Develop Reference

Setting Action Listener and changing background

I've created 3 buttons. They are each displayed twice in a JFrame. I'm having trouble changing the background of the frame. I've set ActionListeners but upon clicking, nothing is changing. May I ask for some help.
public class MyButtons extends JPanel {
public static JFrame frame;
private JButton Red = new JButton("Red");
private JButton Green = new JButton("Green");
private JButton Blue = new JButton("Blue");
public void InitializeButton()
{
Blue.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
frame.setBackground(Color.BLUE);
}
});
Green.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
frame.setBackground(Color.GREEN);
}
});
Red.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
frame.setBackground(Color.RED);
}
});
}
public MyButtons() {
InitializeButton();
add(Red);
add(Green);
add(Blue);
}
public static void main(String[] args) {
frame = new JFrame();
JPanel row1 = new MyButtons();
JPanel row2 = new MyButtons();
row1.setPreferredSize(new Dimension(250, 100));
row2.setPreferredSize(new Dimension(250, 100));
frame.setLayout(new GridLayout(3,2));
frame.add(row1);
frame.add(row2);
frame.pack();
frame.setVisible(true);
}
}

This code works, but probably not as you expected:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MyButtons extends JPanel {
//public static JFrame frame;
// static is rarely a solution of problems in a GUI. ToDo! Change!
static JPanel ui = new JPanel(new GridLayout(2, 0, 20, 20));
private JButton Red = new JButton("Red");
private JButton Green = new JButton("Green");
private JButton Blue = new JButton("Blue");
public void InitializeButton() {
Blue.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
ui.setBackground(Color.BLUE);
}
});
Green.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
ui.setBackground(Color.GREEN);
}
});
Red.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
ui.setBackground(Color.RED);
}
});
}
public MyButtons() {
InitializeButton();
add(Red);
add(Green);
add(Blue);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(250, 100);
}
public static void main(String[] args) {
JFrame frame = new JFrame();
JPanel row1 = new MyButtons();
JPanel row2 = new MyButtons();
//row1.setPreferredSize(new Dimension(250, 100));
//row2.setPreferredSize(new Dimension(250, 100));
//frame.setLayout(new GridLayout(3, 2,10,10));
ui.add(row1);
ui.add(row2);
frame.add(ui);
frame.pack();
frame.setVisible(true);
}
}
N.B. Please learn common Java nomenclature (naming conventions - e.g. EachWordUpperCaseClass, firstWordLowerCaseMethod(), firstWordLowerCaseAttribute unless it is an UPPER_CASE_CONSTANT) and use it consistently.

Updating cards in CardLayout

I need to make GUI which saves the user's input using a linked list and let him/her "browse" through the saved data. I made a simpler version of the code which I included below. My problem is how to "update" the buttons in the browse card after the user entered and saved a text.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class sampleDemo extends JPanel {
NodeSample newNode = new NodeSample();
SampleSave s = new SampleSave();
public static final String CARD_ADD = "Card Add";
public static final String CARD_BROWSE = "Card Browse";
public static CardLayout cardLayout = new CardLayout();
public static JPanel card = new JPanel(cardLayout);
public static sampleDemo sd = new sampleDemo();
public sampleDemo() {
WindowAdd wina = new WindowAdd();
card.add(wina, CARD_ADD);
WindowBrowse winb = new WindowBrowse();
card.add(winb, CARD_BROWSE);
setLayout(new BorderLayout());
add(card, BorderLayout.PAGE_END);
}
public static void createAndShowGUI() {
JPanel buttonPanel = new JPanel();
JButton addButton = new JButton("Add");
JButton browseButton = new JButton("Browse");
addButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
cardLayout.show(card, "Card Add");
}
});
browseButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
cardLayout.show(card, "Card Browse");
}
});
buttonPanel.add(addButton);
buttonPanel.add(browseButton);
JFrame frame = new JFrame("Sample Demo");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(buttonPanel, BorderLayout.PAGE_END);
frame.getContentPane().add(sd);
frame.setSize(300, 200);
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
class WindowAdd extends JPanel {
public ActionListener action;
public WindowAdd() {
init();
}
public void init() {
JTextField textField = new JTextField(10);
NodeSample newNode = new NodeSample();
JPanel content = new JPanel(new FlowLayout());
JButton saveButton = new JButton("Save");
saveButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
newNode.textContent = textField.getText();
s.insert(newNode);
}
});
content.add(textField);
content.add(saveButton);
textField.setText(null);
add(content);
}
}
class WindowBrowse extends JPanel {
public WindowBrowse() {
init();
}
public void init() {
setLayout(new GridLayout(1, 3));
JButton a = new JButton();
JButton b = new JButton();
JButton c = new JButton();
try {
a = new JButton(s.head.textContent);
b = new JButton(s.head.next.textContent);
c = new JButton(s.head.next.next.textContent);
}catch (NullPointerException e) {
//
}
add(a);
add(b);
add(c);
}
}
class NodeSample {
String textContent;
NodeSample next;
}
class SampleSave {
NodeSample head;
NodeSample tail;
public void insert(NodeSample add) {
if(head == null){
head = add;
tail = add;
}else {
add.next = head;
head = add;
}
}
}
}

