How to make two thread communicate through handler? - java

I have form that button can auto re-size their size when mouse hover on button and default their size when mouse is exited. It work normally first time but after i try it more than one time their size is enlarged that i can not control normally.
ImageIcon ima=new ImageIcon("C:\\Users\\chen rina\\Pictures\\win.png");
ImageIcon icon;
Thread thr;
Runnable r=new Runnable() {
#Override
public void run() {
int i=40;
while(i!=80){
try{
Thread.sleep(20);
Image scale=ima.getImage().getScaledInstance(i,i,Image.SCALE_FAST);
icon=new ImageIcon(scale);
btn2.setIcon(icon);
i=i+5;
}
catch(Exception ex){}
}
}
};
private void btn2MouseEntered(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
thr=new Thread(r);
thr.start();
}
Runnable res=new Runnable() {
int i;
#Override
public void run() {
int i=80;
while(i!=40){
try{
Thread.sleep(20);
Image scale=ima.getImage().getScaledInstance(i,i,Image.SCALE_AREA_AVERAGING);
icon=new ImageIcon(scale);
btn2.setIcon(icon);
i=i-5;
}
catch(Exception ex){}
}
}
};
private void btn2MouseExited(java.awt.event.MouseEvent evt) {
thr=new Thread(res);
thr.start();
}

Your code violates Swing thread integrity rules by making Swing calls, here setIcon(...) from within a background state. Having said that, why not simplify all of this by:
Reading in and creating and storing your ImageIcons once and only once
Never ignore exceptions as you're doing. That's unsafe coding.
Most important, use a Swing Timer to simply swap icons every 20 msec, and have no fear about violating Swing threading rules.
Your grow Timer's ActionListener could be as simple as this:
// a private inner class
private class GrowListener implements ActionListener {
private int index = 0;
#Override
public void actionPerformed(ActionEvent e) {
// assuming the button is called button and the list iconList
button.setIcon(iconList.get(index));
index++;
if (index >= iconList.size()) {
((Timer) e.getSource()).stop();
}
}
}
The iconList would look something like:
private List<Icon> iconList = new ArrayList<>();
And you could fill it with code looking something like:
for (int i = startLength; i <= endLength; i += step) {
Image img = originalImg.getScaledInstance(i, i, Image.SCALE_FAST);
iconList.add(new ImageIcon(img));
}
And a more complete and runnable example:
import java.awt.Dimension;
import java.awt.Image;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import javax.imageio.ImageIO;
import javax.swing.*;
#SuppressWarnings("serial")
public class ResizeIconTest extends JPanel {
private static final int PREF_W = 400;
private static final int PREF_H = PREF_W;
private static final int START_LENGTH = 40;
private static final int END_LENGTH = 120;
private static final int STEP = 5;
private static final int TIMER_DELAY = 20;
private static final String URL_SPEC = "https://upload.wikimedia.org/wikipedia/commons/"
+ "thumb/2/2b/Oryx_gazella_-_Etosha_2014_square_crop.jpg/"
+ "600px-Oryx_gazella_-_Etosha_2014_square_crop.jpg";
private JButton button = new JButton();
private ResizeIcon resizeIcon;
public ResizeIconTest() throws IOException {
add(button);
URL imageUrl = new URL(URL_SPEC);
BufferedImage originalImg = ImageIO.read(imageUrl);
resizeIcon = new ResizeIcon(button, originalImg, START_LENGTH,
END_LENGTH, STEP, TIMER_DELAY);
button.setIcon(resizeIcon.getSmallestIcon());
button.addMouseListener(new MouseAdapter() {
#Override
public void mouseEntered(MouseEvent e) {
resizeIcon.grow();
}
#Override
public void mouseExited(MouseEvent e) {
resizeIcon.shrink();
}
});
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
private static void createAndShowGui() {
ResizeIconTest mainPanel = null;
try {
mainPanel = new ResizeIconTest();
} catch (IOException e) {
e.printStackTrace();
System.exit(-1);
}
JFrame frame = new JFrame("ResizeIconTest");
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 ResizeIcon {
private List<Icon> iconList = new ArrayList<>();
private AbstractButton button;
private int delayTime;
private Timer growTimer;
private Timer shrinkTimer;
public ResizeIcon(AbstractButton button, BufferedImage originalImg,
int startLength, int endLength, int step, int delayTime) {
this.button = button;
this.delayTime = delayTime;
for (int i = startLength; i <= endLength; i += step) {
Image img = originalImg.getScaledInstance(i, i, Image.SCALE_FAST);
iconList.add(new ImageIcon(img));
}
}
public Icon getSmallestIcon() {
return iconList.get(0);
}
public void grow() {
if (growTimer != null && growTimer.isRunning()) {
return; // let's not run this multiple times
}
if (button.getIcon() == iconList.get(iconList.size() - 1)) {
return; // don't run if already at largest size
}
growTimer = new Timer(delayTime, new GrowListener());
growTimer.start();
}
public void shrink() {
if (shrinkTimer != null && shrinkTimer.isRunning()) {
return; // let's not run this multiple times
}
if (button.getIcon() == iconList.get(0)) {
return; // don't run if already at smallest size
}
shrinkTimer = new Timer(delayTime, new ShrinkListener());
shrinkTimer.start();
}
private class GrowListener implements ActionListener {
private int index = 0;
#Override
public void actionPerformed(ActionEvent e) {
button.setIcon(iconList.get(index));
index++;
if (index >= iconList.size()) {
((Timer) e.getSource()).stop();
}
}
}
private class ShrinkListener implements ActionListener {
private int index = iconList.size() - 1;
#Override
public void actionPerformed(ActionEvent e) {
button.setIcon(iconList.get(index));
index--;
if (index < 0) {
((Timer) e.getSource()).stop();
}
}
}
}

Related

Java - using Swing Timer to do a task every 1/100 seconds

I'm trying to make a counter that counts every 1/100 of a second until the program is closed, but it appears to be a little slower than that. Here's what I have:
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.FlowLayout;
import javax.swing.*;
public class counterTest extends JFrame
{
JLabel label;
long counter = 0;
String counterStr;
public counterTest()
{
super("counter");
ActionListener listener = new ActionListener()
{
public void actionPerformed(ActionEvent event)
{
counter++;
counterStr = Long.toString(counter);
label.setText(counterStr);
}
};
label = new JLabel();
setLayout(new FlowLayout());
setSize(100,100);
setResizable(false);
setVisible(true);
add(label);
javax.swing.Timer timer = new javax.swing.Timer(10, listener);
timer.setInitialDelay(0);
timer.start();
}
public static void main(String args[])
{
counterTest c = new counterTest();
c.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
The "10" in the line where I declare "timer" should cause "listener" to run every 1/100 second, correct? It seems a bit slower... what is wrong here?
