SizeGroup

class SizeGroup(**properties: Any)

Superclasses: Object

Implemented Interfaces: Buildable

GtkSizeGroup groups widgets together so they all request the same size.

This is typically useful when you want a column of widgets to have the same size, but you can’t use a GtkGrid.

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 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.

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 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 HORIZONTAL or 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 VERTICAL or BOTH.

Note that only non-contextual sizes of every widget are ever consulted by size groups (since size groups have no knowledge of what size a widget will be allocated in one dimension, it cannot derive how much height a widget will receive for a given width). When grouping widgets that trade height for width in mode VERTICAL or BOTH: the height for the minimum width will be the requested height for all widgets in the group. The same is of course true when horizontally grouping width for height widgets.

Widgets that trade height-for-width should set a reasonably large minimum width by way of width_chars for instance. Widgets with static sizes as well as widgets that grow (such as ellipsizing text) need no such considerations.

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.

An example of a UI definition fragment with GtkSizeGroup:

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

Constructors

class SizeGroup

classmethod new(mode: SizeGroupMode) → SizeGroup

Create a new GtkSizeGroup.

Parameters:

mode – the mode for the new size group.

Methods

class SizeGroup

add_widget(widget: Widget) → None

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 set_mode.

When the widget is destroyed or no longer referenced elsewhere, it will be removed from the size group.

Parameters:

widget – the GtkWidget to add

get_mode() → SizeGroupMode

Gets the current mode of the size group.

get_widgets() → list[Widget]

Returns the list of widgets associated with size_group.

remove_widget(widget: Widget) → None

Removes a widget from a GtkSizeGroup.

Parameters:

widget – the GtkWidget to remove

set_mode(mode: SizeGroupMode) → None

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 (HORIZONTAL) all have the same vertical requisition (VERTICAL), or should all have the same requisition in both directions (BOTH).

Parameters:

mode – the mode to set for the size group.

Properties

class SizeGroup

props.mode: SizeGroupMode

The type of the None singleton.

Fields

class SizeGroup

parent_instance