Struct gtk4::Overlay [−][src]
pub struct Overlay(_);
Expand description
Overlay
is a container which contains a single main child, on top
of which it can place “overlay” widgets.
The position of each overlay widget is determined by its
property::Widget::halign
and property::Widget::valign
properties. E.g. a widget with both alignments set to Align::Start
will be placed at the top left corner of the Overlay
container,
whereas an overlay with halign set to Align::Center
and valign set
to Align::End
will be placed a the bottom edge of the Overlay
,
horizontally centered. The position can be adjusted by setting the margin
properties of the child to non-zero values.
More complicated placement of overlays is possible by connecting
to the signal::Overlay::get-child-position
signal.
An overlay’s minimum and natural sizes are those of its main child. The sizes of overlay children are not considered when measuring these preferred sizes.
GtkOverlay as GtkBuildable
The Overlay
implementation of the Buildable
interface
supports placing a child as an overlay by specifying “overlay” as
the “type” attribute of a <child>
element.
CSS nodes
Overlay
has a single CSS node with the name “overlay”. Overlay children
whose alignments cause them to be positioned at an edge get the style classes
“.left”, “.right”, “.top”, and/or “.bottom” according to their position.
Implements
WidgetExt
, glib::ObjectExt
, AccessibleExt
, BuildableExt
, ConstraintTargetExt
, WidgetExtManual
, AccessibleExtManual
Implementations
Creates a new builder-pattern struct instance to construct Overlay
objects.
This method returns an instance of OverlayBuilder
which can be used to create Overlay
objects.
Adds widget
to self
.
The widget will be stacked on top of the main widget
added with set_child()
.
The position at which widget
is placed is determined
from its property::Widget::halign
and
property::Widget::valign
properties.
widget
a Widget
to be added to the container
Sets whether widget
should be clipped within the parent.
widget
an overlay child of Overlay
clip_overlay
whether the child should be clipped
Sets whether widget
is included in the measured size of self
.
The overlay will request the size of the largest child that has
this property set to true
. Children who are not included may
be drawn outside of self
’s allocation if they are too large.
widget
an overlay child of Overlay
measure
whether the child should be measured
pub fn connect_get_child_position<F>(&self, f: F) -> SignalHandlerId where
F: Fn(&Self, &Widget) -> Option<Rectangle> + 'static,
pub fn connect_get_child_position<F>(&self, f: F) -> SignalHandlerId where
F: Fn(&Self, &Widget) -> Option<Rectangle> + 'static,
Emitted to determine the position and size of any overlay child widgets.
A handler for this signal should fill allocation
with
the desired position and size for widget
, relative to
the ‘main’ child of overlay
.
The default handler for this signal uses the widget
’s
halign and valign properties to determine the position
and gives the widget its natural size (except that an
alignment of Align::Fill
will cause the overlay to
be full-width/height). If the main child is a
ScrolledWindow
, the overlays are placed relative
to its contents.
widget
the child widget to position
Returns
true
if the allocation
has been filled
allocation
return location for the allocation
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 Overlay
impl UnwindSafe for Overlay
Blanket 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_property<'a, N, V>(
&self,
property_name: N,
value: V
) -> Result<(), BoolError> where
N: Into<&'a str>,
V: ToValue,
pub fn set_property_from_value<'a, N>(
&self,
property_name: N,
value: &Value
) -> Result<(), BoolError> where
N: Into<&'a str>,
pub fn set_properties_from_value(
&self,
property_values: &[(&str, Value)]
) -> Result<(), BoolError>
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>,
Safety Read more
Safety Read more
Safety Read more
Safety Read more
pub fn connect<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
N: Into<&'a str>,
F: 'static + Fn(&[Value]) -> Option<Value> + Send + Sync,
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
N: Into<&'a str>,
F: 'static + Fn(&[Value]) -> Option<Value>,
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
N: Into<&'a str>,
F: Fn(&[Value]) -> Option<Value>,
Same as connect_unsafe
but takes a SignalId
instead of a signal name.
Emit signal by signal id.
Same as emit
but takes Value
for the arguments.
Emit signal by its name.
Same as emit_by_name
but takes Value
for the arguments.
Emit signal with details by signal id.
Same as emit_with_details
but takes Value
for the arguments.
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 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>,
Returns a SendValue
clone of self
.