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Listeners wouldn't work when a serialized panel is deserialized and retrieved (Java)

I'm designing a JPanel in which there are some buttons which have their own action listeners and would do certain things when clicked (for example, one of them would remove the panel). In case the user closes the program, panels shouldn't be deleted and should be retrieved. for this purpose I serialize panels and deserialize them when needed. but the problem is listeners such as action listeners and mouse listeners wouldn't work when the panel is retrieved. is there any way to solve this problem? or is there any alternative to do the same thing without problem?
My panel code in case it's needed:
import jdk.internal.org.objectweb.asm.commons.SerialVersionUIDAdder;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.URL;
import java.text.Format;
import java.time.LocalDate;
import java.time.LocalTime;
import java.util.Random;
public class Download extends JPanel implements Serializable {
private String fileName;
private boolean removed = false;
private double downloadSpeed;
private double downloadedSize;
private double sizeOfFile;
LocalTime downloadTime;
LocalDate downloadDate;
private boolean checked = false;
private static final long serialVersionUID = 1113799434508676095L;
JLabel test = new JLabel("test");
public Download (MainPage c,URL url,LocalTime time,LocalDate date) {
setLayout(null);
downloadDate = date;
downloadTime = time;
fileName = url.getFile();
JCheckBox checkbox = new JCheckBox();
checkbox.addItemListener(new ItemListener() {
#Override
public void itemStateChanged(ItemEvent e) {
if (e.getStateChange() == ItemEvent.SELECTED)
setChecked(true);
else
setChecked(false);
}
});
checkbox.setBackground(new Color(186,212,215));
checkbox.setBounds(95,42,17,15);
add(checkbox);
MouseAdapter a = new MouseAdapter() {
#Override
public void mouseEntered(MouseEvent e) {
super.mouseEntered(e);
setBackground(new Color(224,235,252));
checkbox.setBackground(new Color(224,235,252));
}
#Override
public void mouseExited(MouseEvent e) {
super.mouseExited(e);
setBackground(new Color(186,212,255));
checkbox.setBackground(new Color(186,212,255));
}
};
UIManager.put("ProgressBar.background", new Color (235,255,255));
UIManager.put("ProgressBar.foreground", new Color (10,109,63));
UIManager.put("ProgressBar.selectionBackground", Color.RED);
UIManager.put("ProgressBar.selectionForeground", Color.GREEN);
setBackground(new Color(186,212,255));
setPreferredSize(new Dimension(600,100));
JPanel file = new JPanel();
/* test fileImg = new test("file.png");
fileImg.setBounds(10,10,40,50);
add(fileImg); */
JLabel fileNameLabel = new JLabel(fileName);
fileNameLabel.setBounds(100,5,400,15);
fileNameLabel.setForeground(new Color(109,111,114));
add(fileNameLabel);
JProgressBar jpb = new JProgressBar(0,100);
Random r = new Random();
jpb.setValue(r.nextInt(100));
jpb.setBounds(100,25,400,10);
JLabel progressBarValue = new JLabel("%" + jpb.getValue() + "");
progressBarValue.setBounds(510,18,25,20);
add(progressBarValue);
this.setBorder(BorderFactory.createMatteBorder(0,0,2,0,new Color(18,42,79)));
addMouseListener(a);
add(jpb);
JButton trash = new JButton(new ImageIcon("trash.png"));
trash.setBounds(130,40,25,25);
/* trash.setContentAreaFilled(false);
trash.setFocusPainted (false);
trash.setBorderPainted(false); */
trash.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("text");
}
});
add(trash);
test.setBounds(180,40,25,25);
test.addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
super.mousePressed(e);
System.out.println("text");
}
});
add(test);
double lower = 0;
double upper = 999.99;
sizeOfFile = Math.random() * (upper - lower) + lower;
downloadSpeed = Math.random() * (upper - lower) + lower;
downloadedSize = jpb.getValue() * sizeOfFile / 100;
JLabel downloadSpeedLabel = new JLabel (String.format ("%.1fKbs",downloadSpeed));
JLabel downloadedSizeLabel = new JLabel (String.format ("%.1fMG / %.2fMG",downloadedSize,sizeOfFile));
downloadedSizeLabel.setForeground(new Color(109,111,114));
downloadSpeedLabel.setForeground(new Color(109,111,114));
downloadSpeedLabel.setBounds(250,35,100,30);
downloadedSizeLabel.setBounds(420,35,150,30);
add(downloadSpeedLabel); add(downloadedSizeLabel);
}
public boolean isRemoved() {
return removed;
}
public void setRemoved(boolean removed) {
this.removed = removed;
}
public String getFileName() {
return fileName;
}
public void setFileName(String fileName) {
this.fileName = fileName;
}
public double getDownloadSpeed() {
return downloadSpeed;
}
public void setDownloadSpeed(double downloadSpeed) {
this.downloadSpeed = downloadSpeed;
}
public double getDownloadedSize() {
return downloadedSize;
}
public void setDownloadedSize(double downloadedSize) {
this.downloadedSize = downloadedSize;
}
public boolean isChecked() {
return checked;
}
public void setChecked(boolean checked) {
this.checked = checked;
}
public double getSizeOfFile() {
return sizeOfFile;
}
public void setSizeOfFile(double size) {
this.sizeOfFile = size;
}
}

How can I solve a string version of a calculation for a simple calculator? [duplicate]

