type: types.literal('MultiWaySyntenyDisplay') | | MultiWaySyntenyDisplay |
| **configuration**configuration: ConfigurationReference(configSchema) | | MultiWaySyntenyDisplay |
| **rowOrder**rowOrder: types.array(types.string) | lanes to pin to the top, in order; lanes it does not name follow densest-first, so the chain a ribbon draws through adjacent lanes is cut as late as possible and most stacks need no order authored at all. A declared property, so it is authorable from a session spec or a config defaultSession | MultiWaySyntenyDisplay |
| hiddenLanes: types.array(types.string) | mate lanes taken out of the stack, so a genome that places nothing in the region of interest stops holding a slot between two that do | MultiWaySyntenyDisplay |
| **id**id: ElementId | | [BaseDisplay](../basedisplay#property-id) |
## Volatiles
| Member | Description | Defined by |
| --- | --- | --- |
| **features**features: undefined as Feature[] | undefined | | MultiWaySyntenyDisplay |
| **laneGenes**laneGenes: undefined as Map<string, LaneGene[]> | undefined | per-lane gene models fetched from each assembly's own gene track, so a lane draws real exon structure at that genome's coordinates | MultiWaySyntenyDisplay |
| **laneLinks**laneLinks: undefined as Map<string, Feature[]> | undefined | alignments between ADJACENT mate lanes, fetched per pair from the same track when the source is an all-vs-all alignment file — the direct records the file holds for that pair, at the lanes' own coordinates | MultiWaySyntenyDisplay |
| **hoveredGroupKey**hoveredGroupKey: undefined as string | undefined | the ortholog group under the pointer; every ribbon of that group highlights, so one hover reads the group across all lanes | MultiWaySyntenyDisplay |
| **hoverTarget**hoverTarget: undefined as HoverTarget | undefined | the glyph, box or ribbon under the pointer — what a click opens and the tooltip names | MultiWaySyntenyDisplay |
| **laneDecisions**laneDecisions: new Map<string, LaneDecision | undefined>() | what the last settle decided per mate lane — contig, orientation, rung and where the lane is pinned to the anchor. Made once per settled block set by the installer in afterAttach, holding each choice until the evidence clearly moves; the frames the lanes draw in are derived from these against the live view | MultiWaySyntenyDisplay |
| **renderOriginPx**renderOriginPx: 0 | the view's scroll offset the stack is laid out against, refreshed with the decisions. Between refreshes a pan is one translate of the whole stack (`dragOffsetPx`), not a relayout of every lane | MultiWaySyntenyDisplay |
| **error**error: undefined as unknown | | [BaseDisplay](../basedisplay#volatile-error) |
| **statusMessage**statusMessage: undefined as string | undefined | | [BaseDisplay](../basedisplay#volatile-statusmessage) |
| **statusProgress**statusProgress: undefined as number | undefined | determinate progress fraction [0,1] for the current status, or undefined when the in-flight phase is indeterminate. Set alongside `statusMessage` by `setStatusMessage`; a display that never shows a bar simply leaves it undefined. | [BaseDisplay](../basedisplay#volatile-statusprogress) |
| **scrollTop**scrollTop: 0 | | [TrackHeightMixin](../trackheightmixin#volatile-scrolltop) |
| **loadedFetchSignature**loadedFetchSignature: undefined as string | undefined | `fetchSignature` as it stood when the held data was committed — the loaded half of this family's freshness compare. Written only by `commitFetchResult` and cleared only by `reload`, so a display cannot stamp data it did not fetch or forget to invalidate on retry; the data itself stays display-owned (arc keeps stale arcs on screen under the loading overlay, HiC keeps the stale matrix). | [GlobalFetchMixin](../globalfetchmixin#volatile-loadedfetchsignature) |
| **forceLoadTrack**forceLoadTrack: false | The force-load button's track-wide approval. Volatile so it never reaches a saved session; the `forceLoad` config slot is the durable form. | [RegionTooLargeMixin](../regiontoolargemixin#volatile-forceloadtrack) |
| **byteEstimate**byteEstimate: undefined as ByteEstimate | undefined | The last byte measurement: bytes, the span they were taken at, and whether zooming has been shown not to shrink them. Survives `clearAllRpcData`; dropped on chromosome navigation and on a tier swap. | [RegionTooLargeMixin](../regiontoolargemixin#volatile-byteestimate) |
