Overlay

open class Overlay : Widget, OverlayProtocol

GtkOverlay is a container which contains a single main child, on top of which it can place “overlay” widgets.

An example GtkOverlay

The position of each overlay widget is determined by its [propertyGtk.Widget:halign] and [propertyGtk.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 [signalGtk.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.

The Overlay type acts as a reference-counted owner of an underlying GtkOverlay instance. It provides the methods that can operate on this data type through OverlayProtocol conformance. Use Overlay as a strong reference or owner of a GtkOverlay instance.

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  • Designated initialiser from the underlying `C` data type.

    This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the Overlay instance.

    Declaration

    Swift

    @inlinable
public init(_ op: UnsafeMutablePointer<GtkOverlay>)

    Parameters

    op

    pointer to the underlying object
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  • Designated initialiser from a constant pointer to the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the Overlay instance.

    Declaration

    Swift

    @inlinable
public init(_ op: UnsafePointer<GtkOverlay>)

    Parameters

    op

    pointer to the underlying object
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  • Optional initialiser from a non-mutating gpointer to the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the Overlay instance.

    Declaration

    Swift

    @inlinable
override public init!(gpointer op: gpointer?)

    Parameters

    op

    gpointer to the underlying object
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  • Optional initialiser from a non-mutating gconstpointer to the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the Overlay instance.

    Declaration

    Swift

    @inlinable
override public init!(gconstpointer op: gconstpointer?)

    Parameters

    op

    pointer to the underlying object
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  • Optional initialiser from a constant pointer to the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the Overlay instance.

    Declaration

    Swift

    @inlinable
public init!(_ op: UnsafePointer<GtkOverlay>?)

    Parameters

    op

    pointer to the underlying object
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  • Optional initialiser from the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the Overlay instance.

    Declaration

    Swift

    @inlinable
public init!(_ op: UnsafeMutablePointer<GtkOverlay>?)

    Parameters

    op

    pointer to the underlying object
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  • Designated initialiser from the underlying C data type. Will retain GtkOverlay. i.e., ownership is transferred to the Overlay instance.

    Declaration

    Swift

    @inlinable
public init(retaining op: UnsafeMutablePointer<GtkOverlay>)

    Parameters

    op

    pointer to the underlying object
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  • Reference intialiser for a related type that implements OverlayProtocol Will retain GtkOverlay.

    Declaration

    Swift

    @inlinable
public init<T>(overlay other: T) where T : OverlayProtocol

    Parameters

    other

    an instance of a related type that implements OverlayProtocol
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  • Unsafe typed initialiser. Do not use unless you know the underlying data type the pointer points to conforms to OverlayProtocol.

    Declaration

    Swift

    @inlinable
override public init<T>(cPointer p: UnsafeMutablePointer<T>)

    Parameters

    cPointer

    pointer to the underlying object
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  • Unsafe typed, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to OverlayProtocol.

    Declaration

    Swift

    @inlinable
override public init<T>(retainingCPointer cPointer: UnsafeMutablePointer<T>)

    Parameters

    cPointer

    pointer to the underlying object
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  • Unsafe untyped initialiser. Do not use unless you know the underlying data type the pointer points to conforms to OverlayProtocol.

    Declaration

    Swift

    @inlinable
override public init(raw p: UnsafeRawPointer)

    Parameters

    p

    raw pointer to the underlying object
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  • Unsafe untyped, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to OverlayProtocol.

    Declaration

    Swift

    @inlinable
override public init(retainingRaw raw: UnsafeRawPointer)
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  • Unsafe untyped initialiser. Do not use unless you know the underlying data type the pointer points to conforms to OverlayProtocol.

    Declaration

    Swift

    @inlinable
public required init(raw p: UnsafeMutableRawPointer)

    Parameters

    p

    mutable raw pointer to the underlying object
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  • Unsafe untyped, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to OverlayProtocol.

    Declaration

    Swift

    @inlinable
required public init(retainingRaw raw: UnsafeMutableRawPointer)

    Parameters

    raw

    mutable raw pointer to the underlying object
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  • Unsafe untyped initialiser. Do not use unless you know the underlying data type the pointer points to conforms to OverlayProtocol.

    Declaration

    Swift

    @inlinable
override public init(opaquePointer p: OpaquePointer)

    Parameters

    p

    opaque pointer to the underlying object
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  • Unsafe untyped, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to OverlayProtocol.

    Declaration

    Swift

    @inlinable
override public init(retainingOpaquePointer p: OpaquePointer)

    Parameters

    p

    opaque pointer to the underlying object
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  • Creates a new GtkOverlay.

    Declaration

    Swift

    @inlinable
public init()
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