type: types.literal('LinearHicDisplay') | | LinearHicDisplay |
| **configuration**configuration: ConfigurationReference(configSchema) | | LinearHicDisplay |
| **id**id: ElementId | | [BaseDisplay](../basedisplay#property-id) |
## Volatiles
| Member | Description | Defined by |
| --- | --- | --- |
| **rpcData**rpcData: null as HicDataResult | null | | LinearHicDisplay |
| **availableNormalizations**availableNormalizations: undefined as string[] | undefined | | LinearHicDisplay |
| **availableResolutions**availableResolutions: undefined as number[] | undefined | | LinearHicDisplay |
| **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 | | LinearHicDisplay |
| **hasResolutions**boolean | Whether the `.hic` file's binsize list has arrived (it comes from the async CoreGetInfo call in afterAttach). Every resolution control — the track-menu stepper, the on-figure dropdown and its enabling checkbox — is gated on this rather than re-deriving `availableResolutions?.length`. | LinearHicDisplay |
| **awaitingPrerequisite**boolean | Retry here is two-stage: `reload()` wakes the info autorun and the contacts one, the contacts one runs first and declines because the header it needs has not landed, and the header arriving wakes it again through the same tracked read. So the retry contract is judged on that later run. Not `fetchInert`, which would be the wrong claim — HiC does want the scrim meanwhile.boolean | | LinearHicDisplay |
| **useColorPercentile**boolean | | LinearHicDisplay |
| **showResolutionControls**boolean | | LinearHicDisplay |
| **selectedNormalization**string | The user's persisted normalization choice. May name a scheme the current `.hic` file doesn't actually offer — `activeNormalization` resolves that. | LinearHicDisplay |
| **activeNormalization**string | The normalization to *request*, resolved against what the file offers (`availableNormalizations`). Falls back to the next-best available scheme when the selection is absent (the parser silently uses NONE otherwise). A pure getter, so opening a file that lacks the selected scheme never writes a config delta / marks the track edited — only an explicit user pick (setActiveNormalization) does.boolean | | LinearHicDisplay |
| **appliedNormalization**string | The normalization the loaded matrix actually carries, which differs from `activeNormalization` whenever the file has no vectors for the requested scheme at the current binsize (KR at 5 kb but nothing at 2.5 Mb is typical). The track menu ticks this, so the radios describe the data on screen rather than the request that produced it. Falls back to the request before any data has landed."fall" | "juicebox" | "viridis" | | LinearHicDisplay |
| **colorMaxScore**number | Where the color ramp saturates. `0` is the "no data to scale against" sentinel; `hasLegendData` is the one place it's interpreted.boolean | Whether there's a color scale worth drawing a legend for: data loaded with a positive saturation point. The single place the `colorMaxScore` "0 means nothing to show" sentinel is interpreted — legend consumers read this, not the raw score. | LinearHicDisplay |
| **showLegendArea**boolean | Whether a legend is drawn: the setting is on AND there is a scale worth drawing one for. Read by both the on-screen overlay panel and the SVG export, so an export can't disagree with the figure it is exporting. `svgLegendWidth()` deliberately does not gate on this — see its note. | LinearHicDisplay |
| **autoResolutionIdx**number | Index into `availableResolutions` that pure auto-mode would pick at the current zoom — largest binsize ≤ 2*bpPerPx, falling back to the finest binsize (idx 0) when nothing qualifies (very zoomed in).number | Vertical squash of the triangle. Bidirectional fill like the LD display: dragging taller than the natural triangle height stretches to fill rather than leaving a blank band below.number | The box the matrix is drawn in: the canvas element's CSS width and the backing store the rendering backends resize to (`renderState`) have to be one number, or the drawn matrix is stretched against the box it sits in. Same name and same reason as the LD display's.number | Index actually used after applying `resolutionBias`, clamped to the valid range so a stale bias from a different zoom level can't index out of bounds. | LinearHicDisplay |
| **effectiveResolution**number | undefined | The actual binsize to fetch at, after auto-pick + bias. | LinearHicDisplay |
| **canStepResolutionFiner**boolean | Whether a finer binsize exists to step to. The stepper controls read this rather than compare indices themselves, so the edges of the file's binsize list are described in one place. | LinearHicDisplay |
| **canStepResolutionCoarser**boolean | Whether a coarser binsize exists to step to. | LinearHicDisplay |
| **viewSignature**string | undefined | HiC's half of `GlobalFetchMixin`'s freshness compare: the static-block set plus the binsize the current zoom calls for, so a pan inside the loaded blocks is a pure redraw and only a real change — a block entering, a zoom (static blocks re-snap, and the binsize may step) — refetches. Undefined until the view is measured and the `.hic` header has landed, which is the prerequisite gate. The normalization axis rides in through the `rpcPropsCacheKey` half the mixin appends.{ viewScale: number; viewOffsetX: number; } | The per-frame map from the payload's pre-rotation data space (origin-relative axis bp / √2) to canvas px, read by the render state, the hit test and the SVG export so the three cannot disagree. Worker output is genomic, so this is pure live-view arithmetic — pan and zoom move it every frame with no refetch — and the one payload-derived term, `originBp`, folds the axis origin back in here, in double precision, which is what keeps float32 instance positions small (see `calcAxisBlocks`). Stale data during a refetch simply draws at its own genomic position under the live map. | LinearHicDisplay |
