3.7 KiB
STRUCT
Overlay
GtkOverlay 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@Gtk.Widget:halign] and [property@Gtk.Widget:valign]
properties. E.g. a widget with both alignments set to %GTK_ALIGN_START
will be placed at the top left corner of the GtkOverlay container,
whereas an overlay with halign set to %GTK_ALIGN_CENTER and valign set
to %GTK_ALIGN_END will be placed a the bottom edge of the GtkOverlay,
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@Gtk.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 GtkOverlay implementation of the GtkBuildable interface
supports placing a child as an overlay by specifying “overlay” as
the “type” attribute of a <child> element.
CSS nodes
GtkOverlay 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.
Properties
updateFunctions
Additional update functions for type extensions.
appearFunctions
Additional appear functions for type extensions.
accessibleRole
The accessible role of the given GtkAccessible implementation.
The accessible role cannot be changed once set.
child
The main child widget.
getChildPosition
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 %GTK_ALIGN_FILL will cause the overlay to
be full-width/height). If the main child is a
GtkScrolledWindow, the overlays are placed relative
to its contents.
overlay
The body for the widget "overlay".
app
The application.
window
The window.
Methods
init()
Initialize Overlay.
container(modifiers:)
Get the widget's view storage.
- Parameter modifiers: The view modifiers.
- Returns: The view storage.
update(_:modifiers:updateProperties:)
Update the widget's view storage.
- Parameters:
- storage: The view storage.
- modifiers: The view modifiers.
- updateProperties: Whether to update the view's properties.
accessibleRole(_:)
The accessible role of the given GtkAccessible implementation.
The accessible role cannot be changed once set.
child(_:)
The main child widget.
getChildPosition(_:)
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 %GTK_ALIGN_FILL will cause the overlay to
be full-width/height). If the main child is a
GtkScrolledWindow, the overlays are placed relative
to its contents.
overlay(_:)
Set the body for "overlay".
- Parameter body: The body.
- Returns: The widget.