Java JTabbedPane, update others tab JLabel value? - java

I have 2 JTabbedPane. I am unable to refresh the data. PLease help, here is my code:
pane1:
//.. some codes...
// This is the ButtonListener
private class ButtonListener implements ActionListener
{
public void actionPerformed (ActionEvent event)
{
userInput = tf.getText(); // tf is JTextField
//System.out.println("the input is "+ finalInput);
pane2.updateData(userInput);
}
}
pane2:
public void updateData(String s){
System.out.println("Update data function is called");
labelUser.setFont(new Font("Arial", Font.BOLD, 30));
labelUser.setText("Updated text here " + s);
}
Here is my main class:
import java.awt.*;
import javax.swing.*;
public class Main {
public static Pane2 p2 = new Pane2();
public static void main(String[] args) {
JFrame f= new JFrame ("My Frame");
f.setDefaultCloseOperation (JFrame .EXIT_ON_CLOSE);
JTabbedPane tp = new JTabbedPane();
p2 = new Pane2();
tp.addTab("Pane1", new PaneFirst(p2));
tp.addTab("Pane2", new PaneSecond());
f.add(tp);
f.pack();
f.setVisible(true);
}
}
The labelUser never updates, but I trace the updateData function, its being called. Why is the text in labelUser not being updated?
EDIT:
"labelUser" come from pane2.java class.

Note: Apparently this didn't fix the problem.
One thing to try would be:
public void updateData(String s){
System.out.println("Update data function is called");
labelUser.setFont(new Font("Arial", Font.BOLD, 30));
labelUser.setText("Updated text here " + s);
repaint(); // add this line to tell your pane to repaint itself
}
There is a chance that your panel is just not getting repainted.

Might be a typo but - in actionPerformed() you store the content of the textfield in userInput but use finalInput to update pane2.

Related

How do you obtain 2 inputs from a user in Jtextfield?

I want the user to type a name for player one and press enter and then for the textfield to be blank again so that the user can type in a name for player 2. so far I can only get player one's name as input but not player two. For some reason my code isn't working. Any help would be greatly appreciated. Thanks in advance.
import java.lang.*;
import java.util.*;
import java.util.List;
import java.io.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
public class mainClass extends JPanel implements ActionListener {
//constant variables to use
static String playerOneName;
static String playerTwoName;
static boolean playerOneNameSet;
static boolean playerTwoNameSet;
private static final long serialVersionUID = 1L;
public mainClass() {
}
public void paintComponent(Graphics g) {
//set background color to white
g.setColor(Color.white);
g.fillRect(0, 0, getWidth(), getHeight());
}
public static void initializeBoard() {
}
public static void main(String[] args) {
// title of frame
JFrame frame = new JFrame("Risk");
JTextField textField = new JTextField(20);
frame.add(textField, BorderLayout.SOUTH);
JLabel welcome = new JLabel("");
welcome.setText("Please Enter name for Player 1 in the text box at the bottom");
frame.add(welcome,BorderLayout.NORTH);
//action listener listens for enter key
textField.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
playerOneName= textField.getText();
System.out.println(playerOneName);
playerOneNameSet = true;
System.out.println(playerOneNameSet);
}
});
if(playerOneNameSet == true) {
JTextField textField2 = new JTextField(20);
frame.add(textField2, BorderLayout.SOUTH);
JLabel welcome2 = new JLabel("");
welcome2.setText("Please Enter name for Player 2 in the text box at the bottom");
frame.add(welcome2,BorderLayout.NORTH);
//action listener listens for enter key
textField2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
playerTwoName= textField2.getText();
System.out.println(playerTwoName);
playerTwoNameSet = true;
System.out.println(playerTwoNameSet);
}
});
}
// make sure it closes correctly
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//frame size in pixels
final int FRAME_WIDTH = 1000;
final int FRAME_HEIGHT = 700;
frame.setSize(FRAME_WIDTH,FRAME_HEIGHT);
// makes sure the frame is visible
frame.setVisible(true);
mainClass main = new mainClass();
frame.add(main);
}
#Override
public void actionPerformed(ActionEvent e) {
}
}
There is one logical error in your code.
If you want to use only one JTextField for two inputs, you do not need to create
two JTextField. Just handle the ActionEvent and update only that JTextField. Here is the code for that:
textField.addActionListener(new java.awt.event.ActionListener()
{
public void actionPerformed(java.awt.event.ActionEvent evt)
{
if (!playerOneNameSet)
{
playerOneName = textField.getText();
textField.setText("");
welcome.setText("Please Enter name for Player 2 in the text box at the
bottom");
playerOneNameSet = true;
}
else
{
playerTwoName = textField.getText();
textField.setText("");
}
}
});
The if part after that is not required. It will also eliminate the use of playerTwoNameSet.
If you want to use two JTextField, then you have to do it in the start properly without any logical flaw.
Logical Error in Detail:
Let me try to show you the flow of your program.
public static void main(String[] args)
{
// title of frame
JFrame frame = new JFrame("Risk");
.
.
.
.
//action listener listens for enter key
textField.addActionListener(new java.awt.event.ActionListener()
{
public void actionPerformed(java.awt.event.ActionEvent evt)
{
playerOneName= textField.getText();
System.out.println(playerOneName);
playerOneNameSet = true;
System.out.println(playerOneNameSet);
}
});
Your code is all good till here. After the above line, this happens
if(playerOneNameSet == true) //It is never executed
The reason this happens because playerOneNameSet is a static variable and its default value is false. This line is only executed once. Once your GUI is created, the main() method will not be called again until you run it again. After that, the control passes to the one JTextField that was created, that too when any ActionEvent is generated. It will never go to the if line after that.
I hope I have helped you. Do comment for any further problems.

