButton;
	
	private StringListener textListener;
	
	public Toolbar() {
		setBorder(BorderFactory.createEtchedBorder());
		
		helloButton = new JButton("Hello");
		goodbyeButton = new JButton("Goodbye");
		
		helloButton.addActionListener(this);
		goodbyeButton.addActionListener(this);
		
		setLayout(new FlowLayout(FlowLayout.LEFT));
		
		add(helloButton);
		add(goodbyeButton);
	}
	
	public void setStringListener(StringListener listener) {
		this.textListener = listener;
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		JButton clicked = (JButton)e.getSource();
		
		if(clicked == helloButton) {
			if(textListener != null) {
				textListener.textEmitted("Hello\n");
			}
		}
		else if(clicked == goodbyeButton) {
			if(textListener != null) {
				textListener.textEmitted("Goodbye\n");
			}
		}
		
	}
}

import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;


public class TextPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JTextArea textArea;
	
	public TextPanel() {
		textArea = new JTextArea();
		
		setLayout(new BorderLayout());
		
		add(new JScrollPane(textArea), BorderLayout.CENTER);
	}
	
	public void appendText(String text) {
		textArea.append(text);
	}
}

public interface StringListener {
	public void textEmitted(String text);
}

import java.awt.BorderLayout;
import javax.swing.JFrame;

public class MainFrame extends JFrame {
	private static final long serialVersionUID = 1L;
	private TextPanel textPanel;
	private Toolbar toolbar;
	private FormPanel formPanel;

	public MainFrame() {
		super("Hello World");

		setLayout(new BorderLayout());

		toolbar = new Toolbar();
		textPanel = new TextPanel();
		formPanel = new FormPanel();

		toolbar.setStringListener(new StringListener() {
			public void textEmitted(String text) {
				textPanel.appendText(text);
			}
		});

		formPanel.setFormListener(new FormListener() {
			public void formEventOccurred(FormEvent e) {
				String name = e.getName();
				String occupation = e.getOccupation();
				int ageCat = e.getAgeCategory();
				String empCat = e.getEmploymentCategory();

				textPanel.appendText(name + ": " + occupation + ": " + ageCat
						+ ", " + empCat + "\n");
			}
		});

		add(formPanel, BorderLayout.WEST);
		add(toolbar, BorderLayout.NORTH);
		add(textPanel, BorderLayout.CENTER);

		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.DefaultComboBoxModel;
import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.Border;


public class FormPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JLabel nameLabel;
	private JLabel occupationLabel;
	private JTextField nameField;
	private JTextField occupationField;
	private JButton okBtn;
	private FormListener formListener;
	private JList ageList;
	private JComboBox empCombo;
	
	public FormPanel() {
		Dimension dim = getPreferredSize();
		dim.width = 250;
		setPreferredSize(dim);
		
		nameLabel = new JLabel("Name: ");
		occupationLabel = new JLabel("Occupation: ");
		nameField = new JTextField(10);
		occupationField = new JTextField(10);
		ageList = new JList();
		empCombo = new JComboBox();
		
		// Set up list box
		DefaultListModel ageModel = new DefaultListModel();
		ageModel.addElement(new AgeCategory(0, "Under 18"));
		ageModel.addElement(new AgeCategory(1, "18 to 65"));
		ageModel.addElement(new AgeCategory(2, "65 or over"));
		ageList.setModel(ageModel);
		
		ageList.setPreferredSize(new Dimension(110, 70));
		ageList.setBorder(BorderFactory.createEtchedBorder());
		ageList.setSelectedIndex(1);
		
		// Set up combo box.
		DefaultComboBoxModel empModel = new DefaultComboBoxModel();
		empModel.addElement("employed");
		empModel.addElement("self-employed");
		empModel.addElement("unemployed");
		empCombo.setModel(empModel);
		empCombo.setSelectedIndex(0);
		empCombo.setEditable(true);
		
		okBtn = new JButton("OK");
		
		okBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				String name = nameField.getText();
				String occupation = occupationField.getText();
				AgeCategory ageCat = (AgeCategory)ageList.getSelectedValue();
				String empCat = (String)empCombo.getSelectedItem();
	
