Class

GtkOverlay

Description [src]

final class Gtk.Overlay : Gtk.Widget
  implements Gtk.Accessible, Gtk.Buildable, Gtk.ConstraintTarget {
  /* No available fields */
}

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 GtkWidget:halign and GtkWidget: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 GtkOverlay::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.

Hierarchy

hierarchy this GtkOverlay implements_0 GtkAccessible this--implements_0 implements_1 GtkBuildable this--implements_1 implements_2 GtkConstraintTarget this--implements_2 ancestor_0 GtkWidget ancestor_0--this ancestor_1 GInitiallyUnowned ancestor_1--ancestor_0 ancestor_2 GObject ancestor_2--ancestor_1

Constructors

gtk_overlay_new

Creates a new GtkOverlay.

Instance methods

gtk_overlay_add_overlay

Adds widget to overlay.

gtk_overlay_get_child

Gets the child widget of overlay.

gtk_overlay_get_clip_overlay

Gets whether widget should be clipped within the parent.

gtk_overlay_get_measure_overlay

Gets whether widgets size is included in the measurement of overlay.

gtk_overlay_remove_overlay

Removes an overlay that was added with gtk_overlay_add_overlay().

gtk_overlay_set_child

Sets the child widget of overlay.

gtk_overlay_set_clip_overlay

Sets whether widget should be clipped within the parent.

gtk_overlay_set_measure_overlay

Sets whether widget is included in the measured size of overlay.

Methods inherited from GtkWidget (162)

Please see GtkWidget for a full list of methods.

Methods inherited from GObject (43)

Please see GObject for a full list of methods.

Methods inherited from GtkAccessible (19)
gtk_accessible_announce

Requests the user’s screen reader to announce the given message.

since: 4.14

gtk_accessible_get_accessible_parent

Retrieves the accessible parent for an accessible object.

since: 4.10

gtk_accessible_get_accessible_role

Retrieves the accessible role of an accessible object.

gtk_accessible_get_at_context

Retrieves the implementation for the given accessible object.

since: 4.10

gtk_accessible_get_bounds

Queries the coordinates and dimensions of this accessible.

since: 4.10

gtk_accessible_get_first_accessible_child

Retrieves the first accessible child of an accessible object.

since: 4.10

gtk_accessible_get_next_accessible_sibling

Retrieves the next accessible sibling of an accessible object.

since: 4.10

gtk_accessible_get_platform_state

Queries a platform state, such as focus.

since: 4.10

gtk_accessible_reset_property

Resets the accessible property to its default value.

gtk_accessible_reset_relation

Resets the accessible relation to its default value.

gtk_accessible_reset_state

Resets the accessible state to its default value.

gtk_accessible_set_accessible_parent

Sets the parent and sibling of an accessible object.

since: 4.10

gtk_accessible_update_next_accessible_sibling

Updates the next accessible sibling.

since: 4.10

gtk_accessible_update_property

Updates a list of accessible properties.

gtk_accessible_update_property_value

Updates an array of accessible properties.

gtk_accessible_update_relation

Updates a list of accessible relations.

gtk_accessible_update_relation_value

Updates an array of accessible relations.

gtk_accessible_update_state

Updates a list of accessible states.

gtk_accessible_update_state_value

Updates an array of accessible states.

Methods inherited from GtkBuildable (1)
gtk_buildable_get_buildable_id

Gets the ID of the buildable object.

Properties

Gtk.Overlay:child

The main child widget.

Properties inherited from GtkWidget (34)
Gtk.Widget:can-focus

Whether the widget or any of its descendents can accept the input focus.

Gtk.Widget:can-target

Whether the widget can receive pointer events.

Gtk.Widget:css-classes

A list of css classes applied to this widget.

Gtk.Widget:css-name

The name of this widget in the CSS tree.

Gtk.Widget:cursor

The cursor used by widget.

Gtk.Widget:focus-on-click

Whether the widget should grab focus when it is clicked with the mouse.

Gtk.Widget:focusable

Whether this widget itself will accept the input focus.

Gtk.Widget:halign

How to distribute horizontal space if widget gets extra space.

Gtk.Widget:has-default

Whether the widget is the default widget.

Gtk.Widget:has-focus

Whether the widget has the input focus.

Gtk.Widget:has-tooltip

Enables or disables the emission of the GtkWidget::query-tooltip signal on widget.

Gtk.Widget:height-request

Overrides for height request of the widget.

Gtk.Widget:hexpand

Whether to expand horizontally.

Gtk.Widget:hexpand-set

Whether to use the hexpand property.

Gtk.Widget:layout-manager

The GtkLayoutManager instance to use to compute the preferred size of the widget, and allocate its children.

Gtk.Widget:margin-bottom

Margin on bottom side of widget.

Gtk.Widget:margin-end

Margin on end of widget, horizontally.

Gtk.Widget:margin-start

Margin on start of widget, horizontally.

Gtk.Widget:margin-top

Margin on top side of widget.

Gtk.Widget:name

The name of the widget.

Gtk.Widget:opacity

The requested opacity of the widget.

Gtk.Widget:overflow

How content outside the widget’s content area is treated.

Gtk.Widget:parent

The parent widget of this widget.

Gtk.Widget:receives-default

Whether the widget will receive the default action when it is focused.

Gtk.Widget:root

The GtkRoot widget of the widget tree containing this widget.

Gtk.Widget:scale-factor

The scale factor of the widget.

Gtk.Widget:sensitive

Whether the widget responds to input.

Gtk.Widget:tooltip-markup

Sets the text of tooltip to be the given string, which is marked up with Pango markup.

Gtk.Widget:tooltip-text

Sets the text of tooltip to be the given string.

Gtk.Widget:valign

How to distribute vertical space if widget gets extra space.

Gtk.Widget:vexpand

Whether to expand vertically.

Gtk.Widget:vexpand-set

Whether to use the vexpand property.

Gtk.Widget:visible

Whether the widget is visible.

Gtk.Widget:width-request

Overrides for width request of the widget.

Properties inherited from GtkAccessible (1)
GtkAccessible:accessible-role

The accessible role of the given GtkAccessible implementation.

Signals

Gtk.Overlay::get-child-position

Emitted to determine the position and size of any overlay child widgets.

Signals inherited from GtkWidget (13)
GtkWidget::destroy

Signals that all holders of a reference to the widget should release the reference that they hold.

GtkWidget::direction-changed

Emitted when the text direction of a widget changes.

GtkWidget::hide

Emitted when widget is hidden.

GtkWidget::keynav-failed

Emitted if keyboard navigation fails.

GtkWidget::map

Emitted when widget is going to be mapped.

GtkWidget::mnemonic-activate

Emitted when a widget is activated via a mnemonic.

GtkWidget::move-focus

Emitted when the focus is moved.

GtkWidget::query-tooltip

Emitted when the widget’s tooltip is about to be shown.

GtkWidget::realize

Emitted when widget is associated with a GdkSurface.

GtkWidget::show

Emitted when widget is shown.

GtkWidget::state-flags-changed

Emitted when the widget state changes.

GtkWidget::unmap

Emitted when widget is going to be unmapped.

GtkWidget::unrealize

Emitted when the GdkSurface associated with widget is destroyed.

Signals inherited from GObject (1)
GObject::notify

The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.