This question already has answers here:
How to evaluate a math expression given in string form?
(26 answers)
Closed 6 years ago.
This is a simple calculator where the user can type out the calculation and hit enter, and the calculator would determine if it is a valid calculation or not. If it is a valid calculation, the calculation is carried out. If not, an error message is written to the screen.
The calculation is carried out part isn't finished.
Can someone suggest a solutions to the getAnswer() method.
It would be very much appreciated.
import java.awt.ComponentOrientation;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;
#SuppressWarnings("serial")
public class Calculator extends JFrame{
private interface CalculatorInterface {
public void writeToScreen(String text);
public void clearScreen();
public String getScreenText();
}
private class CalculatorPanel extends JPanel implements CalculatorInterface {
private class NumberPanel extends JPanel implements CalculatorInterface {
private static final int NUMTOTAL = 10;
private CalculatorPanel calcPanel;
private JButton[] numButtons;
public NumberPanel(CalculatorPanel calcPanel) {
this.calcPanel = calcPanel;
buildLayout();
addButtons();
}
private void buildLayout() {
this.setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);
GridLayout layout = new GridLayout(4,3);
layout.setHgap(1);
layout.setVgap(1);
this.setLayout(new GridLayout(4,3));
}
private void addButtons() {
numButtons = new JButton[NUMTOTAL];
for(int i = numButtons.length -1; i >= 0 ; i--) {
numButtons[i] = new JButton("" + i);
numButtons[i].setPreferredSize(new Dimension(60,40));
numButtons[i].setFont(new Font("Sans serif", Font.PLAIN, 18));
numButtons[i].addActionListener(
new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
String text = ((JButton)e.getSource()).getText().trim();
if(getScreenText().equals("Invalid Calc")) {
clearScreen();
writeToScreen(text);
}else {
writeToScreen(text);
}
}
});
this.add(numButtons[i]);
}
}
#Override
public void writeToScreen(String text) {
calcPanel.writeToScreen(text);
}
#Override
public void clearScreen() {
calcPanel.clearScreen();
}
#Override
public String getScreenText() {
return calcPanel.getScreenText();
}
}
private class OperPanel extends JPanel implements CalculatorInterface {
private static final int ADD = 0;
private static final int SUB = 1;
private static final int MULT = 2;
private static final int DIV = 3;
private static final int OPENB = 4;
private static final int CLOSEB = 5;
private static final int CLEAR = 6;
private static final int EQL = 7;
private static final int OPERTOTAL = 8;
private CalculatorPanel calcPanel;
private JButton[] operButtons;
public OperPanel(CalculatorPanel calcPanel) {
this.calcPanel = calcPanel;
buildLayout();
addButtons();
}
private void buildLayout() {
GridLayout layout = new GridLayout(4,1);
layout.setHgap(1);
layout.setVgap(1);
this.setLayout(new GridLayout(4,1));
}
private void addButtons() {
operButtons = new JButton[OPERTOTAL];
operButtons[ADD] = makeButton(ADD, "+");
operButtons[SUB] = makeButton(SUB, "-");
operButtons[MULT] = makeButton(MULT, "*");
operButtons[DIV] = makeButton(DIV, "/");
operButtons[CLEAR] = makeButton(CLEAR, "CL");
operButtons[EQL] = makeButton(EQL, "=");
operButtons[OPENB] = makeButton(OPENB, "(");
operButtons[CLOSEB] = makeButton(CLOSEB, ")");
for(JButton button: operButtons) {
this.add(button);
}
}
private JButton makeButton(int index, String label) {
operButtons[index] = new JButton(label);
operButtons[index].addActionListener(
new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
String text = ((JButton)e.getSource()).getText();
if(text.equals("=")) {
String screenText = getScreenText();
clearScreen();
try {
writeToScreen(getAnswer(screenText));
}catch(Exception excep) {
writeToScreen("Invalid Calc");
}
}else if(text.equals("CL")) {
clearScreen();
}else {
writeToScreen(text);
}
}
});
return operButtons[index];
}
private String getAnswer(String text) throws Exception {
/*I'm trying to solve for any input by the user e.g
*(the stuff in square brackets represents what is displayed
* on the screen:.
*[1+1] (hits equals) [2]
*[1+2-3] (hits equals) [0]
*[1+2*3] (hits equals) [7]
*[10*(14+1/2)] (hits equals) [145]
*/
throw new Exception();
}
#Override
public String getScreenText() {
return calcPanel.getScreenText();
}
#Override
public void clearScreen() {
calcPanel.clearScreen();
}
#Override
public void writeToScreen(String text) {
calcPanel.writeToScreen(text);
}
}
private NumberPanel numPanel;
private OperPanel operPanel;
private JTextField calcScreen;
public CalculatorPanel(JTextField calcScreen) {
this.calcScreen = calcScreen;
buildNumPanel();
buildOperPanel();
buildCalcPanel();
}
private void buildNumPanel() {
this.numPanel = new NumberPanel(this);
}
private void buildOperPanel() {
this.operPanel = new OperPanel(this);
}
private void buildCalcPanel() {
this.setLayout(new BoxLayout(this, BoxLayout.X_AXIS));
this.add(numPanel);
this.add(operPanel);
}
#Override
public void writeToScreen(String text) {
calcScreen.setText(getScreenText() + text);
}
#Override
public String getScreenText() {
return calcScreen.getText();
}
#Override
public void clearScreen() {
calcScreen.setText("");
}
}
private JPanel mainPanel;
private JTextField calcScreen;
private CalculatorPanel calcPanel;
public Calculator() {
buildScreen();
buildCalcPanel();
buildMainPanel();
buildCalculator();
}
private void buildScreen() {
this.calcScreen = new JTextField();
this.calcScreen.setPreferredSize(new Dimension(150,50));
this.calcScreen.setHorizontalAlignment(JTextField.CENTER);
this.calcScreen.setFont(new Font("Sans serif", Font.PLAIN, 30));
}
private void buildCalcPanel() {
this.calcPanel = new CalculatorPanel(this.calcScreen);
}
private void buildMainPanel() {
this.mainPanel = new JPanel();
this.mainPanel.setBorder(new EmptyBorder(10,10,10,10));
this.mainPanel.setLayout(new BoxLayout(this.mainPanel, BoxLayout.Y_AXIS));
this.mainPanel.add(calcScreen);
this.mainPanel.add(calcPanel);
}
private void buildCalculator() {
this.add(mainPanel);
this.setTitle("Calculator");
this.pack();
this.setLocationRelativeTo(null);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}
public static void main(String[] args) {
#SuppressWarnings("unused")
Calculator calc = new Calculator();
}
}
How can I check to see if a string is a valid calculation for a simple calculator?
Edit 1: Fixed a silly bug in the makeButton() method were I passed in the text of the button to be verified instead of the text on screen. (I'm an idiot.)
Edit 2: Removed the isValid(String text) from the code and make it so the getAnswer() method just threw an exception if input is not a valid calculation.

