refactor: adjust favorite, delete, and archive actions for timeline

- Pass TimelineManager instance to timeline action components
  instead of callbacks
- Move asset update logic (delete, archive, favorite) into
  action components

server/src/services/notification.service.ts

@@ -161,7 +161,24 @@ export class NotificationService extends BaseService {
 
     const [asset] = await this.assetRepository.getByIdsWithAllRelationsButStacks([assetId]);
     if (asset) {
-      this.eventRepository.clientSend('on_asset_update', userId, mapAsset(asset));
+      // need to specify authDto to this mapAsset request, because it tries to prevent
+      // leaking information PR#7580 which expects a userId in the auth options object
+      this.eventRepository.clientSend(
+        'on_asset_update',
+        userId,
+        mapAsset(asset, {
+          auth: {
+            user: {
+              id: userId,
+              isAdmin: false,
+              name: '',
+              email: '',
+              quotaUsageInBytes: 0,
+              quotaSizeInBytes: null,
+            },
+          },
+        }),
+      );
     }
   }
 

web/src/lib/components/timeline/MonthSegment.svelte

@@ -12,7 +12,6 @@
 
   import { mdiCheckCircle, mdiCircleOutline } from '@mdi/js';
 
-  import { fromTimelinePlainDate, getDateLocaleString } from '$lib/utils/timeline-util';
   import { Icon } from '@immich/ui';
   import type { Snippet } from 'svelte';
   import { flip } from 'svelte/animate';
@@ -125,16 +124,6 @@
     return intersectable.filter((int) => int.intersecting);
   }
 
-  const getDayGroupFullDate = (dayGroup: DayGroup): string => {
-    const { month, year } = dayGroup.monthGroup.yearMonth;
-    const date = fromTimelinePlainDate({
-      year,
-      month,
-      day: dayGroup.day,
-    });
-    return getDateLocaleString(date);
-  };
-
   $effect.root(() => {
     if (timelineManager.scrollCompensation.monthGroup === monthGroup) {
       onScrollCompensation(timelineManager.scrollCompensation);
@@ -185,7 +174,7 @@
         </div>
       {/if}
 
-      <span class="w-full truncate first-letter:capitalize" title={getDayGroupFullDate(dayGroup)}>
+      <span class="w-full truncate first-letter:capitalize" title={dayGroup.groupTitleFull}>
         {dayGroup.groupTitle}
       </span>
     </div>

web/src/lib/components/timeline/Scrubber.svelte

@@ -3,7 +3,7 @@
   import type { ScrubberMonth } from '$lib/managers/timeline-manager/types';
   import { mobileDevice } from '$lib/stores/mobile-device.svelte';
   import { getTabbable } from '$lib/utils/focus-util';
-  import { type ScrubberListener } from '$lib/utils/timeline-util';
+  import { type ScrubberListener, type TimelineYearMonth } from '$lib/utils/timeline-util';
   import { Icon } from '@immich/ui';
   import { mdiPlay } from '@mdi/js';
   import { clamp } from 'lodash-es';
@@ -11,18 +11,31 @@
   import { fade, fly } from 'svelte/transition';
 
   interface Props {
+    /** Offset from the top of the timeline (e.g., for headers) */
     timelineTopOffset?: number;
+    /** Offset from the bottom of the timeline (e.g., for footers) */
     timelineBottomOffset?: number;
+    /** Total height of the scrubber component */
     height?: number;
+    /** Timeline manager instance that controls the timeline state */
     timelineManager: TimelineManager;
-    scrubOverallPercent?: number;
-    scrubberMonthPercent?: number;
-    scrubberMonth?: { year: number; month: number };
-    leadout?: boolean;
+    /** Overall scroll percentage through the entire timeline (0-1), used when no specific month is targeted */
+    timelineScrollPercent?: number;
+    /** The percentage of scroll through the month that is currently intersecting the top boundary of the viewport */
+    viewportTopMonthScrollPercent?: number;
+    /** The year/month of the timeline month at the top of the viewport */
+    viewportTopMonth?: TimelineYearMonth;
+    /** Indicates whether the viewport is currently in the lead-out section (after all months) */
+    isInLeadOutSection?: boolean;
+    /** Width of the scrubber component in pixels (bindable for parent component margin adjustments) */
     scrubberWidth?: number;
+    /** Callback fired when user interacts with the scrubber to navigate */
     onScrub?: ScrubberListener;
+    /** Callback fired when keyboard events occur on the scrubber */
     onScrubKeyDown?: (event: KeyboardEvent, element: HTMLElement) => void;
+    /** Callback fired when scrubbing starts */
     startScrub?: ScrubberListener;
+    /** Callback fired when scrubbing stops */
     stopScrub?: ScrubberListener;
   }
 
@@ -31,10 +44,10 @@
     timelineBottomOffset = 0,
     height = 0,
     timelineManager,
-    scrubOverallPercent = 0,
-    scrubberMonthPercent = 0,
-    scrubberMonth = undefined,
-    leadout = false,
+    timelineScrollPercent = 0,
+    viewportTopMonthScrollPercent = 0,
+    viewportTopMonth = undefined,
+    isInLeadOutSection = false,
     onScrub = undefined,
     onScrubKeyDown = undefined,
     startScrub = undefined,
@@ -100,7 +113,7 @@
         offset += scrubberMonthPercent * relativeBottomOffset;
       }
       return offset;
-    } else if (leadout) {
+    } else if (isInLeadOutSection) {
       let offset = relativeTopOffset;
       for (const segment of segments) {
         offset += segment.height;
@@ -111,7 +124,9 @@
       return scrubOverallPercent * (height - (PADDING_TOP + PADDING_BOTTOM));
     }
   };
-  let scrollY = $derived(toScrollFromMonthGroupPercentage(scrubberMonth, scrubberMonthPercent, scrubOverallPercent));
+  let scrollY = $derived(
+    toScrollFromMonthGroupPercentage(viewportTopMonth, viewportTopMonthScrollPercent, timelineScrollPercent),
+  );
   let timelineFullHeight = $derived(timelineManager.scrubberTimelineHeight + timelineTopOffset + timelineBottomOffset);
   let relativeTopOffset = $derived(toScrollY(timelineTopOffset / timelineFullHeight));
   let relativeBottomOffset = $derived(toScrollY(timelineBottomOffset / timelineFullHeight));
@@ -295,12 +310,24 @@
 
     const scrollPercent = toTimelineY(hoverY);
     if (wasDragging === false && isDragging) {
-      void startScrub?.(segmentDate!, scrollPercent, monthGroupPercentY);
-      void onScrub?.(segmentDate!, scrollPercent, monthGroupPercentY);
+      void startScrub?.({
+        scrubberMonth: segmentDate!,
+        overallScrollPercent: scrollPercent,
+        scrubberMonthScrollPercent: monthGroupPercentY,
+      });
+      void onScrub?.({
+        scrubberMonth: segmentDate!,
+        overallScrollPercent: scrollPercent,
+        scrubberMonthScrollPercent: monthGroupPercentY,
+      });
     }
 
     if (wasDragging && !isDragging) {
-      void stopScrub?.(segmentDate!, scrollPercent, monthGroupPercentY);
+      void stopScrub?.({
+        scrubberMonth: segmentDate!,
+        overallScrollPercent: scrollPercent,
+        scrubberMonthScrollPercent: monthGroupPercentY,
+      });
       return;
     }
 
@@ -308,7 +335,11 @@
       return;
     }
 
-    void onScrub?.(segmentDate!, scrollPercent, monthGroupPercentY);
+    void onScrub?.({
+      scrubberMonth: segmentDate!,
+      overallScrollPercent: scrollPercent,
+      scrubberMonthScrollPercent: monthGroupPercentY,
+    });
   };
   /* eslint-disable tscompat/tscompat */
   const getTouch = (event: TouchEvent) => {
@@ -412,7 +443,11 @@
       }
       if (next) {
         event.preventDefault();
-        void onScrub?.({ year: next.year, month: next.month }, -1, 0);
+        void onScrub?.({
+          scrubberMonth: { year: next.year, month: next.month },
+          overallScrollPercent: -1,
+          scrubberMonthScrollPercent: 0,
+        });
         return true;
       }
     }
@@ -422,7 +457,11 @@
         const next = segments[idx + 1];
         if (next) {
           event.preventDefault();
-          void onScrub?.({ year: next.year, month: next.month }, -1, 0);
+          void onScrub?.({
+            scrubberMonth: { year: next.year, month: next.month },
+            overallScrollPercent: -1,
+            scrubberMonthScrollPercent: 0,
+          });
           return true;
         }
       }

