how to keep drawn free hand painted image when resizing the window

[Esmaeil Ashrafi]

here is the whole code of a very simple program just to demonstrate some methods of MouseListener

I absolutely know why when i resize the window(is a frame),anything painted in the frame,but i want to have a solution to avoid that.
I myself tried too much stuff,but never got succeed
I tried to paint on a JPanel wrapped in the JFrame,but didnt work...

appreciate for any help or guide
and this is the code :

  
/*
 *  File: MousePaint.java
 *  Author: Java, Java, Java
 *  Description: This class illustrates the use of methods from
 *   the MouseListener and MouseMotionListener interfaces. The user
 *   draws within a drawing panel by dragging the mouse. The panel
 *   is cleared when the user clicks on a small rectangle in the upper-left
 *   corner of the window.
 */
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class MousePaint extends JPanel implements MouseListener,
                                                 MouseMotionListener {

    private static final int WIDTH = 300, HEIGHT = 300; // Initial size
    private static final int LEFT = 10;                 // Reference points
    private static final int TOP = 10;
    private static final int BORDER = 30;

    private static final Color backColor = Color.gray;  // Background color 
    private static final Color lineColor = Color.red;   // Outline color

    private Point mouse = new Point();                  // Mouse's current location
  
    /**
     *  MousePaint() constructor sets the size of the window and registers
     *  the mouse listeners. A MouseMotionListener listens for drag and move
     *  events. A MoustListener listens for click events.
     */
    public MousePaint() {    
        addMouseMotionListener(this);    // Add mouse and mouse motion listeners
        addMouseListener(this);
        setSize(WIDTH, HEIGHT);
    } // MousePaint()

    /**
     *  paintComponent() paints the component each time it is invoked. It must
     *   distinguish whether the mouse is in the top-left corner of the window,
     *   in which case it clears the window, or whether the user is drawing.
     */
    public void paintComponent(Graphics g) {
        Dimension d = getSize();                              
        g.setColor(lineColor);                              
        g.fillRect(0, 0, LEFT, TOP);                                // The clear rectangle
        g.drawRect(LEFT, TOP, d.width - BORDER, d.height - BORDER); // The drawing area
        g.drawString("Drag to draw; Click the red rectangle to clear.", LEFT, d.height - 5);
        g.setColor(Color.black);                                    // Set drawing color

                   // If the mouse is within the drawing area, draw a dot
        if ((mouse.x > LEFT) && (mouse.x < LEFT + d.width - BORDER)
                         && (mouse.y > TOP) && (mouse.y < TOP + d.height - BORDER))
            g.fillRect(mouse.x, mouse.y, 3, 3); 
      
                   // If the mouse is clicked at top left corner clear the drawing
        if ((mouse.x < LEFT) && (mouse.y < TOP))   
            g.clearRect(LEFT + 1, TOP + 1, d.width - BORDER - 1, d.height - BORDER - 1);  
    } // paintComponent()

  /* Mouse Handling Interfaces:   MouseMotionListener and MouseListener */

    /**
     *  mouseDragged() handles the mouse drag event. In this case it merely
     *   gets the mouse's location and repaints the window.
     */
    public void mouseDragged(MouseEvent e) {   // When the mouse is dragged (mouse motion listener)
        mouse = e.getPoint();                    //  get its coordinates
        repaint();
    }

    /**
     *  mouseClick() handles mouse click events. In this case it just
     *   gets the mouse's location and repaints the window.
     */
    public void mouseClicked(MouseEvent e) {   // When mouse is clicked (mouse listener)
        mouse = e.getPoint();                    //  get its coordinates
        repaint();
    }
    public void mouseEntered(MouseEvent e) { } // These five interface methods are not used
    public void mouseExited(MouseEvent e)  { } //  but must be defined.
    public void mousePressed(MouseEvent e) { } 
    public void mouseReleased(MouseEvent e){ }   
    public void mouseMoved(MouseEvent e)   { }


    /**
     *  main() creates a top-level window and gives it a drawing panel.
     */
    public static void main(String args[]) {
        JFrame f = new JFrame("Drawing Window");  // Create the top-level window
        MousePaint mp = new MousePaint();         // And give it a drawing panel
        f.getContentPane().add(mp);
        f.setSize(mp.WIDTH, mp.HEIGHT);
        f.setVisible(true);
        f.addWindowListener(new WindowAdapter() {      // Quit the application
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    } // main()
} // MousePaint
  

[Rob Camick]

Custom Painting Approaches

[Esmaeil Ashrafi]

