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JAVA - JFrame not looking proper when called from action listener

I have a problem with one of my frames not looking as it should, when it is called upon the press of a button.
The frame looks as if it was rendered improperly, the label text in it is shortened, however when i move the same line of code outside the action listener, it works as it should.
I have a sort of main menu, with two buttons, only the Generate Menu works at the moment, it looks like this:
https://i.imgur.com/k1Ne5v9.png
The code for the action listener:
runMenuButt.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("Generate Menu pressed");
mF.dispose();
MenuGenerator.generateTheMenu();
}
});
The result looks wrong: https://i.imgur.com/n86y4CD.png
The frame is also unresponsive, clikcing X does not, while it should close the frame and the application.
However changing the code to:
runMenuButt.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("Generate Menu pressed");
//mF.dispose();
}
});
MenuGenerator.generateTheMenu();
Produces correct look: https://i.imgur.com/TFbkmAO.png
The code for the "Main menu"
public static void openMainMenu() {
Font menuFont = new Font("Courier",Font.BOLD,16);
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
mF.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mF.setSize(465,230);
mF.setLocation(dim.width/2-mF.getSize().width/2, dim.height/2-mF.getSize().height/2);
mF.getContentPane().setBackground(Color.WHITE);
Color blueSteel = new Color(70,107,176);
JPanel p = new JPanel();
p.setSize(600,50);
p.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
p.setLocation((mF.getWidth() - p.getWidth()) /2, 20);
p.setBackground(blueSteel);
JLabel l = new JLabel("Welcome to the menu GENERATORRRR");
l.setFont(menuFont);
l.setForeground(Color.WHITE);
p.add(l, gbc);
JButton runMenuButt = new JButton("Generate Menu");
runMenuButt.setLocation(20 , 90);
JButton manageRecipButt = new JButton("Manage Recipients");
manageRecipButt.setLocation(240 , 90);
menuUtilities.formatButton(runMenuButt);
menuUtilities.formatButton(manageRecipButt);
mF.setResizable(false);
mF.setLayout(null);
mF.add(runMenuButt);
mF.add(manageRecipButt);
mF.add(p);
mF.setVisible(true);
runMenuButt.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("Generate Menu pressed");
//mF.dispose();
}
});
MenuGenerator.generateTheMenu();
manageRecipButt.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(null, "Not supported yet", "Function not yet available",JOptionPane.INFORMATION_MESSAGE);
}
});
//System.out.println(mF.getContentPane().getSize());
}
And the status bar:
public class StatusBar {
private static JLabel statusLabel= new JLabel("Starting");
private static JFrame statusFrame = new JFrame("Generation Status");
public static void createStatusBar() {
Font menuFont = new Font(Font.MONOSPACED,Font.BOLD,20);
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
statusFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
statusFrame.setSize(700,100);
JPanel p = new JPanel();
p.setPreferredSize(new Dimension(100,100));
statusLabel.setFont(menuFont);
p.add(statusLabel);
statusFrame.add(p,BorderLayout.CENTER);
statusFrame.setLocation(dim.width/2-statusFrame.getSize().width/2, dim.height/2-statusFrame.getSize().height/2);
statusFrame.setVisible(true);
}
public static void setStatusBar(String statusText) {
statusLabel.setText(statusText);
statusLabel.paintImmediately(statusLabel.getVisibleRect());
statusLabel.revalidate();
}
public static void closeStatusBar(){
statusFrame.dispose();
}
}
I create the bar with this line:
StatusBar.createStatusBar();
Why does the status bar not render properly when the MenuGenerator.generateTheMenu(); is called from the action listener?
Here is minimal code that reproduces this behavior for anyone who would like to test it: It also uses class for the StatusBar, which is already posted.
public class MinimalClass {
private static JFrame mF = new JFrame("Main Menu");
public static void main(String[] args) {
openMainMenu();
}
public static void openMainMenu() {
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
mF.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mF.setSize(465,230);
mF.setLocation(dim.width/2-mF.getSize().width/2, dim.height/2-mF.getSize().height/2);
mF.getContentPane().setBackground(Color.WHITE);
JButton runMenuButt = new JButton("Generate Menu");
runMenuButt.setLocation(20 , 90);
runMenuButt.setSize(200 , 85);
mF.setResizable(false);
mF.setLayout(null);
mF.add(runMenuButt);
mF.setVisible(true);
runMenuButt.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("Generate Menu pressed");
mF.dispose();
generateTheMenu();
}
});
}
public static void generateTheMenu() {
System.setProperty("sun.java2d.cmm", "sun.java2d.cmm.kcms.KcmsServiceProvider");
String rawMenuOutput = "";
try {
rawMenuOutput= getMenuInJavaNow();
} catch (Exception e){
System.out.println("Something went terribly wrong");
}
System.out.println(rawMenuOutput);
}
public static String getMenuInJavaNow() throws IOException {
String rawMenuOutput = "Restaurant Menu" ;
rawMenuOutput = rawMenuOutput + "Test line";
String []menuOtpArr = new String [3];
try {
StatusBar.createStatusBar();
TimeUnit.SECONDS.sleep(2);
StatusBar.setStatusBar("Test1");
TimeUnit.SECONDS.sleep(2);
menuOtpArr[0]="Test line";
StatusBar.setStatusBar("Test2");
TimeUnit.SECONDS.sleep(2);
menuOtpArr[1]="Test line";
StatusBar.setStatusBar("Test3");
TimeUnit.SECONDS.sleep(2);
menuOtpArr[2]="Test line";
StatusBar.setStatusBar("Test4");
TimeUnit.SECONDS.sleep(2);
StatusBar.closeStatusBar();
} catch (Exception e) {
}
for (int i=0;i < menuOtpArr.length;i++) {
rawMenuOutput = rawMenuOutput + "\n\n" +menuOtpArr[i];
}
return rawMenuOutput;
}
}
Thank you for your time

