Gtk

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Description:

Content:

Classes:

• ATContext - `GtkATContext` is an abstract class provided by GTK to communicate to platform-specific assistive technologies API.
• AboutDialog - The `GtkAboutDialog` offers a simple way to display information about a program.
• ActionBar - `GtkActionBar` is designed to present contextual actions.
• ActivateAction - A `GtkShortcutAction` that calls activate.
• Adjustment - `GtkAdjustment` is a model for a numeric value.
• AlternativeTrigger - A `GtkShortcutTrigger` that combines two triggers.
• AnyFilter - `GtkAnyFilter` matches an item when at least one of its filters matches.
• AppChooserButton - The `GtkAppChooserButton` lets the user select an application.
• AppChooserDialog - `GtkAppChooserDialog` shows a `GtkAppChooserWidget` inside a `GtkDialog`.
• AppChooserWidget - `GtkAppChooserWidget` is a widget for selecting applications.
• Application - `GtkApplication` is a high-level API for writing applications.
• ApplicationWindow - `GtkApplicationWindow` is a `GtkWindow` subclass that integrates with `GtkApplication`.
• AspectFrame - `GtkAspectFrame` preserves the aspect ratio of its child.
• Assistant - `GtkAssistant` is used to represent a complex as a series of steps.
• AssistantPage - `GtkAssistantPage` is an auxiliary object used by `GtkAssistant.
• BinLayout - `GtkBinLayout` is a `GtkLayoutManager` subclass useful for create "bins" of widgets.
• Bitset - A `GtkBitset` represents a set of unsigned integers.
• BookmarkList - `GtkBookmarkList` is a list model that wraps `GBookmarkFile`.
• BoolFilter - `GtkBoolFilter` evaluates a boolean `GtkExpression` to determine whether to include items.
• Box - The `GtkBox` widget arranges child widgets into a single row or column.
• BoxLayout - `GtkBoxLayout` is a layout manager that arranges children in a single row or column.
• BuildableParseContext - An opaque context struct for `GtkBuildableParser`.
• Builder - A `GtkBuilder` reads XML descriptions of a user interface and instantiates the described objects.
• BuilderCScope - A `GtkBuilderScope` implementation for the C language.
• BuilderListItemFactory - `GtkBuilderListItemFactory` is a `GtkListItemFactory` that creates widgets by instantiating `GtkBuilder` UI templates.
• Button - The `GtkButton` widget is generally used to trigger a callback function that is called when the button is pressed.
• CClosureExpression - A variant of `GtkClosureExpression` using a C closure.
• Calendar - `GtkCalendar` is a widget that displays a Gregorian calendar, one month at a time.
• CallbackAction - A `GtkShortcutAction` that invokes a callback.
• CellArea - An abstract class for laying out `GtkCellRenderer`s
• CellAreaBox - A cell area that renders GtkCellRenderers into a row or a column
• CellAreaContext - Stores geometrical information for a series of rows in a GtkCellArea
• CellRenderer - An object for rendering a single cell
• CellRendererAccel - Renders a keyboard accelerator in a cell
• CellRendererCombo - Renders a combobox in a cell
• CellRendererPixbuf - Renders a pixbuf in a cell
• CellRendererProgress - Renders numbers as progress bars
• CellRendererSpin - Renders a spin button in a cell
• CellRendererSpinner - Renders a spinning animation in a cell
• CellRendererText - Renders text in a cell
• CellRendererToggle - Renders a toggle button in a cell
• CellView - A widget displaying a single row of a GtkTreeModel
• CenterBox - `GtkCenterBox` arranges three children in a row, keeping the middle child centered as well as possible.
• CenterLayout - `GtkCenterLayout` is a layout manager that manages up to three children.
• CheckButton - A `GtkCheckButton` places a label next to an indicator.
• ClosureExpression - An expression using a custom `GClosure` to compute the value from its parameters.
• ColorButton - The `GtkColorButton` allows to open a color chooser dialog to change the color.
• ColorChooserDialog - A dialog for choosing a color.
• ColorChooserWidget - The `GtkColorChooserWidget` widget lets the user select a color.
• ColumnView - `GtkColumnView` presents a large dynamic list of items using multiple columns with headers.
• ColumnViewColumn - `GtkColumnViewColumn` represents the columns being added to `GtkColumnView`.
• ComboBox - A `GtkComboBox` is a widget that allows the user to choose from a list of valid choices.
• ComboBoxText - A `GtkComboBoxText` is a simple variant of `GtkComboBox` for text-only use cases.
• ConstantExpression - A constant value in a `GtkExpression`.
• Constraint - `GtkConstraint` describes a constraint between attributes of two widgets, expressed as a linear equation.
• ConstraintGuide - A `GtkConstraintGuide` is an invisible layout element in a `GtkConstraintLayout`.
• ConstraintLayout - A layout manager using constraints to describe relations between widgets.
• ConstraintLayoutChild - `GtkLayoutChild` subclass for children in a `GtkConstraintLayout`.
• CssProvider - `GtkCssProvider` is an object implementing the `GtkStyleProvider` interface for CSS.
• CssSection - Defines a part of a CSS document.
• CssStyleChange
• CustomFilter - `GtkCustomFilter` determines whether to include items with a callback.
• CustomLayout - `GtkCustomLayout` uses closures for size negotiation.
• CustomSorter - `GtkCustomSorter` is a `GtkSorter` implementation that sorts via a callback function.
• Dialog - Dialogs are a convenient way to prompt the user for a small amount of input.
• DirectoryList - `GtkDirectoryList` is a list model that wraps enumerate_children_async.
• DragIcon - `GtkDragIcon` is a `GtkRoot` implementation for drag icons.
• DragSource - `GtkDragSource` is an event controller to initiate Drag-And-Drop operations.
• DrawingArea - `GtkDrawingArea` is a widget that allows drawing with cairo.
• DropControllerMotion - `GtkDropControllerMotion` is an event controller tracking the pointer during Drag-and-Drop operations.
• DropDown - `GtkDropDown` is a widget that allows the user to choose an item from a list of options.
• DropTarget - `GtkDropTarget` is an event controller to receive Drag-and-Drop operations.
• DropTargetAsync - `GtkDropTargetAsync` is an event controller to receive Drag-and-Drop operations, asynchronously.
• EditableLabel - A `GtkEditableLabel` is a label that allows users to edit the text by switching to an “edit mode”.
