Develop Reference

Prevent JButton repaint() after click

I have a button. I want to change the background after I click on it. My problem here is the button auto call paintComponent(). How can prevent this? I expect after clicking the button the button will be blue, but it will still be red.
package test;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class ButtonDemo extends JButton implements ActionListener{
public ButtonDemo() {
this.setText("BUTTON TEXT");
this.addActionListener(this);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
setBackground(Color.RED);
}
public static void main(String[] args){
JFrame frame = new JFrame();
JPanel contentPane = new JPanel();
frame.setContentPane(contentPane);
contentPane.add(new ButtonDemo());
frame.setSize(500, 500);
frame.setVisible(true);
}
#Override
public void actionPerformed(ActionEvent e) {
this.setBackground(Color.BLUE);
}
}

My personal gut feeling is that JButton is probably not suited to your desired goal.
Essentially, you want to control when and how the "selected" state of the piece is changed.
Personally, I would have some kind of controller which monitored the mouse events in some way (probably having the piece component delegate the event back to the controller) and some kind of model which control when pieces become selected, this would then notify the controller of the state change and it would make appropriate updates to the UI.
But that's a long process to setup. Instead, I'm demonstrating a simple concept where a component can be selected with the mouse, but only the controller can de-select. In this example, this will allow only a single piece to be selected
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.LineBorder;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class Main {
public static void main(String[] args) {
new Main();
}
public Main() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridLayout(5, 5));
ChangeListener listener = new ChangeListener() {
private PiecePane selectedPiece;
#Override
public void stateChanged(ChangeEvent e) {
if (!(e.getSource() instanceof PiecePane)) { return; }
PiecePane piece = (PiecePane) e.getSource();
// Want to ignore events from the selected piece, as this
// might interfer with the changing of the pieces
if (selectedPiece == piece) { return; }
if (selectedPiece != null) {
selectedPiece.setSelecetd(false);
selectedPiece = null;
}
selectedPiece = piece;
}
};
for (int index = 0; index < 5 * 5; index++) {
PiecePane pane = new PiecePane();
pane.addChangeListener(listener);
add(pane);
}
}
}
public class PiecePane extends JPanel {
private boolean selecetd;
private Color selectedBackground;
private Color normalBackground;
private MouseListener mouseListener;
public PiecePane() {
setBorder(new LineBorder(Color.DARK_GRAY));
mouseListener = new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
setSelecetd(true);
}
};
setNormalBackground(Color.BLUE);
setSelectedBackground(Color.RED);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(50, 50);
}
#Override
public void addNotify() {
super.addNotify();
addMouseListener(mouseListener);
}
#Override
public void removeNotify() {
super.removeNotify();
removeMouseListener(mouseListener);
}
public void addChangeListener(ChangeListener listener) {
listenerList.add(ChangeListener.class, listener);
}
public void removeChangeListener(ChangeListener listener) {
listenerList.remove(ChangeListener.class, listener);
}
protected void fireSelectionChanged() {
ChangeListener[] listeners = listenerList.getListeners(ChangeListener.class);
if (listeners.length == 0) {
return;
}
ChangeEvent evt = new ChangeEvent(this);
for (int index = listeners.length - 1; index >= 0; index--) {
listeners[index].stateChanged(evt);
}
}
public boolean isSelected() {
return selecetd;
}
public void setSelecetd(boolean selecetd) {
if (selecetd == this.selecetd) { return; }
this.selecetd = selecetd;
updateSelectedState();
fireSelectionChanged();
}
public Color getSelectedBackground() {
return selectedBackground;
}
public void setSelectedBackground(Color selectedBackground) {
this.selectedBackground = selectedBackground;
updateSelectedState();
}
public Color getNormalBackground() {
return normalBackground;
}
public void setNormalBackground(Color normalBackground) {
this.normalBackground = normalBackground;
updateSelectedState();
}
protected void updateSelectedState() {
if (isSelected()) {
setBackground(getSelectedBackground());
} else {
setBackground(getNormalBackground());
}
}
}
}

I created a toggle button.
You set the primary color and the alternate color in the class constructor.
When you call the switchColors method, the JButton background changes from the primary color to the alternate color. When you call the switchColors method again, the JButton background changes from the alternate color to the primary color.
In the following example, I put the switchColors method in the actionListener so you can see the color change. Each time you left-click on the JButton, the background color changes.
You would call the switchColors method when you want the JButton background to change from blue to red, and again when you want the JButton background to change from red to blue. It's under your control.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class ButtonDemo extends JButton
implements ActionListener {
private static final long serialVersionUID = 1L;
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame("Button Demo");
frame.setDefaultCloseOperation(
JFrame.EXIT_ON_CLOSE);
JPanel contentPane = new JPanel();
contentPane.setLayout(new BorderLayout());
frame.setContentPane(contentPane);
contentPane.add(new ButtonDemo(Color.BLUE,
Color.RED));
frame.setSize(300, 300);
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
});
}
private boolean primaryBackground;
private Color primaryColor;
private Color alternateColor;
public ButtonDemo(Color primaryColor,
Color alternateColor) {
this.primaryColor = primaryColor;
this.alternateColor = alternateColor;
this.primaryBackground = true;
this.setText("BUTTON TEXT");
this.setBackground(primaryColor);
this.addActionListener(this);
}
public void switchColors() {
primaryBackground = !primaryBackground;
Color color = primaryBackground ? primaryColor :
alternateColor;
this.setBackground(color);
}
#Override
public void actionPerformed(ActionEvent e) {
switchColors();
}
}

