Documentation

The grid bag layout manager places components in a grid of columns and rows, allowing specified components to span multiple columns or rows. Not all columns/rows necessarily have the same width/height. Essentially, GridBagLayout places components in rectangles (cells) in a grid, and then uses the components' preferred sizes to determine how big the cells should be.

GridBagLayout

Use the column and row headers to insert or delete columns/rows and change column/row properties.

GridBagLayout is part of the standard Java distribution.

Extensions

JFormDesigner extends the original GridBagLayout with following features:

Horizontal and vertical gaps
Simply specify the gap size and JFormDesigner automatically computes the GridBagConstraints.insets for all components. This makes designing a form with consistent gaps using GridBagLayout much easier. No longer wrestling with GridBagConstraints.insets.

With gaps: Without gaps:
Left/top layout alignment
The pure GridBagLayout centers the layout within the container if there is enough space. JFormDesigner easily allows you to fix this problem by switching on two options: align left and align top.

With layout alignment: Without layout alignment:
Default component alignment
Allows you to specify a default alignment for components within columns/rows. This is very useful for columns with right aligned labels because you specify the alignment only once for the column and all added labels will automatically aligned to the right.

Layout properties

A container with this layout manager has following layout properties:

Property Name	Description
horizontal gap	The horizontal gap between components. Default is 5.
vertical gap	The vertical gap between components. Default is 5.
align left	If true, aligns the layout to the left side of the container. If false, then the layout is centered horizontally. Default is true.
align top	If true, aligns the layout to the top side of the container. If false, then the layout is centered vertically. Default is true.

These four properties are JFormDesigner extensions to the original GridBagLayout. However, no additional library is required.

Column/row properties

Each column and row has its own properties. Use the column and row headers to change column/row properties.

Property Name	Description
Column/Row	The index of the column/row. Use the arrow buttons (or Alt+Left, Alt+Right, Alt+Up, Alt+Down keys) to edit the properties of the previous or next column/row.
Default alignment	The default alignment of the components within a column/row. Used if the value of the constraints properties "h align" or "v align" is DEFAULT.
Size	The minimum width of a column or height of a row.
Resize behavior	The resize weight of the column/row.

Tip: The column/row context menu allows you to alter many of these options for multi-selections.

Constraints properties

A component contained in a container with this layout manager has following constraints properties:

Property Name	Description
grid x	Specifies the component's horizontal grid origin (column index).
grid y	Specifies the component's vertical grid origin (row index).
grid width	Specifies the component's horizontal grid extend (number of columns). Default is 1.
grid height	Specifies the component's vertical grid extend (number of rows). Default is 1.
h align	The horizontal alignment of the component within its cell. Possible values: DEFAULT, LEFT, CENTER, RIGHT and FILL. Default is DEFAULT.
v align	The vertical alignment of the component within its cell. Possible values: DEFAULT, TOP, CENTER, BOTTOM, FILL, BASELINE (Java 6), ABOVE_BASELINE (Java 6) and BELOW_BASELINE (Java 6). Default is DEFAULT.
weight x	Specifies how to distribute extra horizontal space. Default is 0.0.
weight y	Specifies how to distribute extra vertical space. Default is 0.0.
insets	Specifies the external padding of the component, the minimum amount of space between the component and the edges of its display area. Default is [0,0,0,0].
ipad x	Specifies the internal padding of the component, how much space to add to the minimum width of the component. Default is 0.
ipad y	Specifies the internal padding, that is, how much space to add to the minimum height of the component. Default is 0.

In contrast to the GridBagConstraints API, which uses anchor and fill to specify the alignment and resize behavior of a component, JFormDesigner uses the usual h/v align notation.

Tip: The component context menu allows you to alter the alignment for multi-selections.