Struct Scrollback 

pub struct Scrollback { /* private fields */ }

A handle for publishing content into the terminal scrollback above a split footer.

Cloneable and Send + Sync: background producers keep a clone and publish from their own thread or task. Queued blocks are rendered and committed by the runner on its next loop iteration — at most one tick_rate away — and each block is committed whole, so a block never interleaves with another producer’s.

A block is not a frame: it is written into the terminal’s scrollback once and never repainted. Views that animate, scroll, or depend on later state belong in the footer.

In ScreenMode::Alternate there is no scrollback to write to; the runners discard queued blocks rather than let the queue grow without bound.

Implementations

impl Scrollback

pub const MAX_BLOCK_ROWS: u16 = 4096

Rows a single block may occupy. A measured or requested height past this is clamped, bounding the scratch buffer one block can allocate; publish genuinely long output as several blocks.

pub fn new() -> Self

An empty queue.

pub fn write(&self, build: impl FnOnce(u16) -> Element + Send + 'static)

Queue a view, built at the render width and sized by its own measure.

pub fn write_rows( &self, rows: u16, build: impl FnOnce(u16) -> Element + Send + 'static, )

Queue a view that occupies exactly rows rows, skipping measurement. Content past rows is clipped, as it would be in any other area.

pub fn write_lines(&self, lines: Vec<Line<'static>>)

Queue pre-styled lines — the common case for logs and transcripts.

pub fn is_empty(&self) -> bool

Whether anything is waiting to be published.

pub fn clear(&self)

Drop every queued block without rendering it.

pub fn flush<B: Backend>( &self, terminal: &mut Terminal<B>, theme: &Theme, ) -> Result<bool, B::Error>

Render and commit every queued block above terminal’s inline viewport, returning whether anything was written.

Committing scrolls the terminal, and without the scrolling-regions feature it also clears the viewport, so a true return means the caller must repaint the footer before waiting for input again.

Only an inline viewport has a scrollback to commit into. Against any other viewport the queue is still drained but the blocks go nowhere, which is why the runners call clear instead of this in ScreenMode::Alternate.

Trait Implementations

impl Clone for Scrollback

fn clone(&self) -> Scrollback

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Default for Scrollback

fn default() -> Scrollback

Returns the “default value” for a type.