statusLabel.paintImmediately(statusLabel.getVisibleRect()); seems to masking a larger issue.
The problem is, Swing is single threaded (and NOT thread safe). This means that when you call TimeUnit.SECONDS.sleep(2); from within getMenuInJavaNow, which is called by generateTheMenu, which is called by the ActionListener, it's been called within the context of the Event Dispatching Thread.
This is putting the EDT to sleep, meaning that it isn't processing layout or paint requests (properly)
Start by having a read of Concurrency in Swing for more details
Now, you have a larger issue, how to solve it. For the answer to that question, we require a lot more context then is currently available.
The getMenuInJavaNow seems to be returning some values, to what end I'm not sure.
"A" solution, would be to use a SwingWorker (see Worker Threads and SwingWorker for more details). It provides the ability to execute long running tasks in the background, but also provides the means for sync updates back to the UI, for example...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingWorker;
public class MinimalClass {
private static JFrame mF = new JFrame("Main Menu");
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
openMainMenu();
}
});
}
public static void openMainMenu() {
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
mF.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mF.setLocationRelativeTo(null);
mF.getContentPane().setBackground(Color.WHITE);
JButton runMenuButt = new JButton("Generate Menu");
runMenuButt.setMargin(new Insets(25, 25, 25, 25));
JPanel buttons = new JPanel(new GridLayout(0, 2));
buttons.add(runMenuButt);
mF.add(buttons);
mF.pack();
mF.setVisible(true);
runMenuButt.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("Generate Menu pressed");
mF.dispose();
generateTheMenu();
}
});
}
public static void generateTheMenu() {
System.setProperty("sun.java2d.cmm", "sun.java2d.cmm.kcms.KcmsServiceProvider");
StatusBar.createStatusBar();
SwingWorker<String, String> worker = new SwingWorker<String, String>() {
#Override
protected String doInBackground() throws Exception {
String rawMenuOutput = "Restaurant Menu";
rawMenuOutput = rawMenuOutput + "Test line";
String[] menuOtpArr = new String[3];
try {
TimeUnit.SECONDS.sleep(2);
publish("1234567890123456789012345678901234567890");
TimeUnit.SECONDS.sleep(2);
publish("This is a test");
TimeUnit.SECONDS.sleep(2);
publish("More testing");
TimeUnit.SECONDS.sleep(2);
publish("Still testing");
TimeUnit.SECONDS.sleep(2);
} catch (Exception e) {
}
for (int i = 0; i < menuOtpArr.length; i++) {
rawMenuOutput = rawMenuOutput + "\n\n" + menuOtpArr[i];
}
return rawMenuOutput;
}
#Override
protected void done() {
StatusBar.closeStatusBar();
}
#Override
protected void process(List<String> chunks) {
StatusBar.setStatusBar(chunks.get(chunks.size() - 1));
}
};
worker.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
if (worker.getState() == SwingWorker.StateValue.DONE) {
try {
String result = worker.get();
System.out.println(result);
StatusBar.closeStatusBar();
} catch (InterruptedException | ExecutionException ex) {
ex.printStackTrace();
}
}
}
});
worker.execute();
}
public static class StatusBar {
private static JLabel statusLabel = new JLabel("Starting");
private static JFrame statusFrame = new JFrame("Generation Status");
public static void createStatusBar() {
Font menuFont = new Font(Font.MONOSPACED, Font.BOLD, 20);
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
statusFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
statusFrame.setSize(700, 100);
JPanel p = new JPanel();
p.setBackground(Color.RED);
// p.setPreferredSize(new Dimension(100, 100));
statusLabel.setFont(menuFont);
p.add(statusLabel);
statusFrame.add(p, BorderLayout.CENTER);
statusFrame.setLocationRelativeTo(null);
statusFrame.setVisible(true);
}
public static void setStatusBar(String statusText) {
statusLabel.setText(statusText);
}
public static void closeStatusBar() {
statusFrame.dispose();
}
}
}
Observations...
static is not your friend, especially in cases like this. You really, really, really need to learn to live without it.
setLayout(null) is not doing you any favours, especially in the long run. Take the time to go through Laying Out Components Within a Container and start making proper use of layout managers, they might seem "complicated", but they will save you from a lot of hair loss
Avoid using setPreferred/Minimum/MaximumSize where ever possible, you are robing the component of the ability to provide useful rendering hints which may change across platforms and rendering pipelines
Just a quick follow up question, what is the difference between done and addPropertyListener ? Is there any? Isnt it redundant to use both?
The example here is pretty basic, for me I've used done to handle what the SwingWorker "knows" needs to be done, it doesn't however, know what is to be done with the result.
I've used the PropertyChangeListener to deal with that instead - the point - it's an example.
And I also noticed, that I dont need to actually publish, as calling StatusBar.setStatusBar(""); works as well. Is it necessary to use publish?
In a word YES. Swing is NOT thread safe, calling StatusBar.setStatusBar("") directly can lead to some weird and unexpected results. publish pushes the call into the Event Dispatching Thread, making it safe to update the UI from within.
I have the code for generating the String I want to set as the StatusBar Title in another class, not in the generateTheMenu, therefore it is more convenient for me to simply call .setStatusBar. The not minimal code I have is actually something like this
This is where things like interfaces come in really handy. You "string" generating class "could" either return the resulting text OR you could pass a reference to a interface implementation which is used to "display" it. This way, your SwingWorker could act as a consumer for the String and pass it through the publish method.
There are a number of really important concepts to understand.
You want to decouple your code. This makes it easier to change certain parts of the code without affecting the other parts
You want to be able to "code to interface, not implementation". This goes hand in hand with the first comment. Basically, you want to "hide" the implementation details as much as possible - lots of different reasons for it, but it helps keep your code lean, helps make the follow more understandable and stops one part of the code from accessing another it really has no responsibility to do so (is the string generation really responsible for updating the status bar? IMHO - not really)
There is also a swagger of design patterns available to make solving issues easier. I've already mentioned the concept of "produce/consumer", but this is just one
The "Event Dispatching Thread"
The Event Dispatch Thread
Java Event-Dispatching Thread explanation
Swing threading and the event-dispatch thread