• EmojiChooser - The `GtkEmojiChooser` is used by text widgets such as `GtkEntry` or `GtkTextView` to let users insert Emoji characters.
• Entry - `GtkEntry` is a single line text entry widget.
• EntryBuffer - A `GtkEntryBuffer` hold the text displayed in a `GtkText` widget.
• EntryCompletion - `GtkEntryCompletion` is an auxiliary object to provide completion functionality for `GtkEntry`.
• EventController - `GtkEventController` is the base class for event controllers.
• EventControllerFocus - `GtkEventControllerFocus` is an event controller to keep track of keyboard focus.
• EventControllerKey - `GtkEventControllerKey` is an event controller that provides access to key events.
• EventControllerLegacy - `GtkEventControllerLegacy` is an event controller that provides raw access to the event stream.
• EventControllerMotion - `GtkEventControllerMotion` is an event controller tracking the pointer position.
• EventControllerScroll - `GtkEventControllerScroll` is an event controller that handles scroll events.
• EveryFilter - `GtkEveryFilter` matches an item when each of its filters matches.
• Expander - `GtkExpander` allows the user to reveal its child by clicking on an expander triangle.
• Expression - `GtkExpression` provides a way to describe references to values.
• ExpressionWatch - An opaque structure representing a watched `GtkExpression`.
• FileChooserDialog - `GtkFileChooserDialog` is a dialog suitable for use with “File Open” or “File Save” commands.
• FileChooserNative - `GtkFileChooserNative` is an abstraction of a dialog suitable for use with “File Open” or “File Save as” commands.
• FileChooserWidget - `GtkFileChooserWidget` is a widget for choosing files.
• FileFilter - `GtkFileFilter` filters files by name or mime type.
• Filter - A `GtkFilter` object describes the filtering to be performed by a [class@Gtk.
• FilterListModel - `GtkFilterListModel` is a list model that filters the elements of the underlying model according to a `GtkFilter`.
• Fixed - `GtkFixed` places its child widgets at fixed positions and with fixed sizes.
• FixedLayout - `GtkFixedLayout` is a layout manager which can place child widgets at fixed positions.
• FixedLayoutChild - `GtkLayoutChild` subclass for children in a `GtkFixedLayout`.
• FlattenListModel - `GtkFlattenListModel` is a list model that concatenates other list models.
• FlowBox - A `GtkFlowBox` puts child widgets in reflowing grid.
• FlowBoxChild - `GtkFlowBoxChild` is the kind of widget that can be added to a `GtkFlowBox`.
• FontButton - The `GtkFontButton` allows to open a font chooser dialog to change the font.
• FontChooserDialog - The `GtkFontChooserDialog` widget is a dialog for selecting a font.
• FontChooserWidget - The `GtkFontChooserWidget` widget lets the user select a font.
• Frame - `GtkFrame` is a widget that surrounds its child with a decorative frame and an optional label.
• GLArea - `GtkGLArea` is a widget that allows drawing with OpenGL.
• Gesture - `GtkGesture` is the base class for gesture recognition.
• GestureClick - `GtkGestureClick` is a `GtkGesture` implementation for clicks.
• GestureDrag - `GtkGestureDrag` is a `GtkGesture` implementation for drags.
• GestureLongPress - `GtkGestureLongPress` is a `GtkGesture` for long presses.
• GesturePan - `GtkGesturePan` is a `GtkGesture` for pan gestures.
• GestureRotate - `GtkGestureRotate` is a `GtkGesture` for 2-finger rotations.
• GestureSingle - `GtkGestureSingle` is a `GtkGestures` subclass optimized for singe-touch and mouse gestures.
• GestureStylus - `GtkGestureStylus` is a `GtkGesture` specific to stylus input.
• GestureSwipe - `GtkGestureSwipe` is a `GtkGesture` for swipe gestures.
• GestureZoom - `GtkGestureZoom` is a `GtkGesture` for 2-finger pinch/zoom gestures.
• Grid - `GtkGrid` is a container which arranges its child widgets in rows and columns.
• GridLayout - `GtkGridLayout` is a layout manager which arranges child widgets in rows and columns.
• GridLayoutChild - `GtkLayoutChild` subclass for children in a `GtkGridLayout`.
• GridView - `GtkGridView` presents a large dynamic grid of items.
• HeaderBar - `GtkHeaderBar` is a widget for creating custom title bars for windows.
• IMContext - `GtkIMContext` defines the interface for GTK input methods.
• IMContextSimple - `GtkIMContextSimple` is an input method supporting table-based input methods.
• IMMulticontext - `GtkIMMulticontext` is an input method context supporting multiple, switchable input methods.
• IconPaintable - Contains information found when looking up an icon in `GtkIconTheme`.
• IconTheme - `GtkIconTheme` provides a facility for loading themed icons.
• IconView - `GtkIconView` is a widget which displays data in a grid of icons.
• Image - The `GtkImage` widget displays an image.
• InfoBar - `GtkInfoBar` can be show messages to the user without a dialog.
• Inscription - `GtkInscription` is a widget to show text in a predefined area.
• KeyvalTrigger - A `GtkShortcutTrigger` that triggers when a specific keyval and modifiers are pressed.
• Label - The `GtkLabel` widget displays a small amount of text.
• LayoutChild - `GtkLayoutChild` is the base class for objects that are meant to hold layout properties.
• LayoutManager - Layout managers are delegate classes that handle the preferred size and the allocation of a widget.
• LevelBar - `GtkLevelBar` is a widget that can be used as a level indicator.
• LinkButton - A `GtkLinkButton` is a button with a hyperlink.
• ListBase - `GtkListBase` is the abstract base class for GTK's list widgets.
• ListBox - `GtkListBox` is a vertical list.
• ListBoxRow - `GtkListBoxRow` is the kind of widget that can be added to a `GtkListBox`.
• ListItem - `GtkListItem` is used by list widgets to represent items in a `GListModel`.
• ListItemFactory - A `GtkListItemFactory` creates widgets for the items taken from a `GListModel`.
• ListStore - A list-like data structure that can be used with the [class@Gtk.
• ListView - `GtkListView` presents a large dynamic list of items.
• LockButton - `GtkLockButton` is a widget to obtain and revoke authorizations needed to operate the controls.
• MapListModel - A `GtkMapListModel` maps the items in a list model to different items.
• MediaControls - `GtkMediaControls` is a widget to show controls for a video.
