JPanel created on click not appearing

JPanel created on click not appearing - java

The below code is not my actual code but a concise, runnable remake of what I am trying to achieve. I want the JPanel CP, an instance of clickPanel, to appear when the user clicks on the image in JPanel hasAnImage. I can see in the Netbeans console that the is executing because of the Sys.out.print, but nothing appears on the screen. I have tried setting visible to false then true again and revalidate() in the mousePressed event; the image moves to the left, but nothing appears on the screen. The goal is for CP to appear. What am I missing? Hope my question is clear.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class Testo extends JFrame{
public Testo(){
BufferedImage image = null;
try {
image = ImageIO.read(new File("C:\\Users\\someimage.jpg"));
} catch (IOException ex) {
ex.printStackTrace();
}
;
final JLabel label = new JLabel(new ImageIcon(image));
JPanel hasAnImage = new JPanel();
hasAnImage.addMouseListener(new MouseAdapter(){
#Override //I override only one method for presentation
public void mousePressed(MouseEvent e) {
clickPanel CP = new clickPanel();
hasAnImage.add(CP);
revalidate();
//setVisible(false);
//setVisible(true);
}
});
hasAnImage.add(label);
add(hasAnImage);
setVisible(true);
}
public static void main(String[] args) {
Testo frame = new Testo();
frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.getContentPane().setBackground(Color.WHITE);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public class clickPanel extends JPanel{
public clickPanel() {
setPreferredSize(new Dimension(100,60));
setMaximumSize(new Dimension(100,60));
setBackground(new Color(1.0f,1.0f,1.0f,0.1f));
setBorder(BorderFactory.createMatteBorder(2,2,2,2,Color.GREEN));
System.out.println("This is being executed...");
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setFont(new Font("Arial", Font.PLAIN, 12));
g.setColor(Color.GREEN);
g.drawString("CLICK", 2, 2);
}
}
}

Beyond revalidate();ing the pane, you also need to repaint(); it. Thus your mousePressed method should become:
public void mousePressed(MouseEvent e) {
clickPanel CP = new clickPanel();
hasAnImage.add(CP);
revalidate();
repaint();
}
For further reading: http://docs.oracle.com/javase/7/docs/api/java/awt/Component.html#repaint()

Related

Need to change background on GUI using IntelliJ but background is hiding the buttons

package imgscoring;
import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import static java.lang.System.exit;
public class IMGSCORING
{
private JButton button1;
private JPanel main;
private JButton button2;
private JLabel lblLed;
private JButton button3;
private JLabel label;
private JLabel logo;
private static Image i;
public IMGSCORING() {
button1.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent actionEvent) {
try {
runProgam();
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
button2.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent actionEvent) {
exit(1);
}
});
Image i = Toolkit.getDefaultToolkit().createImage("C:\\Users\\djuwo\\Desktop\\icon.jpg");
}
public static void paint(Graphics g)
{
g.drawImage(i, 0, 0, null);
}
public void runProgam() throws IOException, InterruptedException {
QrScanner run = new QrScanner();
run.runProgram();
}
public JPanel getMain() {
return main;
}
public void setMain(JPanel main) {
this.main = main;
}
public static void main(String[] args) {
JFrame frame = new JFrame(" IMG FORMING Label Generator");
frame.setContentPane(new IMGSCORING().main);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
ImageIcon img = new ImageIcon("C:\\Users\\djuwo\\Desktop\\icon.jpg");
frame.setIconImage(img.getImage());
}
private void createUIComponents() {
// TODO: place custom component creation code here
logo = new JLabel(new ImageIcon("icon.jpg"));
}
}
I am very new to using the gui for Java and based on looking around and seeing others code I can definitely tell mine is way off from how it should look.. Would appreciate feedback on how to properly format my code as well as how to add a background. The program works and buttons respond, icon are changed, etc. But I am unable to change the background. At first I tried the following but that obviously didn't work.
frame.setContentPane(new JLabel(new ImageIcon(ImageIO.read(new File("C:\\Users\\djuwo\\Desktop\\icon.jpg")))));