Synchronized copying display with jProgressBar

I wanted to monitor the progress of my file getting copied from source to destination. I have used synchronized keyword but somehow it not working as i expect it to be, my logic might be wrong. I will be glad if you help me out.
Here is my Code.
public class Download extends javax.swing.JFrame {
int val=0;
private Timer t;
private ActionListener a;
/* Creates new form Download */
public Download() {
initComponents();
jProgressBar1.setValue(val);
a = new ActionListener() {
#Override
public void actionPerformed(ActionEvent ae) {
if (jProgressBar1.getValue() < val)
jProgressBar1.setValue(jProgressBar1.getValue()+1);
else
t.stop();
}
};
}
public synchronized void copy(String source,String url)
{
try {
val+=25;
t=new Timer(200,a);
t.start();
FileInputStream fs = new FileInputStream(source);
FileOutputStream os = new FileOutputStream(url);
int b;
while ((b = fs.read()) != -1) {
os.write(b);
}
os.close();
fs.close();
} catch (Exception E) {
E.printStackTrace();
}
}
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
JFileChooser chooser = new JFileChooser();
chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
String url = null;
int returnValue = chooser.showDialog(null, "Select");
if (returnValue == JFileChooser.APPROVE_OPTION) {
url = chooser.getSelectedFile().getPath();
} else {
dispose();
}
JOptionPane.showMessageDialog(this,"Wait for Completion");
if(CB1.isSelected()==true)
{
File f = new File(getClass().getResource("/PCycle/Ele.pdf").getFile());
String source= f.getAbsolutePath();
copy(source,(url+"\\"+CB1.getText()+".pdf"));
}
if(CB2.isSelected()==true)
{
File f = new File(getClass().getResource("/PCycle/Mech.pdf").getFile());
String source= f.getAbsolutePath();
copy(source,(url+"\\"+CB2.getText()+".pdf"));
}
if(CB3.isSelected()==true)
{
File f = new File(getClass().getResource("/PCycle/Phy.pdf").getFile());
String source= f.getAbsolutePath();
copy(source,(url+"\\"+CB3.getText()+".pdf"));
}
if(CB4.isSelected()==true)
{
File f = new File(getClass().getResource("/PCycle/Civil.pdf").getFile());
String source= f.getAbsolutePath();
copy(source,(url+"\\"+CB4.getText()+".pdf"));
}
JOptionPane.showMessageDialog(this,"Completed");
try {
jProgressBar1.setValue(100);
Thread.sleep(3000);
} catch (InterruptedException ex) {
Logger.getLogger(Download.class.getName()).log(Level.SEVERE, null, ex);
}
System.exit(0);
}
}
Here I tried to implement a logic in such a that, whenever we call "copy" method it will copy the file from one location to another and before that it should run the timer method by which the progress on the jProgressBar is displayed. But unfortunately even after using synchronized it is not displaying the progress for each file.

