Skip to main content

BaseViewModel

Auto-generated from the @jbrowse/mobx-state-tree model in the source — see the developer guide for concepts. Built into JBrowse core. View source.

Holds a view's id, the name shown in its header, its width and whether it is minimized. Every view composes this model.

Properties

MemberDescription
id
id: ElementId
displayName
displayName: types.maybe(types.string)		displayName is displayed in the header of the view, or assembly names being used if none is specified
minimized
minimized: types.stripDefault(types.boolean, false)		collapse the view to its header bar and keep it in the session

Volatiles

MemberDescription
width
number
bodyMounted
boolean		Whether the container has this view's body in the DOM.

ViewContainer mounts a view's body only while an IntersectionObserver reports it on screen, to hold the app under the WebGL2 context ceiling (reference/GPU_PORTABILITY.md). A view below the fold therefore has no canvas, so nothing ever calls markCanvasDrawn and the pre-first-paint term of displayPhase pins every display in it at loading with nothing left to resolve it — which parks [data-app-phase="ready"] for the whole app on a view the user cannot see.

Defaults true so the containers that always mount a body — embedded views, workspace panels, and any test rendering a display directly — are unaffected and need not set it.

The raw flag, written by the container that renders this view's body. A display asks effectiveBodyMounted instead, because a nested view has no container writing its flag.

Getters

MemberDescription
rendersDisplays
boolean		Overridable hook (default true): whether this view's mounted body renders this view's displays. A linear genome view collapsed to its ruler mounts the scalebar and none of its tracks, so a display in it can no more paint than one in a view scrolled off screen. Views nested in this one are unaffected: they paint wherever their bodies are.
effectiveBodyMounted
boolean		Whether this view's displays have a canvas to paint into: its body is in the DOM, counting the views it is nested inside, and the body renders them (rendersDisplays). This is the question a display's phase asks.

bodyMounted alone answers the DOM half only for a view a container renders directly. A view nested in another view (a synteny row, a breakpoint panel) has no container writing its flag, so it reads true forever while its whole subtree is out of the DOM, and every display in it waits for a first paint that nothing will make — the hang this flag prevents, one level down.

An ancestor with no flag at all does not change the answer: only an explicit false unmounts, so a duck-typed stand-in that forgot the flag keeps waiting, a failure that appears as a slow test rather than as a picture of an empty view.
ownTracks
AbstractTrackModel[]		The tracks this view puts in the census, excluding a nested view's.

Empty here, and overridden by the views that have any: the base cannot read self.tracks for them, because what a view keeps under that name is the view's business. react-msaview's holds its MSA annotation rows — {ReactComponent, model} objects with no configuration and no displays — and a base that read them would hand them to the readiness marker as tracks, which would error-page every session holding an MSA view.
ownViews
AbstractViewModel[]		The views nested directly inside this one, which the census counts as separate views — a synteny stack's genome rows, a breakpoint split view's panels.

Empty here for the same reason, and the dotplot is why it has to be a declaration rather than a walk of views: that prop name holds its two 1D axis models, which are view-shaped and are not views the user opened. No structural test separates the two — only the view knows.

Methods

MemberDescription
menuItems
() => MenuItem[]

Actions

MemberDescription
setDisplayName
(name: string) => void
setWidth
(newWidth: number) => void		Sets the view's width, which tells the app when it can start drawing. Certain views like lgv wait for it, because drawing before the width is known may fetch data for regions the view does not need.

A ResizeObserver generally calls setWidth. Views need their width to draw genomic regions properly.
setBodyMounted
(flag: boolean) => void		See bodyMounted. Written by the view's container, which is the only thing that knows whether it rendered the body.
setMinimized
(flag: boolean) => void