In the following solutions, you can see the following steps:
Override paintComponent of JPanel, in order to draw the image in its background.
Add any elements you want in the subclassed JPanel.
Add the subclassed JPanel to the content pane of the JFrame.
setOpaque(false) in the subclassed JPanel in order to show the background (where we paint the image).
In the first solution, I just paint the image once and not care about filling the frame when it is resized:
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Objects;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
public class RegularMain extends JPanel {
private final BufferedImage bimg;
public RegularMain(final BufferedImage bimg) {
//super(); //FlowLayout already.
this.bimg = Objects.requireNonNull(bimg);
//Add your components here:
for (int i = 1; i <= 3; ++i)
super.add(prepare(new JButton("Button " + i)));
//Allow pixels to show through (ie the backgroung image to be shown):
super.setOpaque(false);
//Preparing the preferred size:
final Dimension prefsz = super.getPreferredSize(); //Gets the preferred size, after adding the components to this panel.
super.setPreferredSize(new Dimension(Math.max(prefsz.width, bimg.getWidth()), Math.max(prefsz.height, bimg.getHeight())));
}
#Override
protected void paintComponent(final Graphics g) {
g.drawImage(bimg, 0, 0, this);
super.paintComponent(g);
}
public static JButton prepare(final JButton button) {
button.addActionListener(e -> JOptionPane.showMessageDialog(button, "You clicked \"" + button.getText() + "\"!"));
return button;
}
public static void main(final String[] args) throws IOException {
final JFrame frame = new JFrame("Main frame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new RegularMain(ImageIO.read(new File("your_image.png"))));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
But, another approach is to resize the image to correspond to the panel's size:
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Objects;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
public class TransformMain extends JPanel {
private final BufferedImage bimg;
public TransformMain(final BufferedImage bimg) {
//super(); //FlowLayout already.
this.bimg = Objects.requireNonNull(bimg);
//Add your components here:
for (int i = 1; i <= 3; ++i)
super.add(prepare(new JButton("Button " + i)));
//Allow pixels to show through (ie the backgroung image to be shown):
super.setOpaque(false);
//Preparing the preferred size:
final Dimension prefsz = super.getPreferredSize(); //Gets the preferred size, after adding the components to this panel.
super.setPreferredSize(new Dimension(Math.max(prefsz.width, bimg.getWidth()), Math.max(prefsz.height, bimg.getHeight())));
}
#Override
protected void paintComponent(final Graphics g) {
final Graphics2D g2d = (Graphics2D) g.create();
g2d.scale(getWidth() / (double) bimg.getWidth(), getHeight() / (double) bimg.getHeight());
g2d.drawImage(bimg, 0, 0, this);
g2d.dispose();
super.paintComponent(g);
}
public static JButton prepare(final JButton button) {
button.addActionListener(e -> JOptionPane.showMessageDialog(button, "You clicked \"" + button.getText() + "\"!"));
return button;
}
public static void main(final String[] args) throws IOException {
final JFrame frame = new JFrame("Main frame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new TransformMain(ImageIO.read(new File("your_image.png"))));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
And finally another approach is to make the image a TexturePaint, if you want the image to be repeated:
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.TexturePaint;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
public class TextureMain extends JPanel {
private final TexturePaint paint;
public TextureMain(final BufferedImage bimg) {
//super(); //FlowLayout already.
paint = new TexturePaint(bimg, new Rectangle2D.Double(0, 0, bimg.getWidth(), bimg.getHeight()));
//Add your components here:
for (int i = 1; i <= 3; ++i)
super.add(prepare(new JButton("Button " + i)));
//Allow pixels to show through (ie the backgroung image to be shown):
super.setOpaque(false);
//Preparing the preferred size:
final Dimension prefsz = super.getPreferredSize(); //Gets the preferred size, after adding the components to this panel.
super.setPreferredSize(new Dimension(Math.max(prefsz.width, bimg.getWidth()), Math.max(prefsz.height, bimg.getHeight())));
}
#Override
protected void paintComponent(final Graphics g) {
final Graphics2D g2d = (Graphics2D) g.create();
g2d.setPaint(paint);
g2d.fillRect(0, 0, getWidth(), getHeight());
g2d.dispose();
super.paintComponent(g);
}
public static JButton prepare(final JButton button) {
button.addActionListener(e -> JOptionPane.showMessageDialog(button, "You clicked \"" + button.getText() + "\"!"));
return button;
}
public static void main(final String[] args) throws IOException {
final JFrame frame = new JFrame("Main frame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new TextureMain(ImageIO.read(new File("your_image.png"))));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
The difference in the solutions above is visible when the frame/panel is resized. In the first case, the frame is not supposed to be resized so we only draw the image once, without changing it in size. In the second case the image size follows the panel's size. And in the final case we repeat the image vertically and horizontally up to the panel's size (by using TexturePaint).
All the cases have in common that we paint the image in paintComponent before everything else and that we setOpaque to false.