EDIT: Full code posted.
A Swing Timer is not built to be 100% accurate, and 1/100 may be pushing it's limits. Consider using the Swing Timer but displaying absolute time differences, calculated by getting the time.
e.g.,
private class MyTimerListener implements ActionListener {
private long startTime = 0;
public void reset() {
startTime = System.currentTimeMillis();
}
#Override
public void actionPerformed(ActionEvent e) {
long time = System.currentTimeMillis();
long delta = (time - startTime) / 10L;
label.setText(String.valueOf(delta));
}
}
OK, my mini-program:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import javax.swing.*;
#SuppressWarnings("serial")
public class MyTimer2 extends JPanel implements GuiTimer {
private static final String TIME_FORMAT = "%03d:%03d";
private static final int EXTRA_WIDTH = 50;
private JLabel timerLabel = new JLabel();
private TimerControl timerControl = new TimerControl(this);
public MyTimer2() {
JPanel topPanel = new JPanel();
topPanel.add(new JLabel("Time:"));
topPanel.add(timerLabel);
JPanel centerPanel = new JPanel();
centerPanel.add(new JButton(timerControl.getStartAction()));
centerPanel.add(new JButton(timerControl.getStopAction()));
setLayout(new BorderLayout());
add(topPanel, BorderLayout.PAGE_START);
add(centerPanel, BorderLayout.CENTER);
setDeltaTime(0);
}
#Override
public void setDeltaTime(int delta) {
int secs = (int) delta / 1000;
int mSecs = (int) delta % 1000;
timerLabel.setText(String.format(TIME_FORMAT, secs, mSecs));
}
#Override
public Dimension getPreferredSize() {
Dimension superSz = super.getPreferredSize();
if (isPreferredSizeSet()) {
return superSz;
}
int prefW = superSz.width + EXTRA_WIDTH;
int prefH = superSz.height;
return new Dimension(prefW, prefH);
}
private static void createAndShowGui() {
MyTimer2 mainPanel = new MyTimer2();
JFrame frame = new JFrame("MyTimer2");
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();
}
});
}
}
interface GuiTimer {
public abstract void setDeltaTime(int delta);
}
#SuppressWarnings("serial")
class TimerControl {
private static final int TIMER_DELAY = 10;
private long startTime = 0;
private long pauseTime = 0;
private Timer timer;
private GuiTimer gui;
private StartAction startAction = new StartAction();
private StopAction stopAction = new StopAction();
public TimerControl(GuiTimer gui) {
this.gui = gui;
}
public Action getStopAction() {
return stopAction;
}
public Action getStartAction() {
return startAction;
}
enum State {
START("Start", KeyEvent.VK_S),
PAUSE("Pause", KeyEvent.VK_P);
private String text;
private int mnemonic;
private State(String text, int mnemonic) {
this.text = text;
this.mnemonic = mnemonic;
}
public String getText() {
return text;
}
public int getMnemonic() {
return mnemonic;
}
};
private class StartAction extends AbstractAction {
private State state;
public StartAction() {
setState(State.START);
}
public final void setState(State state) {
this.state = state;
putValue(NAME, state.getText());
putValue(MNEMONIC_KEY, state.getMnemonic());
}
#Override
public void actionPerformed(ActionEvent e) {
if (state == State.START) {
if (timer != null && timer.isRunning()) {
return; // the timer's already running
}
setState(State.PAUSE);
if (startTime <= 0) {
startTime = System.currentTimeMillis();
timer = new Timer(TIMER_DELAY, new TimerListener());
} else {
startTime += System.currentTimeMillis() - pauseTime;
}
timer.start();
} else if (state == State.PAUSE) {
setState(State.START);
pauseTime = System.currentTimeMillis();
timer.stop();
}
}
}
private class StopAction extends AbstractAction {
public StopAction() {
super("Stop");
int mnemonic = KeyEvent.VK_T;
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
if (timer == null) {
return;
}
timer.stop();
startAction.setState(State.START);
startTime = 0;
}
}
private class TimerListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
long time = System.currentTimeMillis();
long delta = time - startTime;
gui.setDeltaTime((int) delta);
}
}
}

Is java swing not working in java 8 update 45?

