Protected Readonly_classProtected_closeClose button (clicked → hide(), surfaces the pill).
Protected Readonly_containerProtected_destroyedProtected_headerDrag handle inside the panel — usually the title row.
Protected Readonly_minProtected Readonly_minProtected Readonly_modalProtected_panelRoot panel element. Populated by subclass in _buildDom().
Protected_pillFloating "reopen" pill shown while the panel is hidden.
Protected Readonly_resizableProtected Readonly_storageProtected Readonly_tierReadonlyonFires while the user drags the panel (one notification per
pointermove during a drag) and once when the drag ends.
Drag changes the panel's CSS left / top but never its
size, so a ResizeObserver on any descendant element never
sees it. Subclasses or hosts that need to track the panel's
viewport position — for example a View
embedded in the body whose shared WebGL canvas must follow
the panel — should subscribe to this and re-read the
panel's bounding rect.
ReadonlyonFires when show() / hide() toggles the panel's visibility.
ReadonlyrendererRenderer used to capture the snapshot image, when set.
ReadonlyviewThe View whose state the panel exports.
true when the panel is mounted and visible (pill hidden).
Protected_bindWire the shared chrome behaviour onto the DOM the subclass built. Idempotent — calling twice is a no-op.
Protected_bindInject eight invisible drag handles (4 edges + 4 corners)
into _panel and wire pointer events. Each handle pins the
panel to absolute left / top on pointerdown (so subsequent
size + position writes take effect over any CSS that uses
right / bottom), then writes new width / height —
and, for north / west edges, new left / top — on
pointermove. onLayoutChanged fires per move and at drag-end;
the saved layout is updated on drag-end.
min-width / min-height enforced from _minWidth /
_minHeight; max-width / max-height are released by
setting them to "none" inline so user-driven size is not
clipped by CSS bounds like max-height: calc(100vh - 32px).
Protected_buildSubclass populates _panel, _pill, _header, _closeBtn
here, and appends _panel + _pill to _container. Called
exactly once, before _bindChrome.
Protected_clampProtected_restoreProtected_saveEngage the header drag from an external pointerdown / move
event so the panel begins following ev immediately. Used by
the drag-to-undock gesture on docked View cells — the cell's
own pointer listener detects motion-past-threshold, replaces
the cell with this freshly-created floating panel, and hands
the live pointer over via this method.
The panel is reflowed so the pointer sits inside its header at
(panelOffsetX, panelOffsetY) from the panel's top-left. Then
setPointerCapture routes all subsequent pointermove /
pointerup events for this pointerId to the panel's own
header, where _bindChrome's existing listeners drive
the drag — no parallel drag loop required.
OptionalpanelOffsetX: numberOptionalpanelOffsetY: numberTear down DOM + global listeners. Idempotent.
Hide the panel and surface the floating reopen pill.
Run saveBCFViewpoint against the current selection and
trigger a JSON download. Updates the footer status with
the result. Public so callers can also drive it from a
keyboard shortcut.
Reveal the panel; hide the floating reopen pill.
Toggle visibility.
StaticgetStaticiconSVG markup for the panel's title-bar glyph — the standard
"export" mark: an up-arrow rising out of an open tray.
Strokes use currentColor so the icon picks up whichever
colour the host element sets.
Staticopen
Abstract base for every floating demo panel. Subclasses build their DOM in
_buildDom(), then call_bindChrome()to activate drag / pill / persistence behaviour.