The problem is you are blocking Swing's Event Dispatching Thread (EDT).
Swing does all drawing when the EDT is not busy responding to events. In this case jButton1ActionPerformed is not returning until all files have been copied. So although a Timer is started during each copy() call, the timers never get a chance to expire, because jButton1ActionPerformed has never returned.
In this case, you want to use a SwingWorker to copy the files in a background thread.
When you want to start copying the files:
start the timer in the main thread
create and start the SwingWorker.
open a model dialog to block further user actions (or otherwise disable the UI)
As the timer expires, your progress bar will advance, and be drawn.
When the SwingWorker is done() (which is executed on the EDT),
stop the timer
dismiss the dialog (or re-enable the UI)
Note: Do not create or access any UI items, or create/start/stop timers, from the background worker thread. These actions must only be performed on the EDT.
Rough example, showing disabling UI element, starting SwingWorker, publishing from the worker to show progress (which file is being download), enabling UI when the worker finishes.
File copy is faked using a 3 seconds sleep.
package progress;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JProgressBar;
import javax.swing.SwingUtilities;
import javax.swing.SwingWorker;
import javax.swing.Timer;
#SuppressWarnings("serial")
public class Download extends JFrame {
public static void main(String[] args) {
SwingUtilities.invokeLater(Download::new);
}
private final JButton downloadBtn = new JButton("Start Download");
private final JProgressBar progressBar = new JProgressBar();
private final Timer timer = new Timer(200, this::timerTick);
Download() {
super("Download Example");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400, 300);
setLocationByPlatform(true);
downloadBtn.addActionListener(this::startDownload);
add(downloadBtn, BorderLayout.PAGE_START);
progressBar.setStringPainted(true);
add(progressBar, BorderLayout.PAGE_END);
setVisible(true);
}
private void startDownload(ActionEvent evt) {
downloadBtn.setEnabled(false);
timer.start();
DownloadWorker worker = new DownloadWorker("File1", "FileB", "AnotherFile");
worker.execute();
}
private void timerTick(ActionEvent evt) {
progressBar.setValue(progressBar.getValue()+2);
}
private class DownloadWorker extends SwingWorker<Void, String> {
private final String[] files;
DownloadWorker(String ...files) {
this.files = files;
progressBar.setValue(0);
}
#Override
protected Void doInBackground() throws Exception {
for(String file : files) {
publish(file);
// Copy the file
Thread.sleep(3000); // Pretend copy takes a few seconds
}
return null;
}
#Override
protected void process(List<String> chunks) {
String file = chunks.get(chunks.size()-1); // Just last published filename
progressBar.setString("Downloading "+file + " ...");
}
#Override
protected void done() {
progressBar.setString("Complete");
progressBar.setValue(100);
timer.stop();
downloadBtn.setEnabled(true); // Re-enable UI
}
}
}

JFrame only shows components at first creation

When I start my application it opens a JFrame (the main window) and a JFilechooser to select an input directory, which is then scanned.
The scan method itself creates a new JFrame which contains a JButton and a JProgressBar and starts a new Thread which scans the selected Directory. Up until this point everything works fine.
Now I change the Directory Path in my Main Window, which calls the scan method again. This time it creates another JFrame which should contain the JProgressBar and the JButton but it shows up empty (The JFrame Title is still set).
update:
minimal example
public class MainWindow
{
private JFrame _frame;
private JTextArea _textArea;
private ProgressBar _progress;
public MainWindow() throws InterruptedException, ExecutionException
{
_frame = new JFrame("Main Window");
_textArea = new JTextArea();
_frame.add(_textArea);
_frame.setSize(200, 200);
_frame.setVisible(true);
_textArea.setText(doStuffinBackground());
_progress.dispose();
}
private String doStuffinBackground() throws InterruptedException,
ExecutionException
{
setUpProgressBar();
ScanWorker scanWorker = new ScanWorker();
scanWorker.execute();
return scanWorker.get();
}
private void setUpProgressBar()
{
// Display progress bar
_progress = new ProgressBar();
}
class ProgressBar extends JFrame
{
public ProgressBar()
{
super();
JProgressBar progressBar = new JProgressBar();
progressBar.setIndeterminate(true);
progressBar.setStringPainted(false);
add(progressBar);
setTitle("Progress Window");
setSize(200, 200);
toFront();
setVisible(true);
}
}
class ScanWorker extends SwingWorker<String, Void>
{
#Override
public String doInBackground() throws InterruptedException
{
int j = 0;
for (int i = 0; i < 10; i++)
{
Thread.sleep(1000);
j += 1;
}
return String.valueOf(j);
}
}
public static void main(String[] args) throws InvocationTargetException,
InterruptedException
{
SwingUtilities.invokeAndWait(new Runnable()
{
public void run()
{
// Start the main controller
try
{
new MainWindow();
}
catch (InterruptedException | ExecutionException e) {}
}
});
}
}