How to display floating tool tip text on a polygon

I have written a Java code to draw a polygon on an image. When I put my cursor inside the polygon it prints "Inside" otherwise "Outside". So the detection of the points inside the polygon is working fine.
But I want to implement the effect of setToolTipText inside the polygon i.e. at the time of mouse hover inside the polygon, it will show the floating text "Inside".
Similar to the effect in this image:
http://www.java2s.com/Code/Java/Swing-JFC/WorkingwithTooltipText.htm
What are the minimal changes to be made in the following code to get the desired effect?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import java.awt.image.*;
import java.awt.Graphics.*;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
class page1 extends JFrame implements MouseListener,MouseMotionListener ,ActionListener
{
JFrame f;
JLabel l;
JPanel p1;
ImageIcon ii;
Image img;
int height;
int width;
Container c;
int pixels[];
PixelGrabber pg;
JPanel panel;
Graphics2D gg;
Polygon pp1=new Polygon();
boolean startHovercurrent,startHoverprev=false;
page1()
{
f=new JFrame("Sample Page");
ii=new ImageIcon("sample.jpg");
img=ii.getImage();
height=ii.getIconHeight();
width=ii.getIconWidth();
pixels=new int[ii.getIconWidth()*ii.getIconHeight()];
pg=new PixelGrabber(img,0,0,ii.getIconWidth(),ii.getIconHeight(),pixels,0,ii.getIconWidth());
try
{
pg.grabPixels();
}
catch(InterruptedException k)
{
}
//add points of polygon
pp1.addPoint(300,300);
pp1.addPoint(380,300);
pp1.addPoint(380,220);
pp1.addPoint(300,220);
l=new JLabel(ii,JLabel.CENTER);
c=f.getContentPane();
JDesktopPane desk = new JDesktopPane();
JInternalFrame p = new JInternalFrame("Image Frame",false, false, true, false);
JScrollPane scroll = new JScrollPane(l);
p.setContentPane(scroll);
p.setBounds(0, 0, 740, 600);
desk.add(p);
p.setVisible(true);
l.addMouseListener(this);
l.addMouseMotionListener(this);
c.add(desk, BorderLayout.CENTER);
f.setSize(1024,738);
f.setVisible(true);
}
public static void main(String args[])
{
new page1();
}
public void mouseClicked(MouseEvent me)
{
}
public void mouseEntered(MouseEvent me)
{
}
public void mouseExited(MouseEvent me)
{
}
public void mousePressed(MouseEvent me)
{
}
public void mouseReleased(MouseEvent me)
{
}
public void mouseMoved(MouseEvent me)
{
boolean contain1;
int mx,my;
gg=(Graphics2D)l.getGraphics();
gg.setColor(new Color(255,0,0) );
gg.fillPolygon(pp1);
mx = me.getX();
my = me.getY();
//check if mouse cursor is inside polygon or not
// do not print anything if next cursor position is in same state
contain1=pp1.contains(mx,my);
if (contain1) {
startHovercurrent = true;
if(startHovercurrent!=startHoverprev)
System.out.println("Inside");
startHoverprev=startHovercurrent;
}
else {
startHovercurrent = false;
if(startHovercurrent!=startHoverprev)
System.out.println("Outside");
startHoverprev=startHovercurrent;
}
}
public void mouseDragged(MouseEvent me)
{
}
public void actionPerformed(ActionEvent ae)
{
}
}

