anchor

When a component is smaller than its display area, the anchor field specifies where to place it in the grid cell. The mnemonic constants you use for this purpose are similar to those used in a BorderLayout but a little more specific. They are

• GridBagConstraints.CENTER
• GridBagConstraints.NORTH
• GridBagConstraints.NORTHEAST
• GridBagConstraints.EAST
• GridBagConstraints.SOUTHEAST
• GridBagConstraints.SOUTH
• GridBagConstraints.SOUTHWEST
• GridBagConstraints.WEST
• GridBagConstraints.NORTHWEST

The default is GridBagConstraints.CENTER. This is not explicitly set in the calculator applet, because the components are large enough, relative to their display areas, that it really doesn't matter where they go and the default of center is fine.