As well mentioned in a previous StackOverflow answer (Evaluating a math expression given in string form), you could use Javascript's ScriptEngine to calculate expressions based on strings that you would retrieve from the Text Field. Place it in a try-catch block first to see if there's an error in the expression. In the catch block, set the variable storing whether its a valid expression or not to false.
boolean validExpression = true;
ScriptEngineManager mgr = new ScriptEngineManager();
ScriptEngine engine = mgr.getEngineByName("JavaScript");
String input = textField.getText() // Modify this to whatever variable you have assigned to your text field
try {
System.out.println(engine.eval(foo));
}
catch (ScriptException e) {
validExpression = false;
System.out.println("Invalid Expression");
}
Make sure you include the following imports:
import javax.script.ScriptEngineManager;
import javax.script.ScriptEngine;
import javax.script.ScriptException;
Although you could try to implement Shunting-Yard Algorithm or another arithmetic parser, this is simply a way more pragmatic solution.

DocumentListener isn't printing a message [duplicate]

This question already has answers here:
How do I compare strings in Java?
(23 answers)
Closed 8 years ago.
I was trying to write a program which would give me a message when something (xx) in this case is typed, but it doesn't print a message. Can you please tell me why that happens ?
I've also checked the code if it's equal to xx when I type it, and it is.
import javax.swing.*;
import java.awt.*;
import javax.swing.text.*;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
class acc
{
public static void main(String[] args)
{
ramka ramka = new ramka();
panel panel1 = new panel();
ramka.show();
ramka.add(panel1);
}
}
class ramka extends JFrame
{
public ramka()
{
setSize(800, 600);
setTitle("Super duper programer");
Container kontener = getContentPane();
textfield pole = new textfield();
kontener.add(pole);
setDefaultCloseOperation(EXIT_ON_CLOSE);
sluchacz listener = new sluchacz();
pole.getDocument().addDocumentListener(listener);
}
}
class panel extends JPanel
{
public void paintComponent(Graphics g)
{
super.paintComponent(g);
}
}
class textfield extends JTextField
{
}
class sluchacz implements DocumentListener
{
#Override
public void changedUpdate(DocumentEvent e)
{}
#Override
public void removeUpdate(DocumentEvent e){}
#Override
public void insertUpdate(DocumentEvent e)
{
try
{
String input = e.getDocument().getText(0, e.getDocument().getLength()).trim();
if(input == "xx")
{
String message = JOptionPane.showInputDialog("You've just typed ''xx''");
}
}
catch(BadLocationException ex)
{
}
}
}

Your problem may be here:
if(input == "xx")
don't use == to check for equality of Strings. Use .equals(...).

jcombobox filter in java - Look and feel independent

I have a simple JComboBox filter code like this :
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
public class FilterComboBox extends JComboBox {
private List<String> array;
public FilterComboBox(List<String> array) {
super(array.toArray());
this.array = array;
this.setEditable(true);
final JTextField textfield = (JTextField) this.getEditor().getEditorComponent();
textfield.addKeyListener(new KeyAdapter() {
public void keyReleased(KeyEvent ke) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
comboFilter(textfield.getText());
}
});
}
});
}
public void comboFilter(String enteredText) {
List<String> filterArray= new ArrayList<String>();
for (int i = 0; i < array.size(); i++) {
if (array.get(i).toLowerCase().contains(enteredText.toLowerCase())) {
filterArray.add(array.get(i));
}
}
if (filterArray.size() > 0) {
this.setModel(new DefaultComboBoxModel(filterArray.toArray()));
this.setSelectedItem(enteredText);
this.showPopup();
}
else {
this.hidePopup();
}
}
/* Testing Codes */
public static List<String> populateArray() {
List<String> test = new ArrayList<String>();
test.add("");
test.add("Mountain Flight");
test.add("Mount Climbing");
test.add("Trekking");
test.add("Rafting");
test.add("Jungle Safari");
test.add("Bungie Jumping");
test.add("Para Gliding");
return test;
}
public static void makeUI() {
JFrame frame = new JFrame("Adventure in Nepal - Combo Filter Test");
FilterComboBox acb = new FilterComboBox(populateArray());
frame.getContentPane().add(acb);
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public static void main(String[] args) throws Exception {
//UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
makeUI();
}
}
The performance of the combo filter is not so good but it is fine for few data set. My problem is - when I remove the comment UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel"); to change look and feel, the filter doesn't work. In WindowsLookAndFeel, the combo box only takes single character in it by replacing the previously entered character.
Can you please tell me whats going on? Manoj Shrestha's answer below helps in some way but , can you please provide some other suggestions to achieve combo box filter in Java?

Firstly you are creating new model everytime and then invoking show popup from code which leads to flickering etc. We can modify the model itself. Secondly you set the currently entered text as selected item which seems to have selectAll behavior as noted by others. I have modified the code as follows:
public void comboFilter(String enteredText) {
if (!this.isPopupVisible()) {
this.showPopup();
}
List<String> filterArray= new ArrayList<String>();
for (int i = 0; i < array.size(); i++) {
if (array.get(i).toLowerCase().contains(enteredText.toLowerCase())) {
filterArray.add(array.get(i));
}
}
if (filterArray.size() > 0) {
DefaultComboBoxModel model = (DefaultComboBoxModel) this.getModel();
model.removeAllElements();
for (String s: filterArray)
model.addElement(s);
JTextField textfield = (JTextField) this.getEditor().getEditorComponent();
textfield.setText(enteredText);
}
}
Hope it works for you.