For this usage, How to Use Tool Tips suggests overriding the getToolTipText() method of the enclosing JComponent. This answer outlines the approach for JMapViewer and ChartPanel. In the example below, getToolTipText() simply returns the name of any Shape that contains() the triggering mouse event. For comparison, the JLabel at window's bottom gets a conventional too tip via setToolTipText().
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Polygon;
import java.awt.Shape;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.ToolTipManager;
/**
* #see https://stackoverflow.com/a/53609066/230513
* #see https://stackoverflow.com/a/25944439/230513
*/
public class ShapeToolTip {
private static class ShapePanel extends JPanel {
private final List<Shape> list = new ArrayList<>();
public ShapePanel() {
Polygon p = new Polygon();
p.addPoint(500, 100);
p.addPoint(500, 400);
p.addPoint(200, 400);
list.add(p);
list.add(new Ellipse2D.Double(100, 100, 200, 200));
ToolTipManager.sharedInstance().registerComponent(this);
}
#Override
public String getToolTipText(MouseEvent e) {
for (Shape shape : list) {
if (shape.contains(e.getX(), e.getY())) {
return shape.getClass().getName();
}
}
return "Outside";
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.blue);
Graphics2D g2d = (Graphics2D) g;
g2d.setStroke(new BasicStroke(2));
for (Shape shape : list) {
g2d.draw(shape);
}
}
#Override
public Dimension getPreferredSize() {
return new Dimension(640, 480);
}
}
private void display() {
JFrame f = new JFrame("ShapeToolTip");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new ShapePanel());
JLabel title = new JLabel("Shape Tool Tip", JLabel.CENTER);
title.setToolTipText("Title");
title.setFont(title.getFont().deriveFont(Font.BOLD, 24));
f.add(title, BorderLayout.SOUTH);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new ShapeToolTip()::display);
}
}

Jbutton acction listener

I am trying to create a form. there is a button that when clicking the button, a photo which is specified would appear. my problem is, when I click the button, the picture pops up and if the cursor passes the form boundary, the image disappears. here is my code:
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import static java.lang.Math.abs;
import static java.lang.Math.min;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
public class SeamCarving extends JFrame
{
public static void main(String[] args) throws IOException {
final BufferedImage input = ImageIO.read(new File("path"));
final BufferedImage[] toPaint = new BufferedImage[]{input};
final Frame frame = new Frame("Seams") {
#Override
public void update(Graphics g) {
final BufferedImage im = toPaint[0];
if (im != null) {
g.clearRect(0, 0, getWidth(), getHeight());
g.drawImage(im, 0, 0, this);
}
}
};
frame.setSize(input.getWidth(), input.getHeight());
frame.setVisible(true);
frame.add(startButton);
startButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
BufferedImage out = input;
out = deleteVerticalSeam(out);
toPaint[0] = out;
frame.repaint();
System.out.println("Do Something Clicked");
}
});
}
}

Don't override update, this isn't how painting is achieved in Swing. Attempting to paint directly to a top level container like JFrame is problematic at best.
Instead, start with a JPanel and use it's paintComponent method instead. Make sure you call super.paintComponent as well.
In fact, you could probably just use a JLabel to display the image instead.
Take a look at;
Performing Custom Painting
How to use labels
For more details
Updated with example
I still think a JLabel would be simpler solution, but what do I know.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class SeamCarving {
public static void main(String[] args) {
new SeamCarving();
}
public SeamCarving() {
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 BufferedImage input;
private BufferedImage[] toPaint;
public TestPane() {
try {
input = ImageIO.read(new File("C:\\hold\\thumbnails\\2005-09-29-3957.jpeg"));
toPaint = new BufferedImage[1];
} catch (IOException ex) {
ex.printStackTrace();
}
setLayout(new GridBagLayout());
JButton startButton = new JButton("Start");
startButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
BufferedImage out = input;
out = input; //deleteVerticalSeam(out);
toPaint[0] = out;
repaint();
System.out.println("Do Something Clicked");
}
});
add(startButton);
}
#Override
public Dimension getPreferredSize() {
return input == null ? new Dimension(400, 400) : new Dimension(input.getWidth(), input.getHeight());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (toPaint[0] != null) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.drawImage(input, 0, 0, this);
g2d.dispose();
}
}
}
}
The problem with overriding update is the paint subsystem can choose to avoid calling and end up calling paint directly, circumventing your painting.
Painting also involves painting child components (like your button) and borders, which you've conveniently discarded by not calling super.update.

Why isn't mouselistener working?

