Struct gtk4::GraphicsOffload

pub struct GraphicsOffload { /* private fields */ }

Available on crate feature v4_14 only.

A widget that allows to bypass gsk rendering for its child by passing the content directly to the compositor.

Graphics offload is an optimization to reduce overhead and battery use that is most useful for video content. It only works on some platforms and in certain situations. GTK will automatically fall back to normal rendering if it doesn’t.

Graphics offload is most efficient if there are no controls drawn on top of the video content.

You should consider using graphics offload for your main widget if it shows frequently changing content (such as a video, or a VM display) and you provide the content in the form of dmabuf textures (see Gdk::DmabufTextureBuilder), in particular if it may be fullscreen.

Numerous factors can prohibit graphics offload:

• Unsupported platforms. Currently, graphics offload only works on Linux with Wayland.

• Clipping, such as rounded corners that cause the video content to not be rectangular

• Unsupported dmabuf formats (see [DisplayExtManual::dmabuf_formats()][crate::gdk::prelude::DisplayExtManual::dmabuf_formats()])

• Translucent video content (content with an alpha channel, even if it isn’t used)

• Transforms that are more complex than translations and scales

• Filters such as opacity, grayscale or similar

To investigate problems related graphics offload, GTK offers debug flags to print out information about graphics offload and dmabuf use:

GDK_DEBUG=offload
GDK_DEBUG=dmabuf

The GTK inspector provides a visual debugging tool for graphics offload.

Properties

black-background

Readable | Writeable

child

The child widget.

Readable | Writeable

enabled

Whether graphics offload is enabled.

Readable | Writeable

Widget

can-focus

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

This property is meant to be set by widget implementations, typically in their instance init function.

Readable | Writeable

can-target

Whether the widget can receive pointer events.

Readable | Writeable

css-classes

A list of css classes applied to this widget.

Readable | Writeable

css-name

The name of this widget in the CSS tree.

This property is meant to be set by widget implementations, typically in their instance init function.

Readable | Writeable | Construct Only

cursor

The cursor used by @widget.

Readable | Writeable

focus-on-click

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

This property is only relevant for widgets that can take focus.

Readable | Writeable

focusable

Whether this widget itself will accept the input focus.

Readable | Writeable

halign

How to distribute horizontal space if widget gets extra space.

Readable | Writeable

has-default

Whether the widget is the default widget.

Readable

has-focus

Whether the widget has the input focus.

Readable

has-tooltip

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

A value of true indicates that @widget can have a tooltip, in this case the widget will be queried using query-tooltip to determine whether it will provide a tooltip or not.

Readable | Writeable

height-request

Override for height request of the widget.

If this is -1, the natural request will be used.

Readable | Writeable

hexpand

Whether to expand horizontally.

Readable | Writeable

hexpand-set

Whether to use the hexpand property.

Readable | Writeable

layout-manager

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

This property is meant to be set by widget implementations, typically in their instance init function.

Readable | Writeable

margin-bottom

Margin on bottom side of widget.

This property adds margin outside of the widget’s normal size request, the margin will be added in addition to the size from WidgetExt::set_size_request() for example.

Readable | Writeable

margin-end

Margin on end of widget, horizontally.

This property supports left-to-right and right-to-left text directions.

This property adds margin outside of the widget’s normal size request, the margin will be added in addition to the size from WidgetExt::set_size_request() for example.

Readable | Writeable

margin-start

Margin on start of widget, horizontally.

This property supports left-to-right and right-to-left text directions.

This property adds margin outside of the widget’s normal size request, the margin will be added in addition to the size from WidgetExt::set_size_request() for example.

Readable | Writeable

margin-top

Margin on top side of widget.

This property adds margin outside of the widget’s normal size request, the margin will be added in addition to the size from WidgetExt::set_size_request() for example.

Readable | Writeable

name

The name of the widget.

Readable | Writeable

opacity

The requested opacity of the widget.

Readable | Writeable

overflow

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

This property is meant to be set by widget implementations, typically in their instance init function.

Readable | Writeable

parent

The parent widget of this widget.

Readable

receives-default

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

Readable | Writeable

root

The Root widget of the widget tree containing this widget.

This will be None if the widget is not contained in a root widget.

Readable

scale-factor

The scale factor of the widget.

Readable

sensitive

Whether the widget responds to input.

Readable | Writeable

tooltip-markup

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

Also see Tooltip::set_markup().

