Alfonso Sanz

Dear all,

I don't reach to understand what happens with the following code upon different Window Managers.


import java.awt.event.*; import java.awt.*; import javax.swing.*; class Gnome extends JFrame {      static JFrame f;    static JButton b;      public static void main(String[] args) {        f = new JFrame("TEST");        JPanel p = new JPanel();            b = new JButton("click");                // add button to panel        p.add(b);        f.add(p);          f.setSize(1200, 1000);        f.toFront();         // XXX        f.requestFocus();    // XXX        f.setVisible(true);                  createDialog(500, 500);        //createDialog(600, 600);    }            public static void createDialog(int x, int y) {        final JDialog d = new JDialog(f, "ZZZ");        JTextField stockNameIn = new JTextField (5);        JPanel main = new JPanel();        JPanel north = new JPanel();        JPanel center = new JPanel();        JPanel south = new JPanel();                main.setLayout (new BorderLayout());        north.setLayout (new FlowLayout());        center.setLayout (new FlowLayout());        south.setLayout (new FlowLayout());                // create a label        JLabel l = new JLabel("Login");        north.add (l);        north.add (stockNameIn);                main.add (north, BorderLayout.NORTH);        main.add (center, BorderLayout.CENTER);        main.add (south, BorderLayout.SOUTH);                d.add(main);        d.setSize(200, 200);        d.removeNotify();        d.setUndecorated(true);        d.setUndecorated(false);        d.setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);        d.setResizable(false);        d.addNotify();                d.setLocation(x, y);        d.getContentPane().setBackground(Color.BLACK);        //d.setModal(true); // XXX MODAL        d.setVisible(true);        d.setAlwaysOnTop(true);          d.addWindowListener(new WindowAdapter(){         @Override public void windowOpened(WindowEvent e) { } @Override public void windowClosing(WindowEvent e) { } @Override public void windowClosed(WindowEvent e) { } @Override public void windowIconified(WindowEvent e) { } @Override public void windowDeiconified(WindowEvent e) { } @Override public void windowActivated(WindowEvent e) { d.toFront(); } @Override public void windowDeactivated(WindowEvent e) { d.toFront(); }        });            }     }

I launch two instances of this code.
When uncommenting line:

d.setModal(true); // XXX MODAL

works ok in Motif Window Manager, GNOME and Win10, but when comment that line and launch the program twice, Win is OK but MWM flickers between both GUIs and in GMOME it is frozen and I have to restart GNOME.

Someone could give me some light in this issue?

Is there any way to know what's occuring at Windows Manager?

Thanks in advance.

Thank you all for your answers.

I didn't think of AoP.

Perhaps PropertyChangeListener could work as well.

@ Carey Brown: Thank you for your comments but it is just an example to show my concern.

@ Tim Moores: Thanks for your fast answer. You are right, but imagine the class having. a hundred of fields. I would like to know some mechanism that allows me to launch bark() when one of the fields mutate without having to write bark() in every setter method. I think it would be a more ellegant approach.

Thanks in advance.

Dear all,

My question is:

Having the class Dog:

public class Dog{ private String DogName; private String DogBreed; private int DogAge; private Dog(String name, String breed, int age){ DogName = name; DogBreed = breed; DogAge = age; } public String getDogName() { return DogName; } public void setDogName(String dogName) { DogName = dogName; } public String getDogBreed() { return DogBreed; } public void setDogBreed(String dogBreed) { DogBreed = dogBreed; } public int getDogAge() { return DogAge; } public void setDogAge(int dogAge) { DogAge = dogAge; } public void bark(){ System.out.println("BARRRRK!"); } }

I would like to implement the observer pattern or something similar in a way that immediately when one of the three fields changes, the bark() method will be called.

Any idea?

Thanks in advance.

Thanks for the quick answers

The idea is for a Swing application to be invoked from a script with a string as param ("remote" is so to speak. In fact must be called from same computer) to update one entry of a JTable asynchronously (No returns).

