Re: Adding Graphics to Jpanel

From:
Knute Johnson <nospam@rabbitbrush.frazmtn.com>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 15 Feb 2010 11:33:56 -0800
Message-ID:
<Ekhen.157875$uH1.105735@newsfe25.iad>
On 2/15/2010 11:12 AM, BEHROUZ wrote:

Hi again,
I just wondering how I can add a Graphics object like rectangle to a
JPanel?
I have following classes and I can add the Label object into MyPanel
but I cant add drawing object (MyRect) into Jpanel.I know that I am
not constructing any thing in MyRect() constructor! so it make sence
for me that nothing will happen in MyPanel when I call for MyRect
constructor but I don't' know how to call the paintComponent with it's
parameters in MyPanel class!
Could you please let me know is it possible to add a drawing into a
panel?
so what's wrong with this code?

# package MyPack;
# import java.awt.Color;
# import java.awt.Graphics;
# import javax.swing.JPanel;
#
# public class MyRect extends JPanel {
#
# public void paintComponent(Graphics g) {
# g.setColor (Color.BLUE);
# g.drawRect (100, 100, 200, 200);
# =======================
# package MyPack;
# import java.awt.Color;
# import javax.swing.JPanel;
#
# public class MyPanel extends JPanel {
#
# MyPanel() {
# setBackground(Color.green);
# // Add Drawing to Jpanel
# MyRect mrect = new MyRect();
# this.add(mrect);
# // Add Component to Jpanel
# MyLabel mlabel = new MyLabel();
# this.add(mlabel);
# }
# }
# =======================
# package MyPack;
#
# import java.awt.Color;
# import java.awt.Font;
# import javax.swing.JLabel;
#
# public class MyLabel extends JLabel{
# public MyLabel() {
# super("Hello, World!");
# setFont(new Font(null, Font.BOLD, 40));
# setForeground(Color.red);
# }
# }
# =======================
# package mypaneltest;
# import javax.swing.JFrame;
#
# public class MyFrame extends JFrame {
# public MyFrame(){
# super("Test");
# setSize(300,200);
# setLocationRelativeTo(null);
# MyPanel pane = new MyPanel();
# add(pane);
# }
# }
# ======================
# package MyPack;
#
# public class Main {
# public static void main(String[] args) {
# new MyFrame().setVisible(true);
# }
# }


Other than it won't compile with all those # symbols in there. You will
get better results from the newsgroup if you post and SSCCE.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class test8 extends JPanel {
     public test8() {
         setPreferredSize(new Dimension(400,300));
     }

     public void paintComponent(Graphics g) {
         g.setColor(getBackground());
         g.fillRect(0,0,getWidth(),getHeight());
         g.setColor(Color.BLUE);
         g.drawRect(40,40,getWidth()-80,getHeight()-80);
         g.setColor(Color.RED);
         g.drawOval(getWidth()/2-40,getHeight()/2-40,80,80);
     }

     public static void main(String[] args) {
         EventQueue.invokeLater(new Runnable() {
             public void run() {
                 JFrame f = new JFrame();
                 f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                 test8 t8 = new test8();
                 f.add(t8);
                 f.pack();
                 f.setVisible(true);
             }
         });
     }
}

--

Knute Johnson
email s/nospam/knute2010/

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