Name: rk38400 Date: 04/13/98


#Description
Clipping in a JScrollPane failed. If we draw into
a component which is in the JScrollPane and
we use getGraphics to get the graphic context
the JScrollPane don't clip the parts away
which are not seen.
I am not sure if this is a bug, or the user
have to make sure to get the "right" context
using getViewport().getGraphics() ?

The Java Code examples gives you an idea what
I mean:
#JAVA-Code

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.lang.*;
import com.sun.java.swing.*;
import com.sun.java.swing.event.*;
import java.beans.*;


public class bug2 extends JFrame implements MouseListener, MouseMotionListener, WindowListener {

  MyComp comp;

  public bug2(){

    addMouseListener(this);
    addMouseMotionListener(this);
    
    JPanel hugo = new JPanel();
    hugo.setPreferredSize(new Dimension(300,300));
    hugo.setBackground(Color.green);

    comp = new MyComp();
    comp.setPreferredSize(new Dimension(400,400));

    JScrollPane scroll = new JScrollPane();
    scroll.setPreferredSize(new Dimension(300,300));
    JPanel fritz = new JPanel();
    fritz.add(scroll);
    fritz.setPreferredSize(new Dimension(300,300));
    fritz.setBackground(Color.yellow);

    getContentPane().setLayout(new GridBagLayout());
    getContentPane().add(scroll);
    getContentPane().add(hugo);

    scroll.getViewport().add(comp);
    pack();

  }


  public void mouseReleased(MouseEvent e) {}

   public void mouseClicked(MouseEvent e) {
     System.out.println("Mouse clicked");
          
     comp.drawLine();

   }

  public void mouseEntered(MouseEvent e) {}

  public void mouseExited(MouseEvent e) {}

  public void mouseDragged(MouseEvent e) { }

   
  public void mouseMoved(MouseEvent e) {}
  

  public void mousePressed(MouseEvent e){}


  public void windowDeactivated(WindowEvent e) {}

 
  public void windowDeiconified(WindowEvent e) {}

 
  public void windowIconified(WindowEvent e) {}

 
  public void windowOpened(WindowEvent e) {}

  public void windowClosed(WindowEvent e) {
    System.exit(0);
  }

  public void windowClosing(WindowEvent e) {
    System.exit(0);
  };

 public void windowActivated(WindowEvent e) {}


  public static void main(String[] args) {
    
    bug2 f = new bug2();
    f.pack();
    f.show();
    
  }

}




class MyComp extends JComponent {


  public MyComp(){
    setSize(100,100);
    setPreferredSize(new Dimension(200,200));
  }

  
  public void paint(Graphics g){
    g.setColor(Color.red);
    g.drawRoundRect(10,10,100,200,30,30);
  }

  public void drawLine(){
    
    Graphics g = getGraphics();
    g.setColor(Color.red);
    g.drawLine(0,0,600,300);
  }




}
(Review ID: 26561)
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