| **gateMeasuredViewportKey**gateMeasuredViewportKey: undefined as string | undefined | The viewport key the gate last asked the adapter about, on either axis. Separate from `byteEstimate` because a density refusal measures no bytes. | [RegionTooLargeMixin](../regiontoolargemixin#volatile-gatemeasuredviewportkey) |
| **canvasDrawn**canvasDrawn: false | flips true on first paint; read by test selectors to detect render | [RenderLifecycleMixin](../renderlifecyclemixin#volatile-canvasdrawn) |
| **currentRenderingBackend**currentRenderingBackend: undefined | current backend reference, updated on context-loss recovery. Typed `unknown` (not generic `B`) on purpose: this mixin is composed by every display via a non-generic factory, so the per-display backend type `B` isn't known here — it's supplied at `attachRenderingBackend` and narrowed with `as B` inside the autoruns. Don't "fix" the cast. | [RenderLifecycleMixin](../renderlifecyclemixin#volatile-currentrenderingbackend) |
| **renderTick**renderTick: 0 | counter the render autorun observes; bumped to force a re-render | [RenderLifecycleMixin](../renderlifecyclemixin#volatile-rendertick) |
| **autorunsInstalled**autorunsInstalled: false | guards attachRenderingBackend so the autorun pair spawns once per instance | [RenderLifecycleMixin](../renderlifecyclemixin#volatile-autorunsinstalled) |
| **renderError**renderError: undefined | the render-backend (GPU/Canvas2D init or context-loss) error, or undefined. Single source of truth for the render-error terminal state: `useRenderingBackend` writes it from the canvas-init mechanism so the model — not React-local hook state — owns every terminal state. Read by `displayPhase` (whose `renderError` term outranks `loading`, suppressing the scrim) and by `DisplayChrome` (shows the retry overlay). | [RenderLifecycleMixin](../renderlifecyclemixin#volatile-rendererror) |
| **activeStopToken**activeStopToken: undefined as StopToken | undefined | stop token of the in-flight fetch, or undefined when idle | [FetchMixin](../fetchmixin#volatile-activestoptoken) |
| **fetchGeneration**fetchGeneration: 0 | bumps at every fetch end; autoruns read it to re-evaluate, and it doubles as the staleness epoch inside runFetch | [FetchMixin](../fetchmixin#volatile-fetchgeneration) |
| **reloadCounter**reloadCounter: 0 | Bumped by `reload()` and read unconditionally by the fetch autoruns, so a user retry re-runs the body even where nothing else moved — after an error every other fetch input is unchanged. It is also the half that survives a `reload()` override that forgets to invalidate, which is the dead Retry button `makeRetryContractCheck` reports. Declared here because this is the one mixin both LGV fetch foundations compose, the same argument that put `fetchInert` below; the comparative family carries its own on `SyntenyFetchStateMixin` (ADR-054). | [FetchMixin](../fetchmixin#volatile-reloadcounter) |
| **statusWindow**statusWindow: createStatusWindow(writeStatus(self)) | This display's status field, and the only thing that writes it: one throttle window, one slot per concurrent operation, so N parallel per-region fetches thin to one stream between them rather than N and a second operation cannot end the first one's label (ADR-081). Lent whole to `createStopTokenRotation` by a display that also runs a bare-autorun fetch — see `StatusReporter`. | [FetchMixin](../fetchmixin#volatile-statuswindow) |
| **fetchCanceled**fetchCanceled: false | true after the user explicitly cancels a load (the loading overlay's cancel button → `cancelFetchByUser`). A durable, blocking state — unlike `cancelFetch`, it does not retrigger the fetch autoruns — so the load stays stopped until the user retries (`reload`) or the viewport changes. Any new fetch clears it (`runFetch` resets it at the start). | [FetchMixin](../fetchmixin#volatile-fetchcanceled) |
| **fetchRotation**number | | MultiWaySyntenyDisplay |
| **viewSignature**string | undefined | staleness axis is the static-block set, same as arc: pan/zoom past a block boundary refetches, a scroll inside the loaded blocks does not | MultiWaySyntenyDisplay |
| **groups**MultiWayGroup[] | anchor-sorted gene groups reconstructed from the pairwise features | MultiWaySyntenyDisplay |
| **featuresAreNameless**boolean | a gene-level source names its features and groups chain on the names; an alignment-level source (all-vs-all PAF) names nothing, which is what makes the per-pair link fetch worth issuing | MultiWaySyntenyDisplay |
| **ribbonColor**string | | MultiWaySyntenyDisplay |
