I need to know how to add a JTextField if one of the JComboBox options is selected, and if the other one is selected I don't want to have that text field there any more.
Here is my code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class GUI extends JFrame{
//Not sure if this code is correct
private JTextField text;
private JComboBox box;
private static String[] selector = {"Option 1", "Option 2"};
public GUI(){
super("Title");
setLayout(new FlowLayout());
box = new JComboBox(selector);
add(box);
box.addItemListener(
new ItemListener(){
public void itemStateChanged(ItemEvent e){
if(){
//what should be in the if statement and what should i type down here to add the
//JTextField to the JFrame?
}
}
}
);
}
}
Try next example, that should help you:
import java.awt.BorderLayout;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class TestFrame extends JFrame {
public TestFrame(){
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
init();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
setVisible(true);
}
});
}
private void init() {
final JComboBox<String> box = new JComboBox<String>(new String[]{"1","2"});
final JTextField f = new JTextField(5);
box.addItemListener(new ItemListener() {
#Override
public void itemStateChanged(ItemEvent e) {
if(e.getStateChange() == ItemEvent.SELECTED){
f.setVisible("1".equals(box.getSelectedItem()));
TestFrame.this.revalidate();
TestFrame.this.repaint();
}
}
});
add(box,BorderLayout.SOUTH);
add(f,BorderLayout.NORTH);
}
public static void main(String... s){
new TestFrame();
}
}
Related
Everything looks ok to me but for some reason, nothing is showing up properly, maybe I missed something but I'm not sure why it's not working, can someone help me out?
** task **
Improve your program by adding two
combo boxes in the frame. Through the combo boxes, the user should be able to
select their preferred fonts and font sizes. The displayed text will then be updated
accordingly (see the figure below).
Here is what its suppose to look like
import javax.swing.*;
import java.awt.BorderLayout;
import java.awt.Dimension;
import javax.swing.JTextField;
import java.awt.*;
import java.awt.event.*;
public class ComboGUI extends JFrame implements ActionListener {
public JButton update;
public JTextField textField;
public JLabel textLabel;
public JComboBox<String> fontBox;
public JComboBox sizeBox;
public String font;
public String size;
public ComboGUI()
{
components();
panels();
actionListener();
}
public void components()
{
this.update = new JButton("update");
this.textField=new JTextField(20);
this.textField.setText("hello");
this.textLabel= new JLabel("GUI");
this.font="Arial";
this.size="20";
this.textLabel.setFont(new Font(this.font, Font.PLAIN, Integer.parseInt(this.size)));
this.fontBox=new JComboBox();
this.fontBox.addItem("Times New Roman");
this.fontBox.addItem("Calibri");
this.sizeBox= new JComboBox();
this.sizeBox.addItem("20");
this.sizeBox.addItem("30");
this.sizeBox.addItem("40");
this.setSize(400, 400);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setLocationRelativeTo(null);
}
public void panels(){
JPanel northPanel =new JPanel();
JLabel fontLabel =new JLabel("Font: ");
JLabel sizeLabel =new JLabel("size: ");
northPanel.add(fontLabel);
//center
BGPanel centerPanel =new BGPanel();
centerPanel.add(this.textLabel);
this.add(centerPanel,BorderLayout.CENTER);
//south
BGPanel southPanel =new BGPanel();
southPanel.add(this.textLabel);
this.add(southPanel,BorderLayout.CENTER);
}
public void actionListener(){
this.update.addActionListener(this);
this.fontBox.addActionListener(this);
this.sizeBox.addActionListener(this);
}
#Override
public void actionPerformed(ActionEvent e){
if(e.getSource()==this.update){
this.textLabel.setText(this.textField.getText());
}
if(e.getSource()==this.fontBox || e.getSource()==this.sizeBox){
this.font=this.fontBox.getSelectedItem().toString();
this.size=this.sizeBox.getSelectedItem().toString();
this.textLabel.setFont(new Font(this.font,Font.PLAIN,Integer.parseInt(this.size)));
}
this.repaint();
}
public static void main(String[] args) {
ComboGUI comb =new ComboGUI();
combo.setVisible(true);
}
}
this is what im getting instead
It looks like you are missing this.setVisible(true); at the end of your constructor.
