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Add functionality to Graphics

This is my code, I want to add functionality to the Rect that I made, like when you click on it, a window pops up
public class codetwo extends JPanel {
public void paintComponent(Graphics g) {
super.paintComponent(g);
this.setBackground(Color.LIGHT_GRAY);
g.setColor(Color.RED);
g.fillRect(110,110, 120, 120);
}
public static void main(String args[]) {
codetwo cd = new codetwo();
JFrame frame = new JFrame("Title");
frame.add(cd);
frame.setSize(440,350);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}

You need to use Mouselistener for this.
public class codetwo extends JPanel {
public void paintComponent(Graphics g) {
super.paintComponent(g);
this.setBackground(Color.LIGHT_GRAY);
g.setColor(Color.RED);
g.fillRect(110,110, 120, 120);
}
public static void main(String args[]) {
codetwo cd = new codetwo();
cd.addMouseListener(new MouseListener(){
#Override
public void mouseClicked(MouseEvent e) {
// TODO Auto-generated method stub
if (e.getX() >= 110 && e.getX() <= 230 && e.getY() >= 110 && e.getY() <= 230) {
JOptionPane.showMessageDialog(cd, "Some one clicked here ?", "Listening", JOptionPane.INFORMATION_MESSAGE);
}
}
#Override
public void mousePressed(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseReleased(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent e) {
// TODO Auto-generated method stub
}
JFrame frame = new JFrame("Title");
frame.add(cd);
frame.setSize(440,350);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}

how can i draw a line on BufferedImage?

I am trying to create some kind of Paint program. I created a BufferedImage and an Graphics2D but i cant draw on it. All what I can see is the BufferedImage itself without any changes.
public class paintapp implements ActionListener, MouseListener, MouseMotionListener
{
public static final int WIDTHBUFF=300;
public static final int HEIGHTBUFF=300;
BufferedImage buffimage=new BufferedImage(WIDTHBUFF,HEIGHTBUFF,BufferedImage.TYPE_INT_BGR);
JLabel imagelabel=new JLabel(new ImageIcon(buffimage));
int s=3;
Color curr_color=Color.BLACK;
int x,y;
public static final int WIDTH=700;
public static final int HEIGHT=700;
public paintapp()
{
Graphics2D g2d=buffimage.createGraphics();
g2d.setBackground(Color.WHITE);
g2d.fillRect(0, 0, WIDTHBUFF,HEIGHTBUFF);
JFrame frame=new JFrame("Painter");
frame.setSize(WIDTH, HEIGHT);
frame.setResizable(false);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.setVisible(true);
Panel buttonpanel=new Panel();
Panel colors=new Panel();
Panel draw=new Panel();
draw.add(imagelabel);
frame.add(draw);
frame.pack();
}
public static void main(String[]args)
{
paintapp paint1=new paintapp();
}
#Override
public void mouseDragged(MouseEvent e) {
Graphics2D g2=buffimage.createGraphics();
g2.setColor(curr_color);
g2.setStroke(new BasicStroke(s));
g2.drawLine(x, y, e.getX(), e.getY());
x=e.getX();
y=e.getY();
}
#Override
public void mouseMoved(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseClicked(MouseEvent e) {
x=e.getX();
y=e.getY();
}
#Override
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mousePressed(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseReleased(MouseEvent e) {
// TODO Auto-generated method stub
}
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
}
}

I see you are poking through and you got things in jumbled up order. If you read the guides you will see how things go.
The first main thing is to add a MouseMotionListener to the drawing thing - be that JLabel JPanel whatever.
The second thing is that once you go outside of the constructor the JFrame is lost (unless you do some fancy things) and cant be accessed to be refreshed, so the system decides when to refresh and you will see - after you add the mouse listener - that your drawing will appear once you hide and show again the drawing window.
So you need to have JFrame as global - why dont you have you class extend JFrame and so no need to have some extra JFrame.

How to check if jPanel is pressed?