				System.out.println(empCat);
				
				FormEvent ev = new FormEvent(this, name, occupation, ageCat.getId(), empCat);
				
				if(formListener != null) {
					formListener.formEventOccurred(ev);
				}
			}
		});
		
		Border innerBorder = BorderFactory.createTitledBorder("Add Person");
		Border outerBorder = BorderFactory.createEmptyBorder(5, 5, 5, 5);
		setBorder(BorderFactory.createCompoundBorder(outerBorder, innerBorder));

		layoutComponents();
	}
	
	public void layoutComponents() {
		
		setLayout(new GridBagLayout());
		
		GridBagConstraints gc = new GridBagConstraints();
		
		//////////// First row ///////////////////////////////////
		
		gc.gridy = 0;
		
		gc.weightx = 1;
		gc.weighty = 0.1;
		
		gc.gridx = 0;
		gc.fill = GridBagConstraints.NONE;
		gc.anchor = GridBagConstraints.LINE_END;
		gc.insets = new Insets(0, 0, 0, 5);
		add(nameLabel, gc);
		
		gc.gridx = 1;
		gc.gridy = 0;
		gc.insets = new Insets(0, 0, 0, 0);
		gc.anchor = GridBagConstraints.LINE_START;
		add(nameField, gc);
		
		////////////Second row ///////////////////////////////////
		
		gc.gridy++;
		
		gc.weightx = 1;
		gc.weighty = 0.1;
		
		gc.gridx = 0;
		gc.insets = new Insets(0, 0, 0, 5);
		gc.anchor = GridBagConstraints.LINE_END;
		add(occupationLabel, gc);
		
		gc.gridx = 1;
		gc.insets = new Insets(0, 0, 0, 0);
		gc.anchor = GridBagConstraints.LINE_START;
		add(occupationField, gc);
		
		////////////Next row ///////////////////////////////////
		
		gc.gridy++;
		
		gc.weightx = 1;
		gc.weighty = 0.2;
		
		gc.gridx = 0;
		gc.insets = new Insets(0, 0, 0, 5);
		gc.anchor = GridBagConstraints.FIRST_LINE_END;
		add(new JLabel("Age: "), gc);
		
		gc.gridx = 1;
		gc.anchor = GridBagConstraints.FIRST_LINE_START;
		gc.insets = new Insets(0, 0, 0, 0);
		add(ageList, gc);
		
		////////////Next row ///////////////////////////////////
		
		gc.gridy++;
		
		gc.weightx = 1;
		gc.weighty = 0.2;
		
		gc.gridx = 0;
		gc.insets = new Insets(0, 0, 0, 5);
		gc.anchor = GridBagConstraints.FIRST_LINE_END;
		add(new JLabel("Employment: "), gc);
		
		gc.gridx = 1;
		gc.anchor = GridBagConstraints.FIRST_LINE_START;
		gc.insets = new Insets(0, 0, 0, 0);
		add(empCombo, gc);
		
		////////////Next row ///////////////////////////////////
		
		gc.gridy++;
		
		gc.weightx = 1;
		gc.weighty = 2.0;
		
		gc.gridx = 1;
		gc.anchor = GridBagConstraints.FIRST_LINE_START;
		gc.insets = new Insets(0, 0, 0, 0);
		add(okBtn, gc);
	}
	
	public void setFormListener(FormListener listener) {
		this.formListener = listener;
	}
}

class AgeCategory {
	private int id;
	private String text;
	
	public AgeCategory(int id, String text) {
		this.id = id;
		this.text = text;
	}
	
	public String toString() {
		return text;
	}
	
	public int getId() {
		return id;
	}
}

import java.util.EventListener;

