Why aren't the JButtons displayed on the JFrame? - java

When I run the program the window and all it's properties are right, but the buttons won't show up, any idea of what I've done wrong?
I have two classes window and TimeTable0:
Here's window:
package timetable0;
import java.awt.event.ActionEvent;
import javax.swing.*;
public class window extends JFrame {
JButton bt1,bt2,bt3,bt4 = new JButton();
JPanel panel = new JPanel();
public void ventana() {
setResizable(false);
setTitle("Time Table");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400,550);
setVisible(true);
bt1.setText("Show Grades");
bt2.setText("Show Time Table");
bt3.setText("");
bt4.setText("");
panel.add(bt1);
panel.add(bt2);
panel.add(bt3);
panel.add(bt4);
}
public void actions (){
bt1.addActionListener((ActionEvent e) -> {
System.out.println("");
});
bt2.addActionListener((ActionEvent e) -> {
System.out.println("");
});
bt3.addActionListener((ActionEvent e) -> {
System.out.println("");
});
bt4.addActionListener((ActionEvent e) -> {
System.out.println("");
});
}
}
And here's TimeTable0:
package timetable0;
public class TimeTable0 {
public static void main(String[] args) {
window menu = new window();
menu.ventana();
menu.actions();
}
}

You aren't adding the JPanel to the frame.
panel.add(bt1);
panel.add(bt2);
panel.add(bt3);
panel.add(bt4);
setContentPane(panel);
You aren't running the program on the Event Dispatch Thread:
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
window menu = new window();
menu.ventana();
menu.actions();
}
});
}
You aren't creating all four buttons:
JButton bt1 = new JButton();
JButton bt2 = new JButton();
JButton bt3 = new JButton();
JButton bt4 = new JButton();

I would have done it this way if you really want to extends your class to a JFrame.
public class Window extends JFrame {
JButton bt1,bt2,bt3,bt4; //Do initialization in the constructor, not here
JPanel panel;
public Window() {
createComponents();
addComponents();
initFrame();
}
private void createComponents(){
panel = new JPanel();
panel.setPreferredSize(new Dimension(800, 600));
bt1 = new JButton("Show Grades");
bt2 = new JButton("Show Time Table");
bt3 = new JButton("btn 3");
bt4 = new JButton("btn 4");
}
private void addComponents(){
panel.add(bt1);
panel.add(bt2);
panel.add(bt3);
panel.add(bt4);
add(panel);
}
private void initFrame(){
setResizable(false);
setTitle("Time Table");
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
setLocationRelativeTo(null);
}
}
Usually I would prefer to extends a class to JPanel instead of extending it to JFrame. After that create a JFrame in the main() and add your customized JPanel into it.

You will need to initialize the buttons and add panel to the JFrame. Also, try moving the setVisible(true) statement to the end of the ventana() method so that it is displayed after the components are added.
public void Ventana() {
bt1 = new JButton("Show Grades");
bt2 = new JButton("Show Time Table");
bt3 = new JButton();
bt4 = new JButton();
...
panel.add(bt4);
add(panel);
setVisible(true); //moved from top
}

You didn't show much codes there, but you should at least try to do this instead:
Note that JButton bt1,bt2,bt3,bt4 = new JButton(); is different from writing it as below:
JButton bt1 = new JButton();
JButton bt2 = new JButton();
JButton bt3 = new JButton();
JButton bt4 = new JButton();
Doing JButton bt1,bt2,bt3,bt4 = new JButton();, you are only creating a JButton object for bt4 and not the rest.
You have also forgotten to add your JPanel into your JFrame.
add(panel); //Add panel to frame

Initialize buttons one by one:
JButton bt1 = new JButton();
JButton bt2 = new JButton();
JButton bt3 = new JButton();
JButton bt4 = new JButton();
Add panel to your frame after you add buttons to your panel:
panel.add(bt1);
panel.add(bt2);
panel.add(bt3);
panel.add(bt4);
setContentPane(panel);