JButton's actionPerformed doesn't change JTextField's text by using .setText() method

I have this code... in it it has a problem as in title: JTextField's text doesn't change when clicking the button. I don't know what the problem is, but I think actionPerformed is executed as the message dialog appears. I tried to use a constructor (of class Start) (instead of function "doIt") but it doesn't work either.
import javax.swing.*;
import java.awt.FlowLayout;
import java.awt.*;
import java.awt.event.*;
public class PalTransfer
{
public static void main(String[] args)
{
Starter starter = new Starter();
starter.doIt();
}
}
class Starter
{
JFrame PTMainFrame = new JFrame("In/Out - arch - access, ...");
JTextField TextFieldOfIP = new JTextField(20);
//String string = "I AM START OF STARTER";
void doIt()
{
PTMainFrame.setSize(900, 400); // Set the frame size
PTMainFrame.setLocationRelativeTo(null);
PTMainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTextField TextFieldOfIP = new JTextField(20);
JButton jBtn = new JButton("I AM A BUTTON!");
PTMainFrame.add(jBtn);
PTMainFrame.add(TextFieldOfIP);
FlowLayout layoutManager = new FlowLayout(0,10,5);
PTMainFrame.setLayout(layoutManager);
TextFieldOfIP.setText("I am doIt() method!"); //+++++++++++++++++++++++++++
jBtn.addActionListener(new ButtonListener());
PTMainFrame.setVisible(true); // to do // put later
}
class ButtonListener implements ActionListener
{
#Override
public void actionPerformed(ActionEvent e)
{
JOptionPane.showMessageDialog(null, "hello?");
TextFieldOfIP.setText("I am actionPerformed of JButton!");
}
}
}
Why have you defined this twice.
JTextField TextFieldOfIP = new JTextField(20);
Remove it from the DoIt() method it will work.
You have your class attribute TextFieldOfIP that your ButtonListeners is doing the setText on. But additional you have a local variable called TextFieldOfIP in your doIt() method. And thats the object you are placing on your JFrame.
Remove this redefinition line: JTextField TextFieldOfIP = new JTextField(20); of your doIt() method. Then you are placing the same object on your JFrame that your ButtonListener is doing the setText on and everything will work as expected.

