Laying Out Components Within a Container

How to Use FlowLayout

The FlowLayout class provides a very simple layout manager that is used, by default, by JPanels. Here's an applet that shows a flow layout in action:

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.

FlowLayout puts components in a row, sized at their preferred size. If the horizontal space in the container is too small to put all the components in one row, FlowLayout uses multiple rows. Within each row, components are centered (the default), left-aligned, or right-aligned as specified when the FlowLayout is created.

Below is the code that creates the FlowLayout and the components it manages. (Here's the whole program. The program runs either within an applet, with the help of AppletButton, or as an application.)

Container contentPane = getContentPane();
contentPane.setLayout(new FlowLayout());
contentpane.setFont(new Font("Helvetica", Font.PLAIN, 14));
   
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 FlowLayout class has three constructors:

public FlowLayout()
public FlowLayout(int alignment)
public FlowLayout(int alignment,
                  int horizontalGap, int verticalGap)

The alignment argument must have the value FlowLayout.LEFT, FlowLayout.CENTER, or FlowLayout.RIGHT. The horizontalGap and verticalGap arguments specify the number of pixels to put between components. If you don't specify a gap value, FlowLayout uses 5 for the default gap value.

Examples that Use FlowLayout

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

Example	Where Described	Notes
FlowWindow.java	This page	Sets up a content pane to use FlowLayout.
ButtonDemo.java	How to Use Buttons, Check Boxes, and Radio Buttons	Uses the default FlowLayout of a JPanel.

Laying Out Components Within a Container