public interface FormListener extends EventListener {
	public void formEventOccurred(FormEvent e);
}

import java.util.EventObject;

public class FormEvent extends EventObject {
	private static final long serialVersionUID = 1L;
	private String name;
	private String occupation;
	private int ageCategory;
	private String empCat;

	public FormEvent(Object source) {
		super(source);
	}
	
	public FormEvent(Object source, String name, String occupation, int ageCat, String empCat) {
		super(source);
		
		this.name = name;
		this.occupation = occupation;
		this.ageCategory = ageCat;
		this.empCat = empCat;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getOccupation() {
		return occupation;
	}

	public void setOccupation(String occupation) {
		this.occupation = occupation;
	}
	
	public int getAgeCategory() {
		return ageCategory;
	}
	
	public String getEmploymentCategory() {
		return empCat;
	}

}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

Check Boxes

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JPanel;


public class Toolbar extends JPanel implements ActionListener {
	private static final long serialVersionUID = 1L;
	private JButton helloButton;
	private JButton goodbyeButton;
	
	private StringListener textListener;
	
	public Toolbar() {
		setBorder(BorderFactory.createEtchedBorder());
		
		helloButton = new JButton("Hello");
		goodbyeButton = new JButton("Goodbye");
		
		helloButton.addActionListener(this);
		goodbyeButton.addActionListener(this);
		
		setLayout(new FlowLayout(FlowLayout.LEFT));
		
		add(helloButton);
		add(goodbyeButton);
	}
	
	public void setStringListener(StringListener listener) {
		this.textListener = listener;
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		JButton clicked = (JButton)e.getSource();
		
		if(clicked == helloButton) {
			if(textListener != null) {
				textListener.textEmitted("Hello\n");
			}
		}
		else if(clicked == goodbyeButton) {
			if(textListener != null) {
				textListener.textEmitted("Goodbye\n");
			}
		}
		
	}
}

import java.awt.BorderLayout;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;


public class TextPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private JTextArea textArea;
	
	public TextPanel() {
		textArea = new JTextArea();
		
		setLayout(new BorderLayout());
		
		add(new JScrollPane(textArea), BorderLayout.CENTER);
	}
	
	public void appendText(String text) {
		textArea.append(text);
	}
}

public interface StringListener {
	public void textEmitted(String text);
}

import java.awt.BorderLayout;
import javax.swing.JFrame;

public class MainFrame extends JFrame {
	private static final long serialVersionUID = 1L;
	private TextPanel textPanel;
	private Toolbar toolbar;
	private FormPanel formPanel;

	public MainFrame() {
		super("Hello World");

		setLayout(new BorderLayout());

		toolbar = new Toolbar();
		textPanel = new TextPanel();
		formPanel = new FormPanel();

		toolbar.setStringListener(new StringListener() {
			public void textEmitted(String text) {
				textPanel.appendText(text);
			}
		});

		formPanel.setFormListener(new FormListener() {
			public void formEventOccurred(FormEvent e) {
				String name = e.getName();
				String occupation = e.getOccupation();
				int ageCat = e.getAgeCategory();
				String empCat = e.getEmploymentCategory();

				textPanel.appendText(name + ": " + occupation + ": " + ageCat
						+ ", " + empCat + "\n");
			}
		});

		add(formPanel, BorderLayout.WEST);
		add(toolbar, BorderLayout.NORTH);
		add(textPanel, BorderLayout.CENTER);

		setSize(600, 500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
}

import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.BorderFactory;
import javax.swing.DefaultComboBoxModel;
import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.Border;

public class FormPanel extends JPanel {

	private JLabel nameLabel;
	private JLabel occupationLabel;
	private JTextField nameField;
	private JTextField occupationField;
	private JButton okBtn;
	private FormListener formListener;
	private JList ageList;
	private JComboBox empCombo;
	private JCheckBox citizenCheck;
	private JTextField taxField;
	private JLabel taxLabel;

	public FormPanel() {
		Dimension dim = getPreferredSize();
		dim.width = 250;
		setPreferredSize(dim);

		nameLabel = new JLabel("Name: ");
		occupationLabel = new JLabel("Occupation: ");
		nameField = new JTextField(10);
		occupationField = new JTextField(10);
		ageList = new JList();
		empCombo = new JComboBox();
		citizenCheck = new JCheckBox();
		taxField = new JTextField(10);
		taxLabel = new JLabel("Tax ID: ");