web/src/lib/components/timeline/Timeline.svelte

@@ -1,46 +1,35 @@
 <script lang="ts">
-  import { afterNavigate, beforeNavigate, goto } from '$app/navigation';
+  import { afterNavigate, beforeNavigate } from '$app/navigation';
   import { page } from '$app/stores';
   import { resizeObserver, type OnResizeCallback } from '$lib/actions/resize-observer';
-  import { shortcuts, type ShortcutOptions } from '$lib/actions/shortcut';
-  import type { Action } from '$lib/components/asset-viewer/actions/action';
-  import type { AbsoluteResult, RelativeResult } from '$lib/components/shared-components/change-date.svelte';
-  import ChangeDate from '$lib/components/shared-components/change-date.svelte';
+  import MonthSegment from '$lib/components/timeline/MonthSegment.svelte';
   import Scrubber from '$lib/components/timeline/Scrubber.svelte';
-  import {
-    setFocusToAsset as setFocusAssetInit,
-    setFocusTo as setFocusToInit,
-  } from '$lib/components/timeline/actions/focus-actions';
-  import { AppRoute, AssetAction } from '$lib/constants';
+  import TimelineAssetViewer from '$lib/components/timeline/TimelineAssetViewer.svelte';
+  import TimelineKeyboardActions from '$lib/components/timeline/actions/TimelineKeyboardActions.svelte';
+  import { AssetAction } from '$lib/constants';
   import HotModuleReload from '$lib/elements/HotModuleReload.svelte';
   import Portal from '$lib/elements/Portal.svelte';
   import Skeleton from '$lib/elements/Skeleton.svelte';
-  import { authManager } from '$lib/managers/auth-manager.svelte';
   import type { DayGroup } from '$lib/managers/timeline-manager/day-group.svelte';
   import type { MonthGroup } from '$lib/managers/timeline-manager/month-group.svelte';
   import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
   import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
   import { assetsSnapshot } from '$lib/managers/timeline-manager/utils.svelte';
-  import ShortcutsModal from '$lib/modals/ShortcutsModal.svelte';
   import type { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
   import { assetViewingStore } from '$lib/stores/asset-viewing.store';
   import { isSelectingAllAssets } from '$lib/stores/assets-store.svelte';
   import { mobileDevice } from '$lib/stores/mobile-device.svelte';
-  import { showDeleteModal } from '$lib/stores/preferences.store';
-  import { searchStore } from '$lib/stores/search.svelte';
-  import { featureFlags } from '$lib/stores/server-config.store';
-  import { handlePromiseError } from '$lib/utils';
-  import { deleteAssets, updateStackedAssetInTimeline, updateUnstackedAssetInTimeline } from '$lib/utils/actions';
-  import { archiveAssets, cancelMultiselect, selectAllAssets, stackAssets } from '$lib/utils/asset-utils';
   import { navigate } from '$lib/utils/navigation';
-  import { getTimes, toTimelineAsset, type ScrubberListener, type TimelineYearMonth } from '$lib/utils/timeline-util';
-  import { AssetVisibility, getAssetInfo, type AlbumResponseDto, type PersonResponseDto } from '@immich/sdk';
-  import { modalManager } from '@immich/ui';
+  import {
+    getSegmentIdentifier,
+    getTimes,
+    type ScrubberListener,
+    type TimelineYearMonth,
+  } from '$lib/utils/timeline-util';
+  import { type AlbumResponseDto, type PersonResponseDto } from '@immich/sdk';
   import { DateTime } from 'luxon';
   import { onMount, type Snippet } from 'svelte';
   import type { UpdatePayload } from 'vite';
-  import DeleteAssetDialog from '../photos-page/delete-asset-dialog.svelte';
-  import TimelineDateGroup from './TimelineDateGroup.svelte';
 
   interface Props {
     isSelectionMode?: boolean;
@@ -103,22 +92,27 @@
     onThumbnailClick,
   }: Props = $props();
 
-  let { isViewing: showAssetViewer, asset: viewingAsset, preloadAssets, gridScrollTarget, mutex } = assetViewingStore;
+  let { isViewing: showAssetViewer, asset: viewingAsset, gridScrollTarget } = assetViewingStore;
 
   let element: HTMLElement | undefined = $state();
 
   let timelineElement: HTMLElement | undefined = $state();
   let showSkeleton = $state(true);
-  let isShowSelectDate = $state(false);
-  let scrubberMonthPercent = $state(0);
-  let scrubberMonth: { year: number; month: number } | undefined = $state(undefined);
-  let scrubOverallPercent: number = $state(0);
+  // The percentage of scroll through the month that is currently intersecting the top boundary of the viewport.
+  // Note: There may be multiple months visible within the viewport at any given time.
+  let viewportTopMonthScrollPercent = $state(0);
+  // The timeline month intersecting the top position of the viewport
+  let viewportTopMonth: { year: number; month: number } | undefined = $state(undefined);
+  // Overall scroll percentage through the entire timeline (0-1)
+  let timelineScrollPercent: number = $state(0);
   let scrubberWidth = $state(0);
 
   // 60 is the bottom spacer element at 60px
   let bottomSectionHeight = 60;
-  let leadout = $state(false);
+  // Indicates whether the viewport is currently in the lead-out section (after all months)
+  let isInLeadOutSection = $state(false);
 
+  const isEmpty = $derived(timelineManager.isInitialized && timelineManager.months.length === 0);
   const maxMd = $derived(mobileDevice.maxMd);
   const usingMobileDevice = $derived(mobileDevice.pointerCoarse);
 
@@ -301,20 +295,19 @@
     scrollTop(scrollToTop);
   };
 
-  // note: don't throttle, debounch, or otherwise make this function async - it causes flicker
-  const onScrub: ScrubberListener = (
-    scrubMonth: { year: number; month: number },
-    overallScrollPercent: number,
-    scrubberMonthScrollPercent: number,
-  ) => {
-    if (!scrubMonth || timelineManager.timelineHeight < timelineManager.viewportHeight * 2) {
+  // note: don't throttle, debounce, or otherwise make this function async - it causes flicker
+  // this function scrolls the timeline to the specified month group and offset, based on scrubber interaction
+  const onScrub: ScrubberListener = (scrubberData) => {
+    const { scrubberMonth, overallScrollPercent, scrubberMonthScrollPercent } = scrubberData;
+
+    if (!scrubberMonth || timelineManager.timelineHeight < timelineManager.viewportHeight * 2) {
       // edge case - scroll limited due to size of content, must adjust - use use the overall percent instead
       const maxScroll = getMaxScroll();
       const offset = maxScroll * overallScrollPercent;
       scrollTop(offset);
     } else {
       const monthGroup = timelineManager.months.find(
-        ({ yearMonth: { year, month } }) => year === scrubMonth.year && month === scrubMonth.month,
+        ({ yearMonth: { year, month } }) => year === scrubberMonth.year && month === scrubberMonth.month,
       );
       if (!monthGroup) {
         return;
@@ -325,7 +318,7 @@
 
   // note: don't throttle, debounch, or otherwise make this function async - it causes flicker
   const handleTimelineScroll = () => {
-    leadout = false;
+    isInLeadOutSection = false;
 
     if (!element) {
       return;
@@ -334,19 +327,19 @@
     if (timelineManager.timelineHeight < timelineManager.viewportHeight * 2) {
       // edge case - scroll limited due to size of content, must adjust -  use the overall percent instead
       const maxScroll = getMaxScroll();
-      scrubOverallPercent = Math.min(1, element.scrollTop / maxScroll);
+      timelineScrollPercent = Math.min(1, element.scrollTop / maxScroll);
 
-      scrubberMonth = undefined;
-      scrubberMonthPercent = 0;
+      viewportTopMonth = undefined;
+      viewportTopMonthScrollPercent = 0;
     } else {
       let top = element.scrollTop;
       if (top < timelineManager.topSectionHeight) {
         // in the lead-in area
-        scrubberMonth = undefined;
-        scrubberMonthPercent = 0;
+        viewportTopMonth = undefined;
+        viewportTopMonthScrollPercent = 0;
         const maxScroll = getMaxScroll();
 
-        scrubOverallPercent = Math.min(1, element.scrollTop / maxScroll);
+        timelineScrollPercent = Math.min(1, element.scrollTop / maxScroll);
         return;
       }
 
@@ -371,15 +364,15 @@
         let next = top - monthGroupHeight * maxScrollPercent;
         // instead of checking for < 0, add a little wiggle room for subpixel resolution
         if (next < -1 && monthGroup) {
-          scrubberMonth = monthGroup;
+          viewportTopMonth = monthGroup;
 
           // allowing next to be at least 1 may cause percent to go negative, so ensure positive percentage
-          scrubberMonthPercent = Math.max(0, top / (monthGroupHeight * maxScrollPercent));
+          viewportTopMonthScrollPercent = Math.max(0, top / (monthGroupHeight * maxScrollPercent));
 
