Help in gridbaglayout

[adeeb alexander]

Hi all
The code below doesnt do what it has to do. I need to place the components on the top left of my panel. But the components be still in the center of panel after giving this also gbc.anchor=GridBagConstraints.NORTHWEST; It doent work until i set gbc.weightx=0.0; and gbc.weighty=0.0;. Here the components get at the top position but the gap in between them is increasing. Someone please help me out. The code is here.

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

public class test extends JFrame
{
	Container c;
	JLabel l1;
	JTextField t1;
	JPanel panel;
	public test()
	{
		c=getContentPane();
		panel=new JPanel();
		GridBagConstraints gbc = new GridBagConstraints();
		GridBagLayout gl=new GridBagLayout();
		panel.setLayout(gl);
	//	gbc.weightx=1.0;
	//	gbc.weighty=1.0;
		gbc.anchor=GridBagConstraints.NORTHWEST;
	
		l1=new JLabel("Name");
		
		t1=new JTextField(25);
		gbc.gridy=0;
		panel.add(l1,gbc);
		panel.add(t1,gbc);
		
		getContentPane().add(panel);
		setSize(600,600);
		setVisible(true);
	}
	
	public static void main(String args[])
	{
		new test();
	}
}  

[Fred Hamilton]

I'm not sure myself, but it looks like the following document addresses your issue, about 3/4 of the way down the page.

http://java.sun.com/developer/onlineTraining/GUI/AWTLayoutMgr/shortcourse.html

[adeeb alexander]

Hi.
Can any one please suggest me to use which layout. I really want to know that which layout is good. I am good in GroupLayouts. Now please suggest me that that sahll i continue with grouplayout or change to other layout.


Thanks and Regards
alexander

[Fred Hamilton]

often a good layout manager is a combination of different layout managers to achieve the desired effect. In that sense, I would say it is difficult to recommend a specific layout for your situation.

The article is very good at describing how to use a combination of different Layout Managers to achieve the desired result.

Try to break your GUI into high level sections, whereby you can describe the layout of these sections relative to each other using a known manager. Then, you can describe the layout within each section by using it's own layout manager. Sort of a nesting of simple layout managers to achieve a more complex end result.

If you could show a picture of your desired layout, it would be easier to advise of specific layout managers to use.

p.s edited for clarity

[Campbell Ritchie]

if you are happy with Group, why not stick with Group?

[Craig Wood]

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

public class TestLayout extends JFrame
{
    public TestLayout()
    {
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        Container c=getContentPane();
        JPanel panel=new JPanel();
        GridBagConstraints gbc = new GridBagConstraints();
        GridBagLayout gl=new GridBagLayout();
        panel.setLayout(gl);
        gbc.weighty=1.0;
        gbc.anchor=GridBagConstraints.NORTHWEST;

        JLabel l1=new JLabel("Name");

        JTextField t1=new JTextField(25);
        gbc.gridy=0;
        // leave gbc.weightx at its default value of zero
        panel.add(l1,gbc);
        gbc.weightx=1.0;
        panel.add(t1,gbc);

        getContentPane().add(panel);
        setSize(600,600);
        setVisible(true);
    }

    public static void main(String[] args)
    {
        new TestLayout();
    }
}

[adeeb alexander]

Hi Craig
Thanks for your example i am able to got little bit into my head and added a label and textfield now the problem is that they are getting placed in the center. When i increase the weigtx and weighty i am able to place in the correct position but i have observed that the value is needed to be increased by 50 and for other row again i have to add more two zeros that is 5000 then only i am getting the components in correct position. Please execute the code if you can. Then you can get my problem. The code is here.

 
   import java.awt.*;  
   import javax.swing.*;  
     
   public class test extends JFrame  
   {  
       public test()  
      {  
          setDefaultCloseOperation(EXIT_ON_CLOSE);  
          Container c=getContentPane();  
           JPanel panel=new JPanel();  
           GridBagConstraints gbc = new GridBagConstraints();  
           GridBagLayout gl=new GridBagLayout();  
           panel.setLayout(gl);  
           gbc.weighty=1.0;  
	   		gbc.insets = new Insets(10, 10, 10, 10);    
           gbc.anchor=GridBagConstraints.NORTHWEST;  
     
           JLabel l1=new JLabel("Name");  
     
           JTextField t1=new JTextField(25);  
           gbc.gridy=0;  
           // leave gbc.weightx at its default value of zero  
           panel.add(l1,gbc);  
           gbc.weightx=1.0;  
           panel.add(t1,gbc);  
           
           gbc.weighty=50; 
           JLabel l2 = new JLabel("Rollno");
           JTextField t2 = new JTextField(25);
           gbc.gridy=1;
           panel.add(l2,gbc);
           gbc.weightx=50;
           panel.add(t2,gbc);
           
           gbc.weighty=5000; 
           JLabel l3 = new JLabel("Class");
           JTextField t3 = new JTextField(25);
           gbc.gridy=2;
           panel.add(l3,gbc);
           gbc.weightx=5000;
           panel.add(t3,gbc);
     
           getContentPane().add(panel);  
           setSize(600,600);  
           setVisible(true);  
       }  
     
       public static void main(String[] args)  
       {  
           new test();  
       }  
   }  

