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@node GtkSizeGroup
@chapter GtkSizeGroup
Grouping widgets so they request the same size

@section Overview
@code{<gtk-size-group>} 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
@code{<gtk-table>} widget.

In detail, the size requested for each widget in a @code{<gtk-size-group>} 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
@code{gtk-size-group-set-mode}) 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
@code{<gtk-size-group>} 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 @samp{GTK_FILL}
flag.

@code{<gtk-size-group>} objects are referenced by each widget in the size group,
so once you have added all widgets to a @code{<gtk-size-group>}, you can drop
the initial reference to the size group with @code{g-object-unref}. If the
widgets in the size group are subsequently destroyed, then they will be removed
from the size group and drop their references on the size group; when all
widgets have been removed, the size group will be freed.

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
@samp{GTK_SIZE_GROUP_HORIZONTAL} or @samp{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 @samp{GTK_SIZE_GROUP_VERTICAL} or
@samp{GTK_SIZE_GROUP_BOTH}.

@section Usage
@include defuns-gtksizegroup.xml.texi

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