• MediaFile - `GtkMediaFile` implements `GtkMediaStream` for files.
• MediaStream - `GtkMediaStream` is the integration point for media playback inside GTK.
• MenuButton - The `GtkMenuButton` widget is used to display a popup when clicked.
• MessageDialog - `GtkMessageDialog` presents a dialog with some message text.
• MnemonicAction - A `GtkShortcutAction` that calls mnemonic_activate.
• MnemonicTrigger - A `GtkShortcutTrigger` that triggers when a specific mnemonic is pressed.
• MountOperation - `GtkMountOperation` is an implementation of `GMountOperation`.
• MultiFilter - `GtkMultiFilter` is the base class for filters that combine multiple filters.
• MultiSelection - `GtkMultiSelection` is a `GtkSelectionModel` that allows selecting multiple elements.
• MultiSorter - `GtkMultiSorter` combines multiple sorters by trying them in turn.
• NamedAction - A `GtkShortcutAction` that activates an action by name.
• NativeDialog - Native dialogs are platform dialogs that don't use `GtkDialog`.
• NeverTrigger - A `GtkShortcutTrigger` that never triggers.
• NoSelection - `GtkNoSelection` is a `GtkSelectionModel` that does not allow selecting anything.
• Notebook - `GtkNotebook` is a container whose children are pages switched between using tabs.
• NotebookPage - `GtkNotebookPage` is an auxiliary object used by `GtkNotebook`.
• NothingAction - A `GtkShortcutAction` that does nothing.
• NumericSorter - `GtkNumericSorter` is a `GtkSorter` that compares numbers.
• ObjectExpression - A `GObject` value in a `GtkExpression`.
• Overlay - `GtkOverlay` is a container which contains a single main child, on top of which it can place “overlay” widgets.
• OverlayLayout - `GtkOverlayLayout` is the layout manager used by `GtkOverlay`.
• OverlayLayoutChild - `GtkLayoutChild` subclass for children in a `GtkOverlayLayout`.
• PadController - `GtkPadController` is an event controller for the pads found in drawing tablets.
• PageSetup - A `GtkPageSetup` object stores the page size, orientation and margins.
• Paned - A widget with two panes, arranged either horizontally or vertically.
• PaperSize - `GtkPaperSize` handles paper sizes.
• ParamSpecExpression - A `GParamSpec` for properties holding a `GtkExpression`.
• PasswordEntry - `GtkPasswordEntry` is an entry that has been tailored for entering secrets.
• PasswordEntryBuffer - A `GtkEntryBuffer` that locks the underlying memory to prevent it from being swapped to disk.
• Picture - The `GtkPicture` widget displays a `GdkPaintable`.
• Popover - `GtkPopover` is a bubble-like context popup.
• PopoverMenu - `GtkPopoverMenu` is a subclass of `GtkPopover` that implements menu behavior.
• PopoverMenuBar - `GtkPopoverMenuBar` presents a horizontal bar of items that pop up popover menus when clicked.
• PrintContext - A `GtkPrintContext` encapsulates context information that is required when drawing pages for printing.
• PrintOperation - `GtkPrintOperation` is the high-level, portable printing API.
• PrintSettings - A `GtkPrintSettings` object represents the settings of a print dialog in a system-independent way.
• ProgressBar - `GtkProgressBar` is typically used to display the progress of a long running operation.
• PropertyExpression - A `GObject` property value in a `GtkExpression`.
• Range - `GtkRange` is the common base class for widgets which visualize an adjustment.
• RecentInfo - `GtkRecentInfo` contains the metadata associated with an item in the recently used files list.
• RecentManager - `GtkRecentManager` manages and looks up recently used files.
• Revealer - A `GtkRevealer` animates the transition of its child from invisible to visible.
• Scale - A `GtkScale` is a slider control used to select a numeric value.
• ScaleButton - `GtkScaleButton` provides a button which pops up a scale widget.
• Scrollbar - The `GtkScrollbar` widget is a horizontal or vertical scrollbar.
• ScrolledWindow - `GtkScrolledWindow` is a container that makes its child scrollable.
• SearchBar - `GtkSearchBar` is a container made to have a search entry.
• SearchEntry - `GtkSearchEntry` is an entry widget that has been tailored for use as a search entry.
• SelectionFilterModel - `GtkSelectionFilterModel` is a list model that presents the selection from a `GtkSelectionModel`.
• Separator - `GtkSeparator` is a horizontal or vertical separator widget.
• Settings - `GtkSettings` provides a mechanism to share global settings between applications.
• Shortcut - A `GtkShortcut` describes a keyboard shortcut.
• ShortcutAction - `GtkShortcutAction` encodes an action that can be triggered by a keyboard shortcut.
• ShortcutController - `GtkShortcutController` is an event controller that manages shortcuts.
• ShortcutLabel - `GtkShortcutLabel` displays a single keyboard shortcut or gesture.
• ShortcutTrigger - `GtkShortcutTrigger` tracks how a `GtkShortcut` should be activated.
• ShortcutsGroup - A `GtkShortcutsGroup` represents a group of related keyboard shortcuts or gestures.
• ShortcutsSection - A `GtkShortcutsSection` collects all the keyboard shortcuts and gestures for a major application mode.
• ShortcutsShortcut - A `GtkShortcutsShortcut` represents a single keyboard shortcut or gesture with a short text.
• ShortcutsWindow - A `GtkShortcutsWindow` shows information about the keyboard shortcuts and gestures of an application.
• SignalAction - A `GtkShortcut`Action that emits a signal.
• SignalListItemFactory - `GtkSignalListItemFactory` is a `GtkListItemFactory` that emits signals to to manage listitems.
• SingleSelection - `GtkSingleSelection` is a `GtkSelectionModel` that allows selecting a single item.
• SizeGroup - `GtkSizeGroup` groups widgets together so they all request the same size.
• SliceListModel - `GtkSliceListModel` is a list model that presents a slice of another model.
• Snapshot - `GtkSnapshot` assists in creating [class@Gsk.
• SortListModel - A `GListModel` that sorts the elements of an underlying model according to a `GtkSorter`.
• Sorter - `GtkSorter` is an object to describe sorting criteria.
• SpinButton - A `GtkSpinButton` is an ideal way to allow the user to set the value of some attribute.
• Spinner - A `GtkSpinner` widget displays an icon-size spinning animation.
• Stack - `GtkStack` is a container which only shows one of its children at a time.