very long answer, I think that exelent example about how different Look and Feel have got implemented methods in API and works
KeyListener isn't proper Listener for Swing JComponents, you really to have bothering with KeyBindings,
KeyListener is simple asynchronous,
JComboBox is Compound JComponent, then there is required override internal JComponents, all output from KeyListener must be wrapped into invokeLater(), notice I can create event from coumpond JComponents that twice invokeLater() doesn't returns expected output to the GUI, only Swing Timer with Swing Action can do that correctly, simple why to bothering wiht that example about wrong way,
code
import java.awt.Component;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.plaf.basic.BasicComboBoxRenderer;
public class ComboBoxHoverOver {
private JComboBox combo = new JComboBox();
public ComboBoxHoverOver() {
combo.setPrototypeDisplayValue("XXXXXXXXXXXXXXXXXXXXXX");
combo.setRenderer(new ComboToolTipRenderer(combo));
combo.addItemListener(new ItemListener() {
#Override
public void itemStateChanged(ItemEvent e) {
//System.out.println(combo.getSelectedItem().toString());
}
});
combo.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
//System.out.println(combo.getSelectedItem().toString());
}
});
combo.addItem("");
combo.addItem("Long text 4");
combo.addItem("Long text 3");
combo.addItem("Long text 2");
combo.addItem("Long text 1");
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(combo);
f.pack();
f.setVisible(true);
}
private class ComboToolTipRenderer extends BasicComboBoxRenderer {
private static final long serialVersionUID = 1L;
private JComboBox combo;
private JList comboList;
ComboToolTipRenderer(JComboBox combo) {
this.combo = combo;
}
#Override
public Component getListCellRendererComponent(JList list, Object value,
int index, boolean isSelected, boolean cellHasFocus) {
super.getListCellRendererComponent(
list, value, index, isSelected, cellHasFocus);
if (comboList == null) {
comboList = list;
KeyAdapter listener = new KeyAdapter() {
#Override
public void keyReleased(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_DOWN || e.getKeyCode() == KeyEvent.VK_UP) {
int x = 5;
int y = comboList.indexToLocation(comboList.getSelectedIndex()).y;
System.out.println(comboList.getSelectedIndex());
}
}
};
combo.addKeyListener(listener);
combo.getEditor().getEditorComponent().addKeyListener(listener);
}
if (isSelected) {
//System.out.println(value.toString());
}
return this;
}
}
public static void main(String[] args) throws ClassNotFoundException,
InstantiationException, IllegalAccessException, UnsupportedLookAndFeelException {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
ComboBoxHoverOver comboBoxHoverOver = new ComboBoxHoverOver();
}
});
}
}
JComboBox is Compound JComponent, then there is required override BasicComboBoxUI, please sorry I lazy to write and simulating too much longer code as code from first point
otherwise all effort from above two point are useless and contraproductive, nothing else, only DOT
please can someone to test follows code in *nix and apple OS X
from my Java6 WinXP compo (all important is hidden in the used methods, enless kudos for anonymous author from former Sun Microsystems)
Substance L&F
WindowsLookAndFeel L&F
Nimbus L&F
Metal L&F
from Java Classes
main
import java.awt.*;
import java.util.ArrayList;
import javax.swing.*;
import javax.swing.UIManager.LookAndFeelInfo;
import org.pushingpixels.substance.api.skin.SubstanceOfficeSilver2007LookAndFeel;
public class AutoCompleteTextField {
private static JFrame frame = new JFrame();
private ArrayList<String> listSomeString = new ArrayList<String>();
private Java2sAutoTextField someTextField = new Java2sAutoTextField(listSomeString);
private ArrayList<String> listSomeAnotherString = new ArrayList<String>();
private Java2sAutoComboBox someComboBox = new Java2sAutoComboBox(listSomeAnotherString);
public AutoCompleteTextField() {
listSomeString.add("-");
listSomeString.add("Snowboarding");
listSomeString.add("Rowing");
listSomeString.add("Knitting");
listSomeString.add("Speed reading");
listSomeString.add("Pool");
listSomeString.add("None of the above");
//
listSomeAnotherString.add("-");
listSomeAnotherString.add("XxxZxx Snowboarding");
listSomeAnotherString.add("AaaBbb Rowing");
listSomeAnotherString.add("CccDdd Knitting");
listSomeAnotherString.add("Eee Fff Speed reading");
listSomeAnotherString.add("Eee Fff Pool");
listSomeAnotherString.add("Eee Fff None of the above");
//
someTextField.setFont(new Font("Serif", Font.BOLD, 16));
someTextField.setForeground(Color.black);
someTextField.setBackground(Color.orange);
someTextField.setName("someTextField");
someTextField.setDataList(listSomeString);
//
someComboBox.setPrototypeDisplayValue("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
someComboBox.setFont(new Font("Serif", Font.BOLD, 16));
someComboBox.setForeground(Color.black);
someComboBox.setBackground(Color.YELLOW);
someComboBox.getEditor().selectAll();
someComboBox.getEditor().getEditorComponent().setBackground(Color.YELLOW);
((JTextField) someComboBox.getEditor().getEditorComponent()).setDisabledTextColor(Color.black);
someComboBox.setName("someComboBox");
someComboBox.setDataList(listSomeAnotherString);
//
frame.setLayout(new GridLayout(0, 1, 10, 10));
frame.add(someTextField);
frame.add(someComboBox);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocation(100, 100);
frame.pack();
frame.setVisible(true);
//
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
someTextField.setText("-");
someComboBox.getEditor().setItem(0);
someComboBox.getEditor().selectAll();
someTextField.grabFocus();
someTextField.requestFocus();
someTextField.setText(someTextField.getText());
someTextField.selectAll();
}
});
}
public static void main(String[] args) {
/*SwingUtilities.invokeLater(new Runnable() {
public void run() {
try {
UIManager.setLookAndFeel(new SubstanceOfficeSilver2007LookAndFeel());
SwingUtilities.updateComponentTreeUI(frame);
} catch (UnsupportedLookAndFeelException e) {
throw new RuntimeException(e);