Related

Java Button disappears after clicking

I'm trying to add a button using an JOptionPane in another button, but after I clicked the original button just keeps disappearing.
I've tried adding the JPanel manually instead of using 'handPanelNPC.getHandPanel()' by iterating through the handPanel.buttons but it stil wont work. I've checked the ArrayList size and it is already inserted properly.
LayoutTesting.java
public class LayoutTesting extends JFrame{
HandPanel handPanelNPC = new HandPanel();
public LayoutTesting(HandPanel handPanel, int type){
Container pane = getContentPane();
if (type==1){
handPanelNPC = handPanel;
}
pane.setLayout(new BorderLayout());
pane.add(handPanelNPC.getHandPanel(), BorderLayout.NORTH);
validate();
repaint();
}
public LayoutTesting(){
Container pane = getContentPane();
pane.setLayout(new BorderLayout());
pane.add(handPanelNPC.getHandPanel(), BorderLayout.NORTH);
}
}
HandPanel.java
public class HandPanel implements ActionListener{
JFrame frame = null;
JPanel panel = new JPanel();
ArrayList<JButton> buttons = new ArrayList<JButton>();
public HandPanel(){
addNewButton();
panel.setLayout(new FlowLayout());
panel.add(buttons.get(0));
}
public JComponent getHandPanel(){
panel = new JPanel();
for(int i=0; i<buttons.size(); i++){
JButton button = buttons.get(i);
panel.add(button);
}
return panel;
}
public void addNewButton(){
JButton button = new JButton();
button.setPreferredSize(new Dimension(40,58));
button.addActionListener(this);
buttons.add(button);
}
public void actionPerformed(ActionEvent e) {
String[] options = {"Summon", "Set", "Add Card"};
int messageType = JOptionPane.QUESTION_MESSAGE;
int code = JOptionPane.showOptionDialog(
frame,
"What would you like to do?",
"Card Name",
0, messageType, null,
options, options[1]);
if (code==2){
addNewButton();
LayoutTesting frame = new LayoutTesting(this, 1);
}
}
}
Main.java
public class Main extends JFrame{
public static void main(String[] args){
LayoutTesting frame = new LayoutTesting();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 300);
frame.setVisible(true);
}
}
You have too many odd things happening in your code to give a simple answer.
Try debugging your own code by looking at this line in HandPanel.java:
LayoutTesting frame = new LayoutTesting(this, 1);
What does it really do? Now remove that line and the button will not disappear. Now try and work out what that line was doing, and why the button disappeared.
Also 'panel.add(buttons.get(0));' does nothing because there is never a button in the array when you make that call (You add the button afterwards in another method).
Here is a rough working demo that lets you add as many new cards as you want to the first frame, and each card has a button that will let you summon a new card.
public class LayoutTesting extends JFrame{
Container pane;
//Add card when button is pressed:
public void addCard(){
Container card = new JPanel();
card.setBackground(Color.red);
JButton newButton = addNewButton();
newButton.setBackground(Color.red);
card.add(newButton);
pane.add(card);
revalidate();
repaint();
}
//Setup window and add button:
public LayoutTesting(){
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400, 300);
setVisible(true);
setLayout(new FlowLayout());
pane = new JPanel();
pane.setLayout(new GridBagLayout());
JButton firstButton = addNewButton();
firstButton.setBackground(Color.green);
add(pane);
add(firstButton);
}
//Create button and action listener:
public JButton addNewButton(){
JButton button = new JButton();
button.setPreferredSize(new Dimension(40, 58));
button.addActionListener(new java.awt.event.ActionListener(){
#Override
public void actionPerformed(java.awt.event.ActionEvent evt){
buttonAction(evt);
}
});
return button;
}
//Action fer each button:
public void buttonAction(ActionEvent e) {
String[] options = {"Summon", "Set", "Add Card"};
int messageType = JOptionPane.QUESTION_MESSAGE;
int code = JOptionPane.showOptionDialog(
this,
"What would you like to do?",
"Card Name",
0, messageType, null,
options, options[1]);
if (code==2){
addCard();
}
}
}