• StackPage - `GtkStackPage` is an auxiliary class used by `GtkStack`.
• StackSidebar - A `GtkStackSidebar` uses a sidebar to switch between `GtkStack` pages.
• StackSwitcher - The `GtkStackSwitcher` shows a row of buttons to switch between `GtkStack` pages.
• Statusbar - A `GtkStatusbar` widget is usually placed along the bottom of an application's main [class@Gtk.
• StringFilter - `GtkStringFilter` determines whether to include items by comparing strings to a fixed search term.
• StringList - `GtkStringList` is a list model that wraps an array of strings.
• StringObject - `GtkStringObject` is the type of items in a `GtkStringList`.
• StringSorter - `GtkStringSorter` is a `GtkSorter` that compares strings.
• StyleContext - `GtkStyleContext` stores styling information affecting a widget.
• Switch - `GtkSwitch` is a "light switch" that has two states: on or off.
• Text - The `GtkText` widget is a single-line text entry widget.
• TextBuffer - Stores text and attributes for display in a `GtkTextView`.
• TextChildAnchor - A `GtkTextChildAnchor` is a spot in a `GtkTextBuffer` where child widgets can be “anchored”.
• TextMark - A `GtkTextMark` is a position in a `GtkTextbuffer` that is preserved across modifications.
• TextTag - A tag that can be applied to text contained in a `GtkTextBuffer`.
• TextTagTable - The collection of tags in a `GtkTextBuffer`
• TextView - A widget that displays the contents of a [ class@Gtk.
• ToggleButton - A `GtkToggleButton` is a button which remains “pressed-in” when clicked.
• Tooltip - `GtkTooltip` is an object representing a widget tooltip.
• TreeExpander - `GtkTreeExpander` is a widget that provides an expander for a list.
• TreeListModel - `GtkTreeListModel` is a list model that can create child models on demand.
• TreeListRow - `GtkTreeListRow` is used by `GtkTreeListModel` to represent items.
• TreeListRowSorter - `GtkTreeListRowSorter` is a special-purpose sorter that will apply a given sorter to the levels in a tree.
• TreeModelFilter - A `GtkTreeModel` which hides parts of an underlying tree model
• TreeModelSort - A GtkTreeModel which makes an underlying tree model sortable
• TreePath - An opaque structure representing a path to a row in a model.
• TreeRowData
• TreeRowReference - A GtkTreeRowReference tracks model changes so that it always refers to the same row (a `GtkTreePath` refers to a position, not a fixed row).
• TreeSelection - The selection object for GtkTreeView
• TreeStore - A tree-like data structure that can be used with the GtkTreeView
• TreeView - A widget for displaying both trees and lists
• TreeViewColumn - A visible column in a [class@Gtk.
• Video - `GtkVideo` is a widget to show a `GtkMediaStream` with media controls.
• Viewport - `GtkViewport` implements scrollability for widgets that lack their own scrolling capabilities.
• VolumeButton - `GtkVolumeButton` is a `GtkScaleButton` subclass tailored for volume control.
• Widget - The base class for all widgets.
• WidgetPaintable - `GtkWidgetPaintable` is a `GdkPaintable` that displays the contents of a widget.
• Window - A `GtkWindow` is a toplevel window which can contain other widgets.
• WindowControls - `GtkWindowControls` shows window frame controls.
• WindowGroup - `GtkWindowGroup` makes group of windows behave like separate applications.
• WindowHandle - `GtkWindowHandle` is a titlebar area widget.

Structs:

• Allocation - The rectangle representing the area allocated for a widget by its parent.
• BitsetIter - An opaque, stack-allocated struct for iterating over the elements of a `GtkBitset`.
• Border - A struct that specifies a border around a rectangular area.
• BuildableParser - A sub-parser for `GtkBuildable` implementations.
• CssLocation - Represents a location in a file or other source of data parsed by the CSS engine.
• PadActionEntry - Struct defining a pad action entry.
• PageRange - A range of pages to print.
• RecentData - Meta-data to be passed to add_full when registering a recently used resource.
• RequestedSize - Represents a request of a screen object in a given orientation.
• Requisition - A `GtkRequisition` represents the desired size of a widget.
• TextIter - An iterator for the contents of a `GtkTextBuffer`.
• TreeIter - The `GtkTreeIter` is the primary structure for accessing a `GtkTreeModel`.

Enums:

• AccessibleAutocomplete - The possible values for the gtk_accessible_property_autocomplete accessible property.
• AccessibleInvalidState - The possible values for the gtk_accessible_state_invalid accessible state.
• AccessibleProperty - The possible accessible properties of a [iface@Accessible].
• AccessibleRelation - The possible accessible relations of a [iface@Accessible].
• AccessibleRole - The accessible role for a [ iface@Accessible] implementation.
• AccessibleSort - The possible values for the gtk_accessible_property_sort accessible property.
• AccessibleState - The possible accessible states of a [iface@Accessible].
• AccessibleTristate - The possible values for the gtk_accessible_state_pressed accessible state.
• Align - Controls how a widget deals with extra space in a single dimension.
• ApplicationInhibitFlags - Types of user actions that may be blocked by `GtkApplication`.
• ArrowType - Used to indicate the direction in which an arrow should point.
• AssistantPageType - Determines the page role inside a `GtkAssistant`.
• BaselinePosition - Baseline position in a row of widgets.
• BorderStyle - Describes how the border of a UI element should be rendered.
• BuilderClosureFlags - The list of flags that can be passed to create_closure.
• ButtonsType - Prebuilt sets of buttons for `GtkDialog`.
• CellRendererAccelMode - The available modes for [property@Gtk.
• CellRendererMode - Identifies how the user can interact with a particular cell.
• CellRendererState - Tells how a cell is to be rendered.
• ConstraintAttribute - The widget attributes that can be used when creating a [class@Constraint].
• ConstraintRelation - The relation between two terms of a constraint.
• ConstraintStrength - The strength of a constraint, expressed as a symbolic constant.
• ContentFit - Controls how a content should be made to fit inside an allocation.
• CornerType - Specifies which corner a child widget should be placed in when packed into a `GtkScrolledWindow.
• CssParserWarning - Warnings that can occur while parsing CSS.
• DebugFlags - Flags to use with set_debug_flags.
• DeleteType - Passed to various keybinding signals for deleting text.
• DialogFlags - Flags used to influence dialog construction.
• DirectionType - Focus movement types.
