Interface LayerSwitchTraceState

Unique identifier for the layer/trace

What this layer is, when the producer named it — see MaidrLayer.name. Announced on a layer switch in place of the trace type, which cannot tell two layers of one kind apart.

The x axis label the layer authored; empty when it authored none, or a blank one -- as FigureState does. Point announcements use the trace's own generic fallback, not this.

The y axis label the layer authored, or empty. See xAxis.

Array of audio states for all lines that intersect at the current point. Used for intersection-aware audio playback in multiline plots. null/undefined for normal points (single line or no intersection).

Number of groups/series in the plot. Only present for multiline plots where plotType === 'multiline'.

Label and name of the group/series the cursor is currently on, e.g. { label: 'Group', value: 'Series 1' }. Only present for multiline plots (plotType === 'multiline') whose data names its groups; absent when the spec authors no names, so consumers can omit group wording rather than announce a positional placeholder.

Plot orientation, if applicable (e.g. bar, box, violin).

Where the first slice of a pie begins, in degrees clockwise from 12 o'clock, as the layer declared it (see MaidrLayer.startAngle). Present only for a pie, whose position announcement places each slice on the dial from here.

Where a tree's node sits among the siblings the arrow keys walk, and at which level. Present for a tree, whose braille grid and pan run across the whole depth -- every node at it, whoever its parent -- while left and right stop at the parent's last child, so neither says where the reader is; and for a directed graph, whose scopes nest as a tree's levels do. index and level are zero-based; parent is the parent's name, absent at the top level.

Which observation of a rug the cursor is on, of how many, in the order the arrow keys walk them: ascending along the axis. Present only for a rug, whose pan follows where the tick is drawn and whose braille grid counts the ticks in each bin, so neither says which observation the reader is on. index is zero-based.