Struct FoldState 

pub struct FoldState { /* private fields */ }

Which fold starts are collapsed. Owned by the editor view; row ranges come from the highlighter per document version.

Implementations

impl FoldState

pub fn new() -> Self

Creates an empty fold state with nothing collapsed.

pub fn toggle(&mut self, start_row: usize) -> bool

Toggles the fold starting at start_row, returning true when the fold ends up collapsed. Toggling a row that starts no range still flips membership so a later recompute revealing a fold there picks it up.

pub fn is_collapsed(&self, start_row: usize) -> bool

Reports whether the fold starting at start_row is collapsed.

pub fn retain(&mut self, ranges: &[FoldRange])

Drops collapsed starts absent from ranges, keeping the set aligned with structural edits that move or delete fold headers.

pub fn hidden_range_at<'a>( &self, ranges: &'a [FoldRange], row: usize, ) -> Option<&'a FoldRange>

Returns the collapsed range hiding row, if any. Ranges must be sorted by start row; headers themselves are never hidden.

pub fn is_row_hidden(&self, ranges: &[FoldRange], row: usize) -> bool

Reports whether row hides inside a collapsed range.

pub fn step_visible_row( &self, ranges: &[FoldRange], row: usize, total_lines: usize, down: bool, ) -> usize

Steps one visible row from row, skipping collapsed spans. Stays put when no visible row exists in that direction.

Trait Implementations

impl Clone for FoldState

fn clone(&self) -> FoldState

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FoldState

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

Formats the value using the given formatter.

impl Default for FoldState

fn default() -> FoldState

Returns the “default value” for a type.