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?
This question is related to
java
swing
input
jtextfield
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.
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");
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)
.
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;
}
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);
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"));
}
}
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
.
For any Swing component (that is, anything that extends JComponent), you can call the setToolTipText(String) method.
For more information, reference the following links:
Source: Stackoverflow.com