Java

button will not display

•

Join Date: Sep 2009

Posts: 10

Reputation: vortex24 is an unknown quantity at this point

Solved Threads: 2

vortex24

Offline

Newbie Poster

button will not display

Nov 4th, 2009

Hi, I am working on code to have a drop down menu from which you can pick items and add a button with that course. Unfortunetally, I can't get the button to display. And help is greatly appreciated.

 Help with Code Tags 
 Java Syntax (Toggle Plain Text) 
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
public class ComboBoxFrame extends JFrame {
	/***/ private static final long serialVersionUID = 1L;
 
	private JComboBox b;
	private String s;
	private int x = 0;
	private JButton g[] = new JButton[10];
 
	private String courses[] = 
		{ "Advanced Functions", "Calculus",  "Chemistry", "Physics" };
 
	public ComboBoxFrame() {
		super("Pick your courses!");
		setLayout(new GridLayout(3, 3));
 
		b = new JComboBox(courses);
 
		b.addItemListener( new ItemListener() {
			public void itemStateChanged(ItemEvent event) {
				if(event.getStateChange() == ItemEvent.SELECTED) {
					s = (String) b.getSelectedItem();
					g[x] = new JButton(s);
					add(g[x]);
					//g[x].addActionListener(this);
					x++; 
				} } } );
 
		add(b);
	}
 
/**	public void actionPerformed(ActionEvent e) {
		String s;
		for(int x = 0; x < 10; x++) {
			s = courses[x];
			if(e.getSource() == s) remove(g[x]);
		}
	}*/
 
	public static void main(String args[]) { 
		ComboBoxFrame comboBoxFrame = new ComboBoxFrame();
		comboBoxFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
	    comboBoxFrame.setSize( 350, 150 );
	    comboBoxFrame.setVisible( true );
	}
}
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class ComboBoxFrame extends JFrame {
	/***/ private static final long serialVersionUID = 1L;
	
	private JComboBox b;
	private String s;
	private int x = 0;
	private JButton g[] = new JButton[10];

	private String courses[] = 
		{ "Advanced Functions", "Calculus",  "Chemistry", "Physics" };

	public ComboBoxFrame() {
		super("Pick your courses!");
		setLayout(new GridLayout(3, 3));

		b = new JComboBox(courses);

		b.addItemListener( new ItemListener() {
			public void itemStateChanged(ItemEvent event) {
				if(event.getStateChange() == ItemEvent.SELECTED) {
					s = (String) b.getSelectedItem();
					g[x] = new JButton(s);
					add(g[x]);
					//g[x].addActionListener(this);
					x++; 
				} } } );
				
		add(b);
	}
	
/**	public void actionPerformed(ActionEvent e) {
		String s;
		for(int x = 0; x < 10; x++) {
			s = courses[x];
			if(e.getSource() == s) remove(g[x]);
		}
	}*/
	
	public static void main(String args[]) { 
		ComboBoxFrame comboBoxFrame = new ComboBoxFrame();
		comboBoxFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
	    comboBoxFrame.setSize( 350, 150 );
	    comboBoxFrame.setVisible( true );
	}
}

•

Join Date: Sep 2008

Posts: 2,226

Reputation: BestJewSinceJC is a splendid one to behold

Solved Threads: 273

BestJewSinceJC BestJewSinceJC is offline

Offline

Nearly a Posting Maven

Nov 4th, 2009

 Help with Code Tags 
 Java Syntax (Toggle Plain Text) 
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
public class ComboBoxFrame extends JFrame {
	/***/ private static final long serialVersionUID = 1L;
 
	private JComboBox b;
	private String s;
	private int x = 0;
	private JButton g[] = new JButton[10];
	private ComboBoxFrame me;
	private String courses[] = 
		{ "Advanced Functions", "Calculus",  "Chemistry", "Physics" };
 
	public ComboBoxFrame() {
		super("Pick your courses!");
		setLayout(new GridLayout(3, 3));
		me = this;
		b = new JComboBox(courses);
 
		b.addItemListener( new ItemListener() {
			public void itemStateChanged(ItemEvent event) {
				if(event.getStateChange() == ItemEvent.SELECTED) {
					s = (String) b.getSelectedItem();
					System.out.println(s);
					g[x] = new JButton(s);
					add(g[x]);
					me.validate();
					//g[x].addActionListener(this);
					x++; 
				} } } );
 
		add(b);
	}
 
/**	public void actionPerformed(ActionEvent e) {
		String s;
		for(int x = 0; x < 10; x++) {
			s = courses[x];
			if(e.getSource() == s) remove(g[x]);
		}
	}*/
 
	public static void main(String args[]) { 
		ComboBoxFrame comboBoxFrame = new ComboBoxFrame();
		comboBoxFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
	    comboBoxFrame.setSize( 350, 150 );
	    comboBoxFrame.setVisible( true );
	}
}
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class ComboBoxFrame extends JFrame {
	/***/ private static final long serialVersionUID = 1L;
	
	private JComboBox b;
	private String s;
	private int x = 0;
	private JButton g[] = new JButton[10];
	private ComboBoxFrame me;
	private String courses[] = 
		{ "Advanced Functions", "Calculus",  "Chemistry", "Physics" };

	public ComboBoxFrame() {
		super("Pick your courses!");
		setLayout(new GridLayout(3, 3));
		me = this;
		b = new JComboBox(courses);