}
}
});*/
/*try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
System.out.println(info.getName());
if ("Nimbus".equals(info.getName())) {
UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (UnsupportedLookAndFeelException e) {
// handle exception
} catch (ClassNotFoundException e) {
// handle exception
} catch (InstantiationException e) {
// handle exception
} catch (IllegalAccessException e) {
// handle exception
}*/
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
AutoCompleteTextField aCTF = new AutoCompleteTextField();
}
});
}
}
AutoComboBox
import java.awt.event.ItemEvent;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.plaf.basic.BasicComboBoxEditor;
public class Java2sAutoComboBox extends JComboBox {
private static final long serialVersionUID = 1L;
private AutoTextFieldEditor autoTextFieldEditor;
private boolean isFired;
private class AutoTextFieldEditor extends BasicComboBoxEditor {
private Java2sAutoTextField getAutoTextFieldEditor() {
return (Java2sAutoTextField) editor;
}
AutoTextFieldEditor(java.util.List<String> list) {
editor = new Java2sAutoTextField(list, Java2sAutoComboBox.this);
}
}
public Java2sAutoComboBox(java.util.List<String> list) {
isFired = false;
autoTextFieldEditor = new AutoTextFieldEditor(list);
setEditable(true);
setModel(new DefaultComboBoxModel(list.toArray()) {
private static final long serialVersionUID = 1L;
#Override
protected void fireContentsChanged(Object obj, int i, int j) {
if (!isFired) {
super.fireContentsChanged(obj, i, j);
}
}
});
setEditor(autoTextFieldEditor);
}
public boolean isCaseSensitive() {
return autoTextFieldEditor.getAutoTextFieldEditor().isCaseSensitive();
}
public void setCaseSensitive(boolean flag) {
autoTextFieldEditor.getAutoTextFieldEditor().setCaseSensitive(flag);
}
public boolean isStrict() {
return autoTextFieldEditor.getAutoTextFieldEditor().isStrict();
}
public void setStrict(boolean flag) {
autoTextFieldEditor.getAutoTextFieldEditor().setStrict(flag);
}
public java.util.List<String> getDataList() {
return autoTextFieldEditor.getAutoTextFieldEditor().getDataList();
}
public void setDataList(java.util.List<String> list) {
autoTextFieldEditor.getAutoTextFieldEditor().setDataList(list);
setModel(new DefaultComboBoxModel(list.toArray()));
}
void setSelectedValue(Object obj) {
if (isFired) {
return;
} else {
isFired = true;
setSelectedItem(obj);
fireItemStateChanged(new ItemEvent(this, 701, selectedItemReminder, 1));
isFired = false;
return;
}
}
#Override
protected void fireActionEvent() {
if (!isFired) {
super.fireActionEvent();
}
}
}
AutoTextField
import java.util.List;
import javax.swing.JTextField;
import javax.swing.text.*;
public class Java2sAutoTextField extends JTextField {
private static final long serialVersionUID = 1L;
private List<String> dataList;
private boolean isCaseSensitive;
private boolean isStrict;
private Java2sAutoComboBox autoComboBox;
public class AutoDocument extends PlainDocument {
private static final long serialVersionUID = 1L;
#Override
public void replace(int i, int j, String s, AttributeSet attributeset)
throws BadLocationException {
super.remove(i, j);
insertString(i, s, attributeset);
}
#Override
public void insertString(int i, String s, AttributeSet attributeset)
throws BadLocationException {
if (s == null || "".equals(s)) {
return;
}
String s1 = getText(0, i);
String s2 = getMatch(s1 + s);
int j = (i + s.length()) - 1;
if (isStrict && s2 == null) {
s2 = getMatch(s1);
j--;
} else if (!isStrict && s2 == null) {
super.insertString(i, s, attributeset);
return;
}
if (autoComboBox != null && s2 != null) {
autoComboBox.setSelectedValue(s2);
}
super.remove(0, getLength());
super.insertString(0, s2, attributeset);
setSelectionStart(j + 1);
setSelectionEnd(getLength());
}
#Override
public void remove(int i, int j) throws BadLocationException {
int k = getSelectionStart();
if (k > 0) {
k--;
}
String s = getMatch(getText(0, k));
if (!isStrict && s == null) {
super.remove(i, j);
} else {
super.remove(0, getLength());
super.insertString(0, s, null);
}
if (autoComboBox != null && s != null) {
autoComboBox.setSelectedValue(s);
}
try {
setSelectionStart(k);
setSelectionEnd(getLength());
} catch (Exception exception) {
}
}
}
public Java2sAutoTextField(List<String> list) {
isCaseSensitive = false;
isStrict = true;
autoComboBox = null;
if (list == null) {
throw new IllegalArgumentException("values can not be null");
} else {
dataList = list;
init();
return;
}
}
Java2sAutoTextField(List<String> list, Java2sAutoComboBox b) {
isCaseSensitive = false;
isStrict = true;
autoComboBox = null;
if (list == null) {
throw new IllegalArgumentException("values can not be null");
} else {
dataList = list;
autoComboBox = b;
init();
return;
}
}
private void init() {
setDocument(new AutoDocument());
if (isStrict && dataList.size() > 0) {
setText(dataList.get(0).toString());
}
}
private String getMatch(String s) {
for (int i = 0; i < dataList.size(); i++) {
String s1 = dataList.get(i).toString();
if (s1 != null) {
if (!isCaseSensitive
&& s1.toLowerCase().startsWith(s.toLowerCase())) {
return s1;
}
if (isCaseSensitive && s1.startsWith(s)) {
return s1;
}
}
}
return null;
}
#Override
public void replaceSelection(String s) {
AutoDocument _lb = (AutoDocument) getDocument();
if (_lb != null) {
try {
int i = Math.min(getCaret().getDot(), getCaret().getMark());
int j = Math.max(getCaret().getDot(), getCaret().getMark());
_lb.replace(i, j - i, s, null);
} catch (Exception exception) {
}
}
}
public boolean isCaseSensitive() {
return isCaseSensitive;
}
public void setCaseSensitive(boolean flag) {
isCaseSensitive = flag;
}
public boolean isStrict() {
return isStrict;
}
public void setStrict(boolean flag) {
isStrict = flag;
}
public List<String> getDataList() {
return dataList;
}
public void setDataList(List<String> list) {
if (list == null) {
throw new IllegalArgumentException("values can not be null");
} else {
dataList = list;
return;
}
}
}
EDIT
output from Win7 64b / Java7
Metal L&F
Windows L&F (funny empty white space near Button in JComboBox)
Nimbus L&F
feel free for edit(s)