From the basic looks of your scan method, you are blocking the Event Dispatching Thread, when you scan the directory, which is preventing it from updating the UI.
Specifically, you don't seem to truly understand what Callable and FutureTask are actually used for or how to use them properly...
Calling FutureTask#run will call the Callable's call method...from within the current thread context.
Take a look at Concurrency in Swing for more details...
Instead of trying to use FutureTask and Callable in this manner, consider using a SwingWorker, which is designed to do this kind of work (and uses Callable and FutureTask internally)
Have a look at Worker Threads and SwingWorker for more details
Now, before you jump down my throat and tell me that "it works the first time I ran it", that's because you're not starting your UI properly. All Swing UI's should be create and manipulated from within the context of the Event Dispatching Thread. You main method is executed in, what is commonly called, the "main thread", which is not the same as the EDT. This is basically setting up fluke situation in where the first time you call scan, you are not running within the context of the EDT, allowing it to work ... and breaking the single thread rules of Swing in the process...
Take a look at Initial Threads for more details...
I would also consider using a JDialog instead of another frame, even if it's not modal, it makes for a better paradigm for your application, as it really should only have a single main frame.
Updated based on new code
So, basically, return scanWorker.get(); is a blocking call. It will wait until the doInBackground method completes, which means it's block the EDT, still...'
Instead, you should be making use of the publish, process and/or done methods of the SwingWorker
import java.util.ArrayList;
import java.util.List;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JProgressBar;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
import javax.swing.SwingWorker;
public class MainWindow {
private JFrame _frame;
private JTextArea _textArea;
private ProgressBar _progress;
public MainWindow() {
_frame = new JFrame("Main Window");
_textArea = new JTextArea();
_frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
_frame.add(new JScrollPane(_textArea));
_frame.setSize(200, 200);;
_frame.setVisible(true);
doStuffinBackground();
}
private void doStuffinBackground() {
// _progress = new ProgressBar();
// ScanWorker scanWorker = new ScanWorker();
// scanWorker.execute();
// return scanWorker.get();
_progress = new ProgressBar();
ScanWorker worker = new ScanWorker(_textArea, _progress);
worker.execute();
_progress.setVisible(true);
}
class ProgressBar extends JDialog {
public ProgressBar() {
super(_frame, "Scanning", true);
JProgressBar progressBar = new JProgressBar();
progressBar.setIndeterminate(true);
progressBar.setStringPainted(false);
add(progressBar);
setTitle("Progress Window");
pack();
setLocationRelativeTo(_frame);
}
}
class ScanWorker extends SwingWorker<List<String>, String> {
private JTextArea textArea;
private ProgressBar progressBar;
protected ScanWorker(JTextArea _textArea, ProgressBar _progress) {
this.textArea = _textArea;
this.progressBar = _progress;
}
#Override
protected void process(List<String> chunks) {
for (String value : chunks) {
textArea.append(value + "\n");
}
}
#Override
public List<String> doInBackground() throws Exception {
System.out.println("...");
int j = 0;
List<String> results = new ArrayList<>(25);
for (int i = 0; i < 10; i++) {
Thread.sleep(1000);
j += 1;
System.out.println(j);
results.add(Integer.toString(j));
publish(Integer.toString(j));
}
return results;
}
#Override
protected void done() {
progressBar.dispose();
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new MainWindow();
}
});
}
}

