Struct ScrollMetrics 

pub struct ScrollMetrics { /* private fields */ }

Precomputed values for proportional scrollbars.

All positions are tracked in subcell units (1/8 of a terminal cell). Use this type to compute thumb length, travel, and hit testing without rendering anything. The inputs are:

• content_len and viewport_len in logical units (zero treated as 1)
• track_cells in terminal cells

Implementations

impl ScrollMetrics

pub fn from_lengths( lengths: ScrollLengths, offset: usize, track_cells: u16, ) -> Self

Build metrics using a crate::ScrollLengths helper.

pub fn new(lengths: ScrollLengths, offset: usize, track_cells: u16) -> Self

Build metrics for the given content and viewport lengths.

The track_cells parameter is the number of terminal cells available for the track (height for vertical scrollbars, width for horizontal). The lengths are logical units. When content_len is smaller than viewport_len, the thumb fills the track to indicate no scrolling. Zero lengths are treated as 1.

pub const fn content_len(&self) -> usize

Returns the current content length in logical units.

pub const fn viewport_len(&self) -> usize

Returns the current viewport length in logical units.

pub const fn offset(&self) -> usize

Returns the current content offset in logical units.

pub const fn track_cells(&self) -> usize

Returns the track length in terminal cells.

pub const fn track_len(&self) -> usize

Returns the track length in subcells.

pub const fn thumb_len(&self) -> usize

Returns the thumb length in subcells.

pub const fn thumb_start(&self) -> usize

Returns the thumb start position in subcells.

pub const fn max_offset(&self) -> usize

Returns the maximum scrollable offset in subcells.

pub const fn thumb_travel(&self) -> usize

Returns the maximum thumb travel in subcells.

pub const fn thumb_range(&self) -> Range<usize>

Returns the thumb range in subcell coordinates.

pub const fn hit_test(&self, position: usize) -> HitTest

Returns whether a subcell position hits the thumb or the track.

pub fn thumb_start_for_offset(&self, offset: usize) -> usize

Converts an offset (in subcells) to a thumb start position (in subcells).

Larger offsets move the thumb toward the end of the track, clamped to the maximum travel.

pub fn offset_for_thumb_start(&self, thumb_start: usize) -> usize

Converts a thumb start position (in subcells) to an offset (in subcells).

Thumb positions beyond the end of travel are clamped to the maximum offset.

pub fn cell_fill(&self, cell_index: usize) -> CellFill

Returns how much of a cell is filled by the thumb.

The cell_index is in terminal cells, not subcells. Use this to select the correct glyph for the track or thumb.

Trait Implementations

impl Clone for ScrollMetrics

fn clone(&self) -> ScrollMetrics

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ScrollMetrics

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

Formats the value using the given formatter.

impl PartialEq for ScrollMetrics

fn eq(&self, other: &ScrollMetrics) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ScrollMetrics

impl Eq for ScrollMetrics

impl StructuralPartialEq for ScrollMetrics