The indicators pane

crates/vike-studio/src/indicators.rs is the Studio's window onto the indicator registry. Its header describes a pane that browses the single-series indicators, configures a selection's parameters, and previews the computed series over the currently loaded bars; the browse and compute helpers are pure and unit-tested, and the egui render is thin over them. The registry itself, every indicator with its parameters and defaults, is the indicators tree.

Browsing

The search box's hint reads "Search 171 indicators…" — the count the pane's header states for the registry's single-series entries. grouped_search is the one list-building function: a case-insensitive substring match over an indicator's short name and its pretty name (an empty query matches everything), grouped by category in a fixed display order, skipping empty groups. The order is CATEGORY_ORDER's — Trend, Momentum, Volatility, Volume, Statistics, Patterns, Price, Structure — with the labels Category::label in crates/vike-indicators/src/registry.rs gives them (the first is the Overlap category). It is a fixed array rather than a map because Category is a plain discriminant enum with no ordering of its own.

Each group renders as an accent-coloured heading over selectable rows showing the pretty name; the selected entry's pretty name and (short_name) sit above its parameters. A selection is stored by name, so it survives re-filtering the search box.

Parameters

IndicatorsPane::select resets the parameters to the registry's defaults — default_params, in the order the indicator's constructor takes them, and empty for parameterless indicators such as vwap or obv — and clears any stale preview or error. Each parameter becomes a slider over the registry's declared min..=max with its step and its name as the trailing label; the slider is sized to the panel so a long parameter name cannot push the icon rail off-screen, which the pane's comment records as exactly the over-wide row the old layout allowed.

Compute and preview

The Compute button returns true to the shell for one frame, and the shell does the rest — IndicatorsPane::ui never touches the store, which is what keeps the pane's logic testable. StudioState::compute_indicator_preview loads the picked slice's bars synchronously; the compute is linear in the bar count and cheap, so unlike Run it needs no worker thread. Three refusals surface as the pane's own error line:

• no slice picked — "pick a data slice first";
• a tick slice — "indicators need a bar slice — pick one from the Data combo", because indicators are bar-series maths;
• a load failure, with the store's message.

compute_indicator coerces the raw slider values against the parameter specs, builds a fresh instance, and batch-computes it over the bars with vectorize — one output vector per declared output line, empty vectors for empty input. The explicit coercion is cheap and idempotent even though every registry constructor coerces internally; the registry's own doc asks external callers to do it anyway. compute_indicator_matches_a_hand_computed_sma pins the result against a hand-computed mean.

The preview is a 160-pixel plot, one line per output series named from the indicator's output list (falling back to the indicator's name), with NaN samples — the warm-up — filtered out of the points rather than drawn. Until Compute is pressed the pane says "Press Compute to preview."