           // compensate for lost precision/rounding errors advance to the next bucket, if present
-          if (scrubberMonthPercent > 0.9999 && i + 1 < monthsLength - 1) {
-            scrubberMonth = timelineManager.months[i + 1].yearMonth;
-            scrubberMonthPercent = 0;
+          if (viewportTopMonthScrollPercent > 0.9999 && i + 1 < monthsLength - 1) {
+            viewportTopMonth = timelineManager.months[i + 1].yearMonth;
+            viewportTopMonthScrollPercent = 0;
           }
 
           found = true;
@@ -388,200 +381,25 @@
         top = next;
       }
       if (!found) {
-        leadout = true;
-        scrubberMonth = undefined;
-        scrubberMonthPercent = 0;
-        scrubOverallPercent = 1;
+        isInLeadOutSection = true;
+        viewportTopMonth = undefined;
+        viewportTopMonthScrollPercent = 0;
+        timelineScrollPercent = 1;
       }
     }
   };
 
-  const trashOrDelete = async (force: boolean = false) => {
-    isShowDeleteConfirmation = false;
-    await deleteAssets(
-      !(isTrashEnabled && !force),
-      (assetIds) => timelineManager.removeAssets(assetIds),
-      assetInteraction.selectedAssets,
-      !isTrashEnabled || force ? undefined : (assets) => timelineManager.addAssets(assets),
-    );
-    assetInteraction.clearMultiselect();
-  };
-
-  const onDelete = () => {
-    const hasTrashedAsset = assetInteraction.selectedAssets.some((asset) => asset.isTrashed);
-
-    if ($showDeleteModal && (!isTrashEnabled || hasTrashedAsset)) {
-      isShowDeleteConfirmation = true;
-      return;
-    }
-    handlePromiseError(trashOrDelete(hasTrashedAsset));
-  };
-
-  const onForceDelete = () => {
-    if ($showDeleteModal) {
-      isShowDeleteConfirmation = true;
-      return;
-    }
-    handlePromiseError(trashOrDelete(true));
-  };
-
-  const onStackAssets = async () => {
-    const result = await stackAssets(assetInteraction.selectedAssets);
-
-    updateStackedAssetInTimeline(timelineManager, result);
-
-    onEscape();
-  };
-
-  const toggleArchive = async () => {
-    const visibility = assetInteraction.isAllArchived ? AssetVisibility.Timeline : AssetVisibility.Archive;
-    const ids = await archiveAssets(assetInteraction.selectedAssets, visibility);
-    timelineManager.updateAssetOperation(ids, (asset) => {
-      asset.visibility = visibility;
-      return { remove: false };
-    });
-    deselectAllAssets();
-  };
-
   const handleSelectAsset = (asset: TimelineAsset) => {
     if (!timelineManager.albumAssets.has(asset.id)) {
       assetInteraction.selectAsset(asset);
     }
   };
 
-  const handlePrevious = async () => {
-    const release = await mutex.acquire();
-    const laterAsset = await timelineManager.getLaterAsset($viewingAsset);
-
-    if (laterAsset) {
-      const preloadAsset = await timelineManager.getLaterAsset(laterAsset);
-      const asset = await getAssetInfo({ ...authManager.params, id: laterAsset.id });
-      assetViewingStore.setAsset(asset, preloadAsset ? [preloadAsset] : []);
-      await navigate({ targetRoute: 'current', assetId: laterAsset.id });
-    }
-
-    release();
-    return !!laterAsset;
-  };
-
-  const handleNext = async () => {
-    const release = await mutex.acquire();
-    const earlierAsset = await timelineManager.getEarlierAsset($viewingAsset);
-
-    if (earlierAsset) {
-      const preloadAsset = await timelineManager.getEarlierAsset(earlierAsset);
-      const asset = await getAssetInfo({ ...authManager.params, id: earlierAsset.id });
-      assetViewingStore.setAsset(asset, preloadAsset ? [preloadAsset] : []);
-      await navigate({ targetRoute: 'current', assetId: earlierAsset.id });
-    }
-
-    release();
-    return !!earlierAsset;
-  };
-
-  const handleRandom = async () => {
-    const randomAsset = await timelineManager.getRandomAsset();
-
-    if (randomAsset) {
-      const asset = await getAssetInfo({ ...authManager.params, id: randomAsset.id });
-      assetViewingStore.setAsset(asset);
-      await navigate({ targetRoute: 'current', assetId: randomAsset.id });
-      return asset;
-    }
-  };
-
-  const handleClose = async (asset: { id: string }) => {
-    assetViewingStore.showAssetViewer(false);
-    showSkeleton = true;
-    $gridScrollTarget = { at: asset.id };
-    await navigate({ targetRoute: 'current', assetId: null, assetGridRouteSearchParams: $gridScrollTarget });
-  };
-
-  const handlePreAction = async (action: Action) => {
-    switch (action.type) {
-      case removeAction:
-      case AssetAction.TRASH:
-      case AssetAction.RESTORE:
-      case AssetAction.DELETE:
-      case AssetAction.ARCHIVE:
-      case AssetAction.SET_VISIBILITY_LOCKED:
-      case AssetAction.SET_VISIBILITY_TIMELINE: {
-        // find the next asset to show or close the viewer
-        // eslint-disable-next-line @typescript-eslint/no-unused-expressions
-        (await handleNext()) || (await handlePrevious()) || (await handleClose(action.asset));
-
-        // delete after find the next one
-        timelineManager.removeAssets([action.asset.id]);
-        break;
-      }
-    }
-  };
-  const handleAction = (action: Action) => {
-    switch (action.type) {
-      case AssetAction.ARCHIVE:
-      case AssetAction.UNARCHIVE:
-      case AssetAction.FAVORITE:
-      case AssetAction.UNFAVORITE: {
-        timelineManager.updateAssets([action.asset]);
-        break;
-      }
-
-      case AssetAction.ADD: {
-        timelineManager.addAssets([action.asset]);
-        break;
-      }
-
-      case AssetAction.UNSTACK: {
-        updateUnstackedAssetInTimeline(timelineManager, action.assets);
-        break;
-      }
-      case AssetAction.REMOVE_ASSET_FROM_STACK: {
-        timelineManager.addAssets([toTimelineAsset(action.asset)]);
-        if (action.stack) {
-          //Have to unstack then restack assets in timeline in order to update the stack count in the timeline.
-          updateUnstackedAssetInTimeline(
-            timelineManager,
-            action.stack.assets.map((asset) => toTimelineAsset(asset)),
-          );
-          updateStackedAssetInTimeline(timelineManager, {
-            stack: action.stack,
-            toDeleteIds: action.stack.assets
-              .filter((asset) => asset.id !== action.stack?.primaryAssetId)
-              .map((asset) => asset.id),
-          });
-        }
-        break;
-      }
-      case AssetAction.SET_STACK_PRIMARY_ASSET: {
-        //Have to unstack then restack assets in timeline in order for the currently removed new primary asset to be made visible.
-        updateUnstackedAssetInTimeline(
-          timelineManager,
-          action.stack.assets.map((asset) => toTimelineAsset(asset)),
-        );
-        updateStackedAssetInTimeline(timelineManager, {
-          stack: action.stack,
-          toDeleteIds: action.stack.assets
-            .filter((asset) => asset.id !== action.stack.primaryAssetId)
-            .map((asset) => asset.id),
-        });
-        break;
-      }
-    }
-  };
-
   let lastAssetMouseEvent: TimelineAsset | null = $state(null);
 
   let shiftKeyIsDown = $state(false);
 
-  const deselectAllAssets = () => {
-    cancelMultiselect(assetInteraction);
-  };
-
   const onKeyDown = (event: KeyboardEvent) => {
-    if (searchStore.isSearchEnabled) {
-      return;
-    }
-
     if (event.key === 'Shift') {
       event.preventDefault();
       shiftKeyIsDown = true;
@@ -589,16 +407,11 @@
   };
 
   const onKeyUp = (event: KeyboardEvent) => {
-    if (searchStore.isSearchEnabled) {
-      return;
-    }
-
     if (event.key === 'Shift') {
       event.preventDefault();
       shiftKeyIsDown = false;
     }
   };
-
   const handleSelectAssetCandidates = (asset: TimelineAsset | null) => {
     if (asset) {
       void selectAssetCandidates(asset);
@@ -670,7 +483,7 @@
           break;
         }
         if (started) {
-          await timelineManager.loadMonthGroup(monthGroup.yearMonth);
+          await timelineManager.loadSegment(monthGroup.identifier);
           for (const asset of monthGroup.assetsIterator()) {
             if (deselect) {
               assetInteraction.removeAssetFromMultiselectGroup(asset.id);
@@ -724,72 +537,6 @@
     assetInteraction.setAssetSelectionCandidates(assets);
   };
 