This component is called autocomplete and is included in a so called swing extensions porject.
Just have a look at: http://swingx.java.net/
There is a webstart: http://swinglabs-demos.java.net/demos/swingxset6/swingxset.jnlp
Autocomplete is the Menu to select. Have fun and less error prone code :)

obviously the glitch is in the textfield component used. What happens is, when windows look and feel is used , the text in this component is selected just as using the line "textfield.selectAll();", and hence when you type anything else the selected text is cleared form the textfield component. So in the below code the caret position of this component is adjusted. This is how it works, first store the current caret position of text field in a variable "currentCaretPosition", then move the caret position to the beginning in the text in the component. After filtering restoring the caret position back to the "currentCaretPosition" variable value. I hope it works as you want it to.
The refined code is given below:-
/****Beginning of code****/
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
public class FilterComboBox extends JComboBox {
private List<String> array;
private int currentCaretPosition=0;
public FilterComboBox(List<String> array) {
super(array.toArray());
this.array = array;
this.setEditable(true);
final JTextField textfield = (JTextField) this.getEditor().getEditorComponent();
textfield.addKeyListener(new KeyAdapter() {
public void keyPressed(KeyEvent ke) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
currentCaretPosition=textfield.getCaretPosition();
if(textfield.getSelectedText()==null)
{
textfield.setCaretPosition(0);
comboFilter(textfield.getText());
textfield.setCaretPosition(currentCaretPosition);
}
}
});
}
});
}
public void comboFilter(String enteredText) {
List<String> filterArray= new ArrayList<String>();
for (int i = 0; i < array.size(); i++) {
if (array.get(i).toLowerCase().contains(enteredText.toLowerCase())) {
filterArray.add(array.get(i));
}
}
if (filterArray.size() > 0) {
this.setModel(new DefaultComboBoxModel(filterArray.toArray()));
this.setSelectedItem(enteredText);
this.showPopup();
}
else {
this.hidePopup();
}
}
/* Testing Codes */
public static List<String> populateArray() {
List<String> test = new ArrayList<String>();
test.add("");
test.add("Mountain Flight");
test.add("Mount Climbing");
test.add("Trekking");
test.add("Rafting");
test.add("Jungle Safari");
test.add("Bungie Jumping");
test.add("Para Gliding");
return test;
}
public static void makeUI() {
JFrame frame = new JFrame("Adventure in Nepal - Combo Filter Test");
FilterComboBox acb = new FilterComboBox(populateArray());
frame.getContentPane().add(acb);
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public static void main(String[] args) throws Exception {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
makeUI();
}
}
/******* End of code**********/

It looks like, as you mentioned, when user inputs any texts in combobox, the Windows Look & Feel selects (highlights) the entered text. So, when you press another key, it replaces the previous one. So, the solution is not to highlight the entered texts. You can achieve this by adding any one of the following statements in your keylistener.
textfield.setCaretPosition(textfield.getText().length());
OR
textfield.setSelectionStart(textfield.getText().length());
So, your keylistener should look like this :
final JTextField textfield = (JTextField) this.getEditor().getEditorComponent();
textfield.addKeyListener(new KeyAdapter() {
public void keyReleased(KeyEvent ke) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
comboFilter(textfield.getText());
textfield.setCaretPosition(textfield.getText().length());
}
});
}
});

Java JTextField with input hint

I would like to add a hint value to my javax.swing.JTextField. It should look like Firefox rendering of <input type="text" title="bla">. This creates an edit field with the text 'bla' in the background. If the textbox has focus the title-text disappears and just reappears if the user leaves the editbox without text.
Is there a (free) swing component that does something like this?

You could create your own:
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import javax.swing.*;
public class Main {
public static void main(String[] args) {
final JFrame frame = new JFrame();
frame.setLayout(new BorderLayout());
final JTextField textFieldA = new HintTextField("A hint here");
final JTextField textFieldB = new HintTextField("Another hint here");
frame.add(textFieldA, BorderLayout.NORTH);
frame.add(textFieldB, BorderLayout.CENTER);
JButton btnGetText = new JButton("Get text");
btnGetText.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
String message = String.format("textFieldA='%s', textFieldB='%s'",
textFieldA.getText(), textFieldB.getText());
JOptionPane.showMessageDialog(frame, message);
}
});
frame.add(btnGetText, BorderLayout.SOUTH);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.setVisible(true);
frame.pack();
}
}
class HintTextField extends JTextField implements FocusListener {
private final String hint;
private boolean showingHint;
public HintTextField(final String hint) {
super(hint);
this.hint = hint;
this.showingHint = true;
super.addFocusListener(this);
}
#Override
public void focusGained(FocusEvent e) {
if(this.getText().isEmpty()) {
super.setText("");
showingHint = false;
}
}
#Override
public void focusLost(FocusEvent e) {
if(this.getText().isEmpty()) {
super.setText(hint);
showingHint = true;
}
}
#Override
public String getText() {
return showingHint ? "" : super.getText();
}
}
If you're still on Java 1.5, replace the this.getText().isEmpty() with this.getText().length() == 0.

