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Trail: Creating a GUI with JFC/Swing
Lesson: Laying Out Components Within a Container

How to Use GridLayout

Here's an applet that shows a GridLayout (in the API reference documentation) in action.

Click this figure to run the applet.
This is a picture of the applet's GUI. To run the applet, click the picture. The applet will appear in a new browser window.

A GridLayout places components in a grid of cells. Each component takes all the available space within its cell, and each cell is exactly the same size. If you resize the GridLayout window, you'll see that the GridLayout changes the cell size so that the cells are as large as possible, given the space available to the container.

Below is the code that creates the GridLayout and the components it manages. You can find the whole program in (in a .java source file). The program runs either within an applet (with the help of AppletButton (in a .java source file)) or as an application.

Container contentPane = getContentPane();

contentPane.setLayout(new GridLayout(0,2));

contentPane.add(new JButton("Button 1"));
contentPane.add(new JButton("2"));
contentPane.add(new JButton("Button 3"));
contentPane.add(new JButton("Long-Named Button 4"));
contentPane.add(new JButton("Button 5"));
The constructor tells the GridLayout class to create an instance that has two columns and as many rows as necessary.

The GridLayout API

The GridLayout class has two constructors:
public GridLayout(int rows, int columns)
public GridLayout(int rows, int columns,
                  int horizontalGap, int verticalGap)
At least one of the rows and columns arguments must be nonzero. The horizontalGap and verticalGap arguments to the second constructor allow you to specify the number of pixels between cells. If you don't specify gaps, their values default to zero. In the applet above, any apparent gaps are the result of the buttons reserving extra space around their apparent display area.

Examples that Use GridLayout

The following table lists some of the examples that use grid layout.

Example Where Described Notes
GridWindow This page Uses a 2-column grid.
LabelDemo How to Use Labels (in the Creating a GUI with JFC/Swing trail) Uses a 3-row grid.
Converter The Anatomy of a Swing-Based Program (in the Creating a GUI with JFC/Swing trail) Uses the 4-argument GridLayout constructor.

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