-  const onSelectStart = (e: Event) => {
-    if (assetInteraction.selectionActive && shiftKeyIsDown) {
-      e.preventDefault();
-    }
-  };
-
-  let isTrashEnabled = $derived($featureFlags.loaded && $featureFlags.trash);
-  let isEmpty = $derived(timelineManager.isInitialized && timelineManager.months.length === 0);
-  let idsSelectedAssets = $derived(assetInteraction.selectedAssets.map(({ id }) => id));
-  let isShortcutModalOpen = false;
-
-  const handleOpenShortcutModal = async () => {
-    if (isShortcutModalOpen) {
-      return;
-    }
-
-    isShortcutModalOpen = true;
-    await modalManager.show(ShortcutsModal, {});
-    isShortcutModalOpen = false;
-  };
-
-  $effect(() => {
-    if (isEmpty) {
-      assetInteraction.clearMultiselect();
-    }
-  });
-
-  const setFocusTo = setFocusToInit.bind(undefined, scrollToAsset, timelineManager);
-  const setFocusAsset = setFocusAssetInit.bind(undefined, scrollToAsset);
-
-  let shortcutList = $derived(
-    (() => {
-      if (searchStore.isSearchEnabled || $showAssetViewer) {
-        return [];
-      }
-
-      const shortcuts: ShortcutOptions[] = [
-        { shortcut: { key: 'Escape' }, onShortcut: onEscape },
-        { shortcut: { key: '?', shift: true }, onShortcut: handleOpenShortcutModal },
-        { shortcut: { key: '/' }, onShortcut: () => goto(AppRoute.EXPLORE) },
-        { shortcut: { key: 'A', ctrl: true }, onShortcut: () => selectAllAssets(timelineManager, assetInteraction) },
-        { shortcut: { key: 'ArrowRight' }, onShortcut: () => setFocusTo('earlier', 'asset') },
-        { shortcut: { key: 'ArrowLeft' }, onShortcut: () => setFocusTo('later', 'asset') },
-        { shortcut: { key: 'D' }, onShortcut: () => setFocusTo('earlier', 'day') },
-        { shortcut: { key: 'D', shift: true }, onShortcut: () => setFocusTo('later', 'day') },
-        { shortcut: { key: 'M' }, onShortcut: () => setFocusTo('earlier', 'month') },
-        { shortcut: { key: 'M', shift: true }, onShortcut: () => setFocusTo('later', 'month') },
-        { shortcut: { key: 'Y' }, onShortcut: () => setFocusTo('earlier', 'year') },
-        { shortcut: { key: 'Y', shift: true }, onShortcut: () => setFocusTo('later', 'year') },
-        { shortcut: { key: 'G' }, onShortcut: () => (isShowSelectDate = true) },
-      ];
-
-      if (assetInteraction.selectionActive) {
-        shortcuts.push(
-          { shortcut: { key: 'Delete' }, onShortcut: onDelete },
-          { shortcut: { key: 'Delete', shift: true }, onShortcut: onForceDelete },
-          { shortcut: { key: 'D', ctrl: true }, onShortcut: () => deselectAllAssets() },
-          { shortcut: { key: 's' }, onShortcut: () => onStackAssets() },
-          { shortcut: { key: 'a', shift: true }, onShortcut: toggleArchive },
-        );
-      }
-
-      return shortcuts;
-    })(),
-  );
-
   $effect(() => {
     if (!lastAssetMouseEvent) {
       assetInteraction.clearAssetSelectionCandidates();
@@ -811,42 +558,22 @@
   $effect(() => {
     if ($showAssetViewer) {
       const { localDateTime } = getTimes($viewingAsset.fileCreatedAt, DateTime.local().offset / 60);
-      void timelineManager.loadMonthGroup({ year: localDateTime.year, month: localDateTime.month });
+      void timelineManager.loadSegment(getSegmentIdentifier({ year: localDateTime.year, month: localDateTime.month }));
     }
   });
 </script>
 
-<svelte:document onkeydown={onKeyDown} onkeyup={onKeyUp} onselectstart={onSelectStart} use:shortcuts={shortcutList} />
+<svelte:document onkeydown={onKeyDown} onkeyup={onKeyUp} />
 
 <HotModuleReload onAfterUpdate={handleAfterUpdate} onBeforeUpdate={handleBeforeUpdate} />
 
-{#if isShowDeleteConfirmation}
-  <DeleteAssetDialog
-    size={idsSelectedAssets.length}
-    onCancel={() => (isShowDeleteConfirmation = false)}
-    onConfirm={() => handlePromiseError(trashOrDelete(true))}
-  />
-{/if}
-
-{#if isShowSelectDate}
-  <ChangeDate
-    title="Navigate to Time"
-    initialDate={DateTime.now()}
-    timezoneInput={false}
-    onConfirm={async (dateString: AbsoluteResult | RelativeResult) => {
-      isShowSelectDate = false;
-      if (dateString.mode == 'absolute') {
-        const asset = await timelineManager.getClosestAssetToDate(
-          (DateTime.fromISO(dateString.date) as DateTime<true>).toObject(),
-        );
-        if (asset) {
-          setFocusAsset(asset);
-        }
-      }
-    }}
-    onCancel={() => (isShowSelectDate = false)}
-  />
-{/if}
+<TimelineKeyboardActions
+  scrollToAsset={(asset) => scrollToAsset(asset) ?? false}
+  {timelineManager}
+  {assetInteraction}
+  bind:isShowDeleteConfirmation
+  {onEscape}
+/>
 
 {#if timelineManager.months.length > 0}
   <Scrubber
@@ -854,10 +581,10 @@
     height={timelineManager.viewportHeight}
     timelineTopOffset={timelineManager.topSectionHeight}
     timelineBottomOffset={bottomSectionHeight}
-    {leadout}
-    {scrubOverallPercent}
-    {scrubberMonthPercent}
-    {scrubberMonth}
+    {isInLeadOutSection}
+    {timelineScrollPercent}
+    {viewportTopMonthScrollPercent}
+    {viewportTopMonth}
     {onScrub}
     bind:scrubberWidth
     onScrubKeyDown={(evt) => {
@@ -933,7 +660,7 @@
           style:transform={`translate3d(0,${absoluteHeight}px,0)`}
           style:width="100%"
         >
-          <TimelineDateGroup
+          <MonthSegment
             {withStacked}
             {showArchiveIcon}
             {assetInteraction}
@@ -964,22 +691,7 @@
 
 <Portal target="body">
   {#if $showAssetViewer}
-    {#await import('../asset-viewer/asset-viewer.svelte') then { default: AssetViewer }}
-      <AssetViewer
-        {withStacked}
-        asset={$viewingAsset}
-        preloadAssets={$preloadAssets}
-        {isShared}
-        {album}
-        {person}
-        preAction={handlePreAction}
-        onAction={handleAction}
-        onPrevious={handlePrevious}
-        onNext={handleNext}
-        onRandom={handleRandom}
-        onClose={handleClose}
-      />
-    {/await}
+    <TimelineAssetViewer bind:showSkeleton {timelineManager} {removeAction} {withStacked} {isShared} {album} {person} />
   {/if}
 </Portal>
 