In order to change the text on a JButton use something similar to this in your action listener
btn.setText(textfield.getText());
This will change the text of whatever button to the text entered in the textfield

Java Smileys Replacing String with Smiley

I'm writing a Chat program. I designed a mock-up gui with smileys where when the user clicks on a smiley(jbutton) it prints it onto a textpane. I managed to add an advanced feature where when a user types in ":)" and sends it, it inserts the smiley instead of the string - using the insertIcon() method. The problem I have is that it only prints the smiley once rather than multiple times. So if I type "Hi :) My name is Jack :)" it only inserts the icon ONCE. Any suggestions?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class SmileyTesterGUI extends JFrame {
JPanel main = new JPanel();
JPanel south = new JPanel();
JPanel messageCenter = new JPanel();
JPanel smileysNorth = new JPanel();
JTextField text;
JTextPane tPane;
Icon happy;
Icon smile;
Icon tongue;
Icon veryHappy;
Icon wink;
Icon laugh;
Icon sad;
Icon verySad;
Icon cry;
public SmileyTesterGUI() {
super("Smileys");
add(main);
main.setLayout(new BorderLayout());
main.add(south, BorderLayout.SOUTH);
south.setLayout(new BorderLayout());
south.add(messageCenter, BorderLayout.CENTER);
south.add(smileysNorth, BorderLayout.NORTH);
// textpane panel
tPane = new JTextPane();
JScrollPane sPane = new JScrollPane(tPane);
main.add(sPane);
tPane.setEditable(false);
// smileysPanel
smileysNorth.setLayout(new GridLayout(1, 0));
JButton smiley1 = new JButton();
JButton smiley2 = new JButton();
JButton smiley3 = new JButton();
JButton smiley4 = new JButton();
JButton smiley5 = new JButton();
JButton smiley6 = new JButton();
JButton smiley7 = new JButton();
JButton smiley8 = new JButton();
JButton smiley9 = new JButton();
smileysNorth.add(smiley1);
smileysNorth.add(smiley2);
smileysNorth.add(smiley3);
smileysNorth.add(smiley4);
smileysNorth.add(smiley5);
smileysNorth.add(smiley6);
smileysNorth.add(smiley7);
smileysNorth.add(smiley8);
smileysNorth.add(smiley9);
// set smileys(icon) to each button - pathed from personal directory
happy = new ImageIcon(getClass().getResource("smileys/Smile1.png"));
smiley1.setIcon(happy);
smile = new ImageIcon(getClass().getResource("smileys/Smile2.png"));
smiley2.setIcon(smile);
tongue = new ImageIcon(getClass().getResource("smileys/Smile3.png"));
smiley3.setIcon(tongue);
veryHappy = new ImageIcon(getClass().getResource("smileys/Smile4.png"));
smiley4.setIcon(veryHappy);
wink = new ImageIcon(getClass().getResource("smileys/Smile5.png"));
smiley5.setIcon(wink);
laugh = new ImageIcon(getClass().getResource("smileys/Smile6.png"));
smiley6.setIcon(laugh);
sad = new ImageIcon(getClass().getResource("smileys/Smile7.png"));