Use KeyListener in a loop

I don't have a lot of experience with KeyListeners but I used one in my application and it works fine except I need to wait for input before my program can continue. For this I made a while loop that loops until the String temp is not null (which would mean there would be input).
The problem is there is no way to type in the JTextField (called input). Below is code from my two methods that are supposed to work together so that the text in my JTextField (input) can be returned (as temp). I'm not sure why this doesn't work or how to fix it.
The keyPressed method for my KeyListener:
public void keyPressed(KeyEvent e)
{
//only sends text if the enter key is pressed
if (e.getKeyCode()==KeyEvent.VK_ENTER)
{
//if there really is text
if (!input.getText().equals(""))
{
//String temp is changed from null to input
temp=input.getText();
//text sent to another JTextField
output.append(temp+"\n");
//input no longer has text
input.setText("");
}
}
}
The method thats trying to get text, also in my KeyListener class
public String getTemp()
{
booleans isNull=temp==null;
//loops until temp is not null
while (isNull)
{
//unnecessary line of code, only used so the loop not empty
isNull=checkTemp();
}
return temp;
}
public boolean checkTemp()
{
return temp==null;
}
Your while loop is a common console program construct, but understand that you're not creating a console program here but rather an event-driven GUI, and in this situation, the while loop fights against the Swing GUI library, and you need to get rid of it. Instead of a while loop with continual polling you now want to respond to events, and if you're listening for user input into a JTextField do not use a KeyListener as this low-level listener can cause unwanted side effects. Instead add a DocumentListener to the JTextField's Document.
Edit: You're listening for the enter key, and so the solution is even easier: add an ActionListener to the JTextField!
e.g.,
input.addActionListener(e -> {
String text = input.getText().trim();
if (text.isEmpty()) {
return;
}
output.append(text + "\n");
input.setText("");
});
More complete example:
import java.awt.BorderLayout;
import java.awt.event.ActionListener;
import javax.swing.*;
public class ChatBox extends JPanel {
private static final int COLS = 40;
private JTextField input = new JTextField(COLS);
private JTextArea output = new JTextArea(20, COLS);
private JButton submitButton = new JButton("Submit");
public ChatBox() {
output.setFocusable(false); // user can't get into output
JScrollPane scrollPane = new JScrollPane(output);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
ActionListener inputListener = e -> {
String text = input.getText().trim();
if (text.isEmpty()) {
return;
}
output.append(text + "\n");
input.setText("");
input.requestFocusInWindow();
};
input.addActionListener(inputListener);
submitButton.addActionListener(inputListener);
JPanel bottomPanel = new JPanel();
bottomPanel.setLayout(new BoxLayout(bottomPanel, BoxLayout.LINE_AXIS));
bottomPanel.add(input);
bottomPanel.add(submitButton);
setLayout(new BorderLayout());
add(scrollPane, BorderLayout.CENTER);
add(bottomPanel, BorderLayout.PAGE_END);
}
private static void createAndShowGui() {
ChatBox mainPanel = new ChatBox();
JFrame frame = new JFrame("Chat Box");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}

Using an Action Listener to change a JPanel's contents [duplicate]