web/src/lib/components/timeline/TimelineAssetViewer.svelte

@@ -0,0 +1,177 @@
+<script lang="ts">
+  import type { Action } from '$lib/components/asset-viewer/actions/action';
+  import { AssetAction } from '$lib/constants';
+  import { authManager } from '$lib/managers/auth-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { assetViewingStore } from '$lib/stores/asset-viewing.store';
+  import { updateStackedAssetInTimeline, updateUnstackedAssetInTimeline } from '$lib/utils/actions';
+  import { navigate } from '$lib/utils/navigation';
+  import { toTimelineAsset } from '$lib/utils/timeline-util';
+  import { getAssetInfo, type AlbumResponseDto, type PersonResponseDto } from '@immich/sdk';
+
+  let { asset: viewingAsset, gridScrollTarget, mutex, preloadAssets } = assetViewingStore;
+
+  interface Props {
+    timelineManager: TimelineManager;
+    showSkeleton: boolean;
+    withStacked?: boolean;
+    isShared?: boolean;
+    album?: AlbumResponseDto | null;
+    person?: PersonResponseDto | null;
+
+    removeAction?:
+      | AssetAction.UNARCHIVE
+      | AssetAction.ARCHIVE
+      | AssetAction.FAVORITE
+      | AssetAction.UNFAVORITE
+      | AssetAction.SET_VISIBILITY_TIMELINE
+      | null;
+  }
+
+  let {
+    timelineManager,
+    showSkeleton = $bindable(false),
+    removeAction,
+    withStacked = false,
+    isShared = false,
+    album = null,
+    person = null,
+  }: Props = $props();
+
+  const handlePrevious = async () => {
+    const release = await mutex.acquire();
+    const laterAsset = await timelineManager.getLaterAsset($viewingAsset);
+
+    if (laterAsset) {
+      const preloadAsset = await timelineManager.getLaterAsset(laterAsset);
+      const asset = await getAssetInfo({ ...authManager.params, id: laterAsset.id });
+      assetViewingStore.setAsset(asset, preloadAsset ? [preloadAsset] : []);
+      await navigate({ targetRoute: 'current', assetId: laterAsset.id });
+    }
+
+    release();
+    return !!laterAsset;
+  };
+
+  const handleNext = async () => {
+    const release = await mutex.acquire();
+    const earlierAsset = await timelineManager.getEarlierAsset($viewingAsset);
+
+    if (earlierAsset) {
+      const preloadAsset = await timelineManager.getEarlierAsset(earlierAsset);
+      const asset = await getAssetInfo({ ...authManager.params, id: earlierAsset.id });
+      assetViewingStore.setAsset(asset, preloadAsset ? [preloadAsset] : []);
+      await navigate({ targetRoute: 'current', assetId: earlierAsset.id });
+    }
+
+    release();
+    return !!earlierAsset;
+  };
+
+  const handleRandom = async () => {
+    const randomAsset = await timelineManager.getRandomAsset();
+
+    if (randomAsset) {
+      const asset = await getAssetInfo({ ...authManager.params, id: randomAsset.id });
+      assetViewingStore.setAsset(asset);
+      await navigate({ targetRoute: 'current', assetId: randomAsset.id });
+      return asset;
+    }
+  };
+
+  const handleClose = async (asset: { id: string }) => {
+    assetViewingStore.showAssetViewer(false);
+    showSkeleton = true;
+    $gridScrollTarget = { at: asset.id };
+    await navigate({ targetRoute: 'current', assetId: null, assetGridRouteSearchParams: $gridScrollTarget });
+  };
+
+  const handlePreAction = async (action: Action) => {
+    switch (action.type) {
+      case removeAction:
+      case AssetAction.TRASH:
+      case AssetAction.RESTORE:
+      case AssetAction.DELETE:
+      case AssetAction.ARCHIVE:
+      case AssetAction.SET_VISIBILITY_LOCKED:
+      case AssetAction.SET_VISIBILITY_TIMELINE: {
+        // find the next asset to show or close the viewer
+        // eslint-disable-next-line @typescript-eslint/no-unused-expressions
+        (await handleNext()) || (await handlePrevious()) || (await handleClose(action.asset));
+
+        // delete after find the next one
+        timelineManager.removeAssets([action.asset.id]);
+        break;
+      }
+    }
+  };
+  const handleAction = (action: Action) => {
+    switch (action.type) {
+      case AssetAction.ARCHIVE:
+      case AssetAction.UNARCHIVE:
+      case AssetAction.FAVORITE:
+      case AssetAction.UNFAVORITE: {
+        timelineManager.updateAssets([action.asset]);
+        break;
+      }
+
+      case AssetAction.ADD: {
+        timelineManager.addAssets([action.asset]);
+        break;
+      }
+
+      case AssetAction.UNSTACK: {
+        updateUnstackedAssetInTimeline(timelineManager, action.assets);
+        break;
+      }
+      case AssetAction.REMOVE_ASSET_FROM_STACK: {
+        timelineManager.addAssets([toTimelineAsset(action.asset)]);
+        if (action.stack) {
+          //Have to unstack then restack assets in timeline in order to update the stack count in the timeline.
+          updateUnstackedAssetInTimeline(
+            timelineManager,
+            action.stack.assets.map((asset) => toTimelineAsset(asset)),
+          );
+          updateStackedAssetInTimeline(timelineManager, {
+            stack: action.stack,
+            toDeleteIds: action.stack.assets
+              .filter((asset) => asset.id !== action.stack?.primaryAssetId)
+              .map((asset) => asset.id),
+          });
+        }
+        break;
+      }
+      case AssetAction.SET_STACK_PRIMARY_ASSET: {
+        //Have to unstack then restack assets in timeline in order for the currently removed new primary asset to be made visible.
+        updateUnstackedAssetInTimeline(
+          timelineManager,
+          action.stack.assets.map((asset) => toTimelineAsset(asset)),
+        );
+        updateStackedAssetInTimeline(timelineManager, {
+          stack: action.stack,
+          toDeleteIds: action.stack.assets
+            .filter((asset) => asset.id !== action.stack.primaryAssetId)
+            .map((asset) => asset.id),
+        });
+        break;
+      }
+    }
+  };
+</script>
+
+{#await import('../asset-viewer/asset-viewer.svelte') then { default: AssetViewer }}
+  <AssetViewer
+    {withStacked}
+    asset={$viewingAsset}
+    preloadAssets={$preloadAssets}
+    {isShared}
+    {album}
+    {person}
+    preAction={handlePreAction}
+    onAction={handleAction}
+    onPrevious={handlePrevious}
+    onNext={handleNext}
+    onRandom={handleRandom}
+    onClose={handleClose}
+  />
+{/await}

web/src/lib/components/timeline/actions/ArchiveAction.svelte

@@ -1,5 +1,6 @@
 <script lang="ts">
   import { getAssetControlContext } from '$lib/components/timeline/AssetSelectControlBar.svelte';
+  import type { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
   import type { OnArchive } from '$lib/utils/actions';
   import { archiveAssets } from '$lib/utils/asset-utils';
   import { AssetVisibility } from '@immich/sdk';
@@ -12,9 +13,10 @@
     onArchive?: OnArchive;
     menuItem?: boolean;
     unarchive?: boolean;
+    manager?: TimelineManager;
   }
 
-  let { onArchive, menuItem = false, unarchive = false }: Props = $props();
+  let { onArchive, menuItem = false, unarchive = false, manager }: Props = $props();
 
   let text = $derived(unarchive ? $t('unarchive') : $t('to_archive'));
   let icon = $derived(unarchive ? mdiArchiveArrowUpOutline : mdiArchiveArrowDownOutline);
@@ -24,12 +26,13 @@
   const { clearSelect, getOwnedAssets } = getAssetControlContext();
 
   const handleArchive = async () => {
-    const isArchived = unarchive ? AssetVisibility.Timeline : AssetVisibility.Archive;
-    const assets = [...getOwnedAssets()].filter((asset) => asset.visibility !== isArchived);
+    const visibility = unarchive ? AssetVisibility.Timeline : AssetVisibility.Archive;
+    const assets = [...getOwnedAssets()].filter((asset) => asset.visibility !== visibility);
     loading = true;
-    const ids = await archiveAssets(assets, isArchived as AssetVisibility);
+    const ids = await archiveAssets(assets, visibility as AssetVisibility);
     if (ids) {
-      onArchive?.(ids, isArchived ? AssetVisibility.Archive : AssetVisibility.Timeline);
+      manager?.updateAssetOperation(ids, (asset) => ((asset.visibility = visibility), void 0));
+      onArchive?.(ids, visibility ? AssetVisibility.Archive : AssetVisibility.Timeline);
       clearSelect();
     }
     loading = false;

web/src/lib/components/timeline/actions/DeleteAssetsAction.svelte

@@ -1,6 +1,8 @@
 <script lang="ts">
   import DeleteAssetDialog from '$lib/components/photos-page/delete-asset-dialog.svelte';
   import { getAssetControlContext } from '$lib/components/timeline/AssetSelectControlBar.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
   import { featureFlags } from '$lib/stores/server-config.store';
   import { type OnDelete, type OnUndoDelete, deleteAssets } from '$lib/utils/actions';
   import { IconButton } from '@immich/ui';
@@ -9,13 +11,14 @@
   import MenuOption from '../../shared-components/context-menu/menu-option.svelte';
 
   interface Props {
-    onAssetDelete: OnDelete;
-    onUndoDelete?: OnUndoDelete | undefined;
+    onAssetDelete?: OnDelete;
+    onUndoDelete?: OnUndoDelete;
     menuItem?: boolean;
     force?: boolean;
+    manager?: TimelineManager;
   }
 
-  let { onAssetDelete, onUndoDelete = undefined, menuItem = false, force = !$featureFlags.trash }: Props = $props();
+  let { onAssetDelete, onUndoDelete, menuItem = false, force = !$featureFlags.trash, manager }: Props = $props();
 
   const { clearSelect, getOwnedAssets } = getAssetControlContext();
 
@@ -36,7 +39,12 @@
   const handleDelete = async () => {
     loading = true;
     const assets = [...getOwnedAssets()];
-    await deleteAssets(force, onAssetDelete, assets, onUndoDelete);
+    const undo = (assets: TimelineAsset[]) => {
+      manager?.addAssets(assets);
+      onUndoDelete?.(assets);
+    };
+    await deleteAssets(force, onAssetDelete, assets, undo);
+    manager?.removeAssets(assets.map((asset) => asset.id));
     clearSelect();
     isShowConfirmation = false;
     loading = false;

web/src/lib/components/timeline/actions/FavoriteAction.svelte

@@ -5,6 +5,7 @@
     notificationController,
   } from '$lib/components/shared-components/notification/notification';
   import { getAssetControlContext } from '$lib/components/timeline/AssetSelectControlBar.svelte';
+  import type { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
   import type { OnFavorite } from '$lib/utils/actions';
   import { handleError } from '$lib/utils/handle-error';
   import { updateAssets } from '@immich/sdk';
@@ -16,9 +17,10 @@
     onFavorite?: OnFavorite;
     menuItem?: boolean;
     removeFavorite: boolean;
+    manager?: TimelineManager;
   }
 
