I am trying since 1 hour but I can't access my jtextField from JPanel to Jpanel1.
I am working on a course project in which I have to show the name of the log in user in the JPanel using jlabel but I can't access the jTextField in JPanel from jpanel1.
I make my JTextField1 public Static using this Answer but still unable to catch the values
I am using this code to fetch the values from JPanel in JPanel1. What I am doing is creating a object of JPanel in JPanel1 and then try to fetch the value.
LoginPanel s = new LoginPanel();
String sc=s.jTextField1.getText();
this.jLabel3.setText(sc);
Don't make a variable static for this purpose as you're breaking OOPs rules for no good reason.
Don't create a completely new object if you want to get the state of another object of the same type, since the two objects will be completely different instances.
If you need to have one object query the state of another (here the state being the text held within the JTextField), then give the the object with the JTextField a public getter field that will return the text in its JTextField and have the first object call this method when needed.
The first object will of course need a valid reference to the displayed object with the text field. How this is done will depend on the structure of your program, something we have no idea of at the moment.
Often the problem is when to obtain the text, since if you try to obtain the text before the user has had a chance to enter anything, then your code won't work. To avoid this, this is usually done in an event listener, and again the details will depend on the structure of your program and on code not shown.
Sometimes the timing is achieved by displaying the 2nd JPanel within a modal dialog window such as a JDialog or JOptionPane. This method is used most often when trying to get log on information from a user.
For better and more specific help, please make your question more informative. Show actual code, not an image of code. How much code? best would be if you could create and show us a minimal code example program.
For example, using a JOptionPane to display one JPanel and obtain text in a modal fashion:
import java.awt.Component;
import java.awt.event.ActionEvent;
import javax.swing.*;
public class TwoPanels extends JPanel {
private MyPanel1 panel1 = new MyPanel1();
private MyPanel2 panel2 = new MyPanel2();
public TwoPanels() {
add(panel2);
add(new JButton(new AbstractAction("Get Name") {
#Override
public void actionPerformed(ActionEvent arg0) {
Component parent = TwoPanels.this;
String title = "Enter Name";
int messageType = JOptionPane.PLAIN_MESSAGE;
int optionType = JOptionPane.OK_CANCEL_OPTION;
int result = JOptionPane.showConfirmDialog(parent, panel1, title, optionType, messageType);
if (result == JOptionPane.OK_OPTION) {
String name = panel1.getNameText();
panel2.setNameText(name);
}
}
}));
}
private static void createAndShowGui() {
TwoPanels mainPanel = new TwoPanels();
JFrame frame = new JFrame("TwoPanels");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
class MyPanel1 extends JPanel {
private JTextField nameField = new JTextField(10);
public MyPanel1() {
add(new JLabel("Name:"));
add(nameField);
}
public String getNameText() {
return nameField.getText();
}
}
class MyPanel2 extends JPanel {
private JTextField nameField = new JTextField(10);
public MyPanel2() {
nameField.setFocusable(false);
nameField.setEditable(false);
add(new JLabel("Name:"));
add(nameField);
}
public void setNameText(String text) {
nameField.setText(text);
}
}
Related
I have a custom class CustomField that extends JPanel. As I often have to reuse the same pattern, my custom class is made of 2 JLabels and 2 JComboBox.
It's quite simple; the first JComboBox has ON/OFF choices and the second JComboBox is only visible if the first is set to "ON". I can manage this part.
The part that I however don't know who to design it well is that CustomField instances are in another class that is the main JFrame and in this JFrame, some parts will be visible only if the JComboBox from the CustomField class is set to "ON". I thought about using a MouseAdapter, but I don't know it is good practice.
Here is my CustomField class:
public class CustomField extends JPanel {
/**
*
*/
private static final long serialVersionUID = 1L;
JLabel text, portText;
JComboBox<String> testCB, option;
public CustomField(String text, String opt, String tst) {
this.text = new JLabel(text);
String[] onOffOpt= {"OFF", "ON"};
this.option = new JComboBox<String>(onOffOpt);
this.option.setSelectedItem(opt);
this.option.addItemListener(new ItemListener(){
#Override
public void itemStateChanged(ItemEvent ie) {
portText.setVisible(option.getSelectedIndex() == 1);
testCB.setVisible(option.getSelectedIndex() == 1);
}
});
this.portText = new JLabel("Test:");
String[] testChoices = {"Test", "Test2"};
this.testCB = new JComboBox<String>(testChoices);
this.testCB.setSelectedItem(tst);
this.setLayout(new FlowLayout());
add(this.text);
add(this.option);
add(this.portText);
add(this.testCB);
}
}
And here is the main JFrame:
public class Main {
CustomField cf = new CustomField("test", "ON, "Test2");
public static void main(String s[]) {
JFrame frame = new JFrame("Application");
JPanel panel = new JPanel();
panel.setLayout(new FlowLayout());
panel.add(cf);
JLabel labelTest = new JLabel("Label that should be visible or not");
panel.add(labelTest);
frame.add(panel);
frame.setSize(300, 300);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
Basically, I want that the labelTest visibily changes according to the CustomField settings. In the way that it is made, I can not put the labelTest in the CustomField class.