| **ribbonColorBy**MultiWayRibbonColorBy | | MultiWaySyntenyDisplay |
| **drawCurves**boolean | | MultiWaySyntenyDisplay |
| **bridgeSkippedLanes**boolean | | MultiWaySyntenyDisplay |
| **showLaneTicks**boolean | | MultiWaySyntenyDisplay |
| **selectedFeatureId**string | undefined | | MultiWaySyntenyDisplay |
| **anchorAssemblyName**string | | MultiWaySyntenyDisplay |
| **anchorAssembly**string | | MultiWaySyntenyDisplay |
| **rowAssemblies**string[] | mate assemblies densest-first, one lane each below the anchor lane, with any `rowOrder` lanes pinned above them. A paralogy record's mate is the anchor assembly itself; those draw on the anchor's own axis rather than as a lane | MultiWaySyntenyDisplay |
| **visibleBpSpan**number | | MultiWaySyntenyDisplay |
| **visibleGroups**MultiWayGroup[] | the groups whose anchor placement is inside the settled viewport — the population every lane's local frame is fitted to, so panning the anchor re-lays-out the other lanes | MultiWaySyntenyDisplay |
| **tickIntervalBp**number | the one bp interval every lane draws its ticks at, so tick spacing is readable as bp-per-pixel across lanes drawn in different frames | MultiWaySyntenyDisplay |
| **laneGeneAdapters**Map<string, Record<string, unknown>> | per lane, the session's own gene track for that assembly: the first GFF3 feature track declared for it alone. The real pipelines this display connects to (jcvi MCScan, HPRC CAT) derive their gene BEDs from exactly these annotations, so the lane's exon structure comes from the file the table was built from | MultiWaySyntenyDisplay |
| **anchorPlacements**Map<string, AxisPlacement> | where the view draws each visible group's anchor interval, in the view's px before the scroll offset and in the anchor's own direction — start end first, so a horizontally flipped view hands the ribbons the crossed pair it is drawing — with the clipped interval's centre as the coordinate a lane decision can pin to.number | how far the view has scrolled since the stack was laid out: the one live read a pan makes, applied as a translate over the whole stack | MultiWaySyntenyDisplay |
| **anchorReversed**boolean | the anchor axis reads right to left: a horizontally flipped view. A lane's decision is stated against the anchor's order, so this mirrors every lane with the anchor without a re-decision | MultiWaySyntenyDisplay |
| **anchorSpans**Map<string, Span> | the anchor placements in the stack's own px: what the anchor lane draws and what every ribbon out of it starts from | MultiWaySyntenyDisplay |
| **anchorAbsX**Map<string, { coord: AnchorCoord; x: number; }> | the first link of the alignment chain: each visible group's anchor centre and the view's px for it BEFORE the scroll offset, so a settle decision reading this does not re-run on every pan | MultiWaySyntenyDisplay |
| **rowFrames**Map<string, RowFrame | undefined> | each mate lane's local coordinate frame: the settle's decision against where the view draws its pivot now | MultiWaySyntenyDisplay |
| **laneGenesFetchSpecs**{ key: string; specs: LaneGenesFetchSpec[]; } | what the lane-genes autorun fetches: one spec per lane with a gene track, over the quantized window each lane's frame slides in | MultiWaySyntenyDisplay |
| **laneLinksFetchSpecs**{ key: string; specs: LaneLinksFetchSpec[]; } | one spec per ADJACENT mate-lane pair when the source is an all-vs-all alignment file: the upper lane's window queried against the lower lane's assembly, which an all-vs-all adapter answers with the direct records it holds for that pair | MultiWaySyntenyDisplay |
| **laneStack**LaneStack | the stack the picture is drawn from: one `Lane` per assembly, plus the geometry every layer places against. Every layer — bands, ticks, ribbons, glyphs, boxes, headers, the hover outline — is a walk over this, and the on-screen body and the SVG export walk the same one | MultiWaySyntenyDisplay |
| **palette**JBrowsePalette | | MultiWaySyntenyDisplay |
| **ribbonGeometry**RibbonGeometry | the ribbons between each adjacent lane pair as the synteny passes' instance data, in the stack's own px, plus what each ribbon opens | MultiWaySyntenyDisplay |
| **tickGeometry**TickGeometry | | MultiWaySyntenyDisplay |
| **bandCell**MultiWayCell | the opaque bands under the mate lanes, off the lane geometry rather than the stack: the stack moves on every pan and settle, the bands only when a lane comes or goes, and an unchanged cell uploads nothing | MultiWaySyntenyDisplay |
