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.
Details
enum GtkSizeGroupMode
typedef enum {
GTK_SIZE_GROUP_NONE,
GTK_SIZE_GROUP_HORIZONTAL,
GTK_SIZE_GROUP_VERTICAL,
GTK_SIZE_GROUP_BOTH
} GtkSizeGroupMode; |
The mode of the size group determines the directions in which the size
group effects the requested sizes of its component widgets.
gtk_size_group_set_mode ()
Sets the GtkSizeGroupMode of the size group. The mode of the size
group determines whether the widgets in the size group should
all have the same horizontal requisition (GTK_SIZE_GROUP_MODE_HORIZONTAL)
all have the same vertical requisition (GTK_SIZE_GROUP_MODE_VERTICAL),
or should all have the same requisition in both directions.
(GTK_SIZE_GROUP_MODE_BOTH).
gtk_size_group_add_widget ()
Adds a widget to a GtkSizeGroup. In the future, the requisition
of the widget will be determined as the maximum of its requisition
and the requisition of the other widgets in the size group.
Whether this applies horizontally, vertically, or in both directions
depends on the mode of the size group. See gtk_size_group_set_mode().
gtk_size_group_remove_widget ()
Removes a widget from a GtkSizeGroup.