Calling super.approveSelection() within a SwingWorker

I have a customized JFileChooser
Its approveSelection() method is slightly modified:
public void approveSelection()
{
File file = getSelectedFile();
changeGui();
final Object a = makeALongCalcualtion(file);
if (a != null)
{
super.approveSelection();
SwingWorker<Document, Void> open = new SwingWorker<Document, Void>()
{
#Override
protected Document doInBackground() throws Exception
{
return createADocument(a);
}
#Override
protected void done()
{
try
{
if(get() != null)
{
changeGui();
}
else
{
//TODO error message
changeGui();
}
}
catch (InterruptedException | ExecutionException e)
{
//TODO error message
changeGui();
}
}
};
open.execute();
}
else
{
//TODO error message
changeGui();
}
}
The changeGui() method sets a JProgressBar to indeterminate and updates a JLabel with a new string.
If file provided to makeALongCalcualtion(file) is of invalid type, it will return null, otherwise it returns info that is passed to SwingWorker which can use it to acutally create the representation of a file in the program (the Document object).
However, this doesn't work as it should because makeALongCalcualtion(file) isn't called within SwingWorker method, and that blocks the EDT.
In order to fix the problem, I would have to call makeALongCalcualtion(file) within a SwingWorker. I could move that part of the code into the SwingWorker without any problems, but then I would have to (due to my code logic) move super.approveSelection() along with it.
So the bottom line is, how do I call super.approveSelection() from within doInBackground() for this specific case?
//More info
What is supposed to happen:
User selects and opens a file
JLabel and JProgressBar are updated, indeterminate progress starts to play.
If makeALongCalcualtion(file) return null user is warned with an error window, but the JFileChooser stys open, making it possible to choose again when the error window is closed.
Otherwise, super.approveSelection() is called, allowing the chooser to close.
A document is created (but the method that creates the document return null if something goes wrong).
If everything is fine, JLabel updates and progressBar animation is stopped (indeterminate is set to false).
If something goes wrong same thing happens as in step 6, only with different message in JLabel.
What happens:
same
same
same, but when makeALongCalculation(file); begins, progressBar freezes.
same
same
same, but the animation isn't stopped (since the progressbar is frozen), only the frozen "picture" is removed and progressbar returns to it's previous state.
same
EDIT
I have made some alterations to my program and I now have this:
approveSelection():
public void approveSelection()
{
File file = getSelectedFile();
Main.getStatusBar().startOpen();
final WorkOpen open = new WorkOpen(file);
open.execute();
open.addPropertyChangeListener(new PropertyChangeListener()
{
#Override
public void propertyChange(PropertyChangeEvent evt) {
if ("state".equals(evt.getPropertyName())) {
if (evt.getNewValue().equals("DONE"))
{
if (open.failed())
{
//TODO error message
Main.getStatusBar().endOpen(false);
}
else
{
Main.getStatusBar().endOpen(true);
}
}
}
}
});
}
SwingWorker:
class WorkOpen extends SwingWorker<Document, Void>
{
boolean failed = false;
File file;
public boolean failed()
{
return failed;
}
#Override
protected Document doInBackground() throws Exception
{
ArrayList<String> data = Opener.extractData(file);
if (data != null)
{
//My little path/name/similar managing system
FileComplex fullPath = new FileComplex(file.toString());
return Opener.createDocument(fullPath.getFullName(), fullPath.getFullPath(), data);
}
else
{
failed = true;
return null;
}
}
#Override
protected void done()
{
try
{
if(get() != null)
{
Main.addDocument(get());
}
}
catch (InterruptedException | ExecutionException e)
{
failed = true;
}
}
WorkOpen(File file)
{
this.file = file;
}
}
The problem now is where to call super.approveSelection(). It has to wait for the worker to finish executing, yet I can't call it from the property change listener.
What to do here?
EDIT 2
As HovercraftFullOfEels suggested, I fixed my code and it compiled and ran. But the problem of JProgressBar freezeing remained. Also, I had to introduce something I don't know if I should have:
private void superApproveSelection()
{
super.approveSelection();
}
public void approveSelection()
{
final File file = getSelectedFile();
class OpenWorker extends SwingWorker<Boolean, Void>
{
Document document;
Document getDocument()
{
return document;
}
#Override
protected Boolean doInBackground() throws Exception
{
ArrayList<String> data = Opener.extractData(file);
if (data != null)
{
//I had to start the progressBar here, because if invalid
//file was selected (extractData(file) returns null if it was),
//nothing should happen (maybe an error
//window later, handled with a new Runnable() same as this:
SwingUtilities.invokeLater(new Runnable()
{
#Override
public void run()
{
Main.getStatusBar().startOpen();
}
});
FileComplex fullPath = new FileComplex(file.toString());
document = Opener.createDocument(fullPath.getFullName(), fullPath.getFullPath(), data);
return true;
}
else
{
return false;
}
}
};
final OpenWorker opener = new OpenWorker();
opener.addPropertyChangeListener(new PropertyChangeListener()
{
#Override
public void propertyChange(PropertyChangeEvent evt)
{
if ("state".equals(evt.getPropertyName()))
{
if (evt.getNewValue() == SwingWorker.StateValue.DONE)
{
if(opener.getDocument() != null)
{
superApproveSelection();
Main.addDocument(opener.getDocument());
Main.getStatusBar().endOpen(true);
}
else
{
try
{
//I'm retrieveing doInBackground()'s value to see if
//progressBar needs stoping (it also displays some
//text, so it must not be called unless the
//progressBar was started).
if (opener.get())
{
Main.getStatusBar().endOpen(false);
}
}
catch (InterruptedException | ExecutionException e)
{
//TODO error something went wrong
}
}
}
}
}
});
opener.execute();
}