| **laneGlyphCells**Map<string, MultiWayCell> | one cell per lane: its gene models, its placement boxes and its baseline. The one place a jexl color slot is resolved per glyph, so the hover — a render parameter — never re-runs it | MultiWaySyntenyDisplay |
| **renderCells**ReadonlyMap<string, MultiWayCell> | everything the backend holds bytes for, keyed so an unchanged cell keeps its identity across a rebuild of the map and uploads nothing | MultiWaySyntenyDisplay |
| **renderLayers**MultiWayLayer[] | the stack back to front: bands under everything, since they exist to cover the view's gridlines; ribbons; each lane's ticks; each lane's glyphs over its own ribbons | MultiWaySyntenyDisplay |
| **hoveredFeatureId**number | the ribbon feature id the passes highlight: every ribbon of the hovered group shares one, so a hover over any gutter lights the group in all of them | MultiWaySyntenyDisplay |
| **hoveredGroupOutlines**{ lane: Lane; span: Span; }[] | the hovered group's placement in every lane that places it | MultiWaySyntenyDisplay |
| **renderState**MultiWayRenderState | what a frame draws with: the cells' layout and the one live transform | MultiWaySyntenyDisplay |
| **displayPhase**DisplayPhase | the dependent fetches are part of loading until they FIRST land, so an export or a capture never lands between the ortholog fetch and the gene models that fill the lanes. Not for later refetches: those run over lanes that are already drawn, and holding the phase at loading puts the striped scrim over them. A failed lane fetch commits an empty result rather than hanging this at loading (see afterAttach) | MultiWaySyntenyDisplay |
| **parentTrack**AbstractTrackModel | | [BaseDisplay](../basedisplay#getter-parenttrack) |
| **RenderingComponent**FC<…> | | [BaseDisplay](../basedisplay#getter-renderingcomponent) |
| **DisplayBlurb**Record<string, unknown> | | [BaseDisplay](../basedisplay#getter-adapterconfig) |
| **isMinimized**boolean | Returns true if the parent track is minimized. Used to skip expensive operations like autoruns when track is not visible. | [BaseDisplay](../basedisplay#getter-isminimized) |
| **hoveredFeature**unknown | Overridable hook (default `undefined`): what the pointer is currently over, for readers **outside** the display. `LinearGenomeViewContainer` publishes it to `session.hovered`, the view-wide "what is the user pointing at" channel a plugin can subscribe to.string | Overridable hook (default `'feature'`): the SINGULAR word for one of the things this display draws, as a menu row or a chip says it — "Hide this read", "Showing 3 variants".{ type: string; id: string; } | Overridable hook: which widget `openFeatureWidget` opens for one of this display's features. The default is the generic one, which is what a display drawing plain features wants and what the canvas base spelled out by hand.number | | [TrackHeightMixin](../trackheightmixin#getter-height) |
| **resizing**boolean | True for the duration of a height drag on this track, whichever handle is running it. A display whose row geometry is a function of the track height restretches every row per animation frame, and can use this to sit an expensive per-frame layer out of the drag (MAF's dense per-base letter overlay is a Canvas2D pass that scales with rows x columns).number | Overridable hook: how far this display's content can scroll past its viewport, in px. `Infinity` (the default) means "this display doesn't scroll internally" — `setScrollTop` then never clamps and the re-clamp autorun below is inert, so a non-scrolling display pays nothing and, crucially, never evaluates a getter that would read view geometry.RegionHost | The hosting view as the `RegionHost` contract — see `containingHost` for the cast it owns, why the name is `host` and not `view`, and why both foundations still declare the name over one body. | [GlobalFetchMixin](../globalfetchmixin#getter-host) |
| **viewportEmpty**boolean | No content block is on screen, so this display has nothing to fetch and nothing to paint — see `viewportEmpty.ts` for the one viewport that reaches it, how narrow that is, and why the state still has to be terminal rather than a permanent scrim. Both foundations declare it over that one expression, the same way they each declare `host` and `paintInert`. | [GlobalFetchMixin](../globalfetchmixin#getter-viewportempty) |
