PluginContext.isBusy fix + related UI fix

src/mol-plugin-ui/structure/source.tsx

@@ -254,6 +254,7 @@ export class StructureSourceControls extends CollapsableControls<{}, StructureSo
         const { selection } = this.plugin.managers.structure.hierarchy;
         if (selection.structures.length !== 1) return null;
         const pivot = selection.structures[0];
+        if (!pivot.cell.parent) return null;
         const t = StateSelection.tryFindDecorator(this.plugin.state.data, pivot.cell.transform.ref, StateTransforms.Model.TransformStructureConformation);
         if (!t) return;
 

src/mol-plugin/context.ts

@@ -271,9 +271,11 @@ export class PluginContext {
             const isUpdating = this.behaviors.state.isUpdating.value;
             const isAnimating = this.behaviors.state.isAnimating.value;
 
-            if ((isUpdating || isAnimating) && !isBusy.value) {
-                reset();
-                timeout = setTimeout(setBusy, timeoutMs);
+            if (isUpdating || isAnimating) {
+                if (!isBusy.value) {
+                    reset();
+                    timeout = setTimeout(setBusy, timeoutMs);
+                }
             } else {
                 reset();
                 isBusy.next(false);