Here's the code. It prints out the mouse location when it's in the panel but not the JTextArea. I added the mouse listener to the text area as well? The problem is that the coordinates are not consistent throughout the JFrame. Is there a way to just have one mouselistener that covers the entire jframe?
Is there a way to disable the mouse listener in the textarea?
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
public class test extends JFrame {
public test(){
setPreferredSize(new Dimension(600,400));
JPanel p = new JPanel();
p.setBackground(Color.blue);
p.setPreferredSize(new Dimension(600,200));
JTextArea t = new JTextArea();
t.setPreferredSize(new Dimension(600,200));
add(p,BorderLayout.NORTH);
add(t,BorderLayout.SOUTH);
pack();
MouseInput m = new MouseInput();
addMouseMotionListener(m);
t.addMouseMotionListener(m);
setVisible(true);
}
public static void main(String[] args){
new test();
}
public class MouseInput implements MouseMotionListener{
#Override
public void mouseDragged(MouseEvent e) {
}
#Override
public void mouseMoved(MouseEvent e) {
int mx = e.getX();
int my = e.getY();
System.out.println(mx + "," + my);
}
}
}

Think of your mouse events like rain. They fall from the top of your component hierarchy down until something stops them.
Once stopped, they will no long notify other listeners lower in the hierarchy.
In you program you have and JPanel and JTextField sitting on top of another component (the content pane) sitting on a JLayeredPane sitting on top of the frame. Any one of these may be consuming the mouse event.
Try adding the MouseInput to your JPanel, p instead
Updated
This is an example of a global mouse listener (as suggested by #Hovercraft Full Of Eels, it WILL get hammered, as every mouse event will pass through it.
It also demonstrates how to translate a mouse point from it's local context to another context.
import java.awt.AWTEvent;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.AWTEventListener;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class GloablMouseListener {
public static void main(String[] args) {
new GloablMouseListener();
}
public GloablMouseListener() {
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 {
public TestPane() {
setLayout(new BorderLayout());
JPanel panel = new JPanel();
panel.setBackground(Color.BLUE);
JTextArea ta = new JTextArea(10, 20);
add(panel, BorderLayout.NORTH);
add(new JScrollPane(ta), BorderLayout.SOUTH);
Toolkit.getDefaultToolkit().addAWTEventListener(new AWTEventListener() {
#Override
public void eventDispatched(AWTEvent event) {
if (event instanceof MouseEvent) {
MouseEvent e = (MouseEvent) event;
System.out.println("Local point = " + e.getPoint());
Point p = e.getPoint();
Window window = SwingUtilities.getWindowAncestor(e.getComponent());
if (window != e.getSource() && window != null) {
p = SwingUtilities.convertPoint(e.getComponent(), e.getPoint(), window);
}
System.out.println("Global point = " + p);
}
}
}, AWTEvent.MOUSE_EVENT_MASK | AWTEvent.MOUSE_MOTION_EVENT_MASK);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
}

The JTextArea has its own MouseListener/MouseMotionListener that grabs the mouse information before any underlying class with a MouseListener or motion listener can.
This may be fixable by using an AWTEventListener, but I have not tried this myself yet.
Edit
OK, I have tried this as a for instance:
import java.awt.AWTEvent;
import java.awt.Color;
import java.awt.Component;
import java.awt.GridLayout;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.AWTEventListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.*;
#SuppressWarnings("serial")
public class Test2 extends JPanel {
JTextArea textarea = new JTextArea(15, 60);
public Test2() {
JPanel topPanel = new JPanel();
topPanel.setBackground(Color.blue);
setLayout(new GridLayout(0, 1));
add(topPanel);
add(new JScrollPane(textarea));
addMouseMotionListener(new MouseAdapter() {
#Override
public void mouseMoved(MouseEvent e) {
int x = e.getX();
int y = e.getY();
System.out.printf("%20s [%03d, %03d]%n", "From MouseAdapter:", x, y);
}
});
long eventMask = AWTEvent.MOUSE_MOTION_EVENT_MASK;
Toolkit.getDefaultToolkit().addAWTEventListener(new AWTEventListener() {
#Override
public void eventDispatched(AWTEvent awtEvent) {
MouseEvent mouseEvent = (MouseEvent) awtEvent;
Component component = (Component) awtEvent.getSource();
Point location = component.getLocationOnScreen();
Point test2Location = Test2.this.getLocationOnScreen();
// Normalized to find the mouse location relative to the main JPanel,
// the Test2 "this" JPanel.
int x = mouseEvent.getX() + location.x - test2Location.x;
int y = mouseEvent.getY() + location.y - test2Location.y;
System.out.printf("%20s [%03d, %03d]%n", "From AWTEvent:", x, y);
}
}, eventMask );
}
private static void createAndShowGui() {
JFrame frame = new JFrame("Test2");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new Test2());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}

