TableLayout

TableLayout TableLayout

TSC Contents
Front Page
Article Index

	Article Table of Contents

	Introduction
		What is TableLayout?
		Creating a TableLayout

	Column and Row Sizes
		Absolute and Scalable Space
		Order of Allocation
		Rounding Considerations

	Cells
		Adding Components
		Justification
		Multiple Cells

	Final Theory
		Dynamic Rows and Columns
		Preferred Layout Size
		Onward

	Examples
		Simple
		GridLayout Comparison
		GridBagLayout Comparison
		A Typical GUI
		Preferred Rows and Columns
		TableLayoutConstraints
		A RAD Tool

	API Reference
	Download

GridLayout Versus TableLayout

This example shows how TableLayout offers more functionality than GridLayout. The showGridWindow method utilizes GridLayout to lay out its components. The showTableWindow method utilizes TableLayout to provide the same layout. The showTableWindow2 method utilizes TableLayout but allows cells to be selectively empty -- a feature that GridLayout cannot support. The output of this example is shown below.

package example;



import java.awt.*;
import java.awt.event.*;
import javax.swing.JButton;
import layout.TableLayout;



public class GridVersusTable
{

    
    
    protected static Frame showGridWindow ()
    {
        // Create frame
        Frame frame = new Frame("GridLayout");
        frame.setFont (new Font("Helvetica", Font.PLAIN, 14));
        frame.setLayout (new GridLayout(2, 0));
   
        // Create and add buttons
        frame.add (new JButton("One"));
        frame.add (new JButton("Two"));
        frame.add (new JButton("Three"));
        frame.add (new JButton("Four"));

        // Show frame
        frame.pack();
        frame.setLocation (0, 10);
        frame.show();

        return frame;
    }



    protected static Frame showTableWindow ()
    {
        // Create frame
        Frame frame = new Frame("TableLayout");
        frame.setFont (new Font("Helvetica", Font.PLAIN, 14));
        
        // Set layout
        double f = TableLayout.FILL;
        double size[][] = {{f, f}, {f, f}};
        frame.setLayout (new TableLayout(size));
        
        // Create and add buttons
        frame.add (new JButton("One"),   "0, 0");
        frame.add (new JButton("Two"),   "1, 0");
        frame.add (new JButton("Three"), "0, 1");
        frame.add (new JButton("Four"),  "1, 1");

        // Show frame
        frame.pack();
        frame.setLocation (200, 10);
        frame.show();

        return frame;
    }



    protected static Frame showTableWindow2 ()
    {
        // Create frame
        Frame frame = new Frame("TableLayout");
        frame.setFont (new Font("Helvetica", Font.PLAIN, 14));
        
        // Set layout
        double f = TableLayout.FILL;
        double size[][] = {{f, f}, {f, f}};
        frame.setLayout (new TableLayout(size));
        
        // Create and add buttons
        frame.add (new JButton("One"),   "0, 0");
        frame.add (new JButton("Two"),   "1, 1");

        // Show frame
        frame.pack();
        frame.setLocation (400, 10);
        frame.show();

        return frame;
    }



    public static void main (String args[])
    {
        WindowListener listener =
            (new WindowAdapter()
                {
                    public void windowClosing (WindowEvent e)
                    {
                        System.exit (0);
                    }
                }
            );

        Frame frame = showGridWindow();
        frame.addWindowListener(listener);
        
        frame = showTableWindow();
        frame.addWindowListener(listener);

        frame = showTableWindow2();
        frame.addWindowListener(listener);
    }
}

This illustration shows the three frames created by the above program. The first two frames function identically, showing that TableLayout subsumes the functionality of GridLayout. TableLayout does this without requiring more complex code. The third frame in the illustration shows where TableLayout surpasses GridLayout. TableLayout allows cells to be skipped. It also allows the rows and columns to have different sizes. GridLayout does not. GridBagLayout also subsumes the functionality of GridLayout, but at the cost of complexity as our next example will show.

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