If you want to change the background for a short while you can do it with swing Timer:
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class ButtonDemo extends JButton implements ActionListener{
private static final int DELAY = 600; //milliseconds
private final Timer timer;
public ButtonDemo() {
this.setText("BUTTON TEXT");
this.addActionListener(this);
Color defaultCloor = getBackground();
timer = new Timer(DELAY, e-> setBackground(defaultCloor));
timer.setRepeats(false);
}
public static void main(String[] args){
JFrame frame = new JFrame();
JPanel contentPane = new JPanel();
frame.setContentPane(contentPane);
contentPane.add(new ButtonDemo());
frame.setSize(300, 200);
frame.setVisible(true);
}
#Override
public void actionPerformed(ActionEvent e) {
timer.stop();
this.setBackground(Color.RED);
timer.start();
}
}

How to Dispose an opened Jframe from Other

Hi i was wondering how to Dispose a jFrame from another one, cause i want to create a new instance of that class with new values in its textfields, so the First jFrame is this:
public class Frame1 extends javax.swing.JFrame implements ActionListener {
Frame2 f;
public Frame1() {
initComponents();
this.setLocationRelativeTo(null);
}
private void rbtnShowFrame2ActionPerformed(java.awt.event.ActionEvent evt) {
f = new Frame2();
f.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
this.dispose(); //I TRIED TO DISPOSING IT HERE BUT DOESN'T WORK
}
}
So i want in the other jFrame Dispose the jFrame1 only if i trigger the event action performed of a botton, if this doesn't happen i do't want to dispose it, i don't know if i can do it with ActionListener, this is the Second jFrame:
public class Frame2 extends javax.swing.JFrame {
public Frame2() {
initComponents();
this.setLocationRelativeTo(null);
Frame1 f1 = new Frame1();
this.cmdOk.addActionListener(cGUI);
}
private void cmdOkActionPerformed(java.awt.event.ActionEvent evt) {
//Here is where i want to dispose() the other jFrame1
//to create a new instance and pass the value using public static jTextFields
f1.labelNumeroCotizacion.setText(this.labelNumCotizacionEnviar.getText());
f1.setVisible(true);
}
}
Sorry for my Code, i am newbie using OOP! thanks for all guys....

Here is an example of how to dispose a JFrame from another JFrame:
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
public class Demo
{
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
#Override
public void run()
{
FrameA one = new FrameA();
FrameB two = new FrameB(one);
one.setVisible(true);
two.setVisible(true);
}
});
}
}
class FrameA extends JFrame
{
private static final long serialVersionUID = 1812279930292019387L;
public FrameA()
{
super("Frame A");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400, 400);
setLocationRelativeTo(null);
setResizable(false);
}
}
class FrameB extends JFrame
{
private static final long serialVersionUID = 5126089271972476434L;
public FrameB(final JFrame otherFrame)
{
super("Frame B");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400, 400);
setLayout(new GridBagLayout());
setLocationRelativeTo(otherFrame);
JButton button = new JButton("Dispose Other");
button.addActionListener(new ActionListener()
{
#Override
public void actionPerformed(ActionEvent e)
{
otherFrame.dispose();
}
});
add(button);
setResizable(false);
}
}

Paint Swing JButton as disabled

I want to display a normal JButton as disabled, without setting it to setEnabled(false)!
I just want to show that this button is not enabled, but if the user pushs the button it should call the actionlistener as normal.
So what I did is:
import java.awt.Graphics;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class SwingTests {
private static void createWindow() {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
MyButton button = new MyButton("Press");
button.setEnabled(false);
panel.add(button);
frame.add(panel);
frame.setSize(200, 200);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
createWindow();
}
});
}
}
class MyButton extends JButton {
private boolean enabled = false;
public MyButton(String text) {
super(text);
super.setEnabled(true);
}
#Override
protected void paintBorder(Graphics g) {
if (isEnabled())
super.paintBorder(g);
else
; // paint disabled button
}
#Override
protected void paintComponent(Graphics g) {
if (isEnabled())
super.paintComponent(g);
else
; // paint disabled button
}
#Override
public void setEnabled(boolean b) {
enabled = b;
}
#Override
public boolean isEnabled() {
return enabled;
}
}
I "just" need to know what to write in paintComponent(g) and paintBorder(g).