Is there a clean way to do what I want? Should I redesign the actual thing and put all the fields in the same class?
Thanks!
First, you want to expose the combobox's state with a method in CustomField:
public boolean isOn() {
return testCB.getSelectedIndex() == 1;
}
You can get an idea for how listening for state is done by looking at the method signatures in the documentation for various Swing components, which use the standard JavaBean listener pattern: You’ll want to add three public methods, and one protected method:
public void addChangeListener(ChangeListener listener) {
listenerList.add(ChangeListener.class, listener);
}
public void removeChangeListener(ChangeListener listener) {
listenerList.remove(ChangeListener.class, listener);
}
public ChangeListener[] getChangeListeners() {
return listenerList.getListeners(ChangeListener.class);
}
protected void fireChangeListeners() {
ChangeEvent event = new ChangeEvent(this);
for (ChangeListener listener : getChangeListeners()) {
listener.stateChanged(event);
}
}
(The listenerList field is inherited from JComponent.)
Now, you can simply add a call to fireChangeListeners(); whenever you detect that the user has changed the value of the On/Off combobox—that is, you’ll want to call it in your ItemListener.
As you can probably guess, your Main class can now call cf.addChangeListener, and inside that listener adjust the visibility of your label based on the value returned by cf.isOn().
You can learn a lot more by reading these.
I am new to java and creating a Simple gui App. In this simple app, I am trying to write a e-commerce letter for Firms. So, I planned my app something like this..
First i ask to user if he want to write an letter to British Firm or American. For this i use two radio buttons(one for american firm and second for british) and JButton. When user Trigger jbutton then i want to get radiobutton command(which type of letter user want to write).
The problem is I don't have any idea to get Radiobutton command when i trigger jButton. Please give me an Simple Idea(if possible with exapmle not complicated for begginers) to get RadioButtons value..
Here is my java Code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class englet{
static public JFrame f;
static public JPanel p;
static class getTypeOfLetter implements ActionListener{
public void actionPerformed( ActionEvent e){
String btnInput = e.getActionCommand();
System.out.println(btnInput);
}
}
public static void askletter(){
JRadioButton btnRadio1;
JRadioButton btnRadio2;
ButtonGroup btngrp;
JButton btnGo = new JButton("Write");
btnRadio1 = new JRadioButton("Write Letter For American Firm");
btnRadio1.setActionCommand("Amer");
btnRadio2 = new JRadioButton("Write Letter For British Firm");
btnRadio2.setActionCommand("Brit");
btngrp = new ButtonGroup();
btnGo.setActionCommand("WriteTest");
btnGo.addActionListener(new getTypeOfLetter());
btngrp.add(btnRadio1);
btngrp.add(btnRadio2);
p.add(btnRadio1);
p.add(btnRadio2);
p.add(btnGo);
}
englet(){
f = new JFrame("English Letter");
p = new JPanel();
askletter();
f.add(p);
f.setSize(400,200);
f.setVisible(true);
}
public static void main (String[] argv ){
englet i = new englet();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
I am using Notepad++ and CMD.. Not any another tools like netbeans initllli ecplisse.
**RE-EDIT ** I want a possible solution and can satisfy me.. this app works but i am not able to get radiobuttons commmand with jubtton..
You've got several issues:
Over-use of static. Most of the fields and methods of your code should be non-static
You're missing key fields that will be necessary to transmit the information needed. To get the selected JRadioButton, you need to make JRadioButton fields and check which is selected, or (and my preference), you need to make the ButtonGroup variable a field and check which JRadioButton has been selected based on the ButtonModel returned by the ButtonGroup.
You're currently using local variables and these won't be visible throughout the class, which is why either the JRadioButtons or the ButtonModel most be fields (declared in the class).