smiley7.setIcon(sad);
verySad = new ImageIcon(getClass().getResource("smileys/Smile8.png"));
smiley8.setIcon(verySad);
cry = new ImageIcon(getClass().getResource("smileys/Smile9.png"));
smiley9.setIcon(cry);
// smileys print on the textpane
smiley1.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
tPane.insertIcon(new ImageIcon(getClass().getResource(
"smileys/Smile1.png")));
}
});
smiley2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
tPane.insertIcon(new ImageIcon(getClass().getResource(
"smileys/Smile2.png")));
}
});
smiley3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
tPane.insertIcon(new ImageIcon(getClass().getResource(
"smileys/Smile3.png")));
}
});
smiley4.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
tPane.insertIcon(new ImageIcon(getClass().getResource(
"smileys/Smile4.png")));
}
});
smiley5.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
tPane.insertIcon(new ImageIcon(getClass().getResource(
"smileys/Smile5.png")));
}
});
smiley6.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
tPane.insertIcon(new ImageIcon(getClass().getResource(
"smileys/Smile6.png")));
}
});
smiley7.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
tPane.insertIcon(new ImageIcon(getClass().getResource(
"smileys/Smile7.png")));
}
});
smiley8.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
tPane.insertIcon(new ImageIcon(getClass().getResource(
"smileys/Smile8.png")));
}
});
smiley9.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
tPane.insertIcon(new ImageIcon(getClass().getResource(
"smileys/Smile9.png")));
}
});
// messagePanel
messageCenter.setLayout(new BorderLayout());
text = new JTextField();
JButton send = new JButton("Send");
messageCenter.add(text);
messageCenter.add(send, BorderLayout.EAST);
text.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
sendMessage();
}
});
send.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
sendMessage();
}
});
setLocation(500, 0);
setSize(600, 250);
}
public void sendMessage() {
String a = text.getText();
// tPane.setText(a);
// tPane.getText();
if (a.equals(":D")) {
tPane.insertIcon(veryHappy);
} else if (a.equals(":)")) {
tPane.insertIcon(smile);
} else if (a.equals(":(")) {
tPane.insertIcon(sad);
} else if (a.equalsIgnoreCase(":P")) {
tPane.insertIcon(tongue);
} else if (a.equals(";)")) {
tPane.insertIcon(wink);
}
text.setText(null);
text.requestFocus();
}
public static void main(String[] args) {
new SmileyTesterGUI().setVisible(true);
}
}

insertIcon() method of JTextPane uses selection (caret position in simplest case). So in your case you always replace the icon just once.
Your sendMessage() doesn't check multiple occurences of ":)" in the message. Use while loop obtaining indexes of the ":)" and for each index make it selected and then use insertIcon()