| **canRender**boolean | Overrides `RenderLifecycleMixin`'s default-true hook with the LGV precondition both foundations share — see `foundationCanRender`. | [GlobalFetchMixin](../globalfetchmixin#getter-canrender) |
| **fetchSignature**string | undefined | Signature of the fetch the current view and settings call for — the display's `viewSignature` plus the serialized `rpcProps()` axis. What `runGlobalFetch` gates on, captures at issue, and stamps at commit. | [GlobalFetchMixin](../globalfetchmixin#getter-fetchsignature) |
| **dataCurrent**boolean | The shared freshness answer, now derived rather than a hook: data has been committed (`loadedFetchSignature` is only ever written beside it) and it was fetched for the current view and settings. A pan inside the loaded blocks stays current; a block entering, a tier step, a settings change or a `reload()` moves one side of the compare and refetches. | [GlobalFetchMixin](../globalfetchmixin#getter-datacurrent) |
| **paintInert**boolean | Fills `RenderLifecycleMixin`'s `paintInert` hook — see there for why a failed fetch has to read as finished to the consumers outside the display, and `foundationPaintInert` for the second such state and why both fetch families answer it through one function. Overridable, as the hook is: a display with a third inert state of its own says so here. | [GlobalFetchMixin](../globalfetchmixin#getter-paintinert) |
| **svgReady**boolean | Policy single-sourced in `computeSvgReady`; this family supplies only the freshness half, which `foundationSvgReady` reads as `dataCurrent` or the vacuous currency of `viewportEmpty`. Note it requires the dataset to actually be current, NOT merely "not currently fetching": the fetch trigger is a debounced `afterAttach` autorun, so at export time `isLoading` can still be false with no data yet — a `displayPhase !== 'loading'` test would then capture an empty render. Never gates on `canvasDrawn`, which an off-screen export never sets. Off-screen renderers gate on it via `awaitSvgReady(model)`. | [GlobalFetchMixin](../globalfetchmixin#getter-svgready) |
| **gateEnabled**boolean | The opt-in. Overridden with a literal `true` by gated displays, and `check-gated-adapter-budgets` insists on a literal: this mixin returns early on it in an autorun and in `commitFetchBytes`. | [RegionTooLargeMixin](../regiontoolargemixin#getter-gateenabled) |
| **densityGateEnabled**boolean | Whether the density axis applies. `CanvasFeatureGateMixin` contributes `true` beside its measurement; byte-only displays leave it. | [RegionTooLargeMixin](../regiontoolargemixin#getter-densitygateenabled) |
| **byteGateAdapterConfig**Record<string, unknown> | The adapter config the gate measures — the one at `byteGateAdapterPath`. Overridable for a display whose adapter config is synthesized rather than read off the track. | [RegionTooLargeMixin](../regiontoolargemixin#getter-bytegateadapterconfig) |
| **configuredFetchSizeLimit**number | The display's `fetchSizeLimit` slot, from `regionTooLargeConfigSchemaFields`. | [RegionTooLargeMixin](../regiontoolargemixin#getter-configuredfetchsizelimit) |
| **densityTooLarge**boolean | The density axis's verdict; canvas overrides it. | [RegionTooLargeMixin](../regiontoolargemixin#getter-densitytoolarge) |
| **byteGateAdapterPath**string[] | Where on the track config the measured adapter sits. A tiered display overrides this one hook (MAF: `['adapter', 'summaryAdapter']` while `showSummary`), and both the measurement and the budget follow it. | [RegionTooLargeMixin](../regiontoolargemixin#getter-bytegateadapterpath) |
| **adapterFetchSizeLimit**number | undefined | The measured adapter's own `fetchSizeLimit` slot, read off the live track config rather than the `adapterConfig` snapshot, which omits slots at their default. | [RegionTooLargeMixin](../regiontoolargemixin#getter-adapterfetchsizelimit) |
| **configForceLoad**boolean | The declarative `forceLoad` slot. | [RegionTooLargeMixin](../regiontoolargemixin#getter-configforceload) |
| **gateViewport**GateViewport | undefined | What a measurement taken now would be about: the span on screen and a key for the stretch of genome it covers. Undefined until the view is measured, and the mixin's only read of the view. Captured before the fetch's round trip, never at commit. | [RegionTooLargeMixin](../regiontoolargemixin#getter-gateviewport) |
| **byteGateAdapterKey**string | Which tier the estimate is about, as a comparable string. | [RegionTooLargeMixin](../regiontoolargemixin#getter-bytegateadapterkey) |
