Develop Reference

Jlabel change color on mouse click Java

I am adding multiple Jlabel using for loop. What I want is on mouse click, the color of the selected JLabel should change and set to the default color on click of anotherJLabel.

Since you changed the state of the label, you need someway to change it back. The simplest solution is to maintain a reference to the last label that was changed and when the new label is clicked, reset it's state
import java.awt.Color;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
HighlightMouseListener hml = new HighlightMouseListener();
for (int index = 0; index < 10; index++) {
JLabel label = new JLabel("Hello " + index);
label.addMouseListener(hml);
add(label, gbc);
}
}
}
public class HighlightMouseListener extends MouseAdapter {
private JLabel previous;
#Override
public void mouseClicked(MouseEvent e) {
Component source = e.getComponent();
if (!(source instanceof JLabel)) {
return;
}
JLabel label = (JLabel) source;
if (previous != null) {
previous.setBackground(null);
previous.setForeground(null);
previous.setOpaque(false);
}
previous = label;
label.setForeground(Color.WHITE);
label.setBackground(Color.BLUE);
label.setOpaque(true);
}
}
}
I still wonder if a JList would be a better and simpler solution, but since I don't know what you're doing, it's all I can do

Change image in JLabel based on which button the cursor is hovering over?

I have created a Swing interface where I want an icon to appear in a JLabel when the cursor is hovered over a button. The icon will change based in which button the cursor hovers over.
Here is the coding I am using at the moment:
public void iconchange()
{
if(btnPlay.isRolloverEnabled() == true)
{
lblIcon.setIcon(new ImageIcon("Images/Play-icon.png"));
}
}
I know the coding above is wrong, so what can I do to achieve the feature I mentioned above?

Use a ChangeListener on the JButton's ButtonModel to monitor changes to the models state, update your UI based on the state of the model, for example...
public class ChangeHandler implements ChangeListener {
private JLabel label;
private Icon armedIcon;
public ChangeHandler(JLabel label, Icon armedIcon) {
this.armedIcon = armedIcon;
this.label = label;
}
#Override
public void stateChanged(ChangeEvent e) {
ButtonModel model = (ButtonModel) e.getSource();
if (model.isRollover()) {
label.setIcon(armedIcon);
} else {
label.setIcon(null);
}
}
}
This will update the supplied JLabel, changing it's icon to the specified icon when the ButtonModel it's attached to is in the rollOver state
This could be used something like this...
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ButtonModel;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class RollOver {
public static void main(String[] args) {
new RollOver();
}
public RollOver() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JLabel label;
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
// I'm doing this, because I don't have blank icon of 128x128 and my
// icons are both 128x128
label = new JLabel() {
#Override
public Dimension getPreferredSize() {
return new Dimension(128, 128);
}
};
add(label, gbc);
try {
JButton btn = new JButton("Bunnies");
btn.getModel().addChangeListener(new ChangeHandler(label, new ImageIcon(ImageIO.read(getClass().getResource("/Bunny.png")))));
add(btn);
btn = new JButton("Zomnies");
btn.getModel().addChangeListener(new ChangeHandler(label, new ImageIcon(ImageIO.read(getClass().getResource("/Zombi.png")))));
add(btn);
} catch (IOException exp) {
exp.printStackTrace();
}
}
public class ChangeHandler implements ChangeListener {
private JLabel label;
private Icon armedIcon;
public ChangeHandler(JLabel label, Icon armedIcon) {
this.armedIcon = armedIcon;
this.label = label;
}
#Override
public void stateChanged(ChangeEvent e) {
ButtonModel model = (ButtonModel) e.getSource();
if (model.isRollover()) {
label.setIcon(armedIcon);
} else {
label.setIcon(null);
}
}
}
}
}
Take a closer look at How to Use Buttons, Check Boxes, and Radio Buttons for more details