• EditableProperties - The identifiers for [ iface@Gtk.
• EntryIconPosition - Specifies the side of the entry at which an icon is placed.
• EventControllerScrollFlags - Describes the behavior of a `GtkEventControllerScroll`.
• EventSequenceState - Describes the state of a [ struct@Gdk.
• FileChooserAction - Describes whether a `GtkFileChooser` is being used to open existing files or to save to a possibly new file.
• FilterChange - Describes changes in a filter in more detail and allows objects using the filter to optimize refiltering items.
• FilterMatch - Describes the known strictness of a filter.
• FontChooserLevel - Specifies the granularity of font selection that is desired in a `GtkFontChooser`.
• IconLookupFlags - Used to specify options for lookup_icon.
• IconSize - Built-in icon sizes.
• IconViewDropPosition - An enum for determining where a dropped item goes.
• ImageType - Describes the image data representation used by a [class@Gtk.
• InputHints - Describes hints that might be taken into account by input methods or applications.
• InputPurpose - Describes primary purpose of the input widget.
• InscriptionOverflow - The different methods to handle text in Inscription when it doesn't fit the available space.
• Justification - Used for justifying the text inside a [class@Label] widget.
• LevelBarMode - Describes how [class@LevelBar] contents should be rendered.
• License - The type of license for an application.
• MessageType - The type of message being displayed in a [ class@MessageDialog].
• MovementStep - Passed as argument to various keybinding signals for moving the cursor position.
• NaturalWrapMode - Options for selecting a different wrap mode for natural size requests.
• NotebookTab - The parameter used in the action signals of `GtkNotebook`.
• NumberUpLayout - Used to determine the layout of pages on a sheet when printing multiple pages per sheet.
• Ordering - Describes the way two values can be compared.
• Orientation - Represents the orientation of widgets and other objects.
• Overflow - Defines how content overflowing a given area should be handled.
• PackType - Represents the packing location of a children in its parent.
• PadActionType - The type of a pad action.
• PageOrientation - See also set_orientation.
• PageSet - See also gtk_print_job_set_page_set.
• PanDirection - Describes the panning direction of a [ class@GesturePan].
• PickFlags - Flags that influence the behavior of [ method@Widget.
• PolicyType - Determines how the size should be computed to achieve the one of the visibility mode for the scrollbars.
• PopoverMenuFlags - Flags that affect how popover menus are created from a menu model.
• PositionType - Describes which edge of a widget a certain feature is positioned at.
• PrintDuplex - See also set_duplex.
• PrintOperationAction - Determines what action the print operation should perform.
• PrintOperationResult - The result of a print operation.
• PrintPages - See also gtk_print_job_set_pages
• PrintQuality - See also set_quality.
• PrintStatus - The status gives a rough indication of the completion of a running print operation.
• PropagationLimit - Describes limits of a [ class@EventController] for handling events targeting other widgets.
• PropagationPhase - Describes the stage at which events are fed into a [class@EventController].
• ResponseType - Predefined values for use as response ids in add_button.
• RevealerTransitionType - These enumeration values describe the possible transitions when the child of a `GtkRevealer` widget is shown or hidden.
• ScrollStep - Passed as argument to various keybinding signals.
• ScrollType - Scrolling types.
• ScrollablePolicy - Defines the policy to be used in a scrollable widget when updating the scrolled window adjustments in a given orientation.
• SelectionMode - Used to control what selections users are allowed to make.
• SensitivityType - Determines how GTK handles the sensitivity of various controls, such as combo box buttons.
• ShortcutActionFlags - List of flags that can be passed to action activation.
• ShortcutScope - Describes where [class@Shortcut]s added to a [class@ShortcutController] get handled.
• ShortcutType - GtkShortcutType specifies the kind of shortcut that is being described.
• SizeGroupMode - The mode of the size group determines the directions in which the size group affects the requested sizes of its component widgets.
• SizeRequestMode - Specifies a preference for height-for-width or width-for-height geometry management.
• SortType - Determines the direction of a sort.
• SorterChange - Describes changes in a sorter in more detail and allows users to optimize resorting.
• SorterOrder - Describes the type of order that a `GtkSorter` may produce.
• SpinButtonUpdatePolicy - Determines whether the spin button displays values outside the adjustment bounds.
• SpinType - The values of the GtkSpinType enumeration are used to specify the change to make in spin.
• StackTransitionType - Possible transitions between pages in a `GtkStack` widget.
• StateFlags - Describes a widget state.
• StringFilterMatchMode - Specifies how search strings are matched inside text.
• StyleContextPrintFlags - Flags that modify the behavior of to_string.
• SymbolicColor - The indexes of colors passed to symbolic color rendering, such as [vfunc@Gtk.
• SystemSetting - Values that can be passed to the [ vfunc@Gtk.
• TextDirection - Reading directions for text.
• TextExtendSelection - Granularity types that extend the text selection.
• TextSearchFlags - Flags affecting how a search is done.
• TextViewLayer - Used to reference the layers of `GtkTextView` for the purpose of customized drawing with the ::snapshot_layer vfunc.
• TextWindowType - Used to reference the parts of `GtkTextView`.
• TreeModelFlags - These flags indicate various properties of a `GtkTreeModel`.
• TreeViewColumnSizing - The sizing method the column uses to determine its width.
• TreeViewDropPosition - An enum for determining where a dropped row goes.
• TreeViewGridLines - Used to indicate which grid lines to draw in a tree view.
• Unit - See also set_paper_width.
• WrapMode - Describes a type of line wrapping.

Constants:

• public const int ACCESSIBLE_VALUE_UNDEFINED
  An undefined value.
• public const int BINARY_AGE
  Like [func@get_binary_age], but from the headers used at application compile time, rather than from the library linked against at application run time.
• public const string IM_MODULE_EXTENSION_POINT_NAME
• public const int INPUT_ERROR
  Constant to return from a signal handler for the ::input signal in case of conversion failure.
• public const int INTERFACE_AGE
  Like [func@get_interface_age], but from the headers used at application compile time, rather than from the library linked against at application run time.
• public const uint INVALID_LIST_POSITION
  The value used to refer to a guaranteed invalid position in a `GListModel`.
• public const string LEVEL_BAR_OFFSET_FULL
  The name used for the stock full offset included by `GtkLevelBar`.
• public const string LEVEL_BAR_OFFSET_HIGH
  The name used for the stock high offset included by `GtkLevelBar`.