Changing a String data with Jbuttons in Java

I have a String called s
I have four JButtons b1 b2 b3 b4
By default String s is Hello World
b1 Makes String s toUpperCase
b2 Makes String s toLowerCase
b3 Allows user to change String
b4 Resets String to Hello World
When I run the program I have s set to Hello World but when I click my buttons the String is not changing to its new attribute.
import java.awt.EventQueue;
import java.awt.event.*;
import javax.swing.*;
public class Driver {
String s = "Hell World";
String up;
String low;
private JFrame f;
private JPanel p;
JFrame frame = new JFrame("Add Some Text");
JButton b1 = new JButton("Uppercase");
JButton b2 = new JButton("Lowercase");
JButton b3 = new JButton("New");
JButton b4 = new JButton("Reset");
JLabel jl = new JLabel(s);
public Driver () {
gui();
}
public void gui() {
f = new JFrame("Hello World");
p = new JPanel();
f.add(p);
p.setLayout(null);
p.add(b1);
p.add(b2);
p.add(b3);
p.add(b4);
p.add(jl);
b1.setLocation(27, 80);
b2.setLocation(300, 80);
b3.setLocation(27, 180);
b4.setLocation(300, 180);
jl.setLocation(240, 20);
b1.setSize(230, 80);
b2.setSize(230, 80);
b3.setSize(230, 80);
b4.setSize(230, 80);
jl.setSize(230, 20);
// pack the frame for better cross platform support
f.pack();
// Make it visible
f.setVisible(true);
f.setSize(560,300); // default size is 0,0
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
b1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e){
up = s.toUpperCase();
}
});
b2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e){
low = s.toLowerCase();
}
});
b3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e){
s = JOptionPane.showInputDialog(frame, "");
}
});
b4.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e){
s = "Hello World";
}
});
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
new Driver();
}
});
} // End main Method
} // End class Driver

You have to set the text to the label!
Try this:
b1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e){
jl.setText(s.toUpperCase());
}
});
b2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e){
jl.setText(s.toLowerCase());
}
});
b3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e){
s = JOptionPane.showInputDialog(frame, "");
jl.setText(s);
}
});
b4.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e){
jl.setText("Hello World");
}
});

Actually the String is changing, what happens here that you haven't update the JLabel with the new value for the String:
So your code should look like this:
b3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e){
s = JOptionPane.showInputDialog(frame, "");
jl.setText(s);
}
});
then add the following line in each Action ActionListener.
jl.setText(newValue);// newValue depends on what the ActionListener do.

Focus navigation in keyBinding

In my form, when i press ENTER button in my keyboard, the okAction() method should be invoke (and invoke perfectly).
My problem is in focus state, When i fill the text fields and then press the ENTER button, the okAction() didn't invoked, because the focus is on the second text field (not on the panel).
How fix this problem?
public class T3 extends JFrame implements ActionListener {
JButton cancelBtn, okBtn;
JLabel fNameLbl, lNameLbl, tempBtn;
JTextField fNameTf, lNameTf;
public T3() {
add(createForm(), BorderLayout.NORTH);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400, 500);
setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new T3();
}
});
}
public JPanel createForm() {
JPanel panel = new JPanel();
panel.getInputMap().put(KeyStroke.getKeyStroke("ENTER"), "Button");
panel.getActionMap().put("Button", new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
okAction();
}
});
okBtn = new JButton("Ok");
okBtn.addActionListener(this);
cancelBtn = new JButton("Cancel");
tempBtn = new JLabel();
fNameLbl = new JLabel("First Name");
lNameLbl = new JLabel("Last Name");
fNameTf = new JTextField(10);
fNameTf.setName("FnTF");
lNameTf = new JTextField(10);
lNameTf.setName("LnTF");
panel.add(fNameLbl);
panel.add(fNameTf);
panel.add(lNameLbl);
panel.add(lNameTf);
panel.add(okBtn);
panel.add(cancelBtn);
panel.add(tempBtn);
panel.setLayout(new SpringLayout());
SpringUtilities.makeCompactGrid(panel, 3, 2, 50, 10, 80, 60);
return panel;
}
private void okAction() {
if (fNameTf.getText().trim().length() != 0 && lNameTf.getText().trim().length() != 0) {
System.out.println("Data saved");
} else System.out.println("invalid data");
}
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == okBtn) {
okAction();
}
}
}

Declare a default button for your GUI's JRootPane:
public T3() {
//!! ..... etc...
setVisible(true);
getRootPane().setDefaultButton(okBtn);
}
In fact with a default button set, I don't see that you need to use key bindings.