Add an MouseListener to btnPlay, and use the mouse exit and enter methods
btnPlay.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseEntered(java.awt.event.MouseEvent evt) {
lblIcon.setIcon(new ImageIcon("Images/Play-icon.png"));
}
public void mouseExited(java.awt.event.MouseEvent evt) {
//I assume you want to remove or change the icon afterward
}
});

select many Checkbox in a checkboxgroup java swing

I am working on a Jframe netbeans IDE basically i drag and drop thing in the form i want to make a group of checkboxes at least two groups in one frame and each group has many checkboxes i want to select multiple checkbox in each group and return the value of checked boxes i have read that button group is not applicable in this situation since button group will only have one selection. Any code snippet or idea on how to do this is much appreciated.
UPDATE
Found this sample this is how i want my checkbox to behave only i dont want to put them in table plus there is no table component in netbeans IDE i can drag for this purpose any idea on how to do this is much appreciated

I agree with Trashgod, a JTable is probably a good place to start, another option is to roll your own...
Each "column" is it's own component and allows you to select multiple options, but only within the context of that "group"
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.LayoutManager;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JViewport;
import javax.swing.Scrollable;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridLayout(0, 2));
frame.add(new CheckBoxGroup(new String[]{"Bananas", "Oranages", "Apples", "Pears"}));
frame.add(new CheckBoxGroup(new String[]{"Learn Archery", "Float in the dead sea", "Swing with a whale shark", "Sail the greek islands", "Go skydiving", "Dance in the rain", "Cycle through the Netherlands"}));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class CheckBoxGroup extends JPanel {
private JCheckBox all;
private List<JCheckBox> checkBoxes;
public CheckBoxGroup(String... options) {
checkBoxes = new ArrayList<>(25);
setLayout(new BorderLayout());
JPanel header = new JPanel(new FlowLayout(FlowLayout.LEFT, 1, 1));
all = new JCheckBox("Select All...");
all.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
for (JCheckBox cb : checkBoxes) {
cb.setSelected(all.isSelected());
}
}
});
header.add(all);
add(header, BorderLayout.NORTH);
JPanel content = new ScrollablePane(new GridBagLayout());
content.setBackground(UIManager.getColor("List.background"));
if (options.length > 0) {
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.anchor = GridBagConstraints.NORTHWEST;
gbc.weightx = 1;
for (int index = 0; index < options.length - 1; index++) {
JCheckBox cb = new JCheckBox(options[index]);
cb.setOpaque(false);
checkBoxes.add(cb);
content.add(cb, gbc);
}
JCheckBox cb = new JCheckBox(options[options.length - 1]);
cb.setOpaque(false);
checkBoxes.add(cb);
gbc.weighty = 1;
content.add(cb, gbc);
}
add(new JScrollPane(content));
}
public class ScrollablePane extends JPanel implements Scrollable {
public ScrollablePane(LayoutManager layout) {
super(layout);
}
public ScrollablePane() {
}
#Override
public Dimension getPreferredScrollableViewportSize() {
return new Dimension(100, 100);
}
#Override
public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction) {
return 32;
}
#Override
public int getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction) {
return 32;
}
#Override
public boolean getScrollableTracksViewportWidth() {
boolean track = false;
Container parent = getParent();
if (parent instanceof JViewport) {
JViewport vp = (JViewport) parent;
track = vp.getWidth() > getPreferredSize().width;
}
return track;
}
#Override
public boolean getScrollableTracksViewportHeight() {
boolean track = false;
Container parent = getParent();
if (parent instanceof JViewport) {
JViewport vp = (JViewport) parent;
track = vp.getHeight() > getPreferredSize().height;
}
return track;
}
}
}
}
What it doesn't do is return a list of selected items, but how hard would it be to iterate over the checkBoxes List, check to see if the item is selected or not, extract it's text and add it to another List and return the result...?

Difference between LookAndFeel behavior

I created a JPopupmenu and i added a JTextField. When I am using metal or nimbus everything is alright. The problem is when I switch LookAndFeel to Windows. I can not press right ALT, because if I press this key, JPopupmenu will hide.
Can I use right ALT to write national signs in Windows LookAndFeel?
import javax.swing.*;
import java.awt.event.*;
public class Popup extends JFrame {
JPopupMenu popup;
JPanel panel;
JTextField field;
public Popup(){
setSize(500,400);
try {
//UIManager.setLookAndFeel("javax.swing.plaf.nimbus.NimbusLookAndFeel");
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (ClassNotFoundException | InstantiationException
| IllegalAccessException | UnsupportedLookAndFeelException e1) {
e1.printStackTrace();
}
SwingUtilities.updateComponentTreeUI(this);
popup = new JPopupMenu();
field = new JTextField(10);
popup.add(field);
JButton button = new JButton("Options");
button.addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
popup.show(e.getComponent(), e.getX(), e.getY());
}
});
panel = new JPanel();
panel.add(button);
add(panel);
}
public static void main(String[] args){
Popup pop = new Popup();
pop.setVisible(true);
}
}

