Use MST view instead of partition for pinned track

packages/core/util/index.ts

@@ -1321,24 +1321,6 @@ export function groupBy<T>(array: Iterable<T>, predicate: (v: T) => string) {
   return result
 }
 
-/**
- * Partition an array into two arrays based on a condition. See
- * {@link https://www.30secondsofcode.org/js/s/partition-array/}
- */
-export function partition<T>(
-  array: T[],
-  callback: (value: T, currentIndex: number, originalArray: T[]) => boolean,
-) {
-  // eslint-disable-next-line unicorn/no-array-reduce
-  return array.reduce(
-    (acc, val, i, arr) => {
-      acc[callback(val, i, arr) ? 0 : 1].push(val)
-      return acc
-    },
-    [[] as T[], [] as T[]],
-  )
-}
-
 export function notEmpty<T>(value: T | null | undefined): value is T {
   return value !== null && value !== undefined
 }

plugins/linear-genome-view/src/LinearGenomeView/components/LinearGenomeView.tsx

@@ -2,7 +2,7 @@ import React, { lazy, useEffect, useRef } from 'react'
 import { Button, Paper, Typography } from '@mui/material'
 import { makeStyles } from 'tss-react/mui'
 import { LoadingEllipses, VIEW_HEADER_HEIGHT } from '@jbrowse/core/ui'
-import { getSession, partition } from '@jbrowse/core/util'
+import { getSession } from '@jbrowse/core/util'
 import { observer } from 'mobx-react'
 
 // icons
@@ -72,7 +72,13 @@ function NoTracksActive({ model }: { model: LinearGenomeViewModel }) {
 }
 
 const LinearGenomeView = observer(({ model }: { model: LGV }) => {
-  const { tracks, error, initialized, hasDisplayedRegions } = model
+  const {
+    pinnedTracks,
+    unpinnedTracks,
+    error,
+    initialized,
+    hasDisplayedRegions,
+  } = model
   const ref = useRef<HTMLDivElement>(null)
   const session = getSession(model)
   const { classes } = useStyles()
@@ -111,11 +117,6 @@ const LinearGenomeView = observer(({ model }: { model: LGV }) => {
     }
   }
 
-  const [pinnedTracks, unpinnedTracks] = partition(
-    tracks,
-    track => track.pinned,
-  )
-
   return (
     <div
       className={classes.rel}
@@ -138,7 +139,7 @@ const LinearGenomeView = observer(({ model }: { model: LGV }) => {
         <MiniControlsComponent model={model} />
       </div>
       <TracksContainer model={model}>
-        {!tracks.length ? (
+        {!(pinnedTracks.length + unpinnedTracks.length) ? (
           <NoTracksActive model={model} />
         ) : (
           <>

plugins/linear-genome-view/src/LinearGenomeView/model.ts

@@ -281,6 +281,18 @@ export function stateModelFactory(pluginManager: PluginManager) {
       rightOffset: undefined as undefined | BpOffset,
     }))
     .views(self => ({
+      /**
+       * #getter
+       */
+      get pinnedTracks() {
+        return self.tracks.filter(t => t.pinned)
+      },
+      /**
+       * #getter
+       */
+      get unpinnedTracks() {
+        return self.tracks.filter(t => !t.pinned)
+      },
       /**
        * #getter
        * this is the effective value of the track labels setting, incorporating