• public const string LEVEL_BAR_OFFSET_LOW
  The name used for the stock low offset included by `GtkLevelBar`.
• public const int MAJOR_VERSION
  Like [func@get_major_version], but from the headers used at application compile time, rather than from the library linked against at application run time.
• public const int MAX_COMPOSE_LEN
• public const string MEDIA_FILE_EXTENSION_POINT_NAME
• public const int MICRO_VERSION
  Like [func@get_micro_version], but from the headers used at application compile time, rather than from the library linked against at application run time.
• public const int MINOR_VERSION
  Like [func@get_minor_version], but from the headers used at application compile time, rather than from the library linked against at application run time.
• public const string PAPER_NAME_A3
  Name for the A3 paper size.
• public const string PAPER_NAME_A4
  Name for the A4 paper size.
• public const string PAPER_NAME_A5
  Name for the A5 paper size.
• public const string PAPER_NAME_B5
  Name for the B5 paper size.
• public const string PAPER_NAME_EXECUTIVE
  Name for the Executive paper size.
• public const string PAPER_NAME_LEGAL
  Name for the Legal paper size.
• public const string PAPER_NAME_LETTER
  Name for the Letter paper size.
• public const string PRINT_SETTINGS_COLLATE
• public const string PRINT_SETTINGS_DEFAULT_SOURCE
• public const string PRINT_SETTINGS_DITHER
• public const string PRINT_SETTINGS_DUPLEX
• public const string PRINT_SETTINGS_FINISHINGS
• public const string PRINT_SETTINGS_MEDIA_TYPE
• public const string PRINT_SETTINGS_NUMBER_UP
• public const string PRINT_SETTINGS_NUMBER_UP_LAYOUT
• public const string PRINT_SETTINGS_N_COPIES
• public const string PRINT_SETTINGS_ORIENTATION
• public const string PRINT_SETTINGS_OUTPUT_BASENAME
  The key used by the “Print to file” printer to store the file name of the output without the path to the directory and the file extension.
• public const string PRINT_SETTINGS_OUTPUT_BIN
• public const string PRINT_SETTINGS_OUTPUT_DIR
  The key used by the “Print to file” printer to store the directory to which the output should be written.
• public const string PRINT_SETTINGS_OUTPUT_FILE_FORMAT
  The key used by the “Print to file” printer to store the format of the output.
• public const string PRINT_SETTINGS_OUTPUT_URI
  The key used by the “Print to file” printer to store the URI to which the output should be written.
• public const string PRINT_SETTINGS_PAGE_RANGES
• public const string PRINT_SETTINGS_PAGE_SET
• public const string PRINT_SETTINGS_PAPER_FORMAT
• public const string PRINT_SETTINGS_PAPER_HEIGHT
• public const string PRINT_SETTINGS_PAPER_WIDTH
• public const string PRINT_SETTINGS_PRINTER
• public const string PRINT_SETTINGS_PRINTER_LPI
• public const string PRINT_SETTINGS_PRINT_PAGES
• public const string PRINT_SETTINGS_QUALITY
• public const string PRINT_SETTINGS_RESOLUTION
• public const string PRINT_SETTINGS_RESOLUTION_X
• public const string PRINT_SETTINGS_RESOLUTION_Y
• public const string PRINT_SETTINGS_REVERSE
• public const string PRINT_SETTINGS_SCALE
• public const string PRINT_SETTINGS_USE_COLOR
• public const string PRINT_SETTINGS_WIN32_DRIVER_EXTRA
• public const string PRINT_SETTINGS_WIN32_DRIVER_VERSION
• public const int PRIORITY_RESIZE
  Use this priority for functionality related to size allocation.
• public const int STYLE_PROVIDER_PRIORITY_APPLICATION
  A priority that can be used when adding a `GtkStyleProvider` for application-specific style information.
• public const int STYLE_PROVIDER_PRIORITY_FALLBACK
  The priority used for default style information that is used in the absence of themes.
• public const int STYLE_PROVIDER_PRIORITY_SETTINGS
  The priority used for style information provided via `GtkSettings`.
• public const int STYLE_PROVIDER_PRIORITY_THEME
  The priority used for style information provided by themes.
• public const int STYLE_PROVIDER_PRIORITY_USER
  The priority used for the style information from `$XDG_CONFIG_HOME/gtk-4.0/gtk.
• public const int TEXT_VIEW_PRIORITY_VALIDATE
  The priority at which the text view validates onscreen lines in an idle job in the background.
• public const int TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID
  Uses the default sort function in a [iface@Gtk.
• public const int TREE_SORTABLE_UNSORTED_SORT_COLUMN_ID
  Disables sorting in a [iface@Gtk.

Delegates:

• public delegate int AssistantPageFunc (int current_page)
  Type of callback used to calculate the next page in a `GtkAssistant`.
• public delegate void BuildableParserEndElementFunc (BuildableParseContext context, string element_name) throws Error
• public delegate void BuildableParserErrorFunc (BuildableParseContext context, Error error)
• public delegate void BuildableParserStartElementFunc (BuildableParseContext context, string element_name, string[] attribute_names, string[] attribute_values) throws Error
• public delegate void BuildableParserTextFunc (BuildableParseContext context, string text, size_t text_len) throws Error
• public delegate bool CellAllocCallback (CellRenderer renderer, Rectangle cell_area, Rectangle cell_background)
  The type of the callback functions used for iterating over the cell renderers and their allocated areas inside a `GtkCellArea`, see foreach_alloc.
• public delegate bool CellCallback (CellRenderer renderer)
  The type of the callback functions used for iterating over the cell renderers of a `GtkCellArea`, see @foreach.
• public delegate void CellLayoutDataFunc (CellLayout cell_layout, CellRenderer cell, TreeModel tree_model, TreeIter iter)
  A function which should set the value of cell_layout’s cell renderer(s) as appropriate.
• public delegate void CustomAllocateFunc (Widget widget, int width, int height, int baseline)
  A function to be used by `GtkCustomLayout` to allocate a widget.
• public delegate bool CustomFilterFunc (Object item)
  User function that is called to determine if the item should be matched.
• public delegate void CustomMeasureFunc (Widget widget, Orientation orientation, int for_size, out int minimum, out int natural, out int minimum_baseline, out int natural_baseline)
  A function to be used by `GtkCustomLayout` to measure a widget.
