Struct HelpBuffer 

pub struct HelpBuffer {
    pub id: BufferId,
    pub title: String,
    pub content: Buffer,
    pub scroll: usize,
    pub cursor: Position,
}

One open help buffer. The content is a real Buffer (rope- backed), so it composes with everything else that consumes Buffer – search, motions, syntax highlighting (once a help major mode + tree-sitter grammar lands).

M.3.2.c.5: per-buffer help metadata (links, anchors, highlights) lives on the adjacent HelpMetadata – the App seeds it into buffer_locals[id] at popup-open time so help-mode-owned per-buffer state has a single source of truth. HelpBuffer is now the slim viewport + cursor state; the metadata travels alongside it inside HelpContent.

Fields

id: BufferId

Stable id assigned at creation. Position-history entries (§5.1.1) carry this so <C-o> / <C-i> can route back to the originating buffer when multiple Help buffers coexist (Phase B.1.c). v1 only ever holds one Help buffer at a time – the id still matters because the position history outlives any one Help session and a stale entry must not land on a freshly-opened, unrelated Help.

title: String

content: Buffer

scroll: usize

First visible line index (the popup renderer uses this; a future split/tab/window renderer would use the buffer’s own scroll state instead).

cursor: Position

Cursor position inside the help content. The help overlay behaves like any other buffer – motions move this cursor and scroll auto-adjusts to keep it in view. The terminal cursor is rendered at the screen translation of this position.

Implementations

impl HelpBuffer

pub fn line_count(&self) -> u32

Number of visible content lines (the popup renderer uses this to clamp scroll). CV.3: content space, as the name already promised — it was reading ropey’s raw count, which let the scroll clamp reach one row past the last help line.

pub fn lines(&self) -> Vec<String>

Iterate the rendered lines top-down. Allocates – Buffer doesn’t expose per-line slicing yet. Acceptable for v1; the popup renderer only calls this on a small visible window.

Trait Implementations

impl Clone for HelpBuffer

fn clone(&self) -> HelpBuffer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HelpBuffer

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

Formats the value using the given formatter.