[Craig Wood]

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

public class TestLayout extends JFrame
{
    public TestLayout()
    {
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        Container c=getContentPane();
        JPanel panel=new JPanel();
        GridBagConstraints gbc = new GridBagConstraints();
        GridBagLayout gl=new GridBagLayout();
        panel.setLayout(gl);
        // leave weighty at the default value of zero
        // in order to clump the component rows together
        // we can push them all up together at the end
//        gbc.weighty = 1.0;


        gbc.insets = new Insets(10, 10, 10, 10);
        gbc.anchor=GridBagConstraints.NORTHWEST;

        JLabel l1=new JLabel("Name");

        JTextField t1=new JTextField(25);
        gbc.gridy=0;
        panel.add(l1,gbc);
        gbc.weightx=1.0;
        panel.add(t1,gbc);

//        gbc.weighty=50;
        gbc.weightx = 0;
        JLabel l2 = new JLabel("Rollno");
        JTextField t2 = new JTextField(25);
        gbc.gridy=1;
        panel.add(l2,gbc);
        gbc.weightx=//50;
                    1.0;
        panel.add(t2,gbc);

//        gbc.weighty=5000;
        // now set a non-zero weighty value which will
        // push the this and the rows above up
        gbc.weighty = 1.0;
        gbc.weightx = 0;
        JLabel l3 = new JLabel("Class");
        JTextField t3 = new JTextField(25);
        gbc.gridy=2;
        panel.add(l3,gbc);
        gbc.weightx=//5000;
                    1.0;
        panel.add(t3,gbc);


        getContentPane().add(panel);
        setSize(600,600);
        setVisible(true);
    }

    public static void main(String[] args)
    {
        new TestLayout();
    }
}

[adeeb alexander]

Thanks a lot guyz i have learn t lot about the GridBagLayout. No i have got a simple doubt in the code below. When i arrange the components in the following order
l1 t1 l2 t2
l3 t3
l4 t4

its ok. i can arrange them, but when i reduce the size of t1 i.e t3 is 25 and t1 is 10 then gap between t1 and l2 is increased that is l2 and t2 remains at there old place only. How can i move them closer.


Thanks and Regards
alexander

[Craig Wood]

The components in each row are laid out in columns and their size determines the width of the columns. One way to work with this is to use a separate panel (to bridge across columns) for/in a row.

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

public class TestLayout extends JFrame
{
    public TestLayout()
    {
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        GridBagLayout gridbag=new GridBagLayout();
        JPanel panel=new JPanel(gridbag);
        GridBagConstraints gbc=new GridBagConstraints();
        gbc.anchor=GridBagConstraints.NORTHWEST;

        // Use separate panel for top row components
        // to evenly span the two-column layout below.
        JPanel p=new JPanel(gridbag);
        gbc.insets=new Insets(10,10,10,10);
        p.add(new JLabel("Id"),gbc);
        p.add(new JTextField(10),gbc);
        p.add(new JLabel("Name"),gbc);
        p.add(new JTextField(25),gbc);

        gbc.gridwidth=2;
        gbc.insets=new Insets(0,0,0,0);
        panel.add(p,gbc);

        // Reset gbc for use in panel.
        gbc.gridy=1;
        gbc.fill=GridBagConstraints.NONE;
        gbc.insets=new Insets(10,10,10,10);

        gbc.weightx=0;
        gbc.gridwidth=1;
        panel.add(new JLabel("Rollno"),gbc);
        gbc.weightx=1.0;
        gbc.gridwidth=GridBagConstraints.REMAINDER;
        panel.add(new JTextField(25),gbc);

        // Reset gridy to default so the gridwidth
        // constraint can be used to move to the
        // next row: value REMAINDER => last in row.
        gbc.gridy=GridBagConstraints.RELATIVE;

        gbc.weighty=1.0;
        gbc.weightx=0;
        gbc.gridwidth=1;
        panel.add(new JLabel("Class"),gbc);
        gbc.weightx=1.0;
        gbc.gridwidth=GridBagConstraints.REMAINDER;
        panel.add(new JTextField(25),gbc);

        getContentPane().add(panel);
        setSize(600,300);
//        pack();
        setVisible(true);
        System.out.printf("width=%d  height=%d%n",
                           panel.getWidth(), panel.getHeight());
    }

    public static void main(String[] args)
    {
        new TestLayout();
    }
}