Struct Scrollbar 

pub struct Scrollbar { /* private fields */ }

A vertical scrollbar (typically one cell wide) covering total_len items in a visible_len-row viewport.

offset defaults to 0; track_style/thumb_style default to Style::new(). Set whichever a caller needs via Scrollbar::offset/Scrollbar::track_style/Scrollbar::thumb_style.

track_style fills the whole strip, then crate::draw::thumb_geometry’s span (if any) is redrawn with thumb_style on top. Draws just the plain track, with no thumb, if there’s nothing to scroll: see crate::draw::thumb_geometry.

Deliberately independent of crate::interact: see crate::draw::thumb_geometry and crate::draw::offset_for_pos’s own doc comments for how to make this draggable using Interaction instead.

Examples

use retroglyph_core::{Grid, Rect};
use retroglyph_widgets::{Scrollbar, Surface, Widget};

let area = Rect::new(0, 0, 1, 10);
let mut grid = Grid::new(1, 10);
Scrollbar::new(100, 10)
    .offset(20)
    .render(area, &mut Surface::new(&mut grid, area, 0));

Implementations

impl Scrollbar

pub fn new(total_len: usize, visible_len: usize) -> Self

A scrollbar covering total_len items in a visible_len-row viewport, starting at offset 0 in the default style.

pub const fn offset(self, offset: usize) -> Self

Set the scroll offset the thumb is drawn at.

pub const fn track_style(self, style: Style) -> Self

Set the track’s style.

pub const fn thumb_style(self, style: Style) -> Self

Set the thumb’s style.

pub fn theme(self, theme: Theme) -> Self

Applies theme’s named roles to this scrollbar: track_style becomes theme.panel_bg (the same surface the scrolled content sits on), and thumb_style becomes theme.border: a subtle divider-like color rather than theme.accent, so a themed scrollbar doesn’t compete with an actually-selected/focused control for attention.

Call before any manual Scrollbar::track_style/Scrollbar::thumb_style override you want to keep.

pub fn theme_on(self, theme: Theme, bg: Color) -> Self

Same as Scrollbar::theme, but track_style is drawn on bg instead of theme.panel_bg: for a scrollbar drawn directly on a backdrop other than a themed super::Panel/super::Modal’s fill. Scrollbar::theme is exactly theme_on(theme, theme.panel_bg).

Trait Implementations

impl Clone for Scrollbar

fn clone(&self) -> Scrollbar

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Scrollbar

impl Debug for Scrollbar

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

Formats the value using the given formatter.

impl Widget for Scrollbar

fn render(&self, area: Rect, surface: &mut Surface<'_>)

Draw this widget into area, via surface scoped to it.