The following code is working in jdk 1.8 update 45 and in java 1.8 update 31 but NOT in java 1.8 update 45.
The program is a button moving back and forth until the user presses the button and makes it stop and the text is changed to "MOVE". When the button is pressed again, the button starts moving and the text is changed to "STOP".
In java 8 update 45, the button does not start moving but the text changes. Why?
package mainpackage;
import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class mainPanel implements ActionListener {
JFrame frame1;
JPanel panel1;
JButton button = new JButton("STOP");
boolean buttonPressed = false;
boolean move = true;
// 0 = left & 1 = right
int direction = 1;
int x = 0;
public static void main(String[] args) {
new mainPanel().loadGUI();
}
public void loadGUI() {
frame1 = new JFrame("Moving button");
frame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame1.setVisible(true);
frame1.setSize(300, 58);
frame1.setResizable(false);
panel1 = new JPanel(); // Xwidth=294, Yheight=272
panel1.setSize(300, 30);
panel1.setLayout(null);
frame1.add(panel1);
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
frame1.setLocation(dim.width/2-frame1.getSize().width/2, dim.height/2-frame1.getSize().height/2);
button.setSize(80, 30); //X, Y
panel1.add(button);
button.addActionListener(this);
while(true) moveButton();
}
public void moveButton() {
while(move == true) {
switch(direction) {
// left
case 0: {
while(x > 0) {
if(move == false) break;
button.setLocation(x, 0);
x--;
panel1.repaint();
try {
Thread.sleep(10);
} catch (InterruptedException ex) {
Logger.getLogger(mainPanel.class.getName()).log(Level.SEVERE, null, ex);
}
}
if(buttonPressed == true) {
direction = 0;
buttonPressed = false;
} else if(buttonPressed == false) {
direction = 1;
buttonPressed = false;
}
}
// right
case 1: {
while(x < panel1.getWidth() - button.getWidth()) {
if(move == false) break;
button.setLocation(x, 0);
x++;
panel1.repaint();
try {
Thread.sleep(10);
} catch (InterruptedException ex) {
Logger.getLogger(mainPanel.class.getName()).log(Level.SEVERE, null, ex);
}
}
if(buttonPressed == true) {
direction = 1;
buttonPressed=false;
} else if(buttonPressed == false) {
direction=0;
buttonPressed=false;
}
}
}
}
}
#Override
public void actionPerformed(ActionEvent e) {
if (move == true){
move=false;
} else if (move == false) {
move=true;
}
buttonPressed = true;
if((button.getText()).equals("STOP")) {
button.setText("MOVE");
} else button.setText("STOP");
}
}
Yours is broken code to begin with since it ignores Swing threading rules, and frankly I'm surprised that it worked in previous versions of Java. You're calling a while (true) loop that will tie up any thread that it is called in. Java 8 is correctly trying to start your Swing GUI on the Swing event thread, something that all Swing programs should do. If you get rid of the while (true) loops that risk being called on the Swing event dispatch thread, and instead use a Swing Timer your code should work. The Timer will run a loop in a background thread, but all code called repeatedly in its ActionListener will be called on the Swing event thread.
For example:
import java.awt.Dimension;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class MyMainPanel extends JPanel {
private static final int PREF_W = 300;
private static final int PREF_H = 30;
private static final int TIMER_DELAY = 20;
public static final int DELTA_X = 3;
private JButton moveButton = new JButton(new MoveButtonAction("Move"));
private Timer moveTimer = new Timer(TIMER_DELAY, new MoveTimerListener());
private boolean moveRight = true;
public MyMainPanel() {
moveButton.setSize(moveButton.getPreferredSize());
int y = (getPreferredSize().height - moveButton.getPreferredSize().height) / 2;
moveButton.setLocation(0, y);
setLayout(null); // !! lord I hate this
add(moveButton);
moveTimer.start();
}
#Override
public Dimension getPreferredSize() {
Dimension superSz = super.getPreferredSize();
if (isPreferredSizeSet()) {
return superSz;
}
int prefW = Math.max(superSz.width, PREF_W);
int prefH = Math.max(superSz.height, PREF_H);
return new Dimension(prefW, prefH);
}
private class MoveButtonAction extends AbstractAction {
public MoveButtonAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
moveRight = !moveRight;
}
}
private class MoveTimerListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
if (moveRight) {
if (moveButton.getLocation().x + moveButton.getWidth() >= getWidth()) {
moveRight = false;
}
} else {
if (moveButton.getLocation().x <= 0) {
moveRight = true;
}
}
int x = moveButton.getLocation().x + (moveRight ? DELTA_X : -DELTA_X);
int y = moveButton.getLocation().y;
moveButton.setLocation(new Point(x, y));
repaint();
}
}
private static void createAndShowGui() {
MyMainPanel mainPanel = new MyMainPanel();
JFrame frame = new JFrame("GUI Example");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
You will want to read up on Swing thread safety to see why your program is failing. See Lesson: Concurrency in Swing to see more on this.