• public delegate SizeRequestMode CustomRequestModeFunc (Widget widget)
  Queries a widget for its preferred size request mode.
• public delegate void DrawingAreaDrawFunc (DrawingArea drawing_area, Context cr, int width, int height)
  Whenever drawing_area needs to redraw, this function will be called.
• public delegate bool EntryCompletionMatchFunc (EntryCompletion completion, string key, TreeIter iter)
  A function which decides whether the row indicated by iter matches a given key, and should be displayed as a possible completion for key.
• public delegate void ExpressionNotify ()
  Callback called by watch when the expression value changes.
• public delegate Widget FlowBoxCreateWidgetFunc (Object item)
  Called for flow boxes that are bound to a `GListModel`.
• public delegate bool FlowBoxFilterFunc (FlowBoxChild child)
  A function that will be called whenever a child changes or is added.
• public delegate void FlowBoxForeachFunc (FlowBox box, FlowBoxChild child)
  A function used by selected_foreach.
• public delegate int FlowBoxSortFunc (FlowBoxChild child1, FlowBoxChild child2)
  A function to compare two children to determine which should come first.
• public delegate bool FontFilterFunc (FontFamily family, FontFace face)
  The type of function that is used for deciding what fonts get shown in a `GtkFontChooser`.
• public delegate void IconViewForeachFunc (IconView icon_view, TreePath path)
  A function used by selected_foreach to map all selected rows.
• public delegate Widget ListBoxCreateWidgetFunc (Object item)
  Called for list boxes that are bound to a `GListModel` with bind_model for each item that gets added to the model.
• public delegate bool ListBoxFilterFunc (ListBoxRow row)
  Will be called whenever the row changes or is added and lets you control if the row should be visible or not.
• public delegate void ListBoxForeachFunc (ListBox box, ListBoxRow row)
  A function used by selected_foreach.
• public delegate int ListBoxSortFunc (ListBoxRow row1, ListBoxRow row2)
  Compare two rows to determine which should be first.
• public delegate void ListBoxUpdateHeaderFunc (ListBoxRow row, ListBoxRow? before)
  Whenever row changes or which row is before row changes this is called, which lets you update the header on row.
• public delegate Object MapListModelMapFunc (owned Object item)
  User function that is called to map an item of the original model to an item expected by the map model.
• public delegate void MenuButtonCreatePopupFunc (MenuButton menu_button)
  User-provided callback function to create a popup for a `GtkMenuButton` on demand.
• public delegate void PageSetupDoneFunc (PageSetup page_setup)
  The type of function that is passed to print_run_page_setup_dialog_async.
• public delegate void PrintSettingsFunc (string key, string value)
• public delegate string ScaleFormatValueFunc (Scale scale, double value)
• public delegate bool ShortcutFunc (Widget widget, Variant? args)
  Prototype for shortcuts based on user callbacks.
• public delegate bool TextCharPredicate (unichar ch)
  The predicate function used by forward_find_char and backward_find_char.
• public delegate void TextTagTableForeach (TextTag tag)
  A function used with @foreach, to iterate over every `GtkTextTag` inside a `GtkTextTagTable`.
• public delegate bool TickCallback (Widget widget, FrameClock frame_clock)
  Callback type for adding a function to update animations.
• public delegate void TreeCellDataFunc (TreeViewColumn tree_column, CellRenderer cell, TreeModel tree_model, TreeIter iter)
  A function to set the properties of a cell instead of just using the straight mapping between the cell and the model.
• public delegate int TreeIterCompareFunc (TreeModel model, TreeIter a, TreeIter b)
  A GtkTreeIterCompareFunc should return a negative integer, zero, or a positive integer if a sorts before b, a sorts with b, or a sorts after b respectively.
• public delegate ListModel? TreeListModelCreateModelFunc (Object item)
  Prototype of the function called to create new child models when set_expanded is called.
• public delegate void TreeModelFilterModifyFunc (TreeModel model, TreeIter iter, out Value value, int column)
  A function which calculates display values from raw values in the model.
• public delegate bool TreeModelFilterVisibleFunc (TreeModel model, TreeIter iter)
  A function which decides whether the row indicated by iter is visible.
• public delegate bool TreeModelForeachFunc (TreeModel model, TreePath path, TreeIter iter)
  Type of the callback passed to @foreach to iterate over the rows in a tree model.
• public delegate void TreeSelectionForeachFunc (TreeModel model, TreePath path, TreeIter iter)
  A function used by selected_foreach to map all selected rows.
• public delegate bool TreeSelectionFunc (TreeSelection selection, TreeModel model, TreePath path, bool path_currently_selected)
  A function used by set_select_function to filter whether or not a row may be selected.
• public delegate bool TreeViewColumnDropFunc (TreeView tree_view, TreeViewColumn column, TreeViewColumn prev_column, TreeViewColumn next_column)
  Function type for determining whether column can be dropped in a particular spot (as determined by prev_column and next_column).
• public delegate void TreeViewMappingFunc (TreeView tree_view, TreePath path)
  Function used for map_expanded_rows.
• public delegate bool TreeViewRowSeparatorFunc (TreeModel model, TreeIter iter)
  Function type for determining whether the row pointed to by iter should be rendered as a separator.
• public delegate bool TreeViewSearchEqualFunc (TreeModel model, int column, string key, TreeIter iter)
  A function used for checking whether a row in model matches a search key string entered by the user.
• public delegate void WidgetActionActivateFunc (Widget widget, string action_name, Variant parameter)
  The type of the callback functions used for activating actions installed with install_action.

Methods:

• public ModifierType accelerator_get_default_mod_mask ()
  Gets the modifier mask.
• public string accelerator_get_label (uint accelerator_key, ModifierType accelerator_mods)
  Converts an accelerator keyval and modifier mask into a string which can be used to represent the accelerator to the user.
• public string accelerator_get_label_with_keycode (Display? display, uint accelerator_key, uint keycode, ModifierType accelerator_mods)
  Converts an accelerator keyval and modifier mask into a string that can be displayed to the user.
• public string accelerator_name (uint accelerator_key, ModifierType accelerator_mods)
  Converts an accelerator keyval and modifier mask into a string parseable by accelerator_parse.
• public string accelerator_name_with_keycode (Display? display, uint accelerator_key, uint keycode, ModifierType accelerator_mods)
  Converts an accelerator keyval and modifier mask into a string parseable by accelerator_parse_with_keycode.