Try adding a MouseListener to your application's GlassPane.
See these following link. It includes a Java Web Start demo of something similar to what you want to do.
How to Use Root Panes

Displaying image on clicking JButton

Im trying to display an image upon clicking a JButton but upon execution the image is not displayed when button is clicked.
import javax.swing.JButton;
import javax.swing.JFrame;
import java.awt.Color;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.Graphics;
import java.awt.Image;
import javax.swing.ImageIcon;
import javax.swing.JApplet;
import java.awt.*;
public class new2 extends JFrame implements ActionListener
{
private boolean b1,b2;
Container contentPane= getContentPane();
JButton awar=new JButton("#war");
JButton arrow=new JButton("arrow");
private Image image1,image2;
public new2()
{
setSize(400, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
contentPane.setLayout(new FlowLayout());
awar.addActionListener(this);
contentPane.add(awar).setVisible(true);
arrow.addActionListener(this);
contentPane.add(arrow).setVisible(true);
}
public void init()
{
image1=Toolkit.getDefaultToolkit().getImage("#war.jpeg");
image2=Toolkit.getDefaultToolkit().getImage("arrow.gif");
}
public void paint(Graphics g)
{
if(b1==true)
{
g.drawImage(image1,0,0,this);
}
else if(b2==true)
{
g.drawImage(image2,0,0,this);
}
}
public void actionPerformed(ActionEvent event)
{
String actionCommand = event.getActionCommand();
if(actionCommand.equals("#war"))
{
b1=true;
}
else if(actionCommand.equals("arrow"))
{
b2=true;
}
}
public static void main(String args[])
{
new2 m=new new2();
m.setVisible(true);
}
}

..display an image upon clicking a JButton but upon execution the image is not displayed when button is clicked.
Use a JToggleButton as shown here.

The buttons should set the boolean variables, but your paint2 is never called after the action preformed method. Secondly, it doesn't really even paint anything, it never gets graphics and will cause NPEs.

You should override the JFrame.paint(Graphics g) method.
Whenever you want to refresh the content of the JFrame instance call the JFrame.repaint() method.

/**
*
*/
package com.samples;
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.WindowConstants;
/**
* #author
*
*/
public class MyFrame extends JFrame implements ActionListener {
private static String SHOW_ACTION = "show";
private static String HIDE_ACTION = "hide";
private Image image = null;
private boolean showImage = false;
public MyFrame(String filename) {
setTitle("MyWindow");
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setSize(800, 600);
this.image = new ImageIcon(filename).getImage();
Container container = getContentPane();
container.setLayout(new BorderLayout());
container.add(createControls(), BorderLayout.SOUTH);
}
private JPanel createControls() {
JButton showButton = new JButton("Show");
showButton.addActionListener(this);
showButton.setActionCommand(SHOW_ACTION);
JButton hideButton = new JButton("Hide");
hideButton.addActionListener(this);
hideButton.setActionCommand(HIDE_ACTION);
JPanel panel = new JPanel();
panel.setLayout(new FlowLayout(FlowLayout.CENTER));
panel.add(showButton);
panel.add(hideButton);
return panel;
}
#Override
public void paint(Graphics g) {
super.paint(g);
if (showImage) {
g.drawImage(image, 0, 0, image.getWidth(null), image.getHeight(null), null);
}
}
#Override
public void actionPerformed(ActionEvent event) {
String actionCommand = event.getActionCommand();
if (SHOW_ACTION.equals(actionCommand)) {
showImage = true;
} else if (HIDE_ACTION.equals(actionCommand)) {
showImage = false;
}
repaint();
}
/**
* #param args
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
MyFrame frame = new MyFrame("resources/image.jpg");
frame.setVisible(true);
}
});
}
}

Develop Reference

Java is a programming language and computing platform first released by Sun Microsystems in 1995.

JPanel created on click not appearing - java

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