-  let { onFavorite, menuItem = false, removeFavorite }: Props = $props();
+  let { onFavorite, menuItem = false, removeFavorite, manager }: Props = $props();
 
   let text = $derived(removeFavorite ? $t('remove_from_favorites') : $t('to_favorite'));
   let icon = $derived(removeFavorite ? mdiHeartMinusOutline : mdiHeartOutline);
@@ -39,11 +41,7 @@
       if (ids.length > 0) {
         await updateAssets({ assetBulkUpdateDto: { ids, isFavorite } });
       }
-
-      for (const asset of assets) {
-        asset.isFavorite = isFavorite;
-      }
-
+      manager?.updateAssetOperation(ids, (asset) => ((asset.isFavorite = isFavorite), void 0));
       onFavorite?.(ids, isFavorite);
 
       notificationController.show({

web/src/lib/components/timeline/actions/TimelineKeyboardActions.svelte

@@ -0,0 +1,221 @@
+<script lang="ts">
+  import { goto } from '$app/navigation';
+  import { shortcuts, type ShortcutOptions } from '$lib/actions/shortcut';
+  import DeleteAssetDialog from '$lib/components/photos-page/delete-asset-dialog.svelte';
+  import ChangeDate, {
+    type AbsoluteResult,
+    type RelativeResult,
+  } from '$lib/components/shared-components/change-date.svelte';
+  import {
+    setFocusToAsset as setFocusAssetInit,
+    setFocusTo as setFocusToInit,
+  } from '$lib/components/timeline/actions/focus-actions';
+  import { AppRoute } from '$lib/constants';
+  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
+  import ShortcutsModal from '$lib/modals/ShortcutsModal.svelte';
+  import type { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
+  import { assetViewingStore } from '$lib/stores/asset-viewing.store';
+  import { showDeleteModal } from '$lib/stores/preferences.store';
+  import { searchStore } from '$lib/stores/search.svelte';
+  import { featureFlags } from '$lib/stores/server-config.store';
+  import { handlePromiseError } from '$lib/utils';
+  import { deleteAssets, updateStackedAssetInTimeline } from '$lib/utils/actions';
+  import { archiveAssets, cancelMultiselect, selectAllAssets, stackAssets } from '$lib/utils/asset-utils';
+  import { AssetVisibility } from '@immich/sdk';
+  import { modalManager } from '@immich/ui';
+  import { DateTime } from 'luxon';
+  let { isViewing: showAssetViewer } = assetViewingStore;
+
+  interface Props {
+    timelineManager: TimelineManager;
+    assetInteraction: AssetInteraction;
+    isShowDeleteConfirmation: boolean;
+    onEscape?: () => void;
+    scrollToAsset: (asset: TimelineAsset) => boolean;
+  }
+
+  let {
+    timelineManager = $bindable(),
+    assetInteraction,
+    isShowDeleteConfirmation = $bindable(false),
+    onEscape,
+    scrollToAsset,
+  }: Props = $props();
+
+  let isShowSelectDate = $state(false);
+
+  const trashOrDelete = async (force: boolean = false) => {
+    isShowDeleteConfirmation = false;
+    await deleteAssets(
+      !(isTrashEnabled && !force),
+      (assetIds) => timelineManager.removeAssets(assetIds),
+      assetInteraction.selectedAssets,
+      !isTrashEnabled || force ? undefined : (assets) => timelineManager.addAssets(assets),
+    );
+    assetInteraction.clearMultiselect();
+  };
+
+  const onDelete = () => {
+    const hasTrashedAsset = assetInteraction.selectedAssets.some((asset) => asset.isTrashed);
+
+    if ($showDeleteModal && (!isTrashEnabled || hasTrashedAsset)) {
+      isShowDeleteConfirmation = true;
+      return;
+    }
+    handlePromiseError(trashOrDelete(hasTrashedAsset));
+  };
+
+  const onForceDelete = () => {
+    if ($showDeleteModal) {
+      isShowDeleteConfirmation = true;
+      return;
+    }
+    handlePromiseError(trashOrDelete(true));
+  };
+
+  const onStackAssets = async () => {
+    const result = await stackAssets(assetInteraction.selectedAssets);
+
+    updateStackedAssetInTimeline(timelineManager, result);
+
+    onEscape?.();
+  };
+
+  const toggleArchive = async () => {
+    const visibility = assetInteraction.isAllArchived ? AssetVisibility.Timeline : AssetVisibility.Archive;
+    const ids = await archiveAssets(assetInteraction.selectedAssets, visibility);
+    timelineManager.updateAssetOperation(ids, (asset) => {
+      asset.visibility = visibility;
+      return { remove: false };
+    });
+    deselectAllAssets();
+  };
+
+  let shiftKeyIsDown = $state(false);
+
+  const deselectAllAssets = () => {
+    cancelMultiselect(assetInteraction);
+  };
+
+  const onKeyDown = (event: KeyboardEvent) => {
+    if (searchStore.isSearchEnabled) {
+      return;
+    }
+
+    if (event.key === 'Shift') {
+      event.preventDefault();
+      shiftKeyIsDown = true;
+    }
+  };
+
+  const onKeyUp = (event: KeyboardEvent) => {
+    if (searchStore.isSearchEnabled) {
+      return;
+    }
+
+    if (event.key === 'Shift') {
+      event.preventDefault();
+      shiftKeyIsDown = false;
+    }
+  };
+
+  const onSelectStart = (e: Event) => {
+    if (assetInteraction.selectionActive && shiftKeyIsDown) {
+      e.preventDefault();
+    }
+  };
+
+  const isTrashEnabled = $derived($featureFlags.loaded && $featureFlags.trash);
+  const isEmpty = $derived(timelineManager.isInitialized && timelineManager.months.length === 0);
+  const idsSelectedAssets = $derived(assetInteraction.selectedAssets.map(({ id }) => id));
+  let isShortcutModalOpen = false;
+
+  const handleOpenShortcutModal = async () => {
+    if (isShortcutModalOpen) {
+      return;
+    }
+
+    isShortcutModalOpen = true;
+    await modalManager.show(ShortcutsModal, {});
+    isShortcutModalOpen = false;
+  };
+
+  $effect(() => {
+    if (isEmpty) {
+      assetInteraction.clearMultiselect();
+    }
+  });
+
+  const setFocusTo = setFocusToInit.bind(undefined, scrollToAsset, timelineManager);
+  const setFocusAsset = setFocusAssetInit.bind(undefined, scrollToAsset);
+
+  let shortcutList = $derived(
+    (() => {
+      if (searchStore.isSearchEnabled || $showAssetViewer) {
+        return [];
+      }
+
+      const shortcuts: ShortcutOptions[] = [
+        { shortcut: { key: '?', shift: true }, onShortcut: handleOpenShortcutModal },
+        { shortcut: { key: '/' }, onShortcut: () => goto(AppRoute.EXPLORE) },
+        { shortcut: { key: 'A', ctrl: true }, onShortcut: () => selectAllAssets(timelineManager, assetInteraction) },
+        { shortcut: { key: 'ArrowRight' }, onShortcut: () => setFocusTo('earlier', 'asset') },
+        { shortcut: { key: 'ArrowLeft' }, onShortcut: () => setFocusTo('later', 'asset') },
+        { shortcut: { key: 'D' }, onShortcut: () => setFocusTo('earlier', 'day') },
+        { shortcut: { key: 'D', shift: true }, onShortcut: () => setFocusTo('later', 'day') },
+        { shortcut: { key: 'M' }, onShortcut: () => setFocusTo('earlier', 'month') },
+        { shortcut: { key: 'M', shift: true }, onShortcut: () => setFocusTo('later', 'month') },
+        { shortcut: { key: 'Y' }, onShortcut: () => setFocusTo('earlier', 'year') },
+        { shortcut: { key: 'Y', shift: true }, onShortcut: () => setFocusTo('later', 'year') },
+        { shortcut: { key: 'G' }, onShortcut: () => (isShowSelectDate = true) },
+      ];
+      if (onEscape) {
+        shortcuts.push({ shortcut: { key: 'Escape' }, onShortcut: onEscape });
+      }
+
+      if (assetInteraction.selectionActive) {
+        shortcuts.push(
+          { shortcut: { key: 'Delete' }, onShortcut: onDelete },
+          { shortcut: { key: 'Delete', shift: true }, onShortcut: onForceDelete },
+          { shortcut: { key: 'D', ctrl: true }, onShortcut: () => deselectAllAssets() },
+          { shortcut: { key: 's' }, onShortcut: () => onStackAssets() },
+          { shortcut: { key: 'a', shift: true }, onShortcut: toggleArchive },
+        );
+      }
+
+      return shortcuts;
+    })(),
+  );
+</script>
+
+<svelte:document onkeydown={onKeyDown} onkeyup={onKeyUp} onselectstart={onSelectStart} use:shortcuts={shortcutList} />
+
+{#if isShowDeleteConfirmation}
+  <DeleteAssetDialog
+    size={idsSelectedAssets.length}
+    onCancel={() => (isShowDeleteConfirmation = false)}
+    onConfirm={() => handlePromiseError(trashOrDelete(true))}
+  />
+{/if}
+
+{#if isShowSelectDate}
+  <ChangeDate
+    withDuration={false}
+    title="Navigate to Time"
+    initialDate={DateTime.now()}
+    timezoneInput={false}
+    onConfirm={async (dateString: AbsoluteResult | RelativeResult) => {
+      isShowSelectDate = false;
+      if (dateString.mode == 'absolute') {
+        const asset = await timelineManager.getClosestAssetToDate(
+          (DateTime.fromISO(dateString.date) as DateTime<true>).toObject(),
+        );
+        if (asset) {
+          setFocusAsset(asset);
+        }
+      }
+    }}
+    onCancel={() => (isShowSelectDate = false)}
+  />
+{/if}