		// Set up tax ID
		taxLabel.setEnabled(false);
		taxField.setEnabled(false);

		citizenCheck.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				boolean isTicked = citizenCheck.isSelected();
				taxLabel.setEnabled(isTicked);
				taxField.setEnabled(isTicked);
			}
		});

		// Set up list box
		DefaultListModel ageModel = new DefaultListModel();
		ageModel.addElement(new AgeCategory(0, "Under 18"));
		ageModel.addElement(new AgeCategory(1, "18 to 65"));
		ageModel.addElement(new AgeCategory(2, "65 or over"));
		ageList.setModel(ageModel);

		ageList.setPreferredSize(new Dimension(110, 70));
		ageList.setBorder(BorderFactory.createEtchedBorder());
		ageList.setSelectedIndex(1);

		// Set up combo box.
		DefaultComboBoxModel empModel = new DefaultComboBoxModel();
		empModel.addElement("employed");
		empModel.addElement("self-employed");
		empModel.addElement("unemployed");
		empCombo.setModel(empModel);
		empCombo.setSelectedIndex(0);
		empCombo.setEditable(true);

		okBtn = new JButton("OK");

		okBtn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				String name = nameField.getText();
				String occupation = occupationField.getText();
				AgeCategory ageCat = (AgeCategory) ageList.getSelectedValue();
				String empCat = (String) empCombo.getSelectedItem();
				String taxId = taxField.getText();
				boolean usCitizen = citizenCheck.isSelected();

				System.out.println(empCat);

				FormEvent ev = new FormEvent(this, name, occupation, ageCat
						.getId(), empCat, taxId, usCitizen);

				if (formListener != null) {
					formListener.formEventOccurred(ev);
				}
			}
		});

		Border innerBorder = BorderFactory.createTitledBorder("Add Person");
		Border outerBorder = BorderFactory.createEmptyBorder(5, 5, 5, 5);
		setBorder(BorderFactory.createCompoundBorder(outerBorder, innerBorder));

		layoutComponents();
	}

	public void layoutComponents() {

		setLayout(new GridBagLayout());

		GridBagConstraints gc = new GridBagConstraints();

		// ////////// First row ///////////////////////////////////

		gc.gridy = 0;

		gc.weightx = 1;
		gc.weighty = 0.1;

		gc.gridx = 0;
		gc.fill = GridBagConstraints.NONE;
		gc.anchor = GridBagConstraints.LINE_END;
		gc.insets = new Insets(0, 0, 0, 5);
		add(nameLabel, gc);

		gc.gridx = 1;
		gc.gridy = 0;
		gc.insets = new Insets(0, 0, 0, 0);
		gc.anchor = GridBagConstraints.LINE_START;
		add(nameField, gc);

		// //////////Second row ///////////////////////////////////

		gc.gridy++;

		gc.weightx = 1;
		gc.weighty = 0.1;

		gc.gridx = 0;
		gc.insets = new Insets(0, 0, 0, 5);
		gc.anchor = GridBagConstraints.LINE_END;
		add(occupationLabel, gc);

		gc.gridx = 1;
		gc.insets = new Insets(0, 0, 0, 0);
		gc.anchor = GridBagConstraints.LINE_START;
		add(occupationField, gc);

