SizeGroup provides a mechanism for grouping a number of widgets together so
they all request the same amount of space. This is typically useful when you
want a column of widgets to have the same size, but you can't use a
Table
widget.
In detail, the size requested for each widget in a SizeGroup is the maximum
of the sizes that would have been requested for each widget in the size group
if they were not in the size group. The mode of the size group (see
setMode(SizeGroupMode)
determines whether this applies to the
horizontal size, the vertical size, or both sizes.
Note that size groups only affect the amount of space requested, not the size
that the widgets finally receive. If you want the widgets in a SizeGroup to
actually be the same size, you need to pack them in such a way that they get
the size they request and not more. For example, if you are packing your
widgets into a table, you would not include the GTK_FILL flag.
Widgets can be part of multiple size groups; GTK+ will compute the horizontal
size of a widget from the horizontal requisition of all widgets that can be
reached from the widget by a chain of size groups of type
GTK_SIZE_GROUP_HORIZONTAL or GTK_SIZE_GROUP_BOTH, and the vertical size from
the vertical requisition of all widgets that can be reached from the widget
by a chain of size groups of type GTK_SIZE_GROUP_VERTICAL or
GTK_SIZE_GROUP_BOTH.