I have JPanel called panelCrtanje.
I need to change cBox state if it is pressed.
final PadDraw drawPad = new PadDraw();
panelCrtanje.setLayout(new BorderLayout());
panelCrtanje.add(drawPad, BorderLayout.CENTER);
It works before I add drawPad to panelCrtanje using this:
private void panelCrtanjeMousePressed(java.awt.event.MouseEvent evt) {
slikaC.setSelected(true);
}
PadDraw looks like this
public PadDraw(){
setDoubleBuffered(false);
addMouseListener(new MouseAdapter(){
public void mousePressed(MouseEvent e){
oldX = e.getX();
oldY = e.getY();
}
});
addMouseMotionListener(new MouseMotionAdapter()){
public void mouseDragged(MouseEvent e){
currentX = e.getX();
currentY = e.getY();
if(graphics2D != null) {
graphics2D.setStroke(new BasicStroke(18F,BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND));
graphics2D.drawLine(oldX, oldY, currentX, currentY);
repaint();
oldX = currentX;
oldY = currentY;
}
}
});
}

You need to use MouseEvent properly. To use it the class needs to implement MouseListener. Then you need to create a listener for the mouse event like so:
panelCrtanje.addMouseListener();
Then use these methods that are required in MouseListener and MotionMouseListener
#Override
public void mouseClicked(java.awt.event.MouseEvent e) {
// TODO In HERE do what you want to do
}
#Override
public void mousePressed(java.awt.event.MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseReleased(java.awt.event.MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseEntered(java.awt.event.MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(java.awt.event.MouseEvent e) {
// TODO Auto-generated method stub
When the mouse is clicked: mouseClicked
When the mouse is held down but not moved: mousePressed
When the mouse is released: mouseReleased
When the mouse enters the window: mouseEntered
When the mouse leaves the window: mouseExited
That is how you can use the mouseListener to do different things.

you should register a MouseListener on panelCartanje, I have used an anonymous inner class to do this.
panelCrtanje.addMouseListener(new MouseAdapter(){
#Override
public void mousePressed(MouseEvent e) {
/// cBox state change goes here . . .
}
});

This was the solution
MouseAdapter adap = new MouseAdapter(){
public void mousePressed(MouseEvent e) {
slikaC.setSelected(true);
}
};