| **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) |
| **displayPhase**DisplayPhase | The display's mutually-exclusive visual state, mapped in `foundationDisplayPhase` — every foundation calls it and supplies only its staleness argument, so a term added to `computeLoadingTerm` reaches all of them without being wired twice.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.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.boolean | Whether the legend is drawn. Resolved through the promotable-slot tiers (`resolveConf`): an explicit track value customizes it either way, otherwise it follows the session-wide default for this display type, falling back to the slot's `promotedBase`. | [LegendMixin](../legendmixin#getter-showlegend) |
| **showLegendDisplayTypeDefault**Pin | The "make the current legend visibility the default for all tracks" control. Symmetric, so it promotes whichever value the track currently shows. `showLegendCheckboxItem` takes this as its `pin`. | [LegendMixin](../legendmixin#getter-showlegenddisplaytypedefault) |
## Methods
| Member | Description | Defined by |
| --- | --- | --- |
| **rpcProps**() => { normalization: string; } | | LinearHicDisplay |
| **hitTest**(mouseX: number, mouseY: number) => HicContactItem | undefined | Inverse of the view transform: takes mouse coords (canvas-relative) and returns the contact bin under the cursor, or undefined. The forward transform is `viewTransform`; this is its inverse so hit-testing always matches what was drawn. | LinearHicDisplay |
| **renderState**HicRenderState | Computed per-frame render state for the GPU backend. Read by the autorun lifecycle on every change to any tracked observable. Always resolved (a bare getter must never hand back undefined) — it's pure view/settings geometry, and "no data yet" is the render callback's gate, not a nullable state. The one data-derived field, `binWidth`, rides with the payload instead (see HicUploadData). | LinearHicDisplay |
| **svgLegendWidth**() => number | Width of the SVG legend (consumed by SVGLinearGenomeView), via the shared helper — see `gradientSvgLegendWidth` for why it reserves on the setting alone rather than gating on `hasLegendData`. | LinearHicDisplay |
| () => MenuItem[] | | LinearHicDisplay |
| **renderSvg**(opts: ExportSvgDisplayOptions) => Promise<ReactNode> | | LinearHicDisplay |
| **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 |
| --- | --- | --- |
| **setRpcData**(data: HicDataResult) => void | `runGlobalFetch` stamps the signature this was fetched for (`GlobalFetchMixin.commitFetchResult`) in the same transaction. | LinearHicDisplay |
| **startRenderingBackend**(backend: HicRenderingBackend) => void | Called by the React hook (`useRenderingBackend`) when the HAL resolves. Wires the backend into the mixin-owned autorun pair via `attachRenderingBackend`. | LinearHicDisplay |
| **setUseLogScale**(f: boolean) => void | | LinearHicDisplay |
| **setUseColorPercentile**(f: boolean) => void | | LinearHicDisplay |
| **setShowResolutionControls**(f: boolean) => void | | LinearHicDisplay |
| **setColorScheme**(f: "fall" | "juicebox" | "viridis") => void | | LinearHicDisplay |
| **setActiveNormalization**(f: string) => void | Persist the user's explicit normalization pick. Resolution against what the file offers happens in the `activeNormalization` getter, so this only fires on a real user choice. | LinearHicDisplay |
| **setAvailableNormalizations**(f: string[]) => void | Record what the `.hic` file offers. Resolution lives in the `activeNormalization` getter (which falls back off this list when the user's `selectedNormalization` isn't available), so this doesn't write the selection — opening a file that lacks the selected scheme never marks the track edited. | LinearHicDisplay |
| **setSquashToHeight**(arg: boolean) => void | | LinearHicDisplay |
| **setAvailableResolutions**(f: number[]) => void | | LinearHicDisplay |
| **resetResolutionBias**() => void | Reset to pure auto-mode: bias 0, binsize follows zoom directly. | LinearHicDisplay |
| **setResolutionIdx**(idx: number) => void | Lock the display to `availableResolutions[idx]`, stored the way the config slot wants it: an offset from whatever pure auto-mode would pick at the current zoom, so a locked choice keeps shifting consistently as the user zooms rather than pinning an absolute binsize.(binSize: number) => void | Lock to a specific binsize (from the overlay dropdown). No-op if the binsize isn't one the file offers. | LinearHicDisplay |
| **stepResolution**(delta: number) => void | Step one entry finer (negative delta) or coarser (positive) from the binsize currently in effect. A step at either edge lands on the edge rather than indexing out of bounds — the menu's stepper disables there, and this keeps that from being the only thing standing between a bad index and a fetch. | LinearHicDisplay |
| **setStatusMessage**(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.(arg: boolean) => void | | [LegendMixin](../legendmixin#action-setshowlegend) |