This question is about Frames, Java and Processing.
This questions sounds pretty convoluted but its really not. I'll try keep this to a simple minimum. I'm creating a small ball in a maze game to get my head around physics and rendering. It's been a good experience so far but I've hit a bit of a brick wall.
The general layout I decided on was to contain PApplets within a AWT Frame and have the Frame close. The reason for this is because I was told that you should only have on instance of a Papplet at a time.
PApplet is the Applet class in Processing, a rendering library.
I have 3 classes here including the main
public class Menu extends PApplet
{
//images and buttons
PImage background, playbtn1, playbtn2, hsbtn1, hsbtn2, abbtn1, abbtn2, exbtn1, exbtn2;
FBox pBtn, hBtn, eBtn;
FWorld menu;
//simple constructor
public Menu()
{
}
public void setup()
{
size(600, 400);
smooth();
Fisica.init(this);
menu = new FWorld();
//loading and placing images
background = loadImage("MenuAlt.jpg");
System.out.println(background);
playbtn1 = loadImage("play1.gif");
playbtn2 = loadImage("play2.gif");
hsbtn1 = loadImage("high1.gif");
hsbtn2 = loadImage("high2.gif");
exbtn1 = loadImage("exit1.gif");
exbtn2 = loadImage("exit2.gif");
//loading and placing buttons
pBtn = new FBox(120, 150);
pBtn.setPosition(135, 215);
pBtn.setDrawable(false);
hBtn = new FBox(120, 150);
hBtn.setPosition(295, 215);
hBtn.setDrawable(false);
eBtn = new FBox(120, 150);
eBtn.setPosition(455, 215);
eBtn.setDrawable(false);
//add item to world
menu.add(pBtn);
menu.add(hBtn);
menu.add(eBtn);
}
public void draw()
{
image(background, 0, 0);
image(playbtn1, 80, 140);
image(hsbtn1, 237, 135);
image(exbtn1, 400, 140);
mouseOver();
menu.draw();
}
//close this frame an open a new level, high score or exit
//depending on what the use clicks
public void mousePressed()
{
FBody pressed = menu.getBody(mouseX, mouseY);
if (pressed == pBtn)
{
System.out.println("play game");
this.getParent().getParent().getParent().getParent().setVisible(false);
ExampleFrame x = new ExampleFrame(new Level("level1.txt"));
x.setLocation(this.getParent().getParent().getParent().getParent().getLocation());
}
if (pressed == hBtn)
{
System.out.println("high scores");
this.getParent().getParent().getParent().getParent().setVisible(false);
/* these are just for finding the parent
System.out.println(this.getName());
System.out.println(this.getParent().getName());
System.out.println(this.getParent().getParent().getName());
System.out.println(this.getParent().getParent().getParent().getName());
System.out.println(this.getParent().getParent().getParent().getParent().getName());
*/
ExampleFrame x = new ExampleFrame(new HighScores()); //for testing, you can change this to new menu()
x.setLocation(this.getParent().getParent().getParent().getParent().getLocation());
}
if (pressed == eBtn)
{
System.out.println("exit");
System.exit(0);
}
}
the exampleFrame class
public class ExampleFrame extends JFrame
{
PApplet app;
public ExampleFrame(PApplet emApp)
{
super("Ball Maze Game");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setLocation(200, 200);
app = emApp;
setSize(615,438);
setVisible(true);
setLayout(new BorderLayout());
add(app, BorderLayout.CENTER);
app.init();
}
}
the main
public class Main
{
public static void main(String[] args)
{
ExampleFrame x = new ExampleFrame(new Menu());
}
}
What needs to happen when mousePressed == ebtn is all the stuff in the Frame will be removed and a Highscores Screen will be loaded. highscores is almost the same as menu. There is no need to post code as there is enough here.
The second class is the one which acts as a frame and holds the PApplet
Bottom line, has anyone have any idea how to call the Frame methods from the PApplet or another way to remove all PApplets contents and load another PApplet in?
What needs to happen when mousePressed == ebtn is all the stuff in the Frame will be removed and a Highscores Screen will be loaded
The demo. below of a nested CardLayout adds an ActionListener instead of a MouseListener. It reacts to both mouse and keyboard input.
There are a multitude of other ways to include more than one GUI element in the same screen space. Off the top of my head, JTabbedPane, JSplitPane, JDesktopPane/JInternalFrame, popping the high scores in a JDialog or JOptionPane..
Screenshots
CardLayoutDemo.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class CardLayoutDemo {
public static void main(String[] args) {
Runnable r = new Runnable () {
public void run() {
final JRadioButton game = new JRadioButton("Game", true);
JRadioButton highScores = new JRadioButton("High Scores");
ButtonGroup bg = new ButtonGroup();
bg.add( game );
bg.add( highScores );
JPanel buttons = new JPanel(new
FlowLayout(FlowLayout.CENTER, 5, 5));
buttons.add( game );
buttons.add( highScores );
JPanel gui = new JPanel(new BorderLayout(5,5));
gui.add(buttons, BorderLayout.SOUTH);