This is a convenience property which will take care of getting the tooltip shown if the given string is not None: has-tooltip will automatically be set to true and there will be taken care of query-tooltip in the default signal handler.

Note that if both tooltip-text and tooltip-markup are set, the last one wins.

Readable | Writeable

tooltip-text

Sets the text of tooltip to be the given string.

Also see Tooltip::set_text().

This is a convenience property which will take care of getting the tooltip shown if the given string is not None: has-tooltip will automatically be set to true and there will be taken care of query-tooltip in the default signal handler.

Note that if both tooltip-text and tooltip-markup are set, the last one wins.

Readable | Writeable

valign

How to distribute vertical space if widget gets extra space.

Readable | Writeable

vexpand

Whether to expand vertically.

Readable | Writeable

vexpand-set

Whether to use the vexpand property.

Readable | Writeable

visible

Whether the widget is visible.

Readable | Writeable

width-request

Override for width request of the widget.

If this is -1, the natural request will be used.

Readable | Writeable

Accessible

accessible-role

The accessible role of the given Accessible implementation.

The accessible role cannot be changed once set.

Readable | Writeable

Implements

WidgetExt, [trait@glib::ObjectExt], AccessibleExt, BuildableExt, ConstraintTargetExt, WidgetExtManual, AccessibleExtManual

Implementations

impl GraphicsOffload

pub fn new(child: Option<&impl IsA<Widget>>) -> GraphicsOffload

Creates a new GtkGraphicsOffload widget.

child

the child widget

Returns

the new widget

pub fn builder() -> GraphicsOffloadBuilder

Creates a new builder-pattern struct instance to construct GraphicsOffload objects.

This method returns an instance of GraphicsOffloadBuilder which can be used to create GraphicsOffload objects.

pub fn is_black_background(&self) -> bool

Available on crate feature v4_16 only.

Returns whether the widget draws a black background.

See set_black_background().

Returns

TRUE if black background is drawn

pub fn child(&self) -> Option<Widget>

Gets the child of @self.

Returns

the child widget

pub fn enabled(&self) -> GraphicsOffloadEnabled

Returns whether offload is enabled for @self.

Returns

whether offload is enabled

pub fn set_black_background(&self, value: bool)

Available on crate feature v4_16 only.

Sets whether this GtkGraphicsOffload widget will draw a black background.

A main use case for this is letterboxing where black bars are visible next to the content if the aspect ratio of the content does not match the dimensions of the monitor.

Using this property for letterboxing instead of CSS allows compositors to show content with maximum efficiency, using direct scanout to avoid extra copies in the compositor.

On Wayland, this is implemented using the single-pixel buffer protocol.

value

whether to draw a black background behind the content

pub fn set_child(&self, child: Option<&impl IsA<Widget>>)

Sets the child of @self.

child

the child widget

pub fn set_enabled(&self, enabled: GraphicsOffloadEnabled)

Sets whether this GtkGraphicsOffload widget will attempt to offload the content of its child widget.

enabled

whether to enable offload

pub fn connect_black_background_notify<F: Fn(&Self) + 'static>( &self, f: F ) -> SignalHandlerId

pub fn connect_child_notify<F: Fn(&Self) + 'static>( &self, f: F ) -> SignalHandlerId

pub fn connect_enabled_notify<F: Fn(&Self) + 'static>( &self, f: F ) -> SignalHandlerId

Trait Implementations

impl Clone for GraphicsOffload

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for GraphicsOffload

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for GraphicsOffload

fn default() -> Self

Returns the “default value” for a type.

impl HasParamSpec for GraphicsOffload

type ParamSpec = ParamSpecObject

type SetValue = GraphicsOffload

Preferred value to be used as setter for the associated ParamSpec.

type BuilderFn = fn(_: &str) -> ParamSpecObjectBuilder<'_, GraphicsOffload>

fn param_spec_builder() -> Self::BuilderFn

impl Hash for GraphicsOffload

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for GraphicsOffload

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl ParentClassIs for GraphicsOffload

type Parent = Widget

impl<OT: ObjectType> PartialEq<OT> for GraphicsOffload

fn eq(&self, other: &OT) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<OT: ObjectType> PartialOrd<OT> for GraphicsOffload

fn partial_cmp(&self, other: &OT) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for GraphicsOffload

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for GraphicsOffload

impl IsA<Accessible> for GraphicsOffload

impl IsA<Buildable> for GraphicsOffload

impl IsA<ConstraintTarget> for GraphicsOffload

impl IsA<Widget> for GraphicsOffload