Java - JFrame keeps freezing after I type some Letters into a JTextField

I have no Idea why my JFrame keeps freezeing after I type Letters into the JTextField "Username" and "Password" :/ Could anyone look thru my code and tell my why and fix it please ?
public class Main
{
public static void main(String [ ] args)
{
LoginWindow loginframe = new LoginWindow();
loginframe.setVisible(true);
loginframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
loginframe.initialize();
while(true)
{
try {
Thread.sleep(50);
} catch (InterruptedException e) {
e.printStackTrace();
}
loginframe.Repaint();
}
}
}
FrameClass:
public class LoginWindow extends JFrame implements MouseListener, KeyListener, MouseMotionListener{
public LoginWindow(){
setSize(806, 629);
setResizable(false);
setLayout(new BorderLayout());
background = new JLabel(ResourceLoader.Iconload("/main_01.jpg"));
background.setBounds(0, 0, 800, 600);
add(background);
background.setLayout(null);
Username = new JTextField("", 20);
Username.setForeground(Color.WHITE);
Username.setBounds(312, 433, 170, 40);
Username.setFont(new Font("Impact", Font.BOLD, 25));
Username.setBackground(Color.BLACK);
Username.setBorder(BorderFactory.createMatteBorder(0, 0, 5, 0, Color.BLACK));
background.add(Username);
Password = new JPasswordField("", 20);
Password.setForeground(Color.WHITE);
Password.setBounds(312, 489, 170, 40);
Password.setBackground(Color.BLACK);
Password.setBorder(BorderFactory.createMatteBorder(0, 0, 5, 0, Color.BLACK));
Password.setFont(new Font("Serif", Font.BOLD, 25));
background.add(Password);
}
public void initialize()
{
makestrat();
addKeyListener(this);
requestFocus();
addMouseListener(this);
addMouseMotionListener(this);
}
public void makestrat()
{
createBufferStrategy(2);
strat = getBufferStrategy();
}
public void Repaint()
{
//System.out.println(mouseX + " " + mouseY);
Graphics g = strat.getDrawGraphics();
paintComponents(g);
Draw(g);
g.dispose();
strat.show();
}
public void Update()
{
}
public void Draw(Graphics g)
{
if(((mouseX >= 499) && (mouseX <= 669)) && ((mouseY >= 433)&&( mouseY <= 530))){
g.drawImage(ResourceLoader.ImageLoad("/login_02.jpg"), 502, 459, null);
}else{
g.drawImage(ResourceLoader.ImageLoad("/login_01.jpg"), 502, 459, null);
}
}
private class thehandler implements ActionListener{
#Override
public void actionPerformed(ActionEvent event) {
}
}
public void mouseMoved(MouseEvent event)
{
mouseY = event.getY()-26;
mouseX = event.getX()-3;
}
#Override
public void mouseClicked(MouseEvent e) {
PointerInfo a = MouseInfo.getPointerInfo();
Point point = new Point(a.getLocation());
SwingUtilities.convertPointFromScreen(point, e.getComponent());
double mouseX = (int) point.getX();
double mouseY = (int) point.getY();
System.out.println("(ContainerPos) Mouse clicked! X: " + mouseX + " Y: " + mouseY);
}
#Override
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mousePressed(MouseEvent e) {
}
#Override
public void mouseReleased(MouseEvent e) {
}
#Override
public void keyPressed(KeyEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void keyReleased(KeyEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void keyTyped(KeyEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseDragged(MouseEvent arg0) {
// TODO Auto-generated method stub
}
}

You don't need the while loop with the Thread.sleeap(). It's screwing with your program.
What you're trying to achieve here, a call to repaint continuously, can easily be accomplished with a javax.swing.Timer
Don't explicitly call paintComponent. An actual call to the real repaint() method will do that for you. No need to create an imitation Repaint()
Use a JPanel for painting instead of trying to paint on a JFrame
I would initialize, then set visible
Your code doesn't even compilable, so I can try and make fixes for you.
Use Java naming convention: methods and variable start with lower case letters.
Here's an example of a simple Login Window, using a modal JDialog
Learn how to use Layout Managers instead of relying on setBounds()
Point 2. Your main should look like this
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable(){
public void run(){
LoginWindow loginframe = new LoginWindow();
loginframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
loginframe.initialize();
loginframe.setVisible(true);
}
});
}
And in your constructor, have a javax.swing.Timer instead of your while loop
private Timer timer = null;
private DrawPanel drawPanel = new DrawPanel(); // see below for DrawPanel
public LoginWindow() {
// add drawPanel somewhere
...
timer = new Timer (50, new ActionListener(){
public void actionPerformed(ActionEvent e) {
drawPanel.repaint();
}
});
timer.start();
}
Point 4. Have an inner JPanel class that you do all your painting in, and add that component to the frame. You'll need to override the paintComponent method.
private DrawPanel extends JPanel {
#Override
protected void paintComponent(Graophics g) {
super.paintComponent(g);
Draw(g);
}
}

The obvious thing is that you shouldn't use Swing (or AWT really) off of the AWT Event Dispatch Thread (EDT). Fix with java.awt.EventQueue.invokeLater and java.swing.Timer (not java.util!). Diagnose with jstack(and jps) or the relevant key sequence in the terminal window (um, ctrl-break in Windows, ctrl-3 in Linux).

