OptionalcontainerOptionalrendererRenderer used to capture the snapshot image. When omitted,
the Snapshot option is disabled — saveBCFViewpoint
itself never reads the canvas, so the snapshot field has to
be filled in by the panel from renderer.getSnapshot(view).
OptionalstoragelocalStorage key for persisting drag position + closed
state. Defaults to "xkt-bcf-panel".
View whose state gets captured into the BCF viewpoint. Doubles as the WeakMap key for ExportBCFPanel.openFor idempotence — one panel per View.
OptionalvisibleShow on construction (default true).
DOM container; defaults to
document.body.