Struct gtk::SizeGroup [−][src]
pub struct SizeGroup(_);
Expand description
SizeGroup 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 Grid widget.
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 SizeGroupExt::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. For
example, if you are packing your widgets into a table, you would not
include the GTK_FILL flag.
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 property::Label::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">GTK_SIZE_GROUP_HORIZONTAL</property>
<widgets>
<widget name="radio1"/>
<widget name="radio2"/>
</widgets>
</object>
Implements
SizeGroupExt, glib::ObjectExt, BuildableExt, BuildableExtManual
Implementations
Creates a new builder-pattern struct instance to construct SizeGroup objects.
This method returns an instance of SizeGroupBuilder which can be used to create SizeGroup objects.
Trait Implementations
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <=
operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
Returns the type identifier of Self.
Auto Trait Implementations
impl RefUnwindSafe for SizeGroupimpl UnwindSafe for SizeGroupBlanket Implementations
Mutably borrows from an owned value. Read more
Upcasts an object to a superclass or interface T. Read more
Upcasts an object to a reference of its superclass or interface T. Read more
Tries to downcast to a subclass or interface implementor T. Read more
Tries to downcast to a reference of its subclass or interface implementor T. Read more
Tries to cast to an object of type T. This handles upcasting, downcasting
and casting between interface and interface implementors. All checks are performed at
runtime, while downcast and upcast will do many checks at compile-time already. Read more
Tries to cast to reference to an object of type T. This handles upcasting, downcasting
and casting between interface and interface implementors. All checks are performed at
runtime, while downcast and upcast will do many checks at compile-time already. Read more
Casts to T unconditionally. Read more
Casts to &T unconditionally. Read more
Returns true if the object is an instance of (can be cast to) T.
pub fn set_properties_from_value(
&self,
property_values: &[(&str, Value)]
) -> Result<(), BoolError>pub fn set_property<'a, N, V>(
&self,
property_name: N,
value: V
) -> Result<(), BoolError> where
V: ToValue,
N: Into<&'a str>, pub fn set_property_from_value<'a, N>(
&self,
property_name: N,
value: &Value
) -> Result<(), BoolError> where
N: Into<&'a str>, Safety Read more
Safety Read more
Safety Read more
Safety Read more
pub fn connect_notify<F>(&self, name: Option<&str>, f: F) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec) + Send + Sync, pub fn connect_notify_local<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec), pub unsafe fn connect_notify_unsafe<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: Fn(&T, &ParamSpec), pub fn has_property<'a, N>(&self, property_name: N, type_: Option<Type>) -> bool where
N: Into<&'a str>, pub fn find_property<'a, N>(&self, property_name: N) -> Option<ParamSpec> where
N: Into<&'a str>, pub fn connect<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
F: Fn(&[Value]) -> Option<Value> + Send + Sync + 'static,
N: Into<&'a str>, Same as connect but takes a SignalId instead of a signal name.
pub fn connect_local<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
F: Fn(&[Value]) -> Option<Value> + 'static,
N: Into<&'a str>, Same as connect_local but takes a SignalId instead of a signal name.
pub unsafe fn connect_unsafe<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
F: Fn(&[Value]) -> Option<Value>,
N: Into<&'a str>, Same as connect_unsafe but takes a SignalId instead of a signal name.
Emit signal by signal id.
Emit signal with details by signal id.
Emit signal by it’s name.
pub fn bind_property<'a, O, N, M>(
&'a self,
source_property: N,
target: &'a O,
target_property: M
) -> BindingBuilder<'a> where
O: ObjectType,
N: Into<&'a str>,
M: Into<&'a str>, Same as emit but takes Value for the arguments.
Same as emit_by_name but takes Value for the arguments.
Returns a SendValue clone of self.
impl<'a, T, C> FromValueOptional<'a> for T where
C: ValueTypeChecker<Error = ValueTypeMismatchOrNoneError>,
T: FromValue<'a, Checker = C>,