Why can't I draw an ellipse with this code?

package test;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;
import javax.swing.*;
public class test_bmp extends JPanel implements MouseListener,MouseMotionListener,ActionListener
{
static BufferedImage image;
Color color;
Point start=new Point();
Point end =new Point();
JButton elipse=new JButton("Elipse");
JButton rectangle=new JButton("Rectangle");
JButton line=new JButton("Line");
String selected;
public test_bmp()
{
color = Color.black;
setBorder(BorderFactory.createLineBorder(Color.black));
addMouseListener(this);
addMouseMotionListener(this);
}
public void paintComponent(Graphics g)
{
//super.paintComponent(g);
g.drawImage(image, 0, 0, this);
Graphics2D g2 = (Graphics2D)g;
g2.setPaint(Color.black);
if(selected=="elipse")
{
g2.drawOval(start.x, start.y, (end.x-start.x),(end.y-start.y));
System.out.println("Start : "+start.x+","+start.y);
System.out.println("End : "+end.x+","+end.y);
}
if(selected=="line")
g2.drawLine(start.x,start.y,end.x,end.y);
}
//Draw on Buffered image
public void draw()
{
Graphics2D g2 = image.createGraphics();
g2.setPaint(color);
System.out.println("draw");
if(selected=="line")
g2.drawLine(start.x, start.y, end.x, end.y);
if(selected=="elipse")
{
g2.drawOval(start.x, start.y, (end.x-start.x),(end.y-start.y));
System.out.println("Start : "+start.x+","+start.y);
System.out.println("End : "+end.x+","+end.y);
}
repaint();
g2.dispose();
}
public JPanel addButtons()
{
JPanel buttonpanel=new JPanel();
buttonpanel.setBackground(color.lightGray);
buttonpanel.setLayout(new BoxLayout(buttonpanel,BoxLayout.Y_AXIS));
elipse.addActionListener(this);
rectangle.addActionListener(this);
line.addActionListener(this);
buttonpanel.add(elipse);
buttonpanel.add(Box.createRigidArea(new Dimension(15,15)));
buttonpanel.add(rectangle);
buttonpanel.add(Box.createRigidArea(new Dimension(15,15)));
buttonpanel.add(line);
return buttonpanel;
}
public static void main(String args[])
{
test_bmp application=new test_bmp();
//Main window
JFrame frame=new JFrame("Whiteboard");
frame.setLayout(new BorderLayout());
frame.add(application.addButtons(),BorderLayout.WEST);
frame.add(application);
//size of the window
frame.setSize(600,400);
frame.setLocation(0,0);
frame.setVisible(true);
int w = frame.getWidth();
int h = frame.getHeight();
image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = image.createGraphics();
g2.setPaint(Color.white);
g2.fillRect(0,0,w,h);
g2.dispose();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
#Override
public void mouseClicked(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseEntered(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mousePressed(MouseEvent event)
{
start = event.getPoint();
}
#Override
public void mouseReleased(MouseEvent event)
{
end = event.getPoint();
draw();
}
#Override
public void mouseDragged(MouseEvent e)
{
end=e.getPoint();
repaint();
}
#Override
public void mouseMoved(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==elipse)
selected="elipse";
if(e.getSource()==line)
selected="line";
draw();
}
}
I need to create a paint application. When I draw ellipse by dragging mouse from left to right it displays nothing. Why? Should I use any other function here?

Your program does draw an ellipse when you drag the mouse down and to the right. It's dragging up and/or left that does not work, because Graphics.drawOval does not work with a negative width or height.
Try adding a method like this:
private Shape createEllipse() {
Ellipse2D e = new Ellipse2D.Double();
e.setFrameFromDiagonal(start, end);
return e;
}
Then call it from draw and paintComponent like this:
if(selected=="elipse") {
g2.draw(createEllipse());
}
Also you probably do not need the call to draw() at the end of actionPerformed. If you switch between line and ellipse mode it will draw an ellipse with the same coordinates as the most recent line or vice-versa.
And one coding style issue: Using string literals for selected is confusing (although it does work.) I would define an enum instead.