Enum FrameKind 

pub enum FrameKind {
    Tile,
    Gap,
    Resumed,
}

What a frame-plane message carries.

The gap variant is why this enum exists. A locked workstation, a UAC prompt or a display mode change stops capture dead (see the agent’s screen_capture), and a viewer only ever told about tiles cannot distinguish “the picture is still because nothing is changing” from “we cannot see the screen at all”. Those need different words on screen, so they need different messages on the wire.

Gaps ride the frame plane rather than the control plane because they are part of what the viewer is showing, not a request or a reply — and because arriving in order with the tiles is what makes them meaningful. A gap delivered out of band could easily be painted after the frames that already resumed.

Variants

Tile

Headers carry a FrameMeta; payload is the encoded image.

Gap

Headers carry nothing else; payload is a UTF-8 reason string.

Resumed

Capture works again, but there is nothing new to show yet. No headers beyond the kind, no payload.

Without this, recovery is only observable when the next tile happens to arrive — and a desktop that is reachable but unchanged produces no tiles at all. An operator would keep reading “screen unavailable” for as long as nobody moved a window, long after capture had recovered.

The alternative was to force a full frame on recovery, which would have meant sending several hundred KB to say “nothing changed” — the opposite of the bandwidth argument that shaped this whole format.

Implementations

impl FrameKind

pub fn as_str(self) -> &'static str

pub fn parse(s: &str) -> Option<Self>

Trait Implementations

impl Clone for FrameKind

fn clone(&self) -> FrameKind

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for FrameKind

impl Debug for FrameKind

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

Formats the value using the given formatter.

impl Eq for FrameKind

impl PartialEq for FrameKind

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for FrameKind