Probably as Tim Holloway said, the most elegant approach is a microservice, but I don't want to need tens of jars to solve this "small" issue.

This is because I thought of JMX or RMI to avoid so many dependencies.

Still recomending me a microservice? Can I run a microservice without Web Server? (sorry for my ignorance)

Anywhere to get a short manual?

Thank you all!!

Hi,

I need to create an entry point in my java application to call a method by a shell script passing some params.

I was wondering if is possible to do it via RMI or it is needed in that case for the client to be another java app?

I have thought as different choise  create a MBean and use JMX through some terminal emulator (such as: jmxterm).

Any other idea? By the way, I am using JavaSE

Thanks in advance

Thanks again for your quick answer and your piece of advice.

Hi Stephan,

thanks for your quick answer.


Great, I'll use Robot then for playback, but for recording... I  have seen that it appears I should serialize KeyEvent and MouseEvent, should I?

Thanks in advance.

Dear all,

I would like to save all mouse and keyboard events as well as udp messages received to a file in order to be loaded and played back later on an so analyze the user performance.

I have seen class Robot but it seems quite old.

Perhaps there are newer frameworks doing this easily.

I don't know very well how to begin.

Could someone recommend me any technology, framework,... compatible with Swing?

Thaks in advance.

Thanks Rob for your prompt and expert answer. Indeed seemed to be linked to focus loss.

Hello,

taking as example the code from:
https://docs.oracle.com/javase/tutorial/uiswing/examples/components/index.html#ListDemo,

being like this:

