Struct Layout 

pub struct Layout { /* private fields */ }

Where a text’s rows break at a given width.

Implementations

impl Layout

pub fn describes(&self, text: &Text) -> bool

Whether this layout still describes text.

The only safe precondition for anything that reads a VisualLine’s byte range against a text — cell_of, position_at_cell, and any caller slicing a row itself. A row count is not a substitute: an edit inside one row leaves it unchanged while every byte range after the edit moves.

pub fn unwrapped(text: &Text) -> Self

Lay text out as one unwrapped visual line per row — no grapheme segmentation, no width measurement, no break search.

For a caller that needs some layout describing text right now and cannot afford compute’s cost this instant (a large buffer, off the keystroke that triggered a full rebuild). describes is true the moment this returns, so nothing downstream has to know the wrap is wrong — only that a genuinely long row will not soft-wrap until a real compute replaces this one. row_count still matches text, which is the invariant every other reader depends on.

pub fn compute( text: &Text, width: usize, metrics: Metrics, hints: &[RowHints<'_>], ) -> Self

Lay text out at width cells.

pub fn relayout_rows( &mut self, text: &Text, hints: &[RowHints<'_>], rows: Range<usize>, line_delta: isize, )

Re-wrap rows in place, leaving the rest alone.

For a caller holding a Change, whose rows is exactly this argument. Rows outside the range must be unchanged in content and in hints; rows inside it may have become any number of visual lines.

pub fn visual_lines(&self) -> &[VisualLine]

pub fn visual_line_count(&self) -> usize

How many visual lines the text occupies. Never zero.

pub fn row_count(&self) -> usize

How many logical rows this layout was built for. A caller comparing this with the text’s row count is asking whether the layout is stale.

pub fn width(&self) -> usize

pub fn visual_row_of(&self, position: Position) -> usize

Which visual line position is drawn on.

pub fn cell_of( &self, text: &Text, hints: &[RowHints<'_>], position: Position, ) -> Cell

Which cell position is drawn in.

Takes the text and the hints because the layout stores where rows break, not what they contain, and a cell is a measurement of content.

pub fn position_at_cell( &self, text: &Text, hints: &[RowHints<'_>], cell: Cell, ) -> Option<Position>

The position drawn at cell, or None if there is no such visual line.

A column past the end of a visual line lands at its end, and a column inside a wide cluster lands on that cluster: a click between the halves of a CJK character means the character.

Trait Implementations

impl Clone for Layout

fn clone(&self) -> Layout

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Layout

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

Formats the value using the given formatter.