Struct RootDamage 

struct RootDamage {
    id: Damage,
    parts: Option<Region>,
    reported: Cell<bool>,
}

The X server’s report that the root window changed, which lets a capture publish a change as it lands instead of on the next tick. None where the server carries no DAMAGE extension, leaving the frame timer to pace the capture by itself.

Reporting is one notification per non-empty region: the server stays quiet until the region is subtracted, which is what Self::clear does to re-arm the next report.

Fields

id: Damage

parts: Option<Region>

The XFixes region Self::take moves a report’s damage into, to read where the root changed; None where the server’s XFixes has no regions.

reported: Cell<bool>

A report read off the connection and not yet acted on. Latched here because reading the connection is what notices one, and that happens well before the frame it wakes.

Implementations

impl RootDamage

fn create(conn: &RustConnection, root: Window) -> Option<Self>

fn reported(&self, conn: &RustConnection) -> bool

Whether the server has reported a change since the last Self::clear, taking in whatever else the connection carries along the way.

fn clear(&self, conn: &RustConnection)

Empty the region behind a report that has been acted on, so the next change is reported in turn; a tick nothing reported leaves the server alone. Called before a grab, which leaves a change racing the grab to wake the next frame instead of being cleared along with what the grab captured.

fn take(&self, conn: &RustConnection) -> Option<Vec<Rectangle>>

Self::clear, saying where the root changed: the damaged rectangles, empty where nothing was reported, None where a change was reported but the server cannot say where.