"In order to fix the problem, I would have to call makeALongCalcualtion(file) within a SwingWorker. I could move that part of the code into the SwingWorker without any problems, but then I would have to (due to my code logic) move super.approveSelection() along with it."
No, not true at all. super.approveSelection() would not have to be called inside of the SwingWorker.
Why not simply create a SwingWorker, add a PropertyChangeListener to it, and when the SwingWorker's state is done, call super.approveSelection() if indicated?
OK, here is my example below. Explanation to follow:
import java.awt.*;
import java.awt.Dialog.ModalityType;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.File;
import java.util.Scanner;
import java.util.concurrent.ExecutionException;
import javax.swing.*;
import javax.swing.text.*;
#SuppressWarnings("serial")
public class ApproveSelectionTest extends JPanel {
private JTextArea textArea = new JTextArea(30, 60);
public ApproveSelectionTest() {
textArea.setEditable(false);
textArea.setFocusable(false);
JPanel btnPanel = new JPanel();
btnPanel.add(new JButton(new MyGetFileAction("Get Text File Text")));
setLayout(new BorderLayout());
add(new JScrollPane(textArea), BorderLayout.CENTER);
add(btnPanel, BorderLayout.PAGE_END);
}
private class MyGetFileAction extends AbstractAction {
public MyGetFileAction(String text) {
super(text);
}
public void actionPerformed(java.awt.event.ActionEvent arg0) {
MyFileChooser myFileChooser = new MyFileChooser();
int result = myFileChooser.showOpenDialog(ApproveSelectionTest.this);
if (result == JFileChooser.APPROVE_OPTION) {
Document doc = myFileChooser.getDocument();
textArea.setDocument(doc);
}
};
}
private static void createAndShowGui() {
ApproveSelectionTest mainPanel = new ApproveSelectionTest();
JFrame frame = new JFrame("ApproveSelectionTest");
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();
}
});
}
}
#SuppressWarnings("serial")
class MyFileChooser extends JFileChooser {
private WorkOpen workOpen = null;
private JDialog progressDialog = null;
public MyFileChooser() {
}
#Override
public void approveSelection() {
JProgressBar progBar = new JProgressBar();
progBar.setIndeterminate(true);
Window win = SwingUtilities.getWindowAncestor(this);
progressDialog = new JDialog(win, "Checking File", ModalityType.APPLICATION_MODAL);
progressDialog.getContentPane().add(progBar);
progressDialog.pack();
progressDialog.setLocationRelativeTo(null);
File file = getSelectedFile();
workOpen = new WorkOpen(file);
workOpen.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent pcEvt) {
if (SwingWorker.StateValue.DONE == pcEvt.getNewValue()) {
if (progressDialog != null) {
progressDialog.dispose();
}
try {
boolean bool = workOpen.get().booleanValue();
if (bool) {
superApproveSelection();
} else {
JOptionPane.showMessageDialog(MyFileChooser.this, "Invalid File Chosen");
}
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
}
}
});
workOpen.execute();
progressDialog.setVisible(true);
}
// ****** this is key *****
private void superApproveSelection() {
super.approveSelection();
}
public Document getDocument() {
if (workOpen == null) {
return null;
} else {
return workOpen.getDocument();
}
}
}
class WorkOpen extends SwingWorker<Boolean, Void> {
private static final long SLEEP_TIME = 4 * 1000;
private Document document = null;
private File file = null;
public WorkOpen(File file) {
this.file = file;
}
#Override
protected Boolean doInBackground() throws Exception {
if (file == null || !file.exists()) {
return Boolean.FALSE;
}
Thread.sleep(SLEEP_TIME);
String fileName = file.getName();
if (fileName.contains(".txt")) {
Scanner scan = new Scanner(file);
StringBuilder stringBuilder = new StringBuilder();
while (scan.hasNextLine()) {
stringBuilder.append(scan.nextLine() + "\n");
}
document = new PlainDocument();
document.insertString(0, stringBuilder.toString(), null);
return Boolean.TRUE;
}
return Boolean.FALSE;
}
public Document getDocument() {
return document;
}
}
Explanation and key points from my example:
This example behaves very simply. You choose a file, and if the file exists and contains ".txt" in its name, then it reads in the document and displays the text in a JTextField.
Else it displays a warning message but leaves the JFileChooser displayed.
Probably the key point: I've given my MyFileChooser class a private superApproveSelection() method that can be called by my PropertyChangeListener. This exposes the super's approveSelection() method to the inner class, one of the problems you were having.
The order of calling code is important in my approveSelection() override.
In this method I first create my JProgressBar and its dialog but don't yet display it immediately. It really doesn't have to be created first, but it sure needs to be displayed last.
I create my SwingWorker, workOpen, but don't yet execute it.
I add my PropertyChangeListener to the SwingWorker before executing the SwingWorker.
I then execute my SwingWorker
I then display my modal JDialog with the indeterminate JProgressBar.
My SwingWorker is structured so that its doInBackground returns a Boolean, not a Document.
I have it create a (very simple) Document if all works out OK that holds the content of the text file, and set a private "doc" field obtainable by a getter method, and then have doInBackground return Boolean.TRUE if all works well.
I've given my doInBackground a Thread.sleep(4000) just to pretend that its action takes a lot of time. Yours of course won't have this.
In the PropertyChangeListener if the SwingWorker is DONE, I'll dispose of the progress bar dialog and then call get() on the SW to get the Boolean result.
If it's Boolean.TRUE, then call the superApproveSelection() method described above.
Else show an error message. Note that since the super's approveSelection() isn't called, the file chooser dialog remains displayed.
If the approveSelection is called then the code that displays my file chooser dialog will get the appropriate return value, will extract the Document from the file chooser and displays the Document in a JTextArea.

