GtkSizeGroup

## GtkSizeGroup GtkSizeGroup — Grouping widgets so they request the same size |

## Includes

    #include <gtk/gtk.h>

## Description

GtkSizeGroup 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 GtkTable widget.

In detail, the size requested for each widget in a GtkSizeGroup 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 `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 GtkSizeGroup 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.

GtkSizeGroup objects are referenced by each widget in the size group, so once you have added all widgets to a GtkSizeGroup, you can drop the initial reference to the size group with `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 `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`.

### GtkSizeGroup as GtkBuildable

Size groups can be specified in a UI definition by placing an <object> element with `class="GtkSizeGroup"` somewhere in the UI definition. The widgets that belong to the size group are specified by a <widgets> element that may contain multiple <widget> elements, one for each member of the size group. The name attribute gives the id of the widget.

Example 40. A UI definition fragment with GtkSizeGroup

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    <object class="GtkSizeGroup">
      <property name="mode">GTK_SIZE_GROUP_HORIZONTAL</property>
      <widgets>
        <widget name="radio1"/>
        <widget name="radio2"/>
      </widgets>
    </object>

## Functions

## Types and Values