Edit: code that stops and starts movement:
import java.awt.Dimension;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
#SuppressWarnings("serial")
public class MyMainPanel extends JPanel {
private static final String MOVE = "Move";
private static final String STOP = "Stop";
private static final int PREF_W = 300;
private static final int PREF_H = 30;
private static final int TIMER_DELAY = 20;
public static final int DELTA_X = 3;
private MoveButtonAction moveButtonAction = new MoveButtonAction(STOP);
private JButton moveButton = new JButton(moveButtonAction);
private Timer moveTimer = new Timer(TIMER_DELAY, new MoveTimerListener());
private boolean moveRight = true;
public MyMainPanel() {
moveButton.setSize(moveButton.getPreferredSize());
int y = (getPreferredSize().height - moveButton.getPreferredSize().height) / 2;
moveButton.setLocation(0, y);
setLayout(null); // !! lord I hate this
add(moveButton);
moveTimer.start();
}
#Override
public Dimension getPreferredSize() {
Dimension superSz = super.getPreferredSize();
if (isPreferredSizeSet()) {
return superSz;
}
int prefW = Math.max(superSz.width, PREF_W);
int prefH = Math.max(superSz.height, PREF_H);
return new Dimension(prefW, prefH);
}
private class MoveButtonAction extends AbstractAction {
public MoveButtonAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
if (MOVE.equals(getValue(NAME))) {
moveTimer.start();
putValue(NAME, STOP);
int mnemonic = (int) STOP.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
} else {
moveTimer.stop();
putValue(NAME, MOVE);
int mnemonic = (int) MOVE.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
AbstractButton button = (AbstractButton) e.getSource();
button.setSize(button.getPreferredSize());
repaint();
}
}
private class MoveTimerListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
if (moveRight) {
if (moveButton.getLocation().x + moveButton.getWidth() >= getWidth()) {
moveRight = false;
}
} else {
if (moveButton.getLocation().x <= 0) {
moveRight = true;
}
}
int x = moveButton.getLocation().x + (moveRight ? DELTA_X : -DELTA_X);
int y = moveButton.getLocation().y;
moveButton.setLocation(new Point(x, y));
repaint();
}
}
private static void createAndShowGui() {
MyMainPanel mainPanel = new MyMainPanel();
JFrame frame = new JFrame("GUI Example");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Just added some methods and fixed some lines in your code, you can try it now:
import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class mainPanel implements ActionListener {
JFrame frame1;
JPanel panel1;
JButton button = new JButton("START");
boolean buttonPressed = false;
boolean move = false;
Timer timer;
int direction = 1;
int x = 0;
public static void main(String[] args) {
new mainPanel().loadGUI();
}
public void loadGUI() {
frame1 = new JFrame("Moving button");
frame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame1.setVisible(true);
frame1.setSize(300, 58);
frame1.setResizable(false);
panel1 = new JPanel(); // Xwidth=294, Yheight=272
panel1.setSize(300, 30);
panel1.setLayout(null);
frame1.add(panel1);
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
frame1.setLocation(dim.width / 2 - frame1.getSize().width / 2, dim.height / 2 - frame1.getSize().height / 2);
button.setSize(80, 30); //X, Y
panel1.add(button);
button.addActionListener(this);
moveButton();
}
public void moveButton() {
if (timer == null) {
initTimer();
}
move = !move;
if (move) {
button.setText("STOP");
direction = (direction == 0) ? 1 : 0;
timer.start();
} else {
button.setText("MOVE");
timer.stop();
}
}
public void initTimer() {
timer = new Timer(10, (e) -> {
switch (direction) {
case 0: // right
x++;
if (x >= panel1.getWidth() - button.getWidth()) {
direction = 1;
}
break;
case 1: // left
x--;
if (x <= 0) {
direction = 0;
}
break;
}
button.setLocation(x, 0);
panel1.repaint();
});
}
#Override
public void actionPerformed(ActionEvent e) {
moveButton();
}
}

timer t = new timer(50, b); t.stop(); is not working

My t.stop(); method is not working. I am going crazy trying to figure out why my stop method is not working.