If you go with ButtonModel above, you must give each JRadioButton an appropriate actionCommand String.
For example:
import java.awt.Component;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class GetRadio extends JPanel {
private static final String[] FIRMS = {"American Firm", "British Firm"};
// You need this field to access it in your listener
private ButtonGroup buttonGroup = new ButtonGroup();
public GetRadio() {
// create JButton and add ActionListener
JButton button = new JButton("Select");
button.addActionListener(new ButtonListener());
// JPanel with a grid layout with one column and variable number of rows
JPanel radioButtonPanel = new JPanel(new GridLayout(0, 1));
radioButtonPanel.setBorder(BorderFactory.createTitledBorder("Select Firm")); // give it a title
for (String firm : FIRMS) {
// create radiobutton and set actionCommand
JRadioButton radioButton = new JRadioButton(firm);
radioButton.setActionCommand(firm);
// add to button group and JPanel
buttonGroup.add(radioButton);;
radioButtonPanel.add(radioButton);
}
// add stuff to main JPanel
add(radioButtonPanel);
add(button);
}
private class ButtonListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
// get button model of selected radio button from ButtonGroup
ButtonModel model = buttonGroup.getSelection();
// if null, no country selected
if (model == null) {
Component component = GetRadio.this;
String message = "You must first select a country!";
String title = "Error: No Country Selected";
int type = JOptionPane.ERROR_MESSAGE;
JOptionPane.showMessageDialog(component, message, title, type);
} else {
// valid country selected
String country = model.getActionCommand();
System.out.println("Letter to " + country);
}
}
}
private static void createAndShowGui() {
GetRadio mainPanel = new GetRadio();
JFrame frame = new JFrame("Get Radio Btn");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
I have two JFrame (JFrame1 and JFrame2) with two JTextField1 and JTextField2. My question is when I write "Hello world " on JTextField2 from Jframe2 and then click on OK button, I see "Hello world " on JTextField1 on Jframe1 class.
How can I do this? I'm sorry if this is a newbie question but I'm learning..
Here is my code:
JFrame2:
private JFrame1 jf1;
private void btn2ActionPerformed(java.awt.event.ActionEvent evt) {
jf1.setjTextField1(this.jTextField2);
}
What you are doing there is actually sending the reference to the actual JTextField from one frame to the other one.
That's probably not a good idea cause both frames would be end up referencing the same visual component.
What you probably want is to keep all visual components separate, but make the text of the second text field equal to the text in the first one.
Something like this:
private void btn2ActionPerformed(java.awt.event.ActionEvent evt) {
jf1.getjTextField1().setText(this.jTextField2.getText());
}
You could use an Observer Pattern or Producer/Consumer Pattern to solve the problem.
The basic idea is, you have something that generates a value and something that either wants to be notified or consume the generated value.
One of the other prinicples you should take the time to learn is also Code to interface (not implementation). This sounds stranger then it is, but the the idea is to reduce the unnecessary exposure of your objects (to unintended/controlled modifications) and decouple your code, so you can change the underlying implementation without affecting any other code which relies on it
Given the nature of your problem, an observer pattern might be more suitable. Most of Swing's listener's are based on the same principle.
We start by defining the contract that the "generator" will use to provide notification of changes...
public interface TextGeneratorObserver {
public void textGenerated(String text);
}
Pretty simple. This means we can safely provide an instance of any object that implements this interface to the generator and know that it won't do anything to our object, because the only thing it knows about is the textGenerated method.
Next, we need something that generates the output we are waiting for...
public class GeneratorPane extends JPanel {
private TextGeneratorObserver observer;
private JTextField field;
private JButton button;
public GeneratorPane(TextGeneratorObserver observer) {
this.observer = observer;
field = new JTextField(10);
button = new JButton("OK");
ActionListener listener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
observer.textGenerated(field.getText());
}
};
button.addActionListener(listener);
field.addActionListener(listener);
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = GridBagConstraints.REMAINDER;
gbc.insets = new Insets(2, 2, 2, 2);
add(field, gbc);
add(button, gbc);
}
}
This is just a simple JPanel, but it requires you to pass a instance of TextGeneratorObserver to it. When the button (or field) triggers the ActionListener, the ActionListener calls the textGenerated to notify the observer that the text has been generated or changed
Now, we need someone to observer it...
