Graphical User Interfaces - JavaTech: An Introduction to Scientific and Technical Computing with Java - page 235

Table 7.1 GridBagConstraints Parameters.

Parameter Description Values

Cell column, row number Values start at 0,0

int gridx, gridy

Number of rows and columns
taken up by the component

≥1

int gridheight, gridwidth

Allotment weight for setting
width & height of a cell

Arbitrary scale. Settings go
according to relative values.
See text for more details

int weightx, weighty

Determines whether
component fills cell in x, y,
both, or none

HORIZONTAL, VERTICAL,
BOTH, NONE

int fill

Position of component within
its cell when fill is not set to
BOTH

CENTER, EAST, SOUTHEAST,
SOUTH, SOUTHWEST,
WEST, NORTHWEST,
NORTH, NORTHEAST

int anchor

Padding added between a
component and cell borders

≥ 0

int ipadx, ipady

Defines padding between
components

≥0

Insets insets

you set the gridx and gridy integer variables in the GridBagConstraints
object for the cell position of the component. The layout examines these values
for all the components to find the number of cells needed in the horizontal and
vertical dimensions.
Table 7.1 lists the parameters in GridBagConstraints along with descrip-
tions and allowed values. The purpose of the parameters is straightforward except
for weightx and weighty . These two parameters determine the allocation of
the available space for a column's width and a row's height when the container
is resized. If the weights are all the same then the column and row widths will
be the same (except for the variations due to the different minimum widths and
heights of components in the cells).
Yo u can vary the weight values to force the columns and rows to span differ-
ent widths and heights. For example, the column with the cell with the largest
weightx gets the biggest allocation of horizontal space. The column with the
next biggest weightx gets the next biggest amount of horizontal space. And so
on. The weighty values work in a similar manner for vertical space allocations
to the rows.
The following code leads to the layout shown in Figure 7.13. The program
demonstrates the use of several of the GridBagConstraints parameters. Note
that the same GridBagConstraints object is used throughout. Only the cell
coordinates and one or more of its other values are changed when it is used with
the addition of the next component.

Figure 7.13 Arranging
components with the
GridBagLayout .