web/src/lib/managers/photostream-manager/PhotostreamManager.svelte.ts

@@ -0,0 +1,316 @@
+import { updateIntersectionMonthGroup } from '$lib/managers/timeline-manager/internal/intersection-support.svelte';
+import { updateGeometry } from '$lib/managers/timeline-manager/internal/layout-support.svelte';
+import { CancellableTask } from '$lib/utils/cancellable-task';
+import { clamp, debounce } from 'lodash-es';
+
+import type {
+  PhotostreamSegment,
+  SegmentIdentifier,
+} from '$lib/managers/photostream-manager/PhotostreamSegment.svelte';
+import type {
+  AssetDescriptor,
+  TimelineAsset,
+  TimelineManagerLayoutOptions,
+  Viewport,
+} from '$lib/managers/timeline-manager/types';
+
+export abstract class PhotostreamManager {
+  isInitialized = $state(false);
+  topSectionHeight = $state(0);
+  bottomSectionHeight = $state(60);
+  abstract get months(): PhotostreamSegment[];
+  timelineHeight = $derived.by(
+    () => this.months.reduce((accumulator, b) => accumulator + b.height, 0) + this.topSectionHeight,
+  );
+  assetCount = $derived.by(() => this.months.reduce((accumulator, b) => accumulator + b.assetsCount, 0));
+
+  topIntersectingMonthGroup: PhotostreamSegment | undefined = $state();
+
+  visibleWindow = $derived.by(() => ({
+    top: this.#scrollTop,
+    bottom: this.#scrollTop + this.viewportHeight,
+  }));
+
+  protected initTask = new CancellableTask(
+    () => (this.isInitialized = true),
+    () => (this.isInitialized = false),
+    () => void 0,
+  );
+
+  #viewportHeight = $state(0);
+  #viewportWidth = $state(0);
+  #scrollTop = $state(0);
+
+  #rowHeight = $state(235);
+  #headerHeight = $state(48);
+  #gap = $state(12);
+
+  #scrolling = $state(false);
+  #suspendTransitions = $state(false);
+  #resetScrolling = debounce(() => (this.#scrolling = false), 1000);
+  #resetSuspendTransitions = debounce(() => (this.suspendTransitions = false), 1000);
+  scrollCompensation: {
+    heightDelta: number | undefined;
+    scrollTop: number | undefined;
+    monthGroup: PhotostreamSegment | undefined;
+  } = $state({
+    heightDelta: 0,
+    scrollTop: 0,
+    monthGroup: undefined,
+  });
+
+  constructor() {}
+
+  setLayoutOptions({ headerHeight = 48, rowHeight = 235, gap = 12 }: TimelineManagerLayoutOptions) {
+    let changed = false;
+    changed ||= this.#setHeaderHeight(headerHeight);
+    changed ||= this.#setGap(gap);
+    changed ||= this.#setRowHeight(rowHeight);
+    if (changed) {
+      this.refreshLayout();
+    }
+  }
+
+  #setHeaderHeight(value: number) {
+    if (this.#headerHeight == value) {
+      return false;
+    }
+    this.#headerHeight = value;
+    return true;
+  }
+
+  get headerHeight() {
+    return this.#headerHeight;
+  }
+
+  #setGap(value: number) {
+    if (this.#gap == value) {
+      return false;
+    }
+    this.#gap = value;
+    return true;
+  }
+
+  get gap() {
+    return this.#gap;
+  }
+
+  #setRowHeight(value: number) {
+    if (this.#rowHeight == value) {
+      return false;
+    }
+    this.#rowHeight = value;
+    return true;
+  }
+
+  get rowHeight() {
+    return this.#rowHeight;
+  }
+
+  set scrolling(value: boolean) {
+    this.#scrolling = value;
+    if (value) {
+      this.suspendTransitions = true;
+      this.#resetScrolling();
+    }
+  }
+
+  get scrolling() {
+    return this.#scrolling;
+  }
+
+  set suspendTransitions(value: boolean) {
+    this.#suspendTransitions = value;
+    if (value) {
+      this.#resetSuspendTransitions();
+    }
+  }
+
+  get suspendTransitions() {
+    return this.#suspendTransitions;
+  }
+
+  set viewportWidth(value: number) {
+    const changed = value !== this.#viewportWidth;
+    this.#viewportWidth = value;
+    this.suspendTransitions = true;
+    void this.updateViewportGeometry(changed);
+  }
+
+  get viewportWidth() {
+    return this.#viewportWidth;
+  }
+
+  set viewportHeight(value: number) {
+    this.#viewportHeight = value;
+    this.#suspendTransitions = true;
+    void this.updateViewportGeometry(false);
+  }
+
+  get viewportHeight() {
+    return this.#viewportHeight;
+  }
+
+  updateSlidingWindow(scrollTop: number) {
+    if (this.#scrollTop !== scrollTop) {
+      this.#scrollTop = scrollTop;
+      this.updateIntersections();
+    }
+  }
+
+  clearScrollCompensation() {
+    this.scrollCompensation = {
+      heightDelta: undefined,
+      scrollTop: undefined,
+      monthGroup: undefined,
+    };
+  }
+
+  updateIntersections() {
+    if (!this.isInitialized || this.visibleWindow.bottom === this.visibleWindow.top) {
+      return;
+    }
+    let topIntersectingMonthGroup = undefined;
+    for (const month of this.months) {
+      updateIntersectionMonthGroup(this, month);
+      if (!topIntersectingMonthGroup && month.actuallyIntersecting) {
+        topIntersectingMonthGroup = month;
+      }
+    }
+    if (topIntersectingMonthGroup !== undefined && this.topIntersectingMonthGroup !== topIntersectingMonthGroup) {
+      this.topIntersectingMonthGroup = topIntersectingMonthGroup;
+    }
+    for (const month of this.months) {
+      if (month === this.topIntersectingMonthGroup) {
+        this.topIntersectingMonthGroup.percent = clamp(
+          (this.visibleWindow.top - this.topIntersectingMonthGroup.top) / this.topIntersectingMonthGroup.height,
+          0,
+          1,
+        );
+      } else {
+        month.percent = 0;
+      }
+    }
+  }
+
+  async init() {
+    this.isInitialized = false;
+    await this.initTask.execute(() => Promise.resolve(undefined), true);
+  }
+
+  public destroy() {
+    this.isInitialized = false;
+  }
+
+  async updateViewport(viewport: Viewport) {
+    if (viewport.height === 0 && viewport.width === 0) {
+      return;
+    }
+
+    if (this.viewportHeight === viewport.height && this.viewportWidth === viewport.width) {
+      return;
+    }
+
+    if (!this.initTask.executed) {
+      await (this.initTask.loading ? this.initTask.waitUntilCompletion() : this.init());
+    }
+
+    const changedWidth = viewport.width !== this.viewportWidth;
+    this.viewportHeight = viewport.height;
+    this.viewportWidth = viewport.width;
+    this.updateViewportGeometry(changedWidth);
+  }
+
+  protected updateViewportGeometry(changedWidth: boolean) {
+    if (!this.isInitialized) {
+      return;
+    }
+    if (this.viewportWidth === 0 || this.viewportHeight === 0) {
+      return;
+    }
+    for (const month of this.months) {
+      updateGeometry(this, month, { invalidateHeight: changedWidth });
+    }
+    this.updateIntersections();
+  }
+
+  createLayoutOptions() {
+    const viewportWidth = this.viewportWidth;
+
+    return {
+      spacing: 2,
+      heightTolerance: 0.15,
+      rowHeight: this.#rowHeight,
+      rowWidth: Math.floor(viewportWidth),
+    };
+  }
+
+  async loadSegment(identifier: SegmentIdentifier, options?: { cancelable: boolean }): Promise<void> {
+    let cancelable = true;
+    if (options) {
+      cancelable = options.cancelable;
+    }
+    const segment = this.getSegmentByIdentifier(identifier);
+    if (!segment) {
+      return;
+    }
+
+    if (segment.loader?.executed) {
+      return;
+    }
+
+    const result = await segment.load(cancelable);
+    if (result === 'LOADED') {
+      updateIntersectionMonthGroup(this, segment);
+    }
+  }
+
+  getSegmentByIdentifier(identifier: SegmentIdentifier) {
+    return this.months.find((segment) => identifier.matches(segment));
+  }
+
+  getSegmentForAssetId(assetId: string) {
+    for (const month of this.months) {
+      const asset = month.assets.find((asset) => asset.id === assetId);
+      if (asset) {
+        return month;
+      }
+    }
+  }
+
+  refreshLayout() {
+    for (const month of this.months) {
+      updateGeometry(this, month, { invalidateHeight: true });
+    }
+    this.updateIntersections();
+  }
+
+  getMaxScrollPercent() {
+    const totalHeight = this.timelineHeight + this.bottomSectionHeight + this.topSectionHeight;
+    return (totalHeight - this.viewportHeight) / totalHeight;
+  }
+
+  getMaxScroll() {
+    return this.topSectionHeight + this.bottomSectionHeight + (this.timelineHeight - this.viewportHeight);
+  }
+
+  retrieveRange(start: AssetDescriptor, end: AssetDescriptor): Promise<TimelineAsset[]> {
+    const range: TimelineAsset[] = [];
+    let collecting = false;
+
+    for (const month of this.months) {
+      for (const asset of month.assets) {
+        if (asset.id === start.id) {
+          collecting = true;
+        }
+        if (collecting) {
+          range.push(asset);
+        }
+        if (asset.id === end.id) {
+          return Promise.resolve(range);
+        }
+      }
+    }
+    return Promise.resolve(range);
+  }
+}