public class ObserverPanel extends JPanel implements TextGeneratorObserver {
private JLabel label;
public ObserverPanel() {
label = new JLabel("...");
add(label);
}
#Override
public void textGenerated(String text) {
label.setText(text);
}
}
This is a simple JPanel which implements the TextGeneratorObserver interface and updates it's JLabel with the new text
Then, we just need to plumb it together
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
ObserverPanel op = new ObserverPanel();
op.setBorder(new CompoundBorder(new LineBorder(Color.RED), new EmptyBorder(10, 10, 10, 10)));
GeneratorPane pp = new GeneratorPane(op);
pp.setBorder(new CompoundBorder(new LineBorder(Color.GREEN), new EmptyBorder(10, 10, 10, 10)));
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridLayout(2, 1));
frame.add(pp);
frame.add(op);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
This is a complete working example I just coded out:
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
class FrameRunner
{
public static void main(String[] args){
MyFrame f1 = new MyFrame("Frame 1");
MyFrame f2 = new MyFrame("Frame 2");
f1.addRef(f2);
f2.addRef(f1);
}
}
class MyFrame extends JFrame{
JTextField txt = new JTextField(8);
JButton btn = new JButton("Send");
MyFrame f = null;
public MyFrame(String title){
super(title);
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
setLayout(new FlowLayout());
setPreferredSize(new Dimension(400, 300));
setVisible(true);
add(btn);
add(txt);
pack();
setLocationRelativeTo(null);
init();
}
public void addRef(MyFrame f){
this.f = f;
}
public void init(){
btn.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
f.update(txt.getText());
}
});
}
public void update(String str){
txt.setText(str);
}
}
In order to make the code short and easier for you to understand. Many of the things I did not following the conventions and I did not modularize the codes. But this should give you a very good idea of how you can pass in the reference of another JFrame.
This code shows an example of how Frame1 has a reference on Frame2. Yet Frame2 also has a reference on Frame1.
Whatever things you type in JFrame1 can be send to JFrame2's textfield. Same for the other way round.
I'm trying to parse String to another frame Using JAVA
i have 2 jFrames. jFrame1 have 1 text field and jFrame 2 have 1 text field. i want to parse jFrame1 text filed's text to jframe2's text field.
It's look like this : But this is not code :(
jFrame2.textfield1.setText(jFrame1.textfield1.gettext());
Anyone know how to parse String to another frame Using JAVA?
Thanks in advance!
Assuming that you have two separate GUIs on the screen at the same time because both textFields have the same reference, each JFrame will be a Object in its own right.
Therefore the only way to access another objects variables is with its methods.
Create a setter method in jFrame2 to change the textField in question.
See Working code below.
import java.awt.*;
import javax.swing.*;
import javax.swing.BoxLayout;
import java.awt.event.*;
public class JframeLink {
public static void main(String[] args)
{
new JframeOneGui();
new JframeTwoGui();
}
//JFrame one Object
public static class JframeOneGui extends JFrame implements ActionListener
{
JPanel jPanelOne = new JPanel();
JTextField textField1 = new JTextField("Message for transfer");
JButton buttonOne = new JButton("Transfer");
public JframeOneGui()
{
//setup swing components
textField1.setSize(100,10);
buttonOne.addActionListener(this);
//setup jPanelOne
jPanelOne.setLayout(new BoxLayout(jPanelOne, 1));
jPanelOne.add(textField1);
jPanelOne.add(buttonOne);
//setup JframeOneGui
this.add("Center",jPanelOne);
this.setLocation(25,25);
this.setTitle("JframeOneGui");
this.setSize(200,200);
this.setResizable(false);
this.setVisible(true);
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource() == buttonOne)
{
//Here we are calling JframeTwoGui's Setter method
JframeTwoGui.setTextFieldOne(textField1.getText());
}
}
}
//JFrame two Object
public static class JframeTwoGui extends JFrame
{
JPanel jPanelOne = new JPanel();
static JTextField textField1 = new JTextField();
public JframeTwoGui()
{
jPanelOne.setLayout(new BoxLayout(jPanelOne, 1));
jPanelOne.add(textField1);
this.add("Center",jPanelOne);
this.setLocation(300,25);
this.setTitle("JframeTwoGui");
this.setSize(200,200);
this.setResizable(false);
this.setVisible(true);
}
//Setter to change TextFieldOne in this Object
public static void setTextFieldOne(String text)
{
textField1.setText(text);
}
}
}
I'm trying to call a method from a panel class, however it does not result in anything. Can panels communicate with each other? Or is there another reason why this isn't working?