Rob Camick wrote:Custom Painting Approaches

Allright,i carefully read the contents of link,checked the source codes and i learned many new things ( like For-each,ArrayList<E>,Graphics2d,BufferedImage,...)
so thank you
But :
those had nothing tto deal with my issue !
Because : in the given example ( even on both approaches ) the program just draw the Rectangles,as we lnow,Rectangle is a class and its instances can be stored ( i.e on that example in class "DrawOnComponent" ) simply as objects in ListArray

While here ( by just take a look at the codes on first post ) , i'm talking about points drwan by mouse that doesnt have any shape ( e.g Rectangle ) to be stored and used later

therefore,i really need more help

thanks again

[pete stein]

Esmaeil Ashrafi wrote:

Rob Camick wrote:Custom Painting Approaches

Allright,i carefully read the contents of link,checked the source codes and i learned many new things ( like For-each,ArrayList<E>,Graphics2d,BufferedImage,...)
so thank you
But :
those had nothing tto deal with my issue !

Please don't jump to conclusions, especially when you are this early in the game. I think that Rob Camick knows your issues and what they involve. If you'd look carefully at his link, you'll see that it has everything to do with your issue. You need to use his same approach but customized to what you are drawing. Rather than have Mouse coordinates in your paint method, you need a collection of points drawn by the mouse that will persist, such as an ArrayList of points, and have your mouse listeners add to this collection and the paintComponent iterate through this collection.

therefore,i really need more help
thanks again

Nope, just need to apply ideas given to your problem, that's all.

For example applying principles in his post...

import javax.swing.*;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.*;
import java.util.ArrayList;
import java.util.List;

@SuppressWarnings("serial")
public class MousePaint2 extends JPanel {

  private static final int WIDTH = 300, HEIGHT = 300;
  private static final int LEFT = 10;
  private static final int TOP = 10;
  private static final int BORDER = 30;

  private static final Color backColor = Color.gray;
  private static final Color lineColor = Color.red;

  // points for rectangles to draw go here
  private List<Point> pointList = new ArrayList<Point>();

  public MousePaint2() {
    MyMouseAdapter myMouseAdapter = new MyMouseAdapter();
    addMouseMotionListener(myMouseAdapter);
    addMouseListener(myMouseAdapter);
    setPreferredSize(new Dimension(WIDTH, HEIGHT));
  }

  public void paintComponent(Graphics g) {
    super.paintComponent(g); // don't forget this call
    Dimension d = getSize();
    g.setColor(lineColor);
    g.fillRect(0, 0, LEFT, TOP);
    g.drawRect(LEFT, TOP, d.width - BORDER, d.height - BORDER);

    g.drawString("Drag to draw; Click the red rectangle to clear.", LEFT, d.height - 5);
    g.setColor(Color.black);

    // paintComponent paints the rects based on points in the list
    for (Point point : pointList) {
      g.fillRect(point.x, point.y, 3, 3);
    }
  }

  private class MyMouseAdapter extends MouseAdapter {
    public void mouseDragged(MouseEvent e) {
      processPoint(e.getPoint());
    }
    
    public void mouseClicked(MouseEvent e) {
      processPoint(e.getPoint());
    }

    // mouse adds to and removes from the point list
    private void processPoint(Point point) {
      Dimension d = getSize();
      if ((point.x > LEFT) && (point.x < LEFT + d.width - BORDER) && (point.y > TOP)
          && (point.y < TOP + d.height - BORDER)) {
        pointList.add(point);
      }
      if ((point.x < LEFT) && (point.y < TOP)) {
        pointList.clear();
      }
      repaint();
    }
  }

  public static void main(String args[]) {
    MousePaint2 mp = new MousePaint2();
    JFrame f = new JFrame("Drawing Window");
    f.getContentPane().add(mp);
    f.pack();
    f.setLocationRelativeTo(null);
    f.setVisible(true);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  }
}

[Esmaeil Ashrafi]

I love this ranch
Dear pete stein i wished you didn't edit your post and save your worth time,because when i read it,i found that how stupid i am and now i'm posting this after i completely resolved my problem.
My mistake was i was thinking about how to retain - and restore the whole drawn image composed of simple points all over the time (although now i,m thinking this is possible by means of BufferedImage from the given link) - and your little comment was a great key,so i made it very fine and even compact my codes,using multy argumental repaint() ...

thank you both pete stein and Rob Camick and the author of that blog taught me many things

another thing :

Please don't jump to conclusions, especially when you are this early in the game.

I didn't mean anything bad,if sound such,i apologze

[pete stein]

Esmaeil Ashrafi wrote:
and now i'm posting this after i completely resolved my problem.

Wonderful!

thank you both pete stein and Rob Camick and the author of that blog taught me many things

You're welcome

another thing :

Please don't jump to conclusions, especially when you are this early in the game.

I didn't mean anything bad,if sound such,i apologze

Not to worry, and no need to apologize.

Best of luck!