Your code should look like this:
public ComboGUI()
{
components();
panels();
actionListener();
this.setVisible(true);
}
incase anyone is trying to do something similar, this is the complete solution
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import java.awt.BorderLayout;
import javax.swing.JButton;
import javax.swing.JComboBox;
public class ComboGUI extends JFrame implements ActionListener{
public void updateLabelText(){
size = fSize.getItemAt(fSize.getSelectedIndex());
font = fStyles.getItemAt(fStyles.getSelectedIndex());
updateLabel.setFont(new Font(font,Font.PLAIN,size));
}
public static BGPanel centrePanel;
public JComboBox<String> fStyles;
public JComboBox<Integer> fSize;
public JButton updateButton;
public JLabel updateLabel;
public JLabel fontLabel;
public JLabel sizeLabel;
public JTextField textField;
public JPanel BottomPanel;
public JPanel topPanel;
private String font;
private int size;
public ComboGUI() {
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setSize(400,400);
this.setLocation(0, 0);
//Top
topPanel = new JPanel();
fontLabel = new JLabel("Font:");
sizeLabel = new JLabel("Font Size:");
fStyles = new JComboBox<String>();
fStyles.addItem("Arial");
fStyles.addItem("TimesRoman");
fStyles.addItem("Serif");
fStyles.addItem("Monospaced");
fStyles.addActionListener(this);
fSize = new JComboBox<Integer>();
fSize.addItem(10);
fSize.addItem(20);
fSize.addItem(30);
fSize.addItem(40);
fSize.addActionListener(this);
topPanel.add(fontLabel);
topPanel.add(fStyles);
topPanel.add(sizeLabel);
topPanel.add(fSize);
//CentrePanel setup
centrePanel = new BGPanel();
updateLabel = new JLabel("I love PDC :)");
centrePanel.add(updateLabel);
//Bottom
BottomPanel = new JPanel();
updateButton = new JButton("Update");
textField = new JTextField(20);
textField.setText("I love PDC :)");
updateButton.addActionListener(this);
BottomPanel.add(textField);
BottomPanel.add(updateButton);
this.add(centrePanel,BorderLayout.CENTER);
this.add(BottomPanel,BorderLayout.SOUTH);
this.add(topPanel,BorderLayout.NORTH);
updateLabelText();
}
public static void main(String[] args) {
ComboGUI combo = new ComboGUI();
combo.setVisible(true);
}
#Override
public void actionPerformed(ActionEvent e) {
if(e.getSource() == updateButton){
updateLabel.setText(textField.getText().trim());
}
if(e.getSource() == fStyles){
updateLabelText();
}
if (e.getSource() == fSize){
updateLabelText();
}
}
}
I want to create a combobox and a textbox. And user will enter a text into the textbox, and the text will be added as an item of combobox.
How can I do it? I wrote a code, but I couldn't find what will I write in actionlistener.
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class Q2 extends JFrame {
JTextField t;
JComboBox combobox = new JComboBox();
public Q2() {
t = new JTextField("Enter text here", 20);
t.setEditable(true);
t.addActionListener(new act());
add(t);
add(combobox);
combobox.addItem(t.getText().toString());
setLayout(new FlowLayout());
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(300, 300);
setLocationRelativeTo(null);
setVisible(true);
}
public class act implements ActionListener {
public void actionPerformed(ActionEvent e) {
}
}
public static void main(String[] args) {
Q2 test = new Q2();
}
}
I added a button, and put the functionality on adding to the JComboBox on the button. Here's an example:
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class Q2 extends JFrame {
JTextField t;
JComboBox combobox;
JButton b;
public Q2() {
combobox = new JComboBox();
t = new JTextField("Enter text here", 20);
t.setEditable(true);
b = new JButton("Add");
b.addActionListener(new act()); //Add ActionListener to button instead.
add(t);
add(combobox);
add(b);
//combobox.addItem(t.getText().toString()); //Moved to ActionListener.
setLayout(new FlowLayout());
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(300, 300);
setLocationRelativeTo(null);
setVisible(true);
}
public class act implements ActionListener {
public void actionPerformed(ActionEvent e) {
combobox.addItem(t.getText()); //Removed .toString() because it returns a string.
}
}
public static void main(String[] args) {
Q2 test = new Q2();
}
}
private JTextComponent comboboxEditor;
Vector ComboData = new Vector();
public void addActionListners() {
//adding action listner to the NameComboBox
this.comboboxEditor = (JTextComponent) yourCombo.getEditor().getEditorComponent();
comboboxEditor.addKeyListener(new KeyAdapter() {
public void keyReleased(KeyEvent evt) {
int i = evt.getKeyCode();
if (i == 10) {
//combobox action on enter
ComboData.add(comboboxEditor.getText());
yourCombo.setListData(ComboData);
}
}
});
}
you have to set your editable property in comboBox to true otherwise you wont able to write on comboBox. make sure you call addActionListners() method
at the startup(constructor). i am giving the combobox the functionality of a jtext field by changing the editor of the combobox to jtextComponent. try this example
Is it possible to check if a jtextfield has been selected / de-selected (ie the text field has been clicked and the cursor is now inside the field)?