Progress bar in Swing (Java) for command tools

I have several C/C++ command line tools that I'm wrapping with Java.Swing as GUI. The command line tools can take minutes to hours. Progress bar seems like a good idea to keep users sane. I'm also thinking it might be nice to wrap a GUI for the progress bar, instead of just using system out. But how?
I'm thinking the command line tools can write percents to stderr and I can somehow read it in java. Not exactly sure what the mechanics for this would be. I'm also not clear on asynchronous display (learned a bit about invokeLater() ). New to Java, and would appreciate general suggestions as well. Thanks.
--- update ---
Thanks everyone for your suggestions. Here's the resulting code.
private void redirectSystemStreams() {
OutputStream out_stderr = new OutputStream() {
#Override
public void write(final int b) throws IOException {
update(String.valueOf((char) b));
}
#Override
public void write(byte[] b, int off, int len) throws IOException {
update(new String(b, off, len));
}
#Override
public void write(byte[] b) throws IOException {
write(b, 0, b.length);
}
};
System.setErr(new PrintStream(out_stderr, true));
}
private void update(final String inputText) {
int value = 20; //parse inputText; make sure your executable calls fflush(stderr) after each fprintf().
jProgressBar.setValue(value);
/* Also one can redirect to a textpane
SwingUtilities.invokeLater(new Runnable() {
public void run() {
//update jTextPane with inputText
}
});
*/
}

That's seems very fragile, better would be to communicate via sockets in a well established protocol or with some sort of RCP ( perhaps Google's protobuf ) or even webservices.
If you still insists you can launch a process in Java with ProcessBuilder that will give you a Process reference of which you can get the InputStream to read the standard output, but again, that seems very fragile to me.
I hope this helps.

For the progress bar part of your problem you can do something like the following. Note that this is just an example to illustrate the point.
Basically, a thread is created to do the work. Presumably this Runner thread will be interacting with your C/C++ code to get its progress. It then calls update on the Progress Bars Dialog class.
import java.awt.BorderLayout;
import java.awt.Dimension;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
public class Main {
private int value;
private Progress pbar;
public static void main(String args[]) {
new Main();
}
public Main() {
pbar = new Progress();
Thread t = new Thread(new Runner());
t.start();
}
class Progress extends JDialog {
JProgressBar pb;
JLabel label;
public Progress() {
super((JFrame) null, "Task In Progress");
pb = new JProgressBar(0, 100);
pb.setPreferredSize(new Dimension(175, 20));
pb.setString("Working");
pb.setStringPainted(true);
pb.setValue(0);
label = new JLabel("Progress: ");
JPanel panel = new JPanel();
panel.add(label);
panel.add(pb);
add(panel, BorderLayout.CENTER);
pack();
setVisible(true);
}
public void update(){
pb.setValue(value);
if(value >= 100){
this.setVisible(false);
this.dispose();
}
}
}
class Runner implements Runnable {
public void run() {
for (int i = 0; i <= 100; i++) {
value++;
pbar.update();
try {
Thread.sleep(50);
} catch (InterruptedException e) {
}
}
}
}
}

// Create a window
JFrame frame = new JFrame("Progress");
// Creates a progress bar and add it to the window
JProgressBar prog = new JProgressBar();
frame.add(prog);
// Run C/C++ application
try {
Process p = Runtime.getRuntime().exec(new String[]{"filename","arg1","arg2","..."});
// Get InputStream
BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
// Update the progress when recieving output from C/C++
new java.util.Timer().schedule(new TimerTask(){
public void run(){
String str = "";
while ((str=br.readLine()!=null) {
prog.setValue(new Integer(str)); // Set Value of Progress Bar
prog.setString(str+"%"); // Set Value to display (in text) on Progress Bar
}
}
},0,100); // Check every 100 milliseconds
// Fit the window to its contents and display it
frame.pack();
frame.setVisible(true);
} catch (Exception e) {
System.out.println("Failed To Launch Program or Failed To Get Input Stream");
}