Java syntax for separating action listeners

Please help me out to separate these ActionListeners in a periodic table that I am attempting to complete. When I execute the program and click on 'H', it opens all the other elements and when the others are clicked, it does not work. So I need a way to separate these using any method...
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class PeriodicTable
{
public static void main (String[] args)
{
JFrame frame = new JFrame("Elements");
frame.setVisible(true);
frame.setSize(1000,1500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
frame.add(panel);
JButton button1 = new JButton("H");
panel.add(button1);
button1.addActionListener (new Action1());
JButton button2 = new JButton("He");
panel.add(button2);
button2.addActionListener (new Action2());
JButton button3 = new JButton("Li");
panel.add(button3);
button3.addActionListener (new Action2());
}
static class Action1 implements ActionListener
{
public void actionPerformed (ActionEvent e)
{
JFrame frame2 = new JFrame("H");
frame2.setVisible(true);
frame2.setSize(1000,1500);
JLabel label = new JLabel("Hydrogen");
JPanel panel = new JPanel();
frame2.add(panel);
panel.add(label);
}
}
static class Action2 implements ActionListener
{
public void actionPerformed (ActionEvent e)
{
JFrame frame3 = new JFrame("He");
frame3.setVisible(true);
frame3.setSize(1000,1500);
JLabel label = new JLabel("Helium");
JPanel panel = new JPanel();
frame3.add(panel);
panel.add(label);
}
}
static class Action3 implements ActionListener
{
public void actionPerformed (ActionEvent e)
{
JFrame frame4 = new JFrame("Li");
frame4.setVisible(true);
frame4.setSize(1000,1500);
JLabel label = new JLabel("Lithium");
JPanel panel = new JPanel();
frame4.add(panel);
panel.add(label);
}
}
}
Thanks in advance.
(note: only the first 3 elements are coded for...)
When I execute the program and click on 'H', it opens all other elements
Only one frame opens for me.
and when the others are clicked, it does not work.
Each button opens a single frame for me.
However, button 3 opens the wrong frame because you add the wrong listener to the button:
//button3.addActionListener (new Action2());
button3.addActionListener (new Action3());
Other issues:
You should add the components to the frame BEFORE making the frame visible.
Don't hardcode screen sizes, you never know what size screen other users will be using
So the order of your code might be something like:
JLabel label = new JLabel("Helium");
JPanel panel = new JPanel();
panel.add(label);
JFrame frame3 = new JFrame("He");
frame3.add(panel);
frame3.pack();
frame3.setVisible(true);
And of course you really don't want to create dozens of separate ActionListeners. You want to make the listener more generic so it can be shared.
Something like:
static class Action implements ActionListener
{
public Action(String element, String description)
{
this.element = element;
this.description = description;
}
public void actionPerformed (ActionEvent e)
{
JLabel label = new JLabel(description);
JPanel panel = new JPanel();
panel.add(label);
JFrame frame3 = new JFrame(element);
frame3.add(panel);
frame3.pack();
frame3.setVisible(true);
}
}
Then when you create the listener you use:
button3.addActionListener (new Action("HE", "Helium"));

how to identify dynamically created jbutton actions

I create two jbuttons in one panel(can be Box).i create same panel dynamically several times in same frame.so if two panels created dynamically those button make with same variable name.But i want to identify buttons one by one for put actions.how to identify dynamically created buttons one by one?
button creating code
public class Jscrollpanetest extends JFrame {
JScrollPane scrollPane;
Box box;
private static int panelCount = 0;
public Jscrollpanetest() {
setPreferredSize(new Dimension(200, 400));
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
scrollPane = new JScrollPane();
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
scrollPane.getVerticalScrollBar().setUnitIncrement(15);
box = Box.createVerticalBox();
scrollPane.getViewport().add(box);
this.add(scrollPane);
this.pack();
this.setLocationRelativeTo(null);
this.setVisible(true);
Timer t = new Timer(1000, new ActionListener() {
public void actionPerformed(ActionEvent ae) {
box.add(new TestPanel(), box.size());
scrollPane.validate();
}
});
t.setRepeats(true);
t.start();
}
public class TestPanel extends JPanel {
int myId = panelCount++;
public TestPanel() {
this.setLayout(new GridBagLayout());
this.setBorder(BorderFactory.createBevelBorder(1));
JButton up = new JButton("^");
JLabel rate = new JLabel("1");
JButton down = new JButton("^");
JLabel label = new JLabel("" + myId);
label.setHorizontalAlignment(JLabel.CENTER);
label.setVerticalAlignment(JLabel.CENTER);
this.setMaximumSize(new Dimension(1000, 200));
this.setPreferredSize(new Dimension(1000, 100));
this.add(label);
this.add(up);
this.add(rate);
this.add(down);
}
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
Jscrollpanetest testScrollPane = new Jscrollpanetest();
}
});
}
}
If use and dynamic created ActionListener there will be no problem. So each button will have its own ActionListener.
If using a common ActionListener must add tags to each button as extend JButton.

JPanel How to make button work?

