problem with adding circle and rectangle

[nicnicnic]

hi i have a little problem

i have 3 buttons in my application when i click on the circle
i can paint the circle

but when i swith to rectangle , i can paint vector of rectangle
but my circle dissapear

and when i switch back to circle button my circle show up again but not the rectangles

any idea why this happening ?

i think i have problem abit to know when to use repaint()

here is the code

import java.util.*;
import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

// This class represents a canvas on which 40×40 pixel squares can be drawn.
// The squares are centered around where the user clicks.
public class SquareCanvas extends JPanel implements ActionListener,MouseListener {

// Keep track of all square center positions
private Vector squares,circles;
String st="";
private Button circleButton,rectangleButton,rectangleButton1;
// Default constructor
public SquareCanvas() 
{
squares = new Vector();
circles = new Vector();
setBackground(Color.white);
circleButton = new Button("Circle"); 
add(circleButton); 
circleButton.addActionListener(this); 
rectangleButton = new Button("Rectangle"); 
add(rectangleButton); 
rectangleButton.addActionListener(this); 
rectangleButton1 = new Button("FillRectangle"); 
add(rectangleButton1); 
rectangleButton1.addActionListener(this); 
addMouseListener(this);

}

// This is the method that is responsible for displaying the contents of the canvas
public void paintComponent(Graphics graphics) 
{
	// Draw the component as before (i.e., default look)
	super.paintComponent(graphics);


	if(st.equals("Rectangle"))
	{
		// Now add all of our squares
		graphics.setColor(Color.RED);	
		Enumeration enumeration = squares.elements();
		
		while(enumeration.hasMoreElements()) 
		{
			Point center = (Point)(enumeration.nextElement());
			graphics.drawRect(center.x-20, center.y-20, 40, 40);
		}	
		repaint();
	}
	else if(st.equals("Circle"))
	{
		graphics.setColor(Color.magenta);	
		graphics.fillRect(20, 20, 40, 40);
		repaint();
	}
}

// These are unused MouseEventHandlers. Note that we could have
// used an Adapter class here. However, a typical drawing
// application would make use of these other events as well.
public void mouseClicked(MouseEvent event) {}
public void mouseEntered(MouseEvent event) {}
public void mouseExited(MouseEvent event) {}
public void mouseReleased(MouseEvent event) {}

// Store the mouse location when it is pressed
public void mousePressed(MouseEvent event) 
{
	squares.add(event.getPoint());
	repaint(); // this will call paintComponent()
}

public void actionPerformed(ActionEvent event) 
{ 
	 if (event.getSource() == circleButton) 
	 {
		 st ="Circle";
		 //repaint();
	 }
	 if (event.getSource() == rectangleButton)
	 { 
		 st ="Rectangle";
		 //repaint();
	 }
	 if (event.getSource() == rectangleButton1) 
	 {
		 st ="FillRectangle";
		 repaint(); 
	 }
	
} 

public static void main(String args[]) 
{
JFrame frame = new JFrame("Square Drawing Example");
frame.getContentPane().add(new SquareCanvas());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(300, 300);
frame.setVisible(true);

}
}

thankz in advance for this big help

[camickr]

You need to repaint the shapes every time.

Custom Painting Approaches shows two ways to do this.

[Fubarable]

duplicate posts closed.

[nicnicnic]

ty for this big help guys ! thats what i need it