I'm using the a timer in my code and I can't get it to stop. Can anyone take a look at it and tell me what's going on?:
/*Gilberto Rose*/
package homework2;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class MultipleBalls extends JFrame implements ActionListener
{
int dx = 2;
int dy = 2;
int x = 1;
int y = 1;
int i = 0;
public static void main(String[] args)
{
Runnable balls = new Ball2();
Thread thread1 = new Thread(balls);
thread1.run();
}
#Override
public void actionPerformed(ActionEvent arg0)
{
repaint();
System.out.println(i++);
}
}// End of Ball class
class Ball2 extends JPanel implements Runnable
{
MultipleBalls b = new MultipleBalls();
JButton g = new JButton("resume");
JButton f = new JButton("suspend");
JButton e = new JButton("-1");
JButton d = new JButton("+1");
List<Ball2> L = new ArrayList<Ball2>();
Timer t = new Timer(50, b);
public int x = 6;
public void loopstop()
{
t.stop();
}// end of loopstop method
Ball2()
{
controller4();
controller3();
controller2();
controller();
add(d);
add(e);
add(f);
add(g);
}// End of Ball2 constructor
public void run()
{
Ball2 c = new Ball2();
b.setSize(500, 500);
b.setVisible(true);
b.add(c);
t.start();
} // End of run method
public void controller()
{
d.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
L.add(new Ball2());
}
});
}// End of controller
public void controller2()
{
e.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
System.out.println("subtracter");
L.remove(L.size()-1);
}
});
}// End of controller2
public void controller3()
{
f.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
loopstop();
}
});
}// End of controller3
public void controller4()
{
g.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
System.out.println("Resume");
}
});
}// End of controller4
public void paintComponent(Graphics g)
{
if(L.size() > 0)
{
int i = 0;
do
{
g.fillOval(L.get(i).ballx(), L.get(i).bally(), 90, 90);
i++;
}while(i < L.size() && true ); // End of Do while loop
}// End of if statement
}// End of paintComponent
MultipleBalls bb = new MultipleBalls();
public int ballx()
{
if (bb.x == 0 || bb.x == 500)
{
bb.dx *= -1;
} // End of if statement
bb.x += bb.dx;
return bb.x;
}
public int bally()
{
if (bb.y == 0 || bb.y == 500 )
{
bb.dy *= -1;
}// end of if statement
bb.y += bb.dy;
return bb.y;
}// End of bally
}// End of Ball2 class
Your code is extremely convoluted, I believe that it's suffering from something called cyclomatic complexity, so much so, it is difficult for you or us to see what object is creating what other object, and what is running what. And this is your problem. You have at least two MultipleBall objects, two Ball2 objects, and you're starting the Timer for one of the Ball2 objects and stopping it for the other.
The solution: simplify this code greatly.
Create one MultipleBalls object, just one.
Don't have MultipleBalls implement ActionListener. Rather use an anonymous inner class for your ActionListener and create it on the spot where you need it.
Create just one Ball2 object, just one.
Also note that you almost never call run() on a Thread object but rather start(), but having said that, I'm not even sure that you should be using a Thread object where you're using it.
Edit
My main class would be simple, and would simply have a main method and supporting method that gets things started. Something like:
public class MultipleBalls {
private static void createAndShowGui() {
BallsPanel mainPanel = new BallsPanel();
JFrame frame = new JFrame("Multiple Balls");
frame.setDefaultCloseOperation(JFrame.EXIT_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();
}
});
}
}
Edit
For an example of a separation of concerns:
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.swing.*;
public class MultipleBallsZ {
private static void createAndShowGui() {
BallsPanelZ ballsPanel = new BallsPanelZ();
new Control(ballsPanel);
JFrame frame = new JFrame("Multiple Balls");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(ballsPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
#SuppressWarnings("serial")
class BallsPanelZ extends JPanel {
private static final int TIMER_DELAY = 200;
private static final int PREF_W = 400;
private static final int PREF_H = PREF_W;
private Timer timer = new Timer(TIMER_DELAY, new TimerListener());
private int counter = 0;
private Control control = null;
public BallsPanelZ() {
timer.start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
public Timer getTimer() {
return timer;
}
private class TimerListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
counter++;
System.out.printf("Count: %03d%n", counter);
}
}
public void setControl(Control control) {
this.control = control;
for (Action action : control) {
add(new JButton(action));
}
}
}
#SuppressWarnings("serial")
class Control implements Iterable<Action> {
private List<Action> actionList = new ArrayList<>();
private BallsPanelZ ballsPanel;
public Control(BallsPanelZ ballsPanel) {
actionList.add(new PauseAction());
actionList.add(new ResumeAction());
this.ballsPanel = ballsPanel;
ballsPanel.setControl(this);
}
private class PauseAction extends AbstractAction {
public PauseAction() {
super ("Timer Pause");
putValue(MNEMONIC_KEY, KeyEvent.VK_P);
}
#Override
public void actionPerformed(ActionEvent e) {
ballsPanel.getTimer().stop();
}
}
private class ResumeAction extends AbstractAction {
public ResumeAction() {
super("Timer Resume");
putValue(MNEMONIC_KEY, KeyEvent.VK_R);
putValue(DISPLAYED_MNEMONIC_INDEX_KEY, 6);
}
#Override
public void actionPerformed(ActionEvent e) {
ballsPanel.getTimer().restart();
}
}
#Override
public Iterator<Action> iterator() {
return actionList.iterator();
}
}

JProgressBar doesn't update , can't find a clue

nice job , now i just wanna know why if i add into while loop the instruction System.out.println below the progress is shown on both , cmd and Pgbar in the Gui ?? :
while(progress < 99){
System.out.println("into while of PBar Thread progress = "+progress);
if(progress != Path.operationProgress){
operationProgressBar.setValue(progress);
progress = Path.operationProgress;
operationProgressBar.repaint(); } }
need some help around , i can't get the JProgressBar to update, i
can't use SwingWorker, i have to solve this without it . the variable
Path.operationProgress is a static variable from a "Path" class
instance, and it's updated from another thread, so i think the PBar
and Path instances are both executed in user's Threads and not in the
EDT . here is the Code of the progress bar :
import javax.swing.*;
public class Pbar extends Thread {
JProgressBar operationProgressBar;
public Pbar(JProgressBar operationProgressBar) {
this.operationProgressBar = operationProgressBar;
}
#Override
public void run() {
int progress = Path.operationProgress;
while(progress < 99) {
if(progress != Path.operationProgress) {
operationProgressBar.setValue(progress);
progress = Path.operationProgress;
operationProgressBar.repaint();
}}}
}
this is the action that launches the threads :
private javax.swing.JProgressBar operationProgressBar;
private javax.swing.JLabel pathImage;
private javax.swing.JButton simulatedAnnelingButton;
public class TSPGUI extends javax.swing.JFrame {
TSPMG tspInstance;
Path p, result;
String filename = "";
int neighborHood_Type = 1, i = 0;
// ......Constructor Stuff and init()
private void simulatedAnnelingButtonActionPerformed(java.awt.event.ActionEvent evt)
{
Thread sa = new Thread(){
#Override
public void run(){
result = p.SimulatedAnnealing(neighborHood_Type);
String lastCostString = result.Cost() + "";
lastCostLabel.setText(lastCostString);
}};
sa.start();
Pbar pb = new Pbar(operationProgressBar);
pb.start();
}
//Some other Stuff ...
