Interface IndicatorHost

Attach a band drawn behind the plots (an Ichimoku cloud).

Add the pane-legend row (name + inline up/down/hide/maximize/close).

Add a reference level. One options object rather than seven positional arguments: the list grew a width and a dash style in 1.7.1, and a call site of seven bare values is where the next one gets passed in the wrong slot.

Attach an arbitrary primitive to a pane, and detach it again. Carries both the descriptor's drawing layer and whatever a Tier-2 attach lifecycle wants to paint, so those two do not need a host method each.

Optional, like timezone, so a host predating it still satisfies this interface: an indicator that draws simply draws nothing there.

Attach a corner-pinned summary grid to a pane, and detach it again.

Optional instrument identity and source-range notifications.

Emit on the chart's event bus (indicator alerts, and attach's own events).

Recompute whatever the host has marked stale, before a caller reads a value.

Optional, like timezone, so a host predating it still satisfies this interface: one that recomputes eagerly has nothing to flush.

Write a number the way the price axis of that pane writes it.

The legend sits inches from the axis and names the same quantity, so the two disagreeing is the reading a user has to reconcile themselves. Deriving the format here from a tick got that wrong twice over: a study pane carries no tick at all, so a percentage read 0.618 beside an axis saying 0.62, and a price pane's tick alone misses the precision floor and the host's own formatter, so a volume study read seven digits where its axis said 1.20M.

Asking the scale removes the second opinion. Optional so a host driving this module alone still works, falling back to the magnitude ladder.

Forget a disposed instance, including disposal through its public handle.

How many legends already sit on this pane, so rows stack.

Index of a fresh pane for an indicator that wants its own.

Chart wall clock in UTC seconds. Absent means the system clock.

Detach a signal-marker layer. There is no matching add: the layer comes from series.createMarkers() on a plot's own series, so it already lands in the right pane. Removing a series does not remove its primitives, hence this.

Publish an indicator's per-bar colours onto the primary price series, or withdraw them with null. owner is the instance id: a host holds one overlay at a time and only lets its current owner withdraw it, so a second publisher taking over does not get cleared by the first one's teardown.

Optional, like timezone: a host that does not implement it simply gives a barColors descriptor nowhere to publish, and the indicator's own plots are unaffected.

Pin a pane's price scale to a fixed range, or release it with null.

Bars of the primary price series — the calculation input.

The instrument and timeframe on screen, when the host knows them. The host can supply an explicit dataContext instead. Without either hook, a descriptor sees undefined rather than a guessed identity.

Tick size of the named pane's price scale, or undefined when none is set. Optional so a host predating it still satisfies this interface.

Per pane, and the panes genuinely differ: a pane that does not quote the instrument has no tick to report. Pane 0 is the price pane, so it is the one to ask for the instrument's own step.

The chart's configured IANA zone. Optional so a host predating the option still satisfies this interface; absent means the shipped default.

A descriptor is handed bars and settings and never the chart, so this is how the calendar an anchor resets on (a VWAP session, a seasonality month) reaches the calculation. See IndicatorInstance._descriptorSettings.