if it is disabled and a user pushs the button i display an alarm why this button is disabled!
If it looks disabled I am probably not going to push it in the first place. You could achieve this type of effect using tool tips.
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JToggleButton;
import javax.swing.SwingUtilities;
public class TestGUI {
public TestGUI() {
JFrame frame = new JFrame();
final JButton button = new JButton("Press Me");
final JToggleButton enable = new JToggleButton("Enable / Disable");
enable.setSelected(true);
button.setToolTipText("Enabled");
enable.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
if (enable.isSelected()) {
button.setEnabled(true);
button.setToolTipText("Enabled");
} else {
button.setEnabled(false);
button.setToolTipText("Not Enabled");
}
}
});
frame.add(button, BorderLayout.CENTER);
frame.add(enable, BorderLayout.SOUTH);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new TestGUI();
}
});
}
}

if it is disabled and a user pushs the button i display an alarm why this button is disabled!
Add a MouseListener to the button when it is disabled. Then you can handle the mouseClicked() event to display your "alarm".

Why Java ActionListener is not working?

Folks, I intend to implement a simple button ActionListener but it appears to not work.
The java codes are attached as following.....
The program intends to respond the click action from user and change the context of the JLabel
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class Frame extends JFrame implements ActionListener {
public JButton btn = new JButton("Click");
public JLabel display = new JLabel("null");
public JPanel mainPanel = new JPanel();
public Frame() {
mainPanel.add(btn);
mainPanel.add(display);
add(mainPanel);
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == btn) {
display.setText("it works");
System.out.println("it works");
}
}
public static void main(String[] args) {
Frame testFrame = new Frame();
testFrame.pack();
testFrame.setVisible(true);
}
}

Your actionlistener (the JFrame itself) is not added with addActionListener.

You should add ActionListner to the button
public Frame(){
mainPanel.add(btn);
mainPanel.add(display);
btn.addActionListener(this);
add(mainPanel);
}

how to modify current JPanel and JFrame in java

I am using the following code:
class ButtonPanel extends JPanel implements ActionListener
{
public ButtonPanel()
{
yellowButton=new JButton("Yellow");
blueButton=new JButton("Blue");
redButton=new JButton("Red");
add(yellowButton);
add(blueButton);
add(redButton);
yellowButton.addActionListener(this);
blueButton.addActionListener(this);
redButton.addActionListener(this);
}
public void actionPerformed(ActionEvent evt)
{
Object source=evt.getSource();
Color color=getBackground();
if(source==yellowButton) color=Color.yellow;
else if (source==blueButton) color=Color.blue;
else if(source==redButton) color=Color.red;
setBackground(color);
repaint();
}
private JButton yellowButton;
private JButton blueButton;
private JButton redButton;
}
class ButtonFrame extends JFrame
{
public ButtonFrame()
{
setTitle("ButtonTest");
setSize(400,400);
addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
Container contentPane=getContentPane();
contentPane.add(new ButtonPanel());
}
}
public class ButtonTest
{
public static void main(String args[])
{
JFrame frame=new ButtonFrame();
frame.show();
}
}
In actionperformed() I want to modify my panel and add some more component, is there any way to do this?

Yes.
Just call add() for the panel and then revalidate() and repaint();

but in actionperformed() i want to modify my panel and want to add some more component... Is there any way to do this....
Yes, you can add the components to the JPanel or "this" via the add(...) method, and you'll need to call revalidate() and then sometimes repaint() (especially if you also remove components) on the JPanel (this). But before you do this, if you haven't already done so, I think that you'll want to read the tutorials on using the layout managers so you can add components that are well situated.

hmmm I hard to comment anything, there are lots of mistakes, please start with this code
import java.awt.Color;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class ButtonPanel extends JPanel implements ActionListener {
private static final long serialVersionUID = 1L;
private JButton yellowButton;
private JButton blueButton;
private JButton redButton;
public ButtonPanel() {
yellowButton = new JButton("Yellow");
yellowButton.addActionListener(this);
blueButton = new JButton("Blue");
blueButton.addActionListener(this);
redButton = new JButton("Red");
redButton.addActionListener(this);
add(yellowButton);
add(blueButton);
add(redButton);
setPreferredSize(new Dimension(400, 400));
}
#Override
public void actionPerformed(ActionEvent evt) {
Object source = evt.getSource();
Color color = getBackground();
if (source == yellowButton) {
color = Color.yellow;
} else if (source == blueButton) {
color = Color.blue;
} else if (source == redButton) {
color = Color.red;
}
setBackground(color);
revalidate();
repaint();
}
public static void main(String args[]) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame("ButtonTest");
frame.addWindowListener(new WindowAdapter() {
#Override
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
frame.add(new ButtonPanel());
frame.pack();
frame.setVisible(true);
}
});
}
}