• public bool accelerator_parse (string accelerator, out uint accelerator_key, out ModifierType accelerator_mods)
  Parses a string representing an accelerator.
• public bool accelerator_parse_with_keycode (string accelerator, Display? display, out uint accelerator_key, out uint[] accelerator_codes, out ModifierType accelerator_mods)
  Parses a string representing an accelerator.
• public bool accelerator_valid (uint keyval, ModifierType modifiers)
  Determines whether a given keyval and modifier mask constitute a valid keyboard accelerator.
• public void accessible_property_init_value (AccessibleProperty property, Value value)
• public void accessible_relation_init_value (AccessibleRelation relation, Value value)
• public void accessible_state_init_value (AccessibleState state, Value value)
• public bool bitset_iter_init_at (out BitsetIter iter, Bitset @set, uint target, out uint value)
• public bool bitset_iter_init_first (out BitsetIter iter, Bitset @set, out uint value)
• public bool bitset_iter_init_last (out BitsetIter iter, Bitset @set, out uint value)
• public Quark builder_error_quark ()
• public unowned string? check_version (uint required_major, uint required_minor, uint required_micro)
  Checks that the GTK library in use is compatible with the given version.
• public Quark constraint_vfl_parser_error_quark ()
• public void disable_setlocale ()
  Prevents [id@gtk_init] and [id@gtk_init_check] from automatically calling `setlocale (LC_ALL, "")`.
• public int distribute_natural_allocation (int extra_space, RequestedSize[] sizes)
  Distributes extra_space to child sizes by bringing smaller children up to natural size first.
• public bool drag_check_threshold (Widget widget, int start_x, int start_y, int current_x, int current_y)
  Checks to see if a drag movement has passed the GTK drag threshold.
• public Quark file_chooser_error_quark ()
• public uint get_binary_age ()
  Returns the binary age as passed to `libtool`.
• public DebugFlags get_debug_flags ()
  Returns the GTK debug flags that are currently active.
• public unowned Language get_default_language ()
  Returns the `PangoLanguage` for the default language currently in effect.
• public uint get_interface_age ()
  Returns the interface age as passed to `libtool`.
• public TextDirection get_locale_direction ()
  Get the direction of the current locale.
• public uint get_major_version ()
  Returns the major version number of the GTK library.
• public uint get_micro_version ()
  Returns the micro version number of the GTK library.
• public uint get_minor_version ()
  Returns the minor version number of the GTK library.
• public void hsv_to_rgb (float h, float s, float v, out float r, out float g, out float b)
  Converts a color from HSV space to RGB.
• public Quark icon_theme_error_quark ()
• public void init ()
  Call this function before using any other GTK functions in your GUI applications.
• public bool init_check ()
  This function does the same work as init with only a single change: It does not terminate the program if the windowing system can’t be initialized.
• public bool is_initialized ()
  Use this function to check if GTK has been initialized with init or init_check.
• public unowned Native? native_get_for_surface (Surface surface)
• public Ordering ordering_from_cmpfunc (int cmpfunc_result)
• public unowned string paper_size_get_default ()
  Returns the name of the default paper size, which depends on the current locale.
• public List<PaperSize> paper_size_get_paper_sizes (bool include_custom)
  Creates a list of known paper sizes.
• public Quark print_error_quark ()
• public PageSetup print_run_page_setup_dialog (Window? parent, PageSetup? page_setup, PrintSettings settings)
  Runs a page setup dialog, letting the user modify the values from page_setup.
• public void print_run_page_setup_dialog_async (Window? parent, PageSetup? page_setup, PrintSettings settings, PageSetupDoneFunc done_cb)
  Runs a page setup dialog, letting the user modify the values from page_setup.
• public Quark recent_manager_error_quark ()
• public void rgb_to_hsv (float r, float g, float b, out float h, out float s, out float v)
  Converts a color from RGB space to HSV.
• public void set_debug_flags (DebugFlags flags)
  Sets the GTK debug flags.
• public void show_about_dialog (Window? parent, ...)
  A convenience function for showing an application’s about dialog.
• public void show_uri (Window? parent, string uri, uint32 timestamp)
  This function launches the default application for showing a given uri, or shows an error dialog if that fails.
• public void test_accessible_assertion_message_role (string domain, string file, int line, string func, string expr, Accessible accessible, AccessibleRole expected_role, AccessibleRole actual_role)
• public bool test_accessible_has_property (Accessible accessible, AccessibleProperty property)
  Checks whether the `GtkAccessible` has property set.
• public bool test_accessible_has_relation (Accessible accessible, AccessibleRelation relation)
  Checks whether the `GtkAccessible` has relation set.
• public bool test_accessible_has_role (Accessible accessible, AccessibleRole role)
  Checks whether the `GtkAccessible:accessible-role` of the accessible is role.
• public bool test_accessible_has_state (Accessible accessible, AccessibleState state)
  Checks whether the `GtkAccessible` has state set.
• public void test_init (ref unowned string[] argvp, ...)
  This function is used to initialize a GTK test program.
• public unowned Type[] test_list_all_types ()
  Return the type ids that have been registered after calling test_register_all_types.
• public void test_register_all_types ()
  Force registration of all core GTK object types.
• public void test_widget_wait_for_draw (Widget widget)
  Enters the main loop and waits for widget to be “drawn”.
• public ContentProvider tree_create_row_drag_content (TreeModel tree_model, TreePath path)
  Creates a content provider for dragging path from tree_model.
• public bool tree_get_row_drag_data (Value value, out unowned TreeModel? tree_model, out TreePath? path)
  Obtains a tree_model and path from value of target type gtk_type_tree_row_data.
• public void tree_row_reference_deleted (Object proxy, TreePath path)
  Lets a set of row reference created by TreeRowReference.proxy know that the model emitted the ::row-deleted signal.
• public void tree_row_reference_inserted (Object proxy, TreePath path)
  Lets a set of row reference created by TreeRowReference.proxy know that the model emitted the ::row-inserted signal.
• public Expression? value_dup_expression (Value value)
  Retrieves the `GtkExpression` stored inside the given `value`, and acquires a reference to it.
• public unowned Expression? value_get_expression (ref Value value)
  Retrieves the `GtkExpression` stored inside the given `value`.
• public void value_set_expression (ref Value value, Expression expression)
  Stores the given `GtkExpression` inside `value`.
• public void value_take_expression (ref Value value, owned Expression? expression)
  Stores the given `GtkExpression` inside `value`.