		b.addItemListener( new ItemListener() {
			public void itemStateChanged(ItemEvent event) {
				if(event.getStateChange() == ItemEvent.SELECTED) {
					s = (String) b.getSelectedItem();
					System.out.println(s);
					g[x] = new JButton(s);
					add(g[x]);
					me.validate();
					//g[x].addActionListener(this);
					x++; 
				} } } );
				
		add(b);
	}
	
/**	public void actionPerformed(ActionEvent e) {
		String s;
		for(int x = 0; x < 10; x++) {
			s = courses[x];
			if(e.getSource() == s) remove(g[x]);
		}
	}*/
	
	public static void main(String args[]) { 
		ComboBoxFrame comboBoxFrame = new ComboBoxFrame();
		comboBoxFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
	    comboBoxFrame.setSize( 350, 150 );
	    comboBoxFrame.setVisible( true );
	}
}

Now try.

•

Join Date: Sep 2009

Posts: 10

Reputation: vortex24 is an unknown quantity at this point

Solved Threads: 2

vortex24

Offline

Newbie Poster

Nov 4th, 2009

Thanks! One more question; I am trying to get the button to remove itself when clicked, but I can't get it working. Here i tried to call the .remove() method and .repaint(), but I can't get it to remove itself. Some insight to the problem would be great, thanks in advance!

 Help with Code Tags 
 Java Syntax (Toggle Plain Text) 
import java.awt.*;
import java.awt.event.*;
 
import javax.swing.*;
 
public class ComboBoxFrame extends JFrame {
	/***/ private static final long serialVersionUID = 1L;
 
	private JComboBox b;
	private String s;
	private TextFieldHandler handler = new TextFieldHandler();
	private int x = 0;
	private JButton g[] = new JButton[10];
	private ComboBoxFrame me;
	private String courses[] = 
		{ "Advanced Functions", "Calculus",  "Chemistry", "Physics", "English", 
			"History", "Law",  "Politics", "Phys. Ed.", "Accounting" };
 
	public ComboBoxFrame() {
		super("Pick your courses!");
		setLayout(new GridLayout(3, 3));
		me = this;
		b = new JComboBox(courses);
 
		b.addItemListener( new ItemListener() {
			public void itemStateChanged(ItemEvent event) {
				if(event.getStateChange() == ItemEvent.SELECTED) {
					s = (String) b.getSelectedItem();
					System.out.println(s);
					g[x] = new JButton(s);
					g[x].setBorder(null);
					add(g[x]);
					me.validate();
					g[x].addActionListener(handler);
					x++;
				} } } );
 
		add(b);
	}
 
	private class TextFieldHandler implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			String s = "";
			for(int x = 0; x < 10; x++) {
				s = courses[x];
				if(e.getSource() == s) remove(g[x]);
			}
			me.repaint();
		}
	}
 
	public static void main(String args[]) { 
		ComboBoxFrame comboBoxFrame = new ComboBoxFrame();
		comboBoxFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
	    comboBoxFrame.setSize( 350, 150 );
	    comboBoxFrame.setVisible( true );
	}
}
import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

public class ComboBoxFrame extends JFrame {
	/***/ private static final long serialVersionUID = 1L;
	
	private JComboBox b;
	private String s;
	private TextFieldHandler handler = new TextFieldHandler();
	private int x = 0;
	private JButton g[] = new JButton[10];
	private ComboBoxFrame me;
	private String courses[] = 
		{ "Advanced Functions", "Calculus",  "Chemistry", "Physics", "English", 
			"History", "Law",  "Politics", "Phys. Ed.", "Accounting" };

	public ComboBoxFrame() {
		super("Pick your courses!");
		setLayout(new GridLayout(3, 3));
		me = this;
		b = new JComboBox(courses);

		b.addItemListener( new ItemListener() {
			public void itemStateChanged(ItemEvent event) {
				if(event.getStateChange() == ItemEvent.SELECTED) {
					s = (String) b.getSelectedItem();
					System.out.println(s);
					g[x] = new JButton(s);
					g[x].setBorder(null);
					add(g[x]);
					me.validate();
					g[x].addActionListener(handler);
					x++;
				} } } );
				
		add(b);
	}
	
	private class TextFieldHandler implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			String s = "";
			for(int x = 0; x < 10; x++) {
				s = courses[x];
				if(e.getSource() == s) remove(g[x]);
			}
			me.repaint();
		}
	}
	
	public static void main(String args[]) { 
		ComboBoxFrame comboBoxFrame = new ComboBoxFrame();
		comboBoxFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
	    comboBoxFrame.setSize( 350, 150 );
	    comboBoxFrame.setVisible( true );
	}
}

•

Join Date: Sep 2008

Posts: 2,226

Reputation: BestJewSinceJC is a splendid one to behold

Solved Threads: 273

BestJewSinceJC BestJewSinceJC is offline

Offline

Nearly a Posting Maven

Nov 5th, 2009

You need to register an ActionListener with the buttons as they are created, similarly to how you declared the ItemListener (with b.addItemListener). You can find examples of ActionListeners being used online, here is one similar to the ItemListener you used. http://www.javaprogrammingforums.com...ava-swing.html

In your actionPerformed method, you'd just use JFrame's remove() method on the button. So you'd use me.remove((JButton)event.getSource()) where event is the argument to the actionPerformed method.