I am using GridBag.....

[Bshni]

In the below program, I am able to set up the window like I want. The only problem is when I run it, I can't see the graph.
What should I do??
================================================================
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.geom.*;

public class Axis extends JFrame {
TheAxis ta;
void buildConstraints(GridBagConstraints gbc, int gx, int gy,
int gw, int gh, int wx, int wy) {
gbc.gridx = gx;
gbc.gridy = gy;
gbc.gridwidth = gw;
gbc.gridheight = gh;
gbc.weightx = wx;
gbc.weighty = wy;
}


public Axis() {
super("The window");
setSize(500,500);


JButton start = new JButton("Start");
JButton stp = new JButton("Stop");
GridBagLayout gridbag = new GridBagLayout();
GridBagConstraints constraints = new GridBagConstraints();
JPanel pane = new JPanel();
pane.setLayout(gridbag);
buildConstraints(constraints, 0,0,1,1,0,80);
constraints.fill = GridBagConstraints.NONE;
gridbag.setConstraints(ta, constraints);
pane.add(ta);
buildConstraints(constraints, 0,1,1,1,50,20);
gridbag.setConstraints(start, constraints);
pane.add(start);
buildConstraints(constraints, 1,1,1,1,50,20);
gridbag.setConstraints(stp, constraints);
pane.add(stp);
setContentPane(pane);


}
public static void main(String[] arguments) {
Axis frame = new Axis();
ExitWindow exit =new ExitWindow();
frame.addWindowListener(exit);
frame.show();
}

}
class TheAxis extends JPanel {
public void paintComponent(Graphics comp) {
Graphics2D comp2D = (Graphics2D)comp;
setBackground(Color.white);
comp2D.setColor(Color.black);
Line2D.Float ln1 = new Line2D.Float(250f,0f,250f,500f);
Line2D.Float ln2 = new Line2D.Float(0f,250f,500f,250f);
comp2D.fill(ln1);
comp2D.fill(ln2);
comp2D.draw(ln1);
comp2D.draw(ln2);
}
}

class ExitWindow extends WindowAdapter {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
}

[Pravin Panicker]

Hi Bshni
I did some modification to get your code running.
Is this what you wanted ??
-----------------------------------------------------------------
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.geom.*;

public class Axis extends JFrame {
TheAxis ta;
void buildConstraints(GridBagConstraints gbc, int gx, int gy,
int gw, int gh, int wx, int wy) {
gbc.gridx = gx;
gbc.gridy = gy;
gbc.gridwidth = gw;
gbc.gridheight = gh;
gbc.weightx = wx;
gbc.weighty = wy;
}
public Axis() {
super("The window");
setSize(600,600);

JButton start = new JButton("Start");
JButton stp = new JButton("Stop");
GridBagLayout gridbag = new GridBagLayout();
GridBagConstraints constraints = new GridBagConstraints();
JPanel pane = new JPanel();
pane.setLayout(gridbag);
buildConstraints(constraints, 0,0,1,1,0,80);
constraints.fill = GridBagConstraints.NONE;
ta = new TheAxis();
gridbag.setConstraints(ta, constraints);
pane.add(ta);
buildConstraints(constraints, 0,1,1,1,50,20);
gridbag.setConstraints(start, constraints);
pane.add(start);
buildConstraints(constraints, 1,1,1,1,50,20);
gridbag.setConstraints(stp, constraints);
pane.add(stp);
setContentPane(pane);

}
public static void main(String[] arguments) {
Axis frame = new Axis();
ExitWindow exit =new ExitWindow();
frame.addWindowListener(exit);
frame.show();
}

}
class TheAxis extends Canvas { // --------------- Note extending Canvas to do your painting
TheAxis()
{
setSize(500,500); // --------------- Set Size
}
public void paint(Graphics comp)// --------------- Note this
{
paintComponent(comp);
}
public void paintComponent(Graphics comp) {
Graphics2D comp2D = (Graphics2D)comp;
setBackground(Color.white);
comp2D.setColor(Color.blue);
Line2D.Float ln1 = new Line2D.Float(250f,0f,50f,500f);
Line2D.Float ln2 = new Line2D.Float(0f,250f,500f,250f);
comp2D.fill(ln1);
comp2D.fill(ln2);
comp2D.draw(ln1);
comp2D.draw(ln2);
}
}

class ExitWindow extends WindowAdapter {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
}

[Pravin Panicker]

Also note that you hadnt instantiated the TheAxis object .This was causing a NullPointerException

[Frank Carver]

"Bshni",
The Java Ranch has thousands of visitors every week, many with surprisingly similar names. To avoid confusion we have a naming convention, described at http://www.javaranch.com/name.jsp .
We require names to have at least two words, separated by a space, and strongly recommend that you use your full real name. Please choose a new name which meets the requirements.
Thanks.

[Bshni]

Thank you soooo much. I have been asking eGroups for help on this program for weeks. You have given me a clear and understandable correction. You have made my day!!!
I am currently a math teacher changing careers. I do not have any programming experience except from what I read in
SAMS learn Java in 21 days. I am now also reading Thinking in Java by Bruce Eckel. He seems to be explaining it quite well.
I'm also signed up for a 5 day Sun Java course in Edison, NJ for the Java test.
Anything else I should do??
I'm going for Java certification and realized that swing is not on the exam. Could I bother you one more time and ask how does this change JButton, JPanel, and JFrame???

[Randall Twede]

probably your only concern about swing vs awt(for test) is that default layout of Applet is FlowLayout. I believe it is BorderLayout for JApplet.