Here is a simple way that looks good in any L&F:
public class HintTextField extends JTextField {
public HintTextField(String hint) {
_hint = hint;
}
#Override
public void paint(Graphics g) {
super.paint(g);
if (getText().length() == 0) {
int h = getHeight();
((Graphics2D)g).setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
Insets ins = getInsets();
FontMetrics fm = g.getFontMetrics();
int c0 = getBackground().getRGB();
int c1 = getForeground().getRGB();
int m = 0xfefefefe;
int c2 = ((c0 & m) >>> 1) + ((c1 & m) >>> 1);
g.setColor(new Color(c2, true));
g.drawString(_hint, ins.left, h / 2 + fm.getAscent() / 2 - 2);
}
}
private final String _hint;
}

Here is a single class copy/paste solution:
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import javax.swing.plaf.basic.BasicTextFieldUI;
import javax.swing.text.JTextComponent;
public class HintTextFieldUI extends BasicTextFieldUI implements FocusListener {
private String hint;
private boolean hideOnFocus;
private Color color;
public Color getColor() {
return color;
}
public void setColor(Color color) {
this.color = color;
repaint();
}
private void repaint() {
if(getComponent() != null) {
getComponent().repaint();
}
}
public boolean isHideOnFocus() {
return hideOnFocus;
}
public void setHideOnFocus(boolean hideOnFocus) {
this.hideOnFocus = hideOnFocus;
repaint();
}
public String getHint() {
return hint;
}
public void setHint(String hint) {
this.hint = hint;
repaint();
}
public HintTextFieldUI(String hint) {
this(hint,false);
}
public HintTextFieldUI(String hint, boolean hideOnFocus) {
this(hint,hideOnFocus, null);
}
public HintTextFieldUI(String hint, boolean hideOnFocus, Color color) {
this.hint = hint;
this.hideOnFocus = hideOnFocus;
this.color = color;
}
#Override
protected void paintSafely(Graphics g) {
super.paintSafely(g);
JTextComponent comp = getComponent();
if(hint!=null && comp.getText().length() == 0 && (!(hideOnFocus && comp.hasFocus()))){
if(color != null) {
g.setColor(color);
} else {
g.setColor(comp.getForeground().brighter().brighter().brighter());
}
int padding = (comp.getHeight() - comp.getFont().getSize())/2;
g.drawString(hint, 2, comp.getHeight()-padding-1);
}
}
#Override
public void focusGained(FocusEvent e) {
if(hideOnFocus) repaint();
}
#Override
public void focusLost(FocusEvent e) {
if(hideOnFocus) repaint();
}
#Override
protected void installListeners() {
super.installListeners();
getComponent().addFocusListener(this);
}
#Override
protected void uninstallListeners() {
super.uninstallListeners();
getComponent().removeFocusListener(this);
}
}
Use it like this:
TextField field = new JTextField();
field.setUI(new HintTextFieldUI("Search", true));
Note that it is happening in protected void paintSafely(Graphics g).

Take a look at this one: http://code.google.com/p/xswingx/
It is not very difficult to implement it by yourself, btw. A couple of listeners and custom renderer and voila.

For any Swing component (that is, anything that extends JComponent), you can call the setToolTipText(String) method.
For more information, reference the following links:
API Documentation for setToolTipText
"How to Use Tool Tips" tutorial

Have look at WebLookAndFeel at https://github.com/mgarin/weblaf/
WebTextField txtName = new com.alee.laf.text.WebTextField();
txtName.setHideInputPromptOnFocus(false);
txtName.setInputPrompt("Name");
txtName.setInputPromptFont(new java.awt.Font("Ubuntu", 0, 18));
txtName.setInputPromptForeground(new java.awt.Color(102, 102, 102));
txtName.setInputPromptPosition(0);

If you still look for a solution, here's one that combined other answers (Bart Kiers and culmat) for your reference:
import javax.swing.*;
import javax.swing.text.JTextComponent;
import java.awt.*;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
public class HintTextField extends JTextField implements FocusListener
{
private String hint;
public HintTextField ()
{
this("");
}
public HintTextField(final String hint)
{
setHint(hint);
super.addFocusListener(this);
}
public void setHint(String hint)
{
this.hint = hint;
setUI(new HintTextFieldUI(hint, true));
//setText(this.hint);
}
public void focusGained(FocusEvent e)
{
if(this.getText().length() == 0)
{
super.setText("");
}
}
public void focusLost(FocusEvent e)
{
if(this.getText().length() == 0)
{
setHint(hint);
}
}
public String getText()
{
String typed = super.getText();
return typed.equals(hint)?"":typed;
}
}
class HintTextFieldUI extends javax.swing.plaf.basic.BasicTextFieldUI implements FocusListener
{
private String hint;
private boolean hideOnFocus;
private Color color;
public Color getColor()
{
return color;
}
public void setColor(Color color)
{
this.color = color;
repaint();
}
private void repaint()
{
if(getComponent() != null)
{
getComponent().repaint();
}
}
public boolean isHideOnFocus()
{
return hideOnFocus;
}
public void setHideOnFocus(boolean hideOnFocus)
{
this.hideOnFocus = hideOnFocus;
repaint();
}
public String getHint()
{
return hint;
}
public void setHint(String hint)
{
this.hint = hint;
repaint();
}
public HintTextFieldUI(String hint)
{
this(hint, false);
}
public HintTextFieldUI(String hint, boolean hideOnFocus)
{
this(hint, hideOnFocus, null);
}
public HintTextFieldUI(String hint, boolean hideOnFocus, Color color)
{
this.hint = hint;
this.hideOnFocus = hideOnFocus;
this.color = color;
}
protected void paintSafely(Graphics g)
{
super.paintSafely(g);
JTextComponent comp = getComponent();
if(hint != null && comp.getText().length() == 0 && (!(hideOnFocus && comp.hasFocus())))
{
if(color != null)
{
g.setColor(color);
}
else
{
g.setColor(Color.gray);
}
int padding = (comp.getHeight() - comp.getFont().getSize()) / 2;
g.drawString(hint, 5, comp.getHeight() - padding - 1);
}
}
public void focusGained(FocusEvent e)
{
if(hideOnFocus) repaint();
}
public void focusLost(FocusEvent e)
{
if(hideOnFocus) repaint();
}
protected void installListeners()
{
super.installListeners();
getComponent().addFocusListener(this);
}
protected void uninstallListeners()
{
super.uninstallListeners();
getComponent().removeFocusListener(this);
}
}
Usage:
HintTextField field = new HintTextField();
field.setHint("Here's a hint");

This can be achieved by using a focus listener to update the text field content.
Make the class implement the focus listener interface:
class YourClass implements FocusListener
Add a method to catch when focus is gained that blanks the field:
public void focusGained(FocusEvent e) {
if(JTextField1.getText().equals("Username")) {
JTextField1.setText("");
}
}
Add a method to catch when focus is lost to redisplay the default entry if the field was blank:
public void focusLost(FocusEvent e) {
if(JTextField1.getText().equals("")) {
JTextField1.setText("Username");
// you should prevent the form from being processed in this state
// as it will literally contain "Username" for the username
}
}
Register your class as the focus listener for text field:
textField.addFocusListener(this);
Learn more at How to Write a Focus Listener in the Java Tutorials.