//EDIT
thanks to the help below here is a working example
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
#SuppressWarnings("serial")
public class test extends JFrame {
private static JPanel panel = new JPanel();
private static JTextField textField = new JTextField(20);
private static JTextField textField2 = new JTextField(20);
public test() {
panel.add(textField);
panel.add(textField2);
this.add(panel);
}
public static void main(String args[]) {
test frame = new test();
frame.setVisible(true);
frame.setSize(500, 300);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
textField.addFocusListener(new FocusListener() {
#Override
public void focusGained(FocusEvent e) {
System.out.println("selected");
}
#Override
public void focusLost(FocusEvent e) {
System.out.println("de-selected");
}
});
}
}
You will need to use the focusGained and focusLost events to see when it has been selected, and when it is deselected (i.e. gained/lost focus).
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import javax.swing.JTextField;
public class Main {
public static void main(String args[]) {
final JTextField textField = new JTextField();
textField.addFocusListener(new FocusListener() {
#Override
public void focusGained(FocusEvent e) {
//Your code here
}
#Override
public void focusLost(FocusEvent e) {
//Your code here
}
});
}
}
You may try isFocusOwner()
Is it possible to check if a jtextfield has been selected / de-selected
Yes, use focusGained and focusLost events.
the text field has been clicked and the cursor is now inside the field ?
Use isFocusOwner() which returns true if this Component is the focus owner.
if( ((JFrame)getTopLevelAncestor()).getFocusOwner() == textField ) {
....
}
In dialog I need to display one group of controls if some combo is checked and another group of controls otherwise.
I.e. I need 2 layers and I need to switch between them when combo is checked/unchecked. How can I do that?
Thanks
CardLayout works well for this, as suggested below.
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
/** #see http://stackoverflow.com/questions/6432170 */
public class CardPanel extends JPanel {
private static final Random random = new Random();
private static final JPanel cards = new JPanel(new CardLayout());
private static final JComboBox combo = new JComboBox();
private final String name;
public CardPanel(String name) {
this.name = name;
this.setPreferredSize(new Dimension(320, 240));
this.setBackground(new Color(random.nextInt()));
this.add(new JLabel(name));
}
#Override
public String toString() {
return name;
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
create();
}
});
}
private static void create() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
for (int i = 1; i < 9; i++) {
CardPanel p = new CardPanel("Panel " + String.valueOf(i));
combo.addItem(p);
cards.add(p, p.toString());
}
JPanel control = new JPanel();
combo.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JComboBox jcb = (JComboBox) e.getSource();
CardLayout cl = (CardLayout) cards.getLayout();
cl.show(cards, jcb.getSelectedItem().toString());
}
});
control.add(combo);
f.add(cards, BorderLayout.CENTER);
f.add(control, BorderLayout.SOUTH);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
}
I know that it is very simple question, but I can't find a solution.
I have a main swing dialog and other swing dialog. Main dialog has a button.
How can I make that after clicking a button the other dialog opens?
EDIT:
When I try this:
private void jButton1MouseClicked(java.awt.event.MouseEvent evt) {
NewJDialog okno = new NewJDialog();
okno.setVisible(true);
}
I get an error:
Cannot find symbol NewJDialog
The second window is named NewJDialog...
You'll surely want to look at How to Make Dialogs and review the JDialog API. Here's a short example to get started. You might compare it with what you're doing now.
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ButtonGroup;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
public class DialogTest extends JDialog implements ActionListener {
private static final String TITLE = "Season Test";
private enum Season {
WINTER("Winter"), SPRING("Spring"), SUMMER("Summer"), FALL("Fall");
private JRadioButton button;
private Season(String title) {
this.button = new JRadioButton(title);
}
}
private DialogTest(JFrame frame, String title) {
super(frame, title);
JPanel radioPanel = new JPanel();
radioPanel.setLayout(new GridLayout(0, 1, 8, 8));
ButtonGroup group = new ButtonGroup();
for (Season s : Season.values()) {
group.add(s.button);
radioPanel.add(s.button);
s.button.addActionListener(this);
}
Season.SPRING.button.setSelected(true);
this.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
this.add(radioPanel);
this.pack();
this.setLocationRelativeTo(frame);
this.setVisible(true);
}
#Override
public void actionPerformed(ActionEvent e) {
JRadioButton b = (JRadioButton) e.getSource();
JOptionPane.showMessageDialog(null, "You chose: " + b.getText());
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new DialogTest(null, TITLE);
}
});
}
}