Enhance view state management by integrating UiStore for scroll position and selected event persistence

src/components/view/view-event-list.tsx

@@ -17,6 +17,7 @@ import {
     RTCConnection,
     TlsTunnel
 } from '../../types';
+import { UiStore } from '../../model/ui/ui-store';
 
 import {
     getSummaryColor,
@@ -54,6 +55,7 @@ interface ViewEventListProps {
     isPaused: boolean;
 
     contextMenuBuilder: ViewEventContextMenuBuilder;
+    uiStore: UiStore;
 
     moveSelection: (distance: number) => void;
     onSelected: (event: CollectedEvent | undefined) => void;
@@ -767,6 +769,17 @@ export class ViewEventList extends React.Component<ViewEventListProps> {
     private listBodyRef = React.createRef<HTMLDivElement>();
     private listRef = React.createRef<List>();
 
+    private setListBodyRef = (element: HTMLDivElement | null) => {
+        // Update the ref
+        (this.listBodyRef as any).current = element;
+
+        // If the element is being mounted and we haven't restored state yet, do it now
+        if (element && !this.hasRestoredScrollState) {
+            this.restoreScrollPosition();
+            this.hasRestoredScrollState = true;
+        }
+    };
+
     private KeyBoundListWindow = observer(
         React.forwardRef<HTMLDivElement>(
             (props: any, ref) => <div
@@ -816,7 +829,7 @@ export class ViewEventList extends React.Component<ViewEventListProps> {
                 : <AutoSizer>{({ height, width }) =>
                     <Observer>{() =>
                         <List
-                            innerRef={this.listBodyRef}
+                            innerRef={this.setListBodyRef}
                             outerElementType={this.KeyBoundListWindow}
                             ref={this.listRef}
 
@@ -881,17 +894,28 @@ export class ViewEventList extends React.Component<ViewEventListProps> {
     }
 
     private wasListAtBottom = true;
+
     private updateScrolledState = () => {
         requestAnimationFrame(() => { // Measure async, once the scroll has actually happened
             this.wasListAtBottom = this.isListAtBottom();
+
+            // Only save scroll position after we've restored the initial state
+            if (this.hasRestoredScrollState) {
+                const listWindow = this.listBodyRef.current?.parentElement;
+
+                const scrollPosition = this.wasListAtBottom
+                    ? 'end'
+                    : (listWindow?.scrollTop ?? 'end');
+                if (listWindow) {
+                    this.props.uiStore.setViewScrollPosition(scrollPosition);
+                }
+            }
         });
     }
 
-    componentDidMount() {
-        this.updateScrolledState();
-    }
+    private hasRestoredScrollState = false;
 
-    componentDidUpdate() {
+    componentDidUpdate(prevProps: ViewEventListProps) {
         if (this.listBodyRef.current?.parentElement?.contains(document.activeElement)) {
             // If we previously had something here focused, and we've updated, update
             // the focus too, to make sure it's in the right place.
@@ -902,6 +926,25 @@ export class ViewEventList extends React.Component<ViewEventListProps> {
         // scroll there again ourselves now.
         if (this.wasListAtBottom && !this.isListAtBottom()) {
             this.listRef.current?.scrollToItem(this.props.events.length - 1);
+        } else if (prevProps.selectedEvent !== this.props.selectedEvent && this.props.selectedEvent) {
+            // If the selected event changed and we have a selected event, scroll to it
+            // This handles restoring the selected event when returning to the tab
+            this.scrollToEvent(this.props.selectedEvent);
+        }
+    }
+
+    private restoreScrollPosition = () => {
+        const savedPosition = this.props.uiStore.viewScrollPosition;
+        const listWindow = this.listBodyRef.current?.parentElement;
+        if (listWindow) {
+            if (savedPosition === 'end') {
+                listWindow.scrollTop = listWindow.scrollHeight;
+            } else {
+                // Only restore if we're not close to the current position (avoid unnecessary scrolling)
+                if (Math.abs(listWindow.scrollTop - savedPosition) > 10) {
+                    listWindow.scrollTop = savedPosition;
+                }
+            }
         }
     }
 

src/components/view/view-page.tsx

@@ -207,11 +207,13 @@ class ViewPage extends React.Component<ViewPageProps> {
             filteredEventCount: [filteredEvents.length, events.length]
         };
     }
-
     @computed
     get selectedEvent() {
+        // First try to use the URL-based eventId, then fallback to the persisted selection
+        const targetEventId = this.props.eventId || this.props.uiStore.selectedEventId;
+
         return _.find(this.props.eventsStore.events, {
-            id: this.props.eventId
+            id: targetEventId
         });
     }
 
@@ -242,12 +244,11 @@ class ViewPage extends React.Component<ViewPageProps> {
     );
 
     componentDidMount() {
-        // After first render, scroll to the selected event (or the end of the list) by default:
+        // After first render, if we're jumping to an event, then scroll to it:
         requestAnimationFrame(() => {
             if (this.props.eventId && this.selectedEvent) {
+                this.props.uiStore.setSelectedEventId(this.props.eventId);
                 this.onScrollToCenterEvent(this.selectedEvent);
-            } else {
-                this.onScrollToEnd();
             }
         });
 
@@ -328,6 +329,15 @@ class ViewPage extends React.Component<ViewPageProps> {
         );
     }
 
+    componentDidUpdate(prevProps: ViewPageProps) {
+        // Only clear persisted selection if we're explicitly navigating to a different event via URL
+        // Don't clear it when going from eventId to no eventId (which happens when clearing selection)
+        if (this.props.eventId && prevProps.eventId && this.props.eventId !== prevProps.eventId) {
+            // Clear persisted selection only when explicitly navigating between different events via URL
+            this.props.uiStore.setSelectedEventId(undefined);
+        }
+    }
+
     isSendAvailable() {
         return versionSatisfies(serverVersion.value as string, SERVER_SEND_API_SUPPORTED);
     }
@@ -447,8 +457,8 @@ class ViewPage extends React.Component<ViewPageProps> {
 
                         moveSelection={this.moveSelection}
                         onSelected={this.onSelected}
-
                         contextMenuBuilder={this.contextMenuBuilder}
+                        uiStore={this.props.uiStore}
 
                         ref={this.listRef}
                     />
@@ -491,6 +501,8 @@ class ViewPage extends React.Component<ViewPageProps> {
 
     @action.bound
     onSelected(event: CollectedEvent | undefined) {
+        this.props.uiStore.setSelectedEventId(event?.id);
+
         this.props.navigate(event
             ? `/view/${event.id}`
             : '/view'

src/model/ui/ui-store.ts

@@ -251,6 +251,12 @@ export class UiStore {
     @observable
     expandedViewCard: ExpandableViewCardKey | undefined;
 
+    @observable
+    viewScrollPosition: number | 'end' = 'end';
+
+    @observable
+    selectedEventId: string | undefined;
+
     @computed
     get viewCardProps() {
         return _.mapValues(this.viewCardStates, (state, key) => ({
@@ -436,6 +442,17 @@ export class UiStore {
     @persist @observable
     exportSnippetFormat: string | undefined;
 
+    // Actions for persisting view state when switching tabs
+    @action.bound
+    setViewScrollPosition(position: number | 'end') {
+        this.viewScrollPosition = position;
+    }
+
+    @action.bound
+    setSelectedEventId(eventId: string | undefined) {
+        this.selectedEventId = eventId;
+    }
+
     /**
      * This tracks the context menu state *only if it's not handled natively*. This state
      * is rendered by React as a fallback when DesktopApi.openContextMenu is not available.