JPopupMenu has a very specific set of operation requirements, and yes, they do change between look and feels, that's kind of the point.
What you could do is create you own popup using an undecorated JFrame. The trick here is to mimic as much of the popup as need, for example, auto closer when another component gains focus, the ability to dismiss the popup with the escape key...etc...
This is just a quick example to provide a proof of concept, I'd personally also add a key binding for the escape key, some kind of listener interface to allow the search pane to request that the popup be dismissed and the ability to auto focus some component when the window was made visible, but that's just me...
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowEvent;
import java.awt.event.WindowFocusListener;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TestPopup {
public static void main(String[] args) {
new TestPopup();
}
public TestPopup() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JButton show;
public TestPane() {
setLayout(new GridBagLayout());
show = new JButton("...");
show.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
PopupWindow window = new PopupWindow();
window.show(show, 0, show.getHeight());
}
});
add(show);
}
}
public class SearchPane extends JPanel {
private JList list;
private JTextField search;
public SearchPane() {
setLayout(new BorderLayout());
list = new JList();
list.setPrototypeCellValue("This is just a test");
list.setVisibleRowCount(20);
search = new JTextField(10);
add(new JScrollPane(list));
add(search, BorderLayout.SOUTH);
}
}
public class PopupWindow extends JFrame {
private SearchPane searchPane;
public PopupWindow() {
setUndecorated(true);
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
addWindowFocusListener(new WindowFocusListener() {
#Override
public void windowGainedFocus(WindowEvent e) {
}
#Override
public void windowLostFocus(WindowEvent e) {
dispose();
}
});
searchPane = new SearchPane();
add(searchPane);
pack();
}
public void show(JComponent parent, int x, int y) {
Point point = new Point(x, y);
SwingUtilities.convertPointToScreen(point, parent);
setLocation(point);
setVisible(true);
}
}
}

Is it possible to use a JSlider controlling multiple JTextfield?

I tried to use a JSlider to set text in three JTextFields.
My condition is the slider should work for textfield_1, only when a textfield_1 get its focus, similarly for the other two textfields.
When I tried to use the same slider with other textfield, only the first text field values getting changed.
Expecting valuable suggestions Thanks in Advance.
JSlider slider;
JTextField tf;
tf.addFocusListener(new FoucusListener(){
public void foucusGained(FocusEvent fe){
slider.addChangeListener(new ChangeListener()){
public void stateChanged(ChangeEvent ce){
JSlider slider =(JSlider)ce.getSource();
if(slider.getValueisAdjusting())
tf.setText(String.valueOf(slider.getValue()))
}
});
});

The basic idea is you need to know what field was last selected. The problem is, when you select the slider, it will fire a focus gained event...
The simplest idea would be to use a FocusListener registered only to the text fields and maintain a reference to the last field selected.
When the slider changes, you would simply interact with the last selected field (if it's not null)
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class SliderControl {
public static void main(String[] args) {
new SliderControl();
}
public SliderControl() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JSlider slider;
private JTextField[] fields;
private JTextField selectedField;
public TestPane() {
setLayout(new GridBagLayout());
fields = new JTextField[3];
FocusHandler focusHandler = new FocusHandler();
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
for (int index = 0; index < 3; index++) {
fields[index] = new JTextField(3);
fields[index].addFocusListener(focusHandler);
add(fields[index], gbc);
gbc.gridy++;
}
gbc.fill = GridBagConstraints.HORIZONTAL;
slider = new JSlider();
slider.addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent e) {
if (selectedField != null) {
selectedField.setText(String.valueOf(slider.getValue()));
}
}
});
add(slider, gbc);
}
protected class FocusHandler extends FocusAdapter {
#Override
public void focusGained(FocusEvent e) {
if (e.getComponent() instanceof JTextField) {
selectedField = (JTextField) e.getComponent();
}
}
}
}
}