| **aboveForceLoadFloor**boolean | Whether the span on screen is at or above `AUTO_FORCE_LOAD_BP`, the one comparison against that constant. False on an unmeasured view. | [RegionTooLargeMixin](../regiontoolargemixin#getter-aboveforceloadfloor) |
| **gateExempt**boolean | Nothing may gate on either axis: the `forceLoad` slot or the button. | [RegionTooLargeMixin](../regiontoolargemixin#getter-gateexempt) |
| **estimatedFetchBytes**number | undefined | The stored estimate's bytes; undefined when nothing has been measured. | [RegionTooLargeMixin](../regiontoolargemixin#getter-estimatedfetchbytes) |
| **gateMeasurementStale**boolean | Whether the last measurement is about a viewport the user has since left. True before any measurement. | [RegionTooLargeMixin](../regiontoolargemixin#getter-gatemeasurementstale) |
| **gateByteLimit**number | The byte budget: the adapter's limit, else the display's, doubled below `AUTO_FORCE_LOAD_BP`. Read only through `resolvedByteLimit()`. | [RegionTooLargeMixin](../regiontoolargemixin#getter-gatebytelimit) |
| **gateActive**boolean | Whether the gate may act right now, on any axis: opted in, not exempt, view measured. The view is read last, so an ungated display never touches it. | [RegionTooLargeMixin](../regiontoolargemixin#getter-gateactive) |
| **densityGateActive**boolean | `gateActive` plus the density axis's own terms: the axis is on, and the span is above the floor. | [RegionTooLargeMixin](../regiontoolargemixin#getter-densitygateactive) |
| **tooLargeStatus**RegionTooLargeStatus | The verdict and its banner text, from the stored estimate against `resolvedByteLimit()` and the density axis when it may act. | [RegionTooLargeMixin](../regiontoolargemixin#getter-toolargestatus) |
| **regionTooLarge**boolean | | [RegionTooLargeMixin](../regiontoolargemixin#getter-regiontoolarge) |
| **regionTooLargeReason**string | Banner text for the axis that tripped; empty when not too large. | [RegionTooLargeMixin](../regiontoolargemixin#getter-regiontoolargereason) |
| **zoomCanReleaseGate**boolean | Whether "zoom in to see features" is honest advice. Density always releases on zoom; bytes only if the last zoom-in moved the estimate. | [RegionTooLargeMixin](../regiontoolargemixin#getter-zoomcanreleasegate) |
| **gateSkipsMeasuredViewport**boolean | The skip both fetch skeletons apply: the banner is up and its measurement already describes the viewport on screen. | [RegionTooLargeMixin](../regiontoolargemixin#getter-gateskipsmeasuredviewport) |
| **rendersCanvas**boolean | Overridable hook (default true): whether this display paints a canvas in its **current** configuration, as opposed to a deliberate static placeholder (LD with the triangle off, sequence past base resolution — both render a message where the ` | [RenderLifecycleMixin](../renderlifecyclemixin#getter-renderscanvas) |
| **painted**boolean | **The first-paint answer every consumer outside the display should read**, `canvasDrawn` being only the raw flag: a display that is deliberately not painting a canvas has finished, and saying otherwise is a lie that never resolves.boolean | true while a fetch is active | [FetchMixin](../fetchmixin#getter-isloading) |
| **isLoadingOrCanceled**boolean | `isLoading` widened to cover a user-canceled load. **This, not `isLoading`, is what a `displayPhase` loading term wants.** `cancelFetchByUser` clears the stop token synchronously, so `isLoading` goes false the instant the user clicks Cancel — and the loading overlay that unmounts on it is carrying the Retry button, which is the only way back: the state is deliberately durable, so no autorun restarts the fetch on its own. A bare `isLoading` therefore reads as `ready` over a display that is stopped, empty and offering nothing.boolean | Overridable hook (default false): the states where this display deliberately never fetches, so it holds no data and none is coming. Sequence sets it past base resolution ("Zoom in to see sequence"); LD sets it with the triangle toggled off.boolean | Overridable hook (default false), read only by the dev-only retry check (`makeRetryContractCheck`): "this run declined because a prerequisite fetch in another autorun has not landed, and its arrival wakes this one again". It **defers** the retry verdict to that later run rather than waiving it, so a display cannot spend its retry on a decline it called preliminary.string | The RPC cache key both fetch foundations invalidate on: this display's `rpcProps()` payload serialized to a string. `serializeRpcProps` owns the why, including the silently-dead-axis corollary.(assemblyName: string) => boolean | whether the session holds a lane's genome under any spelling, which is what a navigation onto it needs and a lane drawn from a blocks table does not | MultiWaySyntenyDisplay |
