Struct gdk4::Paintable

#[repr(transparent)]
pub struct Paintable { /* private fields */ }

Paintable is a simple interface used by GTK to represent content that can be painted.

The content of a Paintable can be painted anywhere at any size without requiring any sort of layout. The interface is inspired by similar concepts elsewhere, such as ClutterContent, HTML/CSS Paint Sources, or SVG Paint Servers.

A Paintable can be snapshot at any time and size using PaintableExt::snapshot(). How the paintable interprets that size and if it scales or centers itself into the given rectangle is implementation defined, though if you are implementing a Paintable and don’t know what to do, it is suggested that you scale your paintable ignoring any potential aspect ratio.

The contents that a Paintable produces may depend on the Snapshot passed to it. For example, paintables may decide to use more detailed images on higher resolution screens or when OpenGL is available. A Paintable will however always produce the same output for the same snapshot.

A Paintable may change its contents, meaning that it will now produce a different output with the same snapshot. Once that happens, it will call PaintableExt::invalidate_contents() which will emit the invalidate-contents signal. If a paintable is known to never change its contents, it will set the PaintableFlags::CONTENTS flag. If a consumer cannot deal with changing contents, it may call PaintableExt::current_image() which will return a static paintable and use that.

A paintable can report an intrinsic (or preferred) size or aspect ratio it wishes to be rendered at, though it doesn’t have to. Consumers of the interface can use this information to layout thepaintable appropriately. Just like the contents, the size of a paintable can change. A paintable will indicate this by calling PaintableExt::invalidate_size() which will emit the invalidate-size signal. And just like for contents, if a paintable is known to never change its size, it will set the PaintableFlags::SIZE flag.

Besides API for applications, there are some functions that are only useful for implementing subclasses and should not be used by applications: PaintableExt::invalidate_contents(), PaintableExt::invalidate_size(), new_empty().

Signals

invalidate-contents

Emitted when the contents of the @paintable change.

Examples for such an event would be videos changing to the next frame or the icon theme for an icon changing.

invalidate-size

Emitted when the intrinsic size of the @paintable changes.

This means the values reported by at least one of PaintableExt::intrinsic_width(), PaintableExt::intrinsic_height() or PaintableExt::intrinsic_aspect_ratio() has changed.

Examples for such an event would be a paintable displaying the contents of a toplevel surface being resized.

Implements

PaintableExt

Implementations

impl Paintable

pub const NONE: Option<&'static Paintable> = None

pub fn new_empty(intrinsic_width: i32, intrinsic_height: i32) -> Paintable

Returns a paintable that has the given intrinsic size and draws nothing.

This is often useful for implementing the vfunc::Gdk::Paintable::get_current_image virtual function when the paintable is in an incomplete state (like a Gtk::MediaStream before receiving the first frame).

intrinsic_width

The intrinsic width to report. Can be 0 for no width.

intrinsic_height

The intrinsic height to report. Can be 0 for no height.

Returns

a Paintable

Trait Implementations

impl Clone for Paintable

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 Paintable

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

Formats the value using the given formatter.

impl Display for Paintable

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

Formats the value using the given formatter.

impl HasParamSpec for Paintable

type ParamSpec = ParamSpecObject

type SetValue = Paintable

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

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

fn param_spec_builder() -> Self::BuilderFn

impl Hash for Paintable

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<T: PaintableImpl> IsImplementable<T> for Paintable

fn interface_init(iface: &mut Interface<Self>)

Override the virtual methods of this interface for the given subclass and do other interface initialization.

fn instance_init(_instance: &mut InitializingObject<T>)

Instance specific initialization.

impl Ord for Paintable

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

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

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

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 Paintable

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 Paintable

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for Paintable

impl IsA<Paintable> for GLTexture

impl IsA<Paintable> for MemoryTexture

impl IsA<Paintable> for Texture