Calling the method name() in the leftInput class.
ButtonPanel class.
import model.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ButtonPanel extends JPanel implements View
{
private Prison prison;
private JButton button = new JButton("Allocate Cell");
private LeftInputPanel leftInput;
private CrimePanel crimePanel;
public ButtonPanel(Prison prison, LeftInputPanel leftInput)
{
this.prison = prison;
this.leftInput = leftInput;
setup();
build();
}
public void setup()
{
}
public void build()
{
Dimension size = new Dimension(240, 70);
button.setPreferredSize(size);
button.setMinimumSize(size);
button.setMaximumSize(size);
button.addActionListener(new AllocateListener());
add(button);
}
public void update()
{
leftInput.clear();
}
private class AllocateListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
Criminal criminal = new Criminal(leftInput.name());
prison.add(criminal);
System.out.println(leftInput.name());
}
}
}
leftInput class.
import model.*;
import java.awt.*;
import javax.swing.*;
public class LeftInputPanel extends JPanel
{
private Prison prison;
public JTextField name = new JTextField();
public JTextField days = new JTextField();
public JTextField months = new JTextField();
public JTextField years = new JTextField();
public LeftInputPanel(Prison prison)
{
this.prison = prison;
setup();
build();
}
public void setup()
{
setLayout(new FlowLayout());
Dimension size = new Dimension(100, 190);
setPreferredSize(size);
setMinimumSize(size);
setMaximumSize(size);
}
public void build()
{
JLabel label = new JLabel("Name");
Dimension size = new Dimension(90, 20);
name.setPreferredSize(size);
add(label);
add(name);
Box box = Box.createVerticalBox();
box.add(daysPanel());
box.add(monthsPanel());
box.add(yearsPanel());
add(box);
}
public JPanel daysPanel()
{
JPanel panel = new JPanel();
panel.setLayout(new FlowLayout(FlowLayout.LEFT));
addField(panel, days, " days");
return panel;
}
public JPanel monthsPanel()
{
JPanel panel = new JPanel();
panel.setLayout(new FlowLayout(FlowLayout.LEFT));
addField(panel, months, " months");
return panel;
}
public JPanel yearsPanel()
{
JPanel panel = new JPanel();
panel.setLayout(new FlowLayout(FlowLayout.LEFT));
addField(panel, years, " years");
return panel;
}
public void addField(JPanel panel, JTextField field, String label)
{
Dimension size = new Dimension(30, 20);
field.setPreferredSize(size);
field.setMinimumSize(size);
field.setMaximumSize(size);
panel.add(field);
panel.add(new JLabel(label));
}
public String name()
{
return name.getText();
}
public int days()
{
return Integer.parseInt(days.getText());
}
public int months()
{
return Integer.parseInt(months.getText());
}
public int years()
{
return Integer.parseInt(years.getText());
}
public void clear()
{
name.setText("");
days.setText("");
months.setText("");
years.setText("");
}
}
Do you ever actually construct the LeftInputPanel anywhere? (One would think you'd be getting a null pointer exception in the code at the top).
JPanels are extensions of Component. That means you can always call Component.getParent() to get the immediate container of your component and using that reference, gain access to all sibling components in the container by using Container.getComponents().
More specifically, if you add your panels to the top level container using indexes, then you can specifically request the reference to a sibling component using its index.
This is one way to avoid passing around references to various panels, by using the parent container as a containment context (which is precisely what it is).
And once you have the reference, a class is a class and you obviously can call all visible methods.
What is not working and what are you expecting to happen?
If you expect to be calling a method on an existing object from another object, that is perfectly doable, provided the method is public. The fact that these objects are JPanels are irrelevant.
What you should do is learn how to use the debugger to figure out if your method is being called and the println is occuring but the name is empty, or your method is not called, or any other problem.
If you're using Eclipse, there are some great debugging video tutorials here. But even if you're not using Eclipse you can check them out, and can apply them to whatever IDE you're using. It'll be far more efficient than sprinkling System.out.printlns here and there.
You shouldn't name methods like attributes. For instance, name() should be getName() or something like that. Might solve your problem.
There are a couple things that I see as missing here:
within your actionPerformed method, you declare a field and without trying to initialize it, you try to access it. This will be caught by the compiler.
I dont see anywhere that you create an AllocateListener or attach it to anything in your panel that would trigger the actionPerformed method.