}
If you can't use SwingWorker then use SwingUtilities.invokeLater, e.g.:
if (progress != Path.operationProgress) {
final int progressCopy = progress; // Probably not final so copy is needed
SwingUtilities.invokeLater(new Runnable() {
#Override
void run() {
operationsProgressBar.setValue(progressCopy);
}
});
}
Note: When doing this, everything used in run has to be final or there have to be other measures to access the variables. This code is symbolic in that regard.
You need to do operations on Swing components outside the event dispatching thread, there is no way around this.
I would use a PropertyChangeListener to allow you to make the annealing progress value a "bound" property of the class. Than any observer can follow this property if desired. For example:
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.*;
import javax.swing.event.SwingPropertyChangeSupport;
#SuppressWarnings("serial")
public class TspGui2 extends JPanel {
private static final String ANNEALING_PROGRESS = "Annealing Progress";
private JProgressBar progBar = new JProgressBar(0, 100);
private JLabel valueLabel = new JLabel();
private JButton beginAnnealingBtn = new JButton("Begin Annealing");
private MyAnnealing myAnnealing = new MyAnnealing(this);
public TspGui2() {
beginAnnealingBtn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
beginAnnealing();
}
});
myAnnealing.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
if (evt.getPropertyName().equals(MyAnnealing.ANNEALING)) {
// be sure this is done on the EDT
SwingUtilities.invokeLater(new Runnable() {
public void run() {
int annealedValue = myAnnealing.getAnnealedValue();
setValue(annealedValue);
if (annealedValue >= MyAnnealing.MAX_ANNEALED_VALUE) {
beginAnnealingBtn.setEnabled(true);
}
}
});
}
}
});
progBar.setString(ANNEALING_PROGRESS);
progBar.setStringPainted(true);
JPanel northPanel = new JPanel(new GridLayout(1, 0));
northPanel.add(beginAnnealingBtn);
northPanel.add(valueLabel);
setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
add(northPanel);
add(progBar);
}
public void setValue(int value) {
valueLabel.setText("Value:" + value);
progBar.setValue(value);
}
public void beginAnnealing() {
beginAnnealingBtn.setEnabled(false);
setValue(0);
myAnnealing.reset();
new Thread(new Runnable() {
public void run() {
myAnnealing.beginAnnealing();
}
}).start();
}
private static void createAndShowGui() {
TspGui2 mainPanel = new TspGui2();
JFrame frame = new JFrame("TspGui2");
frame.setDefaultCloseOperation(JFrame.EXIT_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 MyAnnealing {
public static final String ANNEALING = "Annealing";
public static final int MAX_ANNEALED_VALUE = 100;
private SwingPropertyChangeSupport propChangeSupport =
new SwingPropertyChangeSupport(this);
private TspGui2 gui;
private int annealedValue;
public MyAnnealing(TspGui2 gui) {
this.gui = gui;
}
public void addPropertyChangeListener(
PropertyChangeListener listener) {
propChangeSupport.addPropertyChangeListener(listener);
}
public void removePropertyChangeListener(
PropertyChangeListener listener) {
propChangeSupport.removePropertyChangeListener(listener);
}
public void reset() {
setAnnealedValue(0);
}
// simulate some long process...
