OptionalcollapsedStart collapsed.
OptionalcollapsibleOptionalenabledOptionalentriesDeclared entries, or a function re-resolved against the live graph every time the legend rebuilds (so the list can follow the data).
OptionalfilterableClicking an entry filters the graph. false renders a pure key.
OptionalhighlightHovering an entry reads its category off the canvas: the elements it stands for
keep their look, everything else dims until the pointer leaves. Works on a
filterable: false key too — pointing at a category asks nothing of the graph.
OptionalidStable identity: the section's own filter key (__legend:<id>) and the
section field of the legendToggle event.
OptionalkeyDerived mode: the data key whose distinct values become the entries, each
swatch sampled from the renderer's resolved style. Read off nodes, or off edges
when scope is 'edge'. Also supplies the default predicate when
entries are declared without one.
OptionalmaxEntries shown before the list scrolls.
OptionalscopeWhich collection this section keys on. 'edge' lists the graph's relation
kinds with a line swatch — stroke colour, dash and marker as the renderer
resolved them — and its toggles hide edge layers: the nodes stay put, and so
do the layout, the selection and the camera.
An edge section filters whether or not UI.filter.edgeFacets declares its
key: given one it drives that facet, so the panel and the legend are two views
of one filter; without one it reserves a facet of its own.
OptionalshowShow a per-entry element count.
OptionaltitleHeader text, used verbatim (so it can be translated).
One section of the legend: a key for one dimension of the data. These are LegendOptions minus
position— a section never claims a corner of the canvas, the card it is stacked in does (see LegendGroupOptions).