Struct wayland_server::protocol::wl_subsurface::WlSubsurface

pub struct WlSubsurface { /* private fields */ }

sub-surface interface to a wl_surface

An additional interface to a wl_surface object, which has been made a sub-surface. A sub-surface has one parent surface. A sub-surface’s size and position are not limited to that of the parent. Particularly, a sub-surface is not automatically clipped to its parent’s area.

A sub-surface becomes mapped, when a non-NULL wl_buffer is applied and the parent surface is mapped. The order of which one happens first is irrelevant. A sub-surface is hidden if the parent becomes hidden, or if a NULL wl_buffer is applied. These rules apply recursively through the tree of surfaces.

The behaviour of a wl_surface.commit request on a sub-surface depends on the sub-surface’s mode. The possible modes are synchronized and desynchronized, see methods wl_subsurface.set_sync and wl_subsurface.set_desync. Synchronized mode caches the wl_surface state to be applied when the parent’s state gets applied, and desynchronized mode applies the pending wl_surface state directly. A sub-surface is initially in the synchronized mode.

Sub-surfaces also have another kind of state, which is managed by wl_subsurface requests, as opposed to wl_surface requests. This state includes the sub-surface position relative to the parent surface (wl_subsurface.set_position), and the stacking order of the parent and its sub-surfaces (wl_subsurface.place_above and .place_below). This state is applied when the parent surface’s wl_surface state is applied, regardless of the sub-surface’s mode. As the exception, set_sync and set_desync are effective immediately.

The main surface can be thought to be always in desynchronized mode, since it does not have a parent in the sub-surfaces sense.

Even if a sub-surface is in desynchronized mode, it will behave as in synchronized mode, if its parent surface behaves as in synchronized mode. This rule is applied recursively throughout the tree of surfaces. This means, that one can set a sub-surface into synchronized mode, and then assume that all its child and grand-child sub-surfaces are synchronized, too, without explicitly setting them.

Destroying a sub-surface takes effect immediately. If you need to synchronize the removal of a sub-surface to the parent surface update, unmap the sub-surface first by attaching a NULL wl_buffer, update parent, and then destroy the sub-surface.

If the parent wl_surface object is destroyed, the sub-surface is unmapped.

A sub-surface never has the keyboard focus of any seat.

The wl_surface.offset request is ignored: clients must use set_position instead to move the sub-surface.

See also the Request enum for this interface.

Trait Implementations

impl Borrow<ObjectId> for WlSubsurface

fn borrow(&self) -> &ObjectId

Immutably borrows from an owned value.

impl Clone for WlSubsurface

fn clone(&self) -> WlSubsurface

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for WlSubsurface

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

Formats the value using the given formatter.

impl Hash for WlSubsurface

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

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 PartialEq<Weak<WlSubsurface>> for WlSubsurface

fn eq(&self, other: &Weak<WlSubsurface>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

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

impl PartialEq for WlSubsurface

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

Tests for self and other values to be equal, and is used by ==.

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

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

impl Resource for WlSubsurface

type Request = Request

The request enum for this interface

type Event<'event> = Event<'event>

The event enum for this interface

fn interface() -> &'static Interface

The interface description

fn id(&self) -> ObjectId

The ID of this object

fn version(&self) -> u32

The version of this object

fn data<U: 'static>(&self) -> Option<&U>

Access the user-data associated with this object

fn object_data(&self) -> Option<&Arc<dyn Any + Send + Sync>>

Access the raw data associated with this object.

fn handle(&self) -> &WeakHandle

Access the backend handle associated with this object

fn from_id(conn: &DisplayHandle, id: ObjectId) -> Result<Self, InvalidId>

Create an object resource from its ID

fn send_event(&self, evt: Self::Event<'_>) -> Result<(), InvalidId>

Send an event to this object

fn parse_request( conn: &DisplayHandle, msg: Message<ObjectId, OwnedFd>, ) -> Result<(Self, Self::Request), DispatchError>

Parse a event for this object

fn write_event<'a>( &self, conn: &DisplayHandle, msg: Self::Event<'a>, ) -> Result<Message<ObjectId, BorrowedFd<'a>>, InvalidId>

Serialize an event for this object

fn client(&self) -> Option<Client>

The client owning this object

fn is_alive(&self) -> bool

Checks if the Wayland object associated with this proxy is still alive

fn post_error(&self, code: impl Into<u32>, error: impl Into<String>)

Trigger a protocol error on this object

fn downgrade(&self) -> Weak<Self>

Creates a weak handle to this object

impl Eq for WlSubsurface