Thread: BorderLayout displays only Center area

Only the BorderLayout.CENTER displays, and it fills the frame. If I comment out the red center, I get a white center (default I assume) filling the frame. I'm obviously missing something basic, but I don't see it Test1 and Test1_panel are in separate files if that matters.

Thanx - Charlie

public class Test1_panel extends JPanel {
public Test1_panel(Color c) {
setBackground(c);
}

public void setSize(int x, int y) {
setPreferredSize(new Dimension(x, y));
}
}

class Test1 {
//----------------------------------------------
// Here's the main function to get things going.
//----------------------------------------------
public static void main(String argv[]) {
Test1_frame tf = new Test1_frame("The banana boat has arrived.");
Container p = tf.getContentPane();
Test1_panel tp1 = new Test1_panel(Color.red);
Test1_panel tp2 = new Test1_panel(Color.green);
Test1_panel tp3 = new Test1_panel(Color.blue);
Test1_panel tp4 = new Test1_panel(Color.yellow);
Test1_panel tp5 = new Test1_panel(Color.black);
p.add(tp2, BorderLayout.NORTH);
p.add(tp1, BorderLayout.CENTER);
p.add(tp5, BorderLayout.WEST);
p.add(tp4, BorderLayout.SOUTH);
p.add(tp3, BorderLayout.EAST);

tf.showIt(300, 300);
}
}

Please post your code correctly per this link.

Here's the code again properly formatted (I hope). Thanks Greg Brannon for the link to the formatting stuff

public class Test1_panel extends JPanel {
    public Test1_panel(Color c) {
        setBackground(c);
    }
 
    public void setSize(int x, int y) {
        setPreferredSize(new Dimension(x, y));
    }
}
 
class Test1 {
//----------------------------------------------
// Here's the main function to get things going.
//----------------------------------------------
    public static void main(String argv[]) {
        Test1_frame tf = new Test1_frame("The banana boat has arrived.");
        Container p = tf.getContentPane();
        Test1_panel tp1 = new Test1_panel(Color.red);
        Test1_panel tp2 = new Test1_panel(Color.green);
        Test1_panel tp3 = new Test1_panel(Color.blue);
        Test1_panel tp4 = new Test1_panel(Color.yellow);
        Test1_panel tp5 = new Test1_panel(Color.black);
        p.add(tp2, BorderLayout.NORTH);
        p.add(tp1, BorderLayout.CENTER);
        p.add(tp5, BorderLayout.WEST);
        p.add(tp4, BorderLayout.SOUTH);
        p.add(tp3, BorderLayout.EAST);
 
        tf.showIt(300, 300);
    }
}

I corrected your code for you, adding comments to explain the corrections. In future, you'll need to show off-stage code, like Test1_frame, in order for us to understand what's happening at your end.

// GB: added necessary imports the lazy way
import javax.swing.*;
import java.awt.*;
 
// GB: promoted to the public class in the file
public class Test1
{
//----------------------------------------------
// Here's the main function to get things going.
//----------------------------------------------
    // GB: in Java, 'functions' are called methods - this
    // is the main() METHOD
    public static void main( String argv[] )
    {
        // i don't know what your Test1_frame is so just used JFrame
        JFrame tf = new JFrame("The banana boat has arrived.");
 
        // GB:  adding to the container has not been necessary since Java 1.4
        // JFrame.add() does the same thing. use an updated tutorial
        // GB: set the preferred size for each of the JPanels
        Container p = tf.getContentPane();
        Test1_panel tp1 = new Test1_panel(Color.red);
        tp1.setPreferredSize( new Dimension( 500, 500 ) );
        Test1_panel tp2 = new Test1_panel(Color.green);
        tp2.setPreferredSize( new Dimension( 400, 50 ) );
        Test1_panel tp3 = new Test1_panel(Color.blue);
        tp3.setPreferredSize( new Dimension( 50, 600 ) );
        Test1_panel tp4 = new Test1_panel(Color.yellow);
        tp4.setPreferredSize( new Dimension( 400, 50 ) );
        Test1_panel tp5 = new Test1_panel(Color.black);
        tp5.setPreferredSize( new Dimension( 50, 600 ) );
 
        p.add(tp2, BorderLayout.NORTH);
        p.add(tp1, BorderLayout.CENTER);
        p.add(tp5, BorderLayout.WEST);
        p.add(tp4, BorderLayout.SOUTH);
        p.add(tp3, BorderLayout.EAST);
 
        // GB: packed the JFrame before rendering to respect
        // preferred size settings
        tf.pack();
 
        // GB: using JFrame's setVisible() method to render
        tf.setVisible( true );
    }
}
 
// GB:  demoted to a non-public class.
class Test1_panel extends JPanel
{
    public Test1_panel(Color c)
    {
        setBackground(c);
    }
 
    // GB: the setSize() method was not only unused, it is inappropriate
    // to override the setSize() method for this demo
}

Greg,

That fixed things, and your code comments were very helpful.

Thanx - Charlie