| **hitTest**(x: number, y: number) => HoverTarget | undefined | what sits under a container-relative point: a lane's glyph or box first, since they draw over the ribbons, then a ribbon through the backend's pick | MultiWaySyntenyDisplay |
| () => MenuItem[] | the same multi-panel launch the view menu and the rubberband offer, from the track that is already showing the lanes: every genome aligning to the visible window gets a full row of its own in a stacked linear synteny view, cut from this track's dataset. Appended to the inherited items rather than replacing them, so a mixin's item is not dropped by being composed under this one | MultiWaySyntenyDisplay |
| **renderingProps**() => number | undefined | The budget the worker enforces and the banner compares against — the one spelling of that pair. Undefined when the gate may not act. | [RegionTooLargeMixin](../regiontoolargemixin#method-resolvedbytelimit) |
| **gateFetchState**() => GateFetchState | The gate as it stands for a fetch about to be issued. Calling it is the capture, which is why it is a method. | [RegionTooLargeMixin](../regiontoolargemixin#method-gatefetchstate) |
## Actions
| Member | Description | Defined by |
| --- | --- | --- |
| **setFeatures**(f: Feature[]) => void | | MultiWaySyntenyDisplay |
| **setLaneGenes**(genes: Map<string, LaneGene[]>) => void | | MultiWaySyntenyDisplay |
| **setLaneLinks**(links: Map<string, Feature[]>) => void | | MultiWaySyntenyDisplay |
| **setHoveredGroupKey**(key: string | undefined) => void | | MultiWaySyntenyDisplay |
| **setLaneFrames**(order: string[]) => void | | MultiWaySyntenyDisplay |
| (names: string[]) => void | | MultiWaySyntenyDisplay |
| **setBridgeSkippedLanes**(flag: boolean) => void | | MultiWaySyntenyDisplay |
| **setRibbonColorBy**(mode: MultiWayRibbonColorBy) => void | | MultiWaySyntenyDisplay |
| **setDrawCurves**(flag: boolean) => void | | MultiWaySyntenyDisplay |
| **setShowLaneTicks**(flag: boolean) => void | | MultiWaySyntenyDisplay |
| **selectFeature**(feature: Feature) => void | | MultiWaySyntenyDisplay |
| **openInNewView**(assemblyName: string, loc: string) => void | a lane's assembly in a linear genome view of its own, at `loc`, with this track along so the new view is the same stack anchored there | MultiWaySyntenyDisplay |
| **reanchor**(assemblyName: string, loc: string) => void | the hosting view onto `assemblyName` at `loc`; the anchor lane reads off the view's first assembly, so the stack re-anchors on its own | MultiWaySyntenyDisplay |
| **setHoverTarget**(target: HoverTarget | undefined) => void | | MultiWaySyntenyDisplay |
| **startRenderingBackend**(backend: MultiWayRenderingBackend) => void | the backend's cells and frame, through the one installer: a cell re-uploads when its identity changes and a frame redraws on anything the render state reads, which on a pan is the drag offset alone | MultiWaySyntenyDisplay |
| **setPointer**(state?: MouseState | undefined) => void | | MultiWaySyntenyDisplay |
| **selectHovered**() => void | | MultiWaySyntenyDisplay |
| **renderSvg**(status?: RpcStatus | undefined) => void | | [BaseDisplay](../basedisplay#action-setstatusmessage) |
| **setError**(error?: unknown) => void | | [BaseDisplay](../basedisplay#action-seterror) |
| **clearHoveredFeature**() => void | Overridable hook (default no-op): drop whatever `hoveredFeature` reports. The writing twin of that getter, and what `installClearHoverOnViewportChange` calls.() => void | base display reload does nothing, see specialized displays for details | [BaseDisplay](../basedisplay#action-reload) |
| **setScrollTop**(scrollTop: number) => void | Clamped into `[0, scrollableHeight]`, so no caller has to remember the bound. Unbounded for a display that leaves `scrollableHeight` at its `Infinity` default. | [TrackHeightMixin](../trackheightmixin#action-setscrolltop) |
| **setHeight**(displayHeight: number) => number | | [TrackHeightMixin](../trackheightmixin#action-setheight) |
| **resizeHeight**(distance: number) => number | | [TrackHeightMixin](../trackheightmixin#action-resizeheight) |