import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.*; /* ListDemo.java requires no other files. */ public class ListDemo extends JPanel                      implements ListSelectionListener {    private JList list;    private DefaultListModel listModel;    private static final String hireString = "Hire";    private static final String fireString = "Fire";    private JButton fireButton;    private JTextField employeeName;    public ListDemo() {        super(new BorderLayout());        listModel = new DefaultListModel();        listModel.addElement("Jane Doe");        listModel.addElement("John Smith");        listModel.addElement("Kathy Green");        //Create the list and put it in a scroll pane.        list = new JList(listModel);        list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);        list.setSelectedIndex(0);        list.addListSelectionListener(this);        list.setVisibleRowCount(5);        JScrollPane listScrollPane = new JScrollPane(list);        JButton hireButton = new JButton(hireString);        HireListener hireListener = new HireListener(hireButton);        hireButton.setActionCommand(hireString);        hireButton.addActionListener(hireListener);        hireButton.setEnabled(false);        fireButton = new JButton(fireString);        fireButton.setActionCommand(fireString);        fireButton.addActionListener(new FireListener());        employeeName = new JTextField(10);        employeeName.addActionListener(hireListener);        employeeName.getDocument().addDocumentListener(hireListener);        String name = listModel.getElementAt(                              list.getSelectedIndex()).toString();        //Create a panel that uses BoxLayout.        JPanel buttonPane = new JPanel();        buttonPane.setLayout(new BoxLayout(buttonPane,                                           BoxLayout.LINE_AXIS));        buttonPane.add(fireButton);        buttonPane.add(Box.createHorizontalStrut(5));        buttonPane.add(new JSeparator(SwingConstants.VERTICAL));        buttonPane.add(Box.createHorizontalStrut(5));        buttonPane.add(employeeName);        buttonPane.add(hireButton);        buttonPane.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));        add(listScrollPane, BorderLayout.CENTER);        add(buttonPane, BorderLayout.PAGE_END);    }    class FireListener implements ActionListener {        public void actionPerformed(ActionEvent e) {            //This method can be called only if            //there's a valid selection            //so go ahead and remove whatever's selected.            int index = list.getSelectedIndex();            listModel.remove(index);            int size = listModel.getSize();            if (size == 0) { //Nobody's left, disable firing.                fireButton.setEnabled(false);            } else { //Select an index.                if (index == listModel.getSize()) {                    //removed item in last position                    index--;                }                list.setSelectedIndex(index);                list.ensureIndexIsVisible(index);            }        }    }    //This listener is shared by the text field and the hire button.    class HireListener implements ActionListener, DocumentListener {        private boolean alreadyEnabled = false;        private JButton button;        public HireListener(JButton button) {            this.button = button;        }        //Required by ActionListener.        public void actionPerformed(ActionEvent e) {            String name = employeeName.getText();            //User didn't type in a unique name...            if (name.equals("") || alreadyInList(name)) {                Toolkit.getDefaultToolkit().beep();                employeeName.requestFocusInWindow();                employeeName.selectAll();                return;            }            int index = list.getSelectedIndex(); //get selected index            if (index == -1) { //no selection, so insert at beginning                index = 0;            } else {           //add after the selected item                index++;            }            listModel.insertElementAt(employeeName.getText(), index);            //If we just wanted to add to the end, we'd do this:            //listModel.addElement(employeeName.getText());            //Reset the text field.            employeeName.requestFocusInWindow();            employeeName.setText("");            //Select the new item and make it visible.            list.setSelectedIndex(index);            list.ensureIndexIsVisible(index);        }        //This method tests for string equality. You could certainly        //get more sophisticated about the algorithm.  For example,        //you might want to ignore white space and capitalization.        protected boolean alreadyInList(String name) {            return listModel.contains(name);        }        //Required by DocumentListener.        public void insertUpdate(DocumentEvent e) {            enableButton();        }        //Required by DocumentListener.        public void removeUpdate(DocumentEvent e) {            handleEmptyTextField(e);        }        //Required by DocumentListener.        public void changedUpdate(DocumentEvent e) {            if (!handleEmptyTextField(e)) {                enableButton();            }        }        private void enableButton() {            if (!alreadyEnabled) {                button.setEnabled(true);            }        }        private boolean handleEmptyTextField(DocumentEvent e) {            if (e.getDocument().getLength() <= 0) {                button.setEnabled(false);                alreadyEnabled = false;                return true;            }            return false;        }    }    //This method is required by ListSelectionListener.    public void valueChanged(ListSelectionEvent e) {        if (e.getValueIsAdjusting() == false) {            if (list.getSelectedIndex() == -1) {            //No selection, disable fire button.                fireButton.setEnabled(false);            } else {            //Selection, enable the fire button.                fireButton.setEnabled(true);            }        }    }    /**     * Create the GUI and show it.  For thread safety,     * this method should be invoked from the     * event-dispatching thread.     */    private static void createAndShowGUI() {        //Create and set up the window.        JFrame frame = new JFrame("ListDemo");        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        //Create and set up the content pane.        JComponent newContentPane = new ListDemo();        newContentPane.setOpaque(true); //content panes must be opaque        frame.setContentPane(newContentPane);        //Display the window.        frame.pack();        frame.setVisible(true);    }    public static void main(String[] args) {        //Schedule a job for the event-dispatching thread:        //creating and showing this application's GUI.        javax.swing.SwingUtilities.invokeLater(new Runnable() {            public void run() {                createAndShowGUI();            }        });    } }



When changing:

       employeeName = new JTextField(10);

by:

       try { employeeName = new JFormattedTextField(new MaskFormatter("UUUUUUUU")); } catch (ParseException e) { e.printStackTrace(); }


behaviour changes so much...

This is:

1) Hire button must be pressed twice instead of one to add a new elemet to JList.
2) If press Hire once the JFormattedTextField is emptied, it shows an element.


I would like to have the advantages of original version but having the Formatter as well.

What changes should I do?

Thanks in advance!!

Great!

thank you all!

Hi Iuliana!

First of all, congratulations for the second edition.

I would like to know if the book covers AOP.

Best Regards.

Thanks Peter for your answer. I did not know the book.
BR

Hello Craig,

My question is about the certificate:

does this book cover the whole matters of the certificate? Could be used as a guide to take the exam  with no taking the Pivotal course ?

does it worth get the certification?

Thanks in advance.