As you read this code, you will realize I got one action event to work, it opens up a new JPanel that displays the button that will run the ballBounce, but for now im stuck trying to get a working button within that frame because that frame is already within a actionEvent, any help?
public class MainJPanelOperation
{
public static void main(String[] a)
{
JPanel panel1 = new JPanel(new GridLayout(5, 10, 1, 1));
JButton t1 = new JButton();
JButton t2 = new JButton();
JButton letsStart = new JButton("Start The Program!");
JButton t3 = new JButton();
JButton t4 = new JButton();
//letsStart.setBounds(200,250,12,12);
panel1.add(t1);
panel1.add(t2);
panel1.add(letsStart);
panel1.add(t3);
panel1.add(t4);
final JFrame frame1 = new JFrame("Game");
frame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame1.add(panel1);
frame1.setSize(1000,1000);
frame1.setVisible(true);
t1.setVisible(false);
t2.setVisible(false);
t3.setVisible(false);
t4.setVisible(false);
letsStart.setBackground(Color.yellow);
panel1.setBackground(Color.black);
letsStart.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
System.out.println("panel 2 main menu intro online");
JPanel panelMM = new JPanel(new GridLayout(5, 10, 1, 0));
JButton MM1 = new JButton("BallBounce");
panelMM.add(MM1);
JFrame frameMM = new JFrame("Game/Main Menu");
frameMM.add(panelMM);
frameMM.setSize(1000,1000);
frameMM.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frameMM.setVisible(true);
frame1.setVisible(false);
}
});//end of start sequence
}
}
JPanel panelMM = new JPanel(new GridLayout(5, 10, 1, 0));
JButton MM1 = new JButton("BallBounce");
panelMM.add(MM1);
final JFrame frameMM = new JFrame("Game/Main Menu");
frameMM.add(panelMM);
frameMM.setSize(1000,1000);
frameMM.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
letsStart.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
System.out.println("panel 2 main menu intro
frameMM.setVisible(true);
frame1.setVisible(false);
}
});
You can make frameMM final and there is no need to have all of your code inside the ActionListener.
Try This :it is working inside a Action Listener.
JButton MM1 = new JButton("BallBoe");
MM1.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
System.out.println("panel 2");
}
});
or class MainJPanelOperation implements ActionListener
You can use class MainJPanelOperation
{
static JButton MM1;
//your code
}
MM1=new JButton("Button");
MM1.addActionListener(this);
write a Method outside Main()
public void ActionPerformed(ActionEvent e)
{
if(e.getSource()==MM1)
{
System.out.print("");
}
if(e.getSource()==Buttonobject)
{
//your code for button Pressing Event
}
}

Action Listener does not work on swing

I have a form , That when i click to save button, "Yes" String should display on my console!
(I use "Yes" String for test!)
But does not work when clicked.
My code:
public final class NewUserFrame1 extends JFrame implements ActionListener {
UserInformation userinfo;
JLabel fnamelbl;
JLabel lnamelbl;
JTextField fntf;
JTextField lntf;
JLabel gndlnl;
JRadioButton malerb;
JRadioButton femalerb;
ButtonGroup bgroup;
JLabel registnm;
JButton savebt;
JButton cancelbt;
JLabel showreglbl;
public NewUserFrame1() {
add(rowComponent(), BorderLayout.CENTER);
setLocation(200, 40);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
}
public JPanel rowComponent() {
JPanel panel = new JPanel();
fnamelbl = new JLabel("First name");
lnamelbl = new JLabel("Last Name");
JLabel fntemp = new JLabel();
JLabel lntemp = new JLabel();
fntf = new JTextField(10);
lntf = new JTextField(10);
gndlnl = new JLabel("Gender");
malerb = new JRadioButton("Male");
femalerb = new JRadioButton("Female");
bgroup = new ButtonGroup();
bgroup.add(malerb);
bgroup.add(femalerb);
registnm = new JLabel("Registration ID is:");
showreglbl = new JLabel("");
JLabel regtemp = new JLabel();
savebt = new JButton("Save");
cancelbt = new JButton("Cancell");
JLabel buttontemp = new JLabel();
panel.add(fnamelbl);
panel.add(fntf);
panel.add(fntemp);
panel.add(lnamelbl);
panel.add(lntf);
panel.add(lntemp);
panel.add(gndlnl);
JPanel radiopanel = new JPanel();
radiopanel.setLayout(new FlowLayout(FlowLayout.LEFT));
radiopanel.add(malerb);
radiopanel.add(femalerb);
panel.add(radiopanel);
panel.add(new JLabel());
panel.add(registnm);
panel.add(showreglbl);
panel.add(regtemp);
panel.add(savebt);
panel.add(cancelbt);
panel.add(buttontemp);
panel.setLayout(new SpringLayout());
SpringUtilities.makeCompactGrid(panel, 5, 3, 50, 10, 80, 60);
return panel;
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
NewUserFrame1 newUserFrame1 = new NewUserFrame1();
}
});
}
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == savebt) {
System.out.print("Yes");
}
}
}
You need to add an ActionListener to your button like so:
savebt.addActionListener(this);
or with an anonymous class, like so:
savebt.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// your code.
}
});
Using anonymous classes (or inner classes) is better because you can't have more than one actionPerformed() method in a given class.
You need to tell the button to invoke the ActionListener:
savebt = new JButton("Save");
savebt.addActionListener(this);
Note if you intend to use the same method for the save and cancel buttons, you'll need to differentiate, perhaps by comparing the source of the ActionEvent against the two buttons.

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