| **expandToContentHeight**() => number | Grow the track by exactly the content it is currently hiding, so a display scrolled over a taller stack ends up showing all of it. The track's resize handle runs this on a double click.(commit: () => void, signature: string) => void | The commit half of `runGlobalFetch`: run the display's own store in the same transaction as the signature stamp, so no observer can see fresh data under a stale signature or the reverse. Being the only writer of `loadedFetchSignature` is what makes `dataCurrent` derivable — a display cannot commit without stamping. | [GlobalFetchMixin](../globalfetchmixin#action-commitfetchresult) |
| **setByteEstimate**() => void | Drops the estimate and the viewport stamp. `forceLoadTrack` survives: it is a track-wide approval. | [RegionTooLargeMixin](../regiontoolargemixin#action-clearbyteestimate) |
| **setForceLoadTrack**(flag: boolean) => void | | [RegionTooLargeMixin](../regiontoolargemixin#action-setforceloadtrack) |
| **commitFetchBytes**() => void | The banner's button: exempt the track on both axes and refetch. | [RegionTooLargeMixin](../regiontoolargemixin#action-forceload) |
| **markCanvasDrawn**() => void | | [RenderLifecycleMixin](../renderlifecyclemixin#action-markcanvasdrawn) |
| **resetCanvasDrawn**() => void | | [RenderLifecycleMixin](../renderlifecyclemixin#action-resetcanvasdrawn) |
| **stopRenderingBackend**() => void | | [RenderLifecycleMixin](../renderlifecyclemixin#action-stoprenderingbackend) |
| **renderNow**() => void | | [RenderLifecycleMixin](../renderlifecyclemixin#action-rendernow) |
| **setRenderError**(error: unknown) => void | set/clear the render-backend error. Called by `useRenderingBackend`: with the error when the canvas factory rejects (or context-loss re-init fails), and with `undefined` on successful (re)init and on retry. | [RenderLifecycleMixin](../renderlifecyclemixin#action-setrendererror) |
| **attachRenderingBackend**() => void | Abort the in-flight fetch (if any) and retire its slot. The shared preamble of both cancel paths; the difference between them is only what they do to `fetchCanceled` / `fetchGeneration` afterward. | [FetchMixin](../fetchmixin#action-stopactivefetch) |
| **openStatusStream**(isCurrent: () => boolean) => StatusStream | Open one operation's slot on the display's status field: an RPC `statusCallback` throttled through the display-wide window and guarded so a callback that fires after the node is torn down (RPCs resolve their status stream asynchronously) is a safe no-op, plus the `clear` that retires the slot when the operation ends.() => void | cancel any in-flight fetch and bump fetchGeneration (always bumps, so callers can retrigger fetch autoruns even when nothing was in flight). This is the *internal* reset `clearAllRpcData` runs — it clears any user-cancel flag so the retrigger actually re-fetches. | [FetchMixin](../fetchmixin#action-cancelfetch) |
| **cancelFetchByUser**() => void | User-initiated cancel from the loading overlay. Stops the in-flight fetch and lands in a durable `fetchCanceled` state. Unlike `cancelFetch`, it does NOT bump fetchGeneration — so the fetch autoruns don't immediately restart the load. The user retries via `reload` (the overlay's retry button), or it clears on the next viewport change. | [FetchMixin](../fetchmixin#action-cancelfetchbyuser) |
| **beforeDestroy**() => void | Release an in-flight fetch's stop token on teardown. Without this, a display destroyed mid-fetch (track/view closed while loading) never signals the worker to abort the now-useless work, and its in-flight HTTP reads keep downloading. MST auto-chains lifecycle hooks, so a composing display can still define its own beforeDestroy. | [FetchMixin](../fetchmixin#action-beforedestroy) |
| **endFetch**(current: boolean, stopToken: StopToken) => void | The `finally` half of `runFetch`'s bookkeeping, an action of its own because `runFetchOnce`'s `finally` resumes on a microtask the flow does not own — a direct volatile write there is outside the action context, which is the one thing hoisting the sequence into a shared function costs. The stale branch is a superseded fetch: whoever superseded it — a newer `begin`, or `cancel` — already released this token. | [FetchMixin](../fetchmixin#action-endfetch) |
| **runFetch**(work: (ctx: FetchContext) => Promise<void>) => Promise<void> | Run a cancel-safe fetch (cancels any prior). The work callback gets a FetchContext with a stopToken to forward to the RPC and an isStale() check to short-circuit commits once the user has moved on.