The GridBagLayout extracts the constraint values and doesn't use the GridBagConstraints again. You must be careful, however, to reset the GridBagConstraints instance variables to their default values when necessary. These constraints specify the number of cells the component uses, not the number of pixels it uses. The default value is 1. Due to a bug in the the 1.0 release of Java, GridBagLayout doesn't allow components to span multiple rows unless the component is in the leftmost column.
Valid values are GridBagConstraints.
The default value is zero. The value is specified as an Insets object. By default, each component has no external padding. Valid values are GridBagConstraints. EAST , GridBagConstraints.