Fix crash on closing linearsynteny track

plugins/linear-comparative-view/src/LinearSyntenyRenderer/components/LinearSyntenyRendering.tsx

@@ -1,6 +1,7 @@
 /* eslint-disable no-continue */
 import React, { useRef, useMemo, useEffect } from 'react'
 import { observer } from 'mobx-react'
+import { isAlive } from 'mobx-state-tree'
 import SimpleFeature, {
   SimpleFeatureSerialized,
   Feature,
@@ -87,18 +88,25 @@ function LinearSyntenyRendering(props: {
     [features],
   )
   const matches = layoutMatches(deserializedFeatures)
+  const views = useMemo(() => {
+    try {
+      const parentView =
+        'type' in displayModel
+          ? (getContainingView(displayModel) as LinearSyntenyViewModel)
+          : undefined
+      return parentView?.views
+    } catch (e) {
+      console.warn('parent view gone')
+      return null
+    }
+  }, [displayModel])
 
-  const parentView =
-    'type' in displayModel
-      ? (getContainingView(displayModel) as LinearSyntenyViewModel)
-      : undefined
-  const { views } = parentView || { views: undefined }
-  const offsets = views && views.map(view => view.offsetPx)
+  const offsets = views?.map(view => view.offsetPx)
   useEffect(() => {
-    if (!(parentView && views && offsets)) {
+    if (!ref.current || !offsets || !views) {
       return
     }
-    if (!ref.current) {
+    if (!isAlive(displayModel)) {
       return
     }
     const ctx = ref.current.getContext('2d')
@@ -217,7 +225,16 @@ function LinearSyntenyRendering(props: {
         }
       }
     })
-  })
+  }, [
+    displayModel,
+    highResolutionScaling,
+    trackIds,
+    width,
+    views,
+    offsets,
+    height,
+    matches,
+  ])
 
   return (
     <canvas