Enum Event

#[non_exhaustive]
pub enum Event<'a> {
    Frame {
        width: u32,
        height: u32,
        offset_x: u32,
        offset_y: u32,
        buffer_flags: u32,
        flags: WEnum<Flags>,
        format: u32,
        mod_high: u32,
        mod_low: u32,
        num_objects: u32,
    },
    Object {
        index: u32,
        fd: BorrowedFd<'a>,
        size: u32,
        offset: u32,
        stride: u32,
        plane_index: u32,
    },
    Ready {
        tv_sec_hi: u32,
        tv_sec_lo: u32,
        tv_nsec: u32,
    },
    Cancel {
        reason: WEnum<CancelReason>,
    },
}

Available on crate feature wayland and Linux only.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Frame

a frame description

Main event supplying the client with information about the frame. If the capture didn’t fail, this event is always emitted first before any other events.

This event is followed by a number of “object” as specified by the “num_objects” argument.

Fields

width: u32

frame width in pixels

height: u32

frame height in pixels

offset_x: u32

crop offset for the x axis

offset_y: u32

crop offset for the y axis

buffer_flags: u32

flags which indicate properties (invert, interlacing), has the same values as zwp_linux_buffer_params_v1:flags

flags: WEnum<Flags>

indicates special frame features

format: u32

format of the frame (DRM_FORMAT_*)

mod_high: u32

drm format modifier, high

mod_low: u32

drm format modifier, low

num_objects: u32

indicates how many objects (FDs) the frame has (max 4)

Object

an object description

Event which serves to supply the client with the file descriptors containing the data for each object.

After receiving this event, the client must always close the file descriptor as soon as they’re done with it and even if the frame fails.

Fields

index: u32

index of the current object

fd: BorrowedFd<'a>

fd of the current object

size: u32

size in bytes for the current object

offset: u32

starting point for the data in the object’s fd

stride: u32

line size in bytes

plane_index: u32

index of the plane the data in the object applies to

Ready

indicates frame is available for reading

This event is sent as soon as the frame is presented, indicating it is available for reading. This event includes the time at which presentation happened at.

The timestamp is expressed as tv_sec_hi, tv_sec_lo, tv_nsec triples, each component being an unsigned 32-bit value. Whole seconds are in tv_sec which is a 64-bit value combined from tv_sec_hi and tv_sec_lo, and the additional fractional part in tv_nsec as nanoseconds. Hence, for valid timestamps tv_nsec must be in [0, 999999999]. The seconds part may have an arbitrary offset at start.

After receiving this event, the client should destroy this object.

Fields

tv_sec_hi: u32

high 32 bits of the seconds part of the timestamp

tv_sec_lo: u32

low 32 bits of the seconds part of the timestamp

tv_nsec: u32

nanoseconds part of the timestamp

Cancel

indicates the frame is no longer valid

If the capture failed or if the frame is no longer valid after the “frame” event has been emitted, this event will be used to inform the client to scrap the frame.

If the failure is temporary, the client may capture again the same source. If the failure is permanent, any further attempts to capture the same source will fail again.

After receiving this event, the client should destroy this object.

Fields

reason: WEnum<CancelReason>

indicates a reason for cancelling this frame capture

Implementations

impl<'a> Event<'a>

pub fn opcode(&self) -> u16

Get the opcode number of this message

Trait Implementations

impl<'a> Debug for Event<'a>

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

Formats the value using the given formatter.