ChartWindow

ChartWindow<T> — a "last N points per series" streaming projection over a crate::ChartModel.

Wraps a ChartModel<T> and exposes the tail window_size points of every series — the live-scrolling-strip-chart pattern (a sensor feed, a log-rate graph, a stock ticker). Unlike crate::ChartAggregate, ChartWindow copies no point data: it tracks, per series, the source index of the window's first visible point (starts) and delegates every read straight through to the source. That means a ChartWindow<T> needs no T: Clone bound at all.

Reactivity

The upstream ChartChange stream is translated, not collapsed to a blanket Reset (unlike crate::SortFilterListModel, where an arbitrary sort-key move makes fine-grained translation unsafe — a fixed-size tail window has no such hazard): a tail append into a full window becomes a PointsRemoved + PointsInserted pair (the window slides), a tail append into a still-growing window becomes a plain PointsInserted, and symmetrically a tail removal (trimming the series' own end — e.g. discarding a bad trailing reading) becomes the mirror-image PointsRemoved + PointsInserted pair: points beyond the new total drop out of the window, and if the window slid backward to stay full, the newly-uncovered prefix is revealed as an insertion. Anything that isn't a clean tail append/removal (a mid-series insert or removal) falls back to a per-series rebuild reported as SeriesDataReplaced.

use teksilo_data::{ChartModel, ChartWindow};
let model: ChartModel<i32> = ChartModel::new();
let s = model.add_series("sensor");
for i in 0..100 {
    model.push_point(s, i, i as f32);
}
let window = ChartWindow::new(model.clone(), 10);
assert_eq!(window.point_count(s), 10); // last 10 points only

Builder methods at a glance

window_size, set_window_size, series_count, series_ids, point_count, with_series, with_point, observe_changes, first_changed_index

API reference

📖 Full rustdoc API for this module

`pub struct ChartWindow`

A "last N points per series" streaming projection over a ChartModel<T>.

See the module documentation for semantics.

#![allow(unused)]
fn main() {
pub struct ChartWindow<T: 'static> { /* fields */ }
}

Methods

`pub fn new(source: ChartModel<T>, window_size: usize) -> Self`

Wrap source, showing only the last window_size points of every series.

`pub fn window_size(&self) -> usize`

The configured window size.

`pub fn set_window_size(&self, window_size: usize)`

Change the window size, rebuilding every series and emitting ChartChange::Reset.

`pub fn series_count(&self) -> usize`

Number of series (same set as the source).

`pub fn series_ids(&self) -> Vec<SeriesId>`

The series ids, in the source's display order.

`pub fn point_count(&self, series: SeriesId) -> usize`

Number of points currently visible in the window for series.

`pub fn with_series<R>( &self, series: SeriesId, f: impl FnOnce(&str, Option<&ColorProp>, bool) -> R, ) -> Option<R>`

Access a series' metadata (delegates straight through to the source). Returns None if series is unknown.

`pub fn with_point<R>( &self, series: SeriesId, index: usize, f: impl FnOnce(&ChartDatum<T>) -> R, ) -> Option<R>`

Access the point at window-local index within series. Returns None if series is unknown or index is outside the window.

`pub fn observe_changes(&self, f: impl Fn(&ChartChange) + 'static) -> ObserverHandle`

`pub fn first_changed_index(&self, series: SeriesId) -> Option<usize>`

First window-local index of series whose content may differ since the latest translated change. Per-series (chart data is 2-level: series, then points), unlike SortFilterListModel::first_changed_index's single flat value. None if series is unknown or unaffected yet.

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