final CardLayout cl = new CardLayout();
final JPanel cards = new JPanel(cl);
gui.add(cards);
cards.add(new JLabel("Level 1"), "game");
cards.add(new JLabel("High Scores"), "scores");
ActionListener al = new ActionListener(){
public void actionPerformed(ActionEvent ae) {
if (game.isSelected()) {
cl.show(cards, "game");
} else {
cl.show(cards, "scores");
}
}
};
game.addActionListener(al);
highScores.addActionListener(al);
JOptionPane.showMessageDialog(null, gui);
}
};
SwingUtilities.invokeLater(r);
}
}
In order to answer How to call the Frame methods from the PApplet?, I have modified your code snippet to bare minimum. In this modified version when the user click mouse button a System.out is fired.
Now there are two ways in which you can access your Frame object. But before that let me state these two points:
When you create a PApplet like new ExampleFrame(new Menu()); and add it in your JFrame like this add(app, BorderLayout.CENTER); then a complex hierarchy of windows/panels are created.
Like this:
javax.swing.JPanel
javax.swing.JLayeredPane
javax.swing.JRootPane
test.ExampleFrame
PApplet provides a public field for setting and accessing your frame object. And amazingly it is called frame :). You can set it before calling app.init();
>>Code
** Checkout the comments in the code**
Modified ExampleFrame.java
import java.awt.BorderLayout;
import javax.swing.JFrame;
import processing.core.PApplet;
public class ExampleFrame extends JFrame
{
private static final long serialVersionUID = 4792534036194728580L;
PApplet app;
public ExampleFrame(PApplet emApp)
{
super("Ball Maze Game");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setLocation(200, 200);
app = emApp;
setSize(615,438);
setVisible(true);
setLayout(new BorderLayout());
add(app, BorderLayout.CENTER);
// Setting my frame object
app.frame = this;
app.init();
}
// Sample Method
public void sampleMethod(String msg)
{
System.out.println("I think '"+ msg +"' called me !!");
}
}
Modified Menu.java
import java.awt.Container;
import processing.core.PApplet;
import processing.core.PImage;
public class Menu extends PApplet
{
private static final long serialVersionUID = -6557167654705489372L;
PImage background;
static String tab = "";
//simple constructor
public Menu()
{
}
public void setup()
{
size(600, 400);
smooth();
background = loadImage("C:/temp/background.jpg");
}
public void draw()
{
image(background, 0, 0);
}
public void mousePressed()
{
Container p = getParent();
tab = "";
// FIRST WAY OF ACCESSING PARENT FRAME
while(p != null)
{
//printParentTree(p);
if(p instanceof ExampleFrame)
{
ExampleFrame myframe = (ExampleFrame)p;
myframe.sampleMethod("First Way");
break;
}
p = p.getParent();
}
// SECOND WAY OF ACCESSING PARENT FRAME
if(frame != null && (frame instanceof ExampleFrame))
{
ExampleFrame myframe = (ExampleFrame)p;
myframe.sampleMethod("Second Way");
}
}
void printParentTree(Container p)
{
System.out.println(tab+p.getClass().getName());
tab +='\t';
}
}
Checkout the public void mousePressed() method.
For completeness, I am also including Main.java.
public class Main {
public static void main(String[] args){
new ExampleFrame(new Menu());
}
}
Now to answer Remove all PApplets contents and load another PApplet in
Well I have not tested it. But you can add a JPanel to your JApplet and do all your drawing on that i.e creating child controls etc. When feel like redrawing then call JPanel.removeAll(). Which as per javadoc:
Removes all the components from this
container. This method also notifies
the layout manager to remove the
components from this container's
layout via the removeLayoutComponent
method.
After this call repaint on the JPanel. Try it out, it might work :).

Can only display one item at a time in GUI

I'm trying to add labels, button, etc. to my GUI but the program only displays the last item added to the window. I don't understand why they are not going one after the other. It almost seems like I am placing them on top of each other. Attached is my code.
import java.awt.*;
import java.awt.event.*;
public class ZooGUIStafford extends Frame {
//Text fields for animal input
TextField ani1, ani2, ani3, ani4, ani5;
public ZooGUIStafford()
{
//Size of window
this.setTitle("Zoo Database");
this.setSize(400, 400);
this.setVisible(true);
//Welcome label
Label welcome = new Label("Welcome to the Zoo Database!");
this.add(welcome);
Label an1 = new Label("Enter animal type 1: ");
this.add(an1);
addWindowListener(new MyWindowAdapter(this));
}
class MyWindowAdapter extends WindowAdapter{
ZooGUIStafford myWindow = null;
MyWindowAdapter(ZooGUIStafford myWindow)
{
this.myWindow = myWindow;
}
public void windowClosing(WindowEvent e)
{
myWindow.setVisible(false);
}
}
public static void main(String args[])
{
new ZooGUIStafford();
}
}
please,
add layout,
this.setLayout(new FlowLayout());
OutPut :

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