public void beginAnnealing() {
long sleepDelay = 100;
while (annealedValue < MAX_ANNEALED_VALUE) {
setAnnealedValue(annealedValue + 1);
try {
Thread.sleep(sleepDelay);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
public int getAnnealedValue() {
return annealedValue;
}
private void setAnnealedValue(int value) {
final int oldValue = this.annealedValue;
this.annealedValue = value;
propChangeSupport.firePropertyChange(ANNEALING, oldValue, annealedValue);
}
}

how can i solve this error

This is the complete code :
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.lang.Thread;
class jProgressBar {
JProgressBar pb;
JButton start;
int i;
jProgressBar() {
buildGUI();
hookUpEvents();
}
public void buildGUI() {
JFrame fr=new JFrame("Progress Bar");
JPanel p=new JPanel();
p.setLayout(new FlowLayout(FlowLayout.CENTER));
JPanel barPanel=new JPanel();
barPanel.setLayout(new GridLayout(2,0,50,50));
pb=new JProgressBar(0,10);
start=new JButton("Start Demo");
fr.add(p);
barPanel.add(start);
barPanel.add(pb);
p.add(barPanel);
fr.setSize(500,500);
fr.setVisible(true);
}
public void hookUpEvents() {
start.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
try {
Runnable r=new Runnable() {
public void run() {
action(ae); // LINE 39
}
};
Thread th=new Thread(r);
th.start();
} catch(Exception exc) {
System.out.println(exc);
}
}
});
}
public void action(ActionEvent ae) {
start.setVisible(false);
try {
Runnable rp=new Runnable() {
public void run() {
i++;
pb.setValue(i);
try {
Thread.sleep(2000);
} catch(Exception exc) {
System.out.println(exc);
}
if(i==5) {
pb.setString("Half Done!");
}
else if(i==10) {
pb.setString("Completed!");
}
}
};
Thread th=new Thread(rp);
th.start();
} catch(Exception exc) {
System.out.println(exc);
}
}
public static void main(String args[]) {
new jProgressBar();
}
}
This is the error produced on cmd:
d:\UnderTest>javac jProgressBar.java
jProgressBar.java:39: local variable ae is accessed from within inner class; needs to be declared fina
l
action(ae);
^
1 error
What is this error and how can I solve this error?
Declare the variable ae as final:
public void actionPerformed(final ActionEvent ae) {
This means that it cannot be assigned a new value, which should be fine according to your current code.
a very nice example for SwingWorker
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
public class SwingWorkerExample extends JFrame implements ActionListener {
private static final long serialVersionUID = 1L;
private final JButton startButton, stopButton;
private JScrollPane scrollPane = new JScrollPane();
private JList listBox = null;
private DefaultListModel listModel = new DefaultListModel();
private final JProgressBar progressBar;
private mySwingWorker swingWorker;
public SwingWorkerExample() {
super("SwingWorkerExample");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
getContentPane().setLayout(new GridLayout(2, 2));
startButton = makeButton("Start");
stopButton = makeButton("Stop");
stopButton.setEnabled(false);
progressBar = makeProgressBar(0, 99);
listBox = new JList(listModel);
scrollPane.setViewportView(listBox);
getContentPane().add(scrollPane);
//Display the window.
pack();
setVisible(true);
}
//Class SwingWorker<T,V> T - the result type returned by this SwingWorker's doInBackground
//and get methods V - the type used for carrying out intermediate results by this SwingWorker's
//publish and process methods
private class mySwingWorker extends javax.swing.SwingWorker<ArrayList<Integer>, Integer> {
//The first template argument, in this case, ArrayList<Integer>, is what s returned by doInBackground(),
//and by get(). The second template argument, in this case, Integer, is what is published with the
//publish method. It is also the data type which is stored by the java.util.List that is the parameter
//for the process method, which recieves the information published by the publish method.
#Override
protected ArrayList<Integer> doInBackground() {
//Returns items of the type given as the first template argument to the SwingWorker class.
if (javax.swing.SwingUtilities.isEventDispatchThread()) {
System.out.println("javax.swing.SwingUtilities.isEventDispatchThread() returned true.");
}
Integer tmpValue = new Integer(1);
ArrayList<Integer> list = new ArrayList<Integer>();
for (int i = 0; i < 100; i++) {
for (int j = 0; j < 100; j++) { //find every 100th prime, just to make it slower
tmpValue = FindNextPrime(tmpValue.intValue());
//isCancelled() returns true if the cancel() method is invoked on this class. That is the proper way
//to stop this thread. See the actionPerformed method.
if (isCancelled()) {
System.out.println("SwingWorker - isCancelled");
return list;
}
}
//Successive calls to publish are coalesced into a java.util.List, which is what is received by process,
//which in this case, isused to update the JProgressBar. Thus, the values passed to publish range from
//1 to 100.
publish(new Integer(i));
list.add(tmpValue);
}
return list;
}//Note, always use java.util.List here, or it will use the wrong list.
#Override
protected void process(java.util.List<Integer> progressList) {
//This method is processing a java.util.List of items given as successive arguments to the publish method.
//Note that these calls are coalesced into a java.util.List. This list holds items of the type given as the
//second template parameter type to SwingWorker. Note that the get method below has nothing to do with the
//SwingWorker get method; it is the List's get method. This would be a good place to update a progress bar.
if (!javax.swing.SwingUtilities.isEventDispatchThread()) {
System.out.println("javax.swing.SwingUtilities.isEventDispatchThread() + returned false.");
}
Integer percentComplete = progressList.get(progressList.size() - 1);
progressBar.setValue(percentComplete.intValue());
}
#Override
protected void done() {
System.out.println("doInBackground is complete");
if (!javax.swing.SwingUtilities.isEventDispatchThread()) {
System.out.println("javax.swing.SwingUtilities.isEventDispatchThread() + returned false.");
}
try {
//Here, the SwingWorker's get method returns an item of the same type as specified as the first type parameter
//given to the SwingWorker class.