		// //////////Next row ///////////////////////////////////

		gc.gridy++;

		gc.weightx = 1;
		gc.weighty = 0.2;

		gc.gridx = 0;
		gc.insets = new Insets(0, 0, 0, 5);
		gc.anchor = GridBagConstraints.FIRST_LINE_END;
		add(new JLabel("Age: "), gc);

		gc.gridx = 1;
		gc.anchor = GridBagConstraints.FIRST_LINE_START;
		gc.insets = new Insets(0, 0, 0, 0);
		add(ageList, gc);

		// //////////Next row ///////////////////////////////////

		gc.gridy++;

		gc.weightx = 1;
		gc.weighty = 0.2;

		gc.gridx = 0;
		gc.insets = new Insets(0, 0, 0, 5);
		gc.anchor = GridBagConstraints.FIRST_LINE_END;
		add(new JLabel("Employment: "), gc);

		gc.gridx = 1;
		gc.anchor = GridBagConstraints.FIRST_LINE_START;
		gc.insets = new Insets(0, 0, 0, 0);
		add(empCombo, gc);

		// //////////Next row ///////////////////////////////////

		gc.gridy++;

		gc.weightx = 1;
		gc.weighty = 0.2;

		gc.gridx = 0;
		gc.insets = new Insets(0, 0, 0, 5);
		gc.anchor = GridBagConstraints.FIRST_LINE_END;
		add(new JLabel("US Citizen: "), gc);

		gc.gridx = 1;
		gc.anchor = GridBagConstraints.FIRST_LINE_START;
		gc.insets = new Insets(0, 0, 0, 0);
		add(citizenCheck, gc);

		// //////////Next row ///////////////////////////////////

		gc.gridy++;

		gc.weightx = 1;
		gc.weighty = 0.2;

		gc.gridx = 0;
		gc.insets = new Insets(0, 0, 0, 5);
		gc.anchor = GridBagConstraints.FIRST_LINE_END;
		add(taxLabel, gc);

		gc.gridx = 1;
		gc.anchor = GridBagConstraints.FIRST_LINE_START;
		gc.insets = new Insets(0, 0, 0, 0);
		add(taxField, gc);

		// //////////Next row ///////////////////////////////////

		gc.gridy++;

		gc.weightx = 1;
		gc.weighty = 2.0;

		gc.gridx = 1;
		gc.anchor = GridBagConstraints.FIRST_LINE_START;
		gc.insets = new Insets(0, 0, 0, 0);
		add(okBtn, gc);
	}

	public void setFormListener(FormListener listener) {
		this.formListener = listener;
	}
}

class AgeCategory {
	private int id;
	private String text;

	public AgeCategory(int id, String text) {
		this.id = id;
		this.text = text;
	}

	public String toString() {
		return text;
	}

	public int getId() {
		return id;
	}
}

import java.util.EventListener;

public interface FormListener extends EventListener {
	public void formEventOccurred(FormEvent e);
}

import java.util.EventObject;

public class FormEvent extends EventObject {
	private static final long serialVersionUID = 1L;
	private String name;
	private String occupation;
	private int ageCategory;
	private String empCat;
	private String taxId;
	private boolean usCitizen;

	public FormEvent(Object source) {
		super(source);
	}

	public FormEvent(Object source, String name, String occupation, int ageCat,
			String empCat, String taxId, boolean usCitizen) {
		super(source);

		this.name = name;
		this.occupation = occupation;
		this.ageCategory = ageCat;
		this.empCat = empCat;
		this.taxId = taxId;
		this.usCitizen = usCitizen;
	}

	public String getTaxId() {
		return taxId;
	}

	public boolean isUsCitizen() {
		return usCitizen;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getOccupation() {
		return occupation;
	}

	public void setOccupation(String occupation) {
		this.occupation = occupation;
	}

	public int getAgeCategory() {
		return ageCategory;
	}

	public String getEmploymentCategory() {
		return empCat;
	}

}

import javax.swing.SwingUtilities;

public class App {

	public static void main(String[] args) {
		
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MainFrame();
			}
		});	
	}

}

Andrei Pall

Linux Software Engineering

Getting Started with Swing

Getting Started with Swing

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