Struct gtk4::SizeGroup

#[repr(transparent)]
pub struct SizeGroup { /* private fields */ }

SizeGroup 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 Grid.

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 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 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.

SizeGroup objects are referenced by each widget in the size group, so once you have added all widgets to a SizeGroup, 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 SizeGroupMode::Horizontal or SizeGroupMode::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 SizeGroupMode::Vertical or SizeGroupMode::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 SizeGroupMode::Vertical or SizeGroupMode::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 SizeGroup:

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

Properties

mode

The direction in which the size group affects requested sizes.

Readable | Writeable

Implements

glib::ObjectExt, BuildableExt

Implementations

impl SizeGroup

pub fn new(mode: SizeGroupMode) -> SizeGroup

Create a new SizeGroup.

mode

the mode for the new size group.

Returns

a newly created SizeGroup

pub fn add_widget(&self, widget: &impl IsA<Widget>)

Adds a widget to a SizeGroup.

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.

widget

the Widget to add

pub fn mode(&self) -> SizeGroupMode

Gets the current mode of the size group.

Returns

the current mode of the size group.

pub fn widgets(&self) -> Vec<Widget>

Returns the list of widgets associated with @self.

Returns

a GSList of widgets. The list is owned by GTK and should not be modified.

pub fn remove_widget(&self, widget: &impl IsA<Widget>)

Removes a widget from a SizeGroup.

widget

the Widget to remove

pub fn set_mode(&self, mode: SizeGroupMode)

Sets the SizeGroupMode 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 (SizeGroupMode::Horizontal) all have the same vertical requisition (SizeGroupMode::Vertical), or should all have the same requisition in both directions (SizeGroupMode::Both).

mode

the mode to set for the size group.

pub fn connect_mode_notify<F: Fn(&Self) + 'static>( &self, f: F ) -> SignalHandlerId

Trait Implementations

impl Clone for SizeGroup

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SizeGroup

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for SizeGroup

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl HasParamSpec for SizeGroup

type ParamSpec = ParamSpecObject

type SetValue = SizeGroup

Preferred value to be used as setter for the associated ParamSpec.

type BuilderFn = fn(_: &str) -> ParamSpecObjectBuilder<'_, SizeGroup>

fn param_spec_builder() -> Self::BuilderFn

impl Hash for SizeGroup

fn hash<H>(&self, state: &mut H)where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for SizeGroup

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl ParentClassIs for SizeGroup

type Parent = Object

impl<OT: ObjectType> PartialEq<OT> for SizeGroup

fn eq(&self, other: &OT) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<OT: ObjectType> PartialOrd<OT> for SizeGroup

fn partial_cmp(&self, other: &OT) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for SizeGroup

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for SizeGroup

impl IsA<Buildable> for SizeGroup