ArrayList<Integer> results = get();
for (Integer i : results) {
listModel.addElement(i.toString());
}
} catch (Exception e) {
System.out.println("Caught an exception: " + e);
}
startButton();
}
boolean IsPrime(int num) { //Checks whether a number is prime
int i;
for (i = 2; i <= num / 2; i++) {
if (num % i == 0) {
return false;
}
}
return true;
}
protected Integer FindNextPrime(int num) { //Returns next prime number from passed arg.
do {
if (num % 2 == 0) {
num++;
} else {
num += 2;
}
} while (!IsPrime(num));
return new Integer(num);
}
}
private JButton makeButton(String caption) {
JButton b = new JButton(caption);
b.setActionCommand(caption);
b.addActionListener(this);
getContentPane().add(b);
return b;
}
private JProgressBar makeProgressBar(int min, int max) {
JProgressBar progressBar1 = new JProgressBar();
progressBar1.setMinimum(min);
progressBar1.setMaximum(max);
progressBar1.setStringPainted(true);
progressBar1.setBorderPainted(true);
getContentPane().add(progressBar1);
return progressBar1;
}
private void startButton() {
startButton.setEnabled(true);
stopButton.setEnabled(false);
System.out.println("SwingWorker - Done");
}
#Override
public void actionPerformed(ActionEvent e) {
if ("Start" == null ? e.getActionCommand() == null : "Start".equals(e.getActionCommand())) {
startButton.setEnabled(false);
stopButton.setEnabled(true);
// Note that it creates a new instance of the SwingWorker-derived class. Never reuse an old one.
(swingWorker = new mySwingWorker()).execute(); // new instance
} else if ("Stop" == null ? e.getActionCommand() == null : "Stop".equals(e.getActionCommand())) {
startButton.setEnabled(true);
stopButton.setEnabled(false);
swingWorker.cancel(true); // causes isCancelled to return true in doInBackground
swingWorker = null;
}
}
public static void main(String[] args) {
// Notice that it kicks it off on the event-dispatching thread, not the main thread.
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
SwingWorkerExample swingWorkerExample = new SwingWorkerExample();
}
});
}
}
There are some counterproductive issues present.
Swing is single-thread based, and all actions must be done on the EDT. For that reason, your JProgressBar doesn't update correctly. See also Concurrency in Swing.
Don't use Thread.sleep(int) in Swing, and certainly not in an action listener.
By using Runnable, it is possible to update JProgressBar; but as mentioned, the method must be run from invokeLater().
For that, SwingWorker would be better, as shown below and here.
import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.*;
public class TestProgressBar {
private static void createAndShowUI() {
JFrame frame = new JFrame("TestProgressBar");
frame.getContentPane().add(new TestPBGui().getMainPanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
createAndShowUI();
}
});
}
private TestProgressBar() {
}
}
class TestPBGui {
private JPanel mainPanel = new JPanel();
public TestPBGui() {
JButton yourAttempt = new JButton("Your attempt to show Progress Bar");
JButton myAttempt = new JButton("My attempt to show Progress Bar");
yourAttempt.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
yourAttemptActionPerformed();
}
});
myAttempt.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
myAttemptActionPerformed();
}
});
mainPanel.add(yourAttempt);
mainPanel.add(myAttempt);
}
private void yourAttemptActionPerformed() {
Window thisWin = SwingUtilities.getWindowAncestor(mainPanel);
JDialog progressDialog = new JDialog(thisWin, "Uploading...");
JPanel contentPane = new JPanel();
contentPane.setPreferredSize(new Dimension(300, 100));
JProgressBar bar = new JProgressBar(0, 100);
bar.setIndeterminate(true);
contentPane.add(bar);
progressDialog.setContentPane(contentPane);
progressDialog.pack();
progressDialog.setLocationRelativeTo(null);
Task task = new Task("Your attempt");
task.execute();
progressDialog.setVisible(true);
while (!task.isDone()) {
}
progressDialog.dispose();
}
private void myAttemptActionPerformed() {
Window thisWin = SwingUtilities.getWindowAncestor(mainPanel);
final JDialog progressDialog = new JDialog(thisWin, "Uploading...");
JPanel contentPane = new JPanel();
contentPane.setPreferredSize(new Dimension(300, 100));
final JProgressBar bar = new JProgressBar(0, 100);
bar.setIndeterminate(true);
contentPane.add(bar);
progressDialog.setContentPane(contentPane);
progressDialog.pack();
progressDialog.setLocationRelativeTo(null);
final Task task = new Task("My attempt");
task.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
if (evt.getPropertyName().equalsIgnoreCase("progress")) {
int progress = task.getProgress();
if (progress == 0) {
bar.setIndeterminate(true);
} else {
bar.setIndeterminate(false);
bar.setValue(progress);
progressDialog.dispose();
}
}
}
});
task.execute();
progressDialog.setVisible(true);
}
public JPanel getMainPanel() {
return mainPanel;
}
}
class Task extends SwingWorker<Void, Void> {
private static final long SLEEP_TIME = 4000;
private String text;
public Task(String text) {
this.text = text;
}
#Override
public Void doInBackground() {
setProgress(0);
try {
Thread.sleep(SLEEP_TIME);// imitate a long-running task
} catch (InterruptedException e) {
}
setProgress(100);
return null;
}
#Override
public void done() {
System.out.println(text + " is done");
Toolkit.getDefaultToolkit().beep();
}
}

Categories