Here is a fully working example based on Adam Gawne-Cain's earlier Posting. His solution is simple and actually works exceptionally well.
I've used the following text in a Grid of multiple Fields:
H__|__WWW__+__XXXX__+__WWW__|__H
this makes it possible to easily verify the x/y alignment of the hinted text.
A couple of observations:
- there are any number of solutions out there, but many only work superficially and/or are buggy
- sun.tools.jconsole.ThreadTab.PromptingTextField is a simple solution, but it only shows the prompting text when the Field doesn't have the focus & it's private, but nothing a little cut-and-paste won't fix.
The following works on JDK 8 and upwards:
import java.awt.*;
import java.util.stream.*;
import javax.swing.*;
/**
* #author DaveTheDane, based on a suggestion from Adam Gawne-Cain
*/
public final class JTextFieldPromptExample extends JFrame {
private static JTextField newPromptedJTextField (final String text, final String prompt) {
final String promptPossiblyNullButNeverWhitespace = prompt == null || prompt.trim().isEmpty() ? null : prompt;
return new JTextField(text) {
#Override
public void paintComponent(final Graphics USE_g2d_INSTEAD) {
final Graphics2D g2d = (Graphics2D) USE_g2d_INSTEAD;
super.paintComponent(g2d);
// System.out.println("Paint.: " + g2d);
if (getText().isEmpty()
&& promptPossiblyNullButNeverWhitespace != null) {
g2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
final Insets ins = getInsets();
final FontMetrics fm = g2d.getFontMetrics();
final int cB = getBackground().getRGB();
final int cF = getForeground().getRGB();
final int m = 0xfefefefe;
final int c2 = ((cB & m) >>> 1) + ((cF & m) >>> 1); // "for X in (A, R, G, B) {Xnew = (Xb + Xf) / 2}"
/*
* The hint text color should be halfway between the foreground and background colors so it is always gently visible.
* The variables c0,c1,m,c2 calculate the halfway color's ARGB fields simultaneously without overflowing 8 bits.
* Swing sets the Graphics' font to match the JTextField's font property before calling the "paint" method,
* so the hint font will match the JTextField's font.
* Don't think there are any side effects because Swing discards the Graphics after painting.
* Adam Gawne-Cain, Aug 6 2019 at 15:55
*/
g2d.setColor(new Color(c2, true));
g2d.drawString(promptPossiblyNullButNeverWhitespace, ins.left, getHeight() - fm.getDescent() - ins.bottom);
/*
* y Coordinate based on Descent & Bottom-inset seems to align Text spot-on.
* DaveTheDane, Apr 10 2020
*/
}
}
};
}
private static final GridBagConstraints GBC_LEFT = new GridBagConstraints();
private static final GridBagConstraints GBC_RIGHT = new GridBagConstraints();
/**/ static {
GBC_LEFT .anchor = GridBagConstraints.LINE_START;
GBC_LEFT .fill = GridBagConstraints.HORIZONTAL;
GBC_LEFT .insets = new Insets(8, 8, 0, 0);
GBC_RIGHT.gridwidth = GridBagConstraints.REMAINDER;
GBC_RIGHT.fill = GridBagConstraints.HORIZONTAL;
GBC_RIGHT.insets = new Insets(8, 8, 0, 8);
}
private <C extends Component> C addLeft (final C component) {
this .add (component);
this.gbl.setConstraints(component, GBC_LEFT);
return component;
}
private <C extends Component> C addRight(final C component) {
this .add (component);
this.gbl.setConstraints(component, GBC_RIGHT);
return component;
}
private static final String ALIGN = "H__|__WWW__+__XXXX__+__WWW__|__H";
private final GridBagLayout gbl = new GridBagLayout();
public JTextFieldPromptExample(final String title) {
super(title);
this.setLayout(gbl);
final java.util.List<JTextField> texts = Stream.of(
addLeft (newPromptedJTextField(ALIGN + ' ' + "Top-Left" , ALIGN)),
addRight(newPromptedJTextField(ALIGN + ' ' + "Top-Right" , ALIGN)),
addLeft (newPromptedJTextField(ALIGN + ' ' + "Middle-Left" , ALIGN)),
addRight(newPromptedJTextField( null , ALIGN)),
addLeft (new JTextField("x" )),
addRight(newPromptedJTextField("x", "" )),
addLeft (new JTextField(null )),
addRight(newPromptedJTextField(null, null)),
addLeft (newPromptedJTextField(ALIGN + ' ' + "Bottom-Left" , ALIGN)),
addRight(newPromptedJTextField(ALIGN + ' ' + "Bottom-Right", ALIGN)) ).collect(Collectors.toList());
final JButton button = addRight(new JButton("Get texts"));
/**/ addRight(Box.createVerticalStrut(0)); // 1 last time forces bottom inset
this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
this.setPreferredSize(new Dimension(740, 260));
this.pack();
this.setResizable(false);
this.setVisible(true);
button.addActionListener(e -> {
texts.forEach(text -> System.out.println("Text..: " + text.getText()));
});
}
public static void main(final String[] args) {
SwingUtilities.invokeLater(() -> new JTextFieldPromptExample("JTextField with Prompt"));
}
}