web/src/lib/managers/photostream-manager/PhotostreamSegment.svelte.ts

@@ -0,0 +1,150 @@
+import { CancellableTask } from '$lib/utils/cancellable-task';
+import { handleError } from '$lib/utils/handle-error';
+import { t } from 'svelte-i18n';
+import { get } from 'svelte/store';
+
+import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
+import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
+import type { ViewerAsset } from '$lib/managers/timeline-manager/viewer-asset.svelte';
+
+export type SegmentIdentifier = {
+  matches(segment: PhotostreamSegment): boolean;
+};
+export abstract class PhotostreamSegment {
+  #intersecting = $state(false);
+  actuallyIntersecting = $state(false);
+  #isLoaded = $state(false);
+
+  #height = $state(0);
+  #top = $state(0);
+  #assets = $derived.by(() => this.viewerAssets.map((viewerAsset) => viewerAsset.asset));
+
+  initialCount = $state(0);
+  percent = $state(0);
+
+  assetsCount = $derived.by(() => (this.isLoaded ? this.viewerAssets.length : this.initialCount));
+  loader = new CancellableTask(
+    () => this.markLoaded(),
+    () => this.markCanceled,
+    () => this.handleLoadError,
+  );
+  isHeightActual = $state(false);
+
+  abstract get timelineManager(): PhotostreamManager;
+
+  abstract get identifier(): SegmentIdentifier;
+
+  abstract get id(): string;
+
+  get isLoaded() {
+    return this.#isLoaded;
+  }
+
+  protected markLoaded() {
+    this.#isLoaded = true;
+  }
+
+  protected markCanceled() {
+    this.#isLoaded = false;
+  }
+
+  set intersecting(newValue: boolean) {
+    const old = this.#intersecting;
+    if (old === newValue) {
+      return;
+    }
+    this.#intersecting = newValue;
+    if (newValue) {
+      void this.load(true);
+    } else {
+      this.cancel();
+    }
+  }
+
+  get intersecting() {
+    return this.#intersecting;
+  }
+
+  async load(cancelable: boolean): Promise<'DONE' | 'WAITED' | 'CANCELED' | 'LOADED' | 'ERRORED'> {
+    return await this.loader?.execute(async (signal: AbortSignal) => {
+      await this.fetch(signal);
+    }, cancelable);
+  }
+
+  protected abstract fetch(signal: AbortSignal): Promise<void>;
+
+  get assets(): TimelineAsset[] {
+    return this.#assets;
+  }
+
+  abstract get viewerAssets(): ViewerAsset[];
+
+  set height(height: number) {
+    if (this.#height === height) {
+      return;
+    }
+    const { timelineManager: store, percent } = this;
+    const index = store.months.indexOf(this);
+    const heightDelta = height - this.#height;
+    this.#height = height;
+    const prevMonthGroup = store.months[index - 1];
+    if (prevMonthGroup) {
+      const newTop = prevMonthGroup.#top + prevMonthGroup.#height;
+      if (this.#top !== newTop) {
+        this.#top = newTop;
+      }
+    }
+    for (let cursor = index + 1; cursor < store.months.length; cursor++) {
+      const monthGroup = this.timelineManager.months[cursor];
+      const newTop = monthGroup.#top + heightDelta;
+      if (monthGroup.#top !== newTop) {
+        monthGroup.#top = newTop;
+      }
+    }
+    if (store.topIntersectingMonthGroup) {
+      const currentIndex = store.months.indexOf(store.topIntersectingMonthGroup);
+      if (currentIndex > 0) {
+        if (index < currentIndex) {
+          store.scrollCompensation = {
+            heightDelta,
+            scrollTop: undefined,
+            monthGroup: this,
+          };
+        } else if (percent > 0) {
+          const top = this.top + height * percent;
+          store.scrollCompensation = {
+            heightDelta: undefined,
+            scrollTop: top,
+            monthGroup: this,
+          };
+        }
+      }
+    }
+  }
+
+  get height() {
+    return this.#height;
+  }
+
+  get top(): number {
+    return this.#top + this.timelineManager.topSectionHeight;
+  }
+
+  protected handleLoadError(error: unknown) {
+    const _$t = get(t);
+    handleError(error, _$t('errors.failed_to_load_assets'));
+  }
+
+  cancel() {
+    this.loader?.cancel();
+  }
+
+  layout(_: boolean) {}
+
+  updateIntersection({ intersecting, actuallyIntersecting }: { intersecting: boolean; actuallyIntersecting: boolean }) {
+    this.intersecting = intersecting;
+    this.actuallyIntersecting = actuallyIntersecting;
+  }
+
+  abstract findAssetAbsolutePosition(assetId: string): number;
+}

web/src/lib/managers/timeline-manager/day-group.svelte.ts

@@ -13,6 +13,7 @@ export class DayGroup {
   readonly monthGroup: MonthGroup;
   readonly index: number;
   readonly groupTitle: string;
+  readonly groupTitleFull: string;
   readonly day: number;
   viewerAssets: ViewerAsset[] = $state([]);
 
@@ -26,11 +27,12 @@ export class DayGroup {
   #col = $state(0);
   #deferredLayout = false;
 
-  constructor(monthGroup: MonthGroup, index: number, day: number, groupTitle: string) {
+  constructor(monthGroup: MonthGroup, index: number, day: number, groupTitle: string, groupTitleFull: string) {
     this.index = index;
     this.monthGroup = monthGroup;
     this.day = day;
     this.groupTitle = groupTitle;
+    this.groupTitleFull = groupTitleFull;
   }
 
   get top() {
@@ -127,7 +129,7 @@ export class DayGroup {
 
       const asset = this.viewerAssets[index].asset!;
       const oldTime = { ...asset.localDateTime };
-      let { remove } = operation(asset);
+      let { remove } = operation(asset) ?? { remove: false };
       const newTime = asset.localDateTime;
       if (oldTime.year !== newTime.year || oldTime.month !== newTime.month || oldTime.day !== newTime.day) {
         const { year, month, day } = newTime;

web/src/lib/managers/timeline-manager/internal/intersection-support.svelte.ts

@@ -1,27 +1,23 @@
+import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
+import type { PhotostreamSegment } from '$lib/managers/photostream-manager/PhotostreamSegment.svelte';
 import { TUNABLES } from '$lib/utils/tunables';
-import type { MonthGroup } from '../month-group.svelte';
-import type { TimelineManager } from '../timeline-manager.svelte';
 
 const {
   TIMELINE: { INTERSECTION_EXPAND_TOP, INTERSECTION_EXPAND_BOTTOM },
 } = TUNABLES;
 
-export function updateIntersectionMonthGroup(timelineManager: TimelineManager, month: MonthGroup) {
-  const actuallyIntersecting = calculateMonthGroupIntersecting(timelineManager, month, 0, 0);
+export function updateIntersectionMonthGroup(timelineManager: PhotostreamManager, month: PhotostreamSegment) {
+  const actuallyIntersecting = calculateSegmentIntersecting(timelineManager, month, 0, 0);
   let preIntersecting = false;
   if (!actuallyIntersecting) {
-    preIntersecting = calculateMonthGroupIntersecting(
+    preIntersecting = calculateSegmentIntersecting(
       timelineManager,
       month,
       INTERSECTION_EXPAND_TOP,
       INTERSECTION_EXPAND_BOTTOM,
     );
   }
-  month.intersecting = actuallyIntersecting || preIntersecting;
-  month.actuallyIntersecting = actuallyIntersecting;
-  if (preIntersecting || actuallyIntersecting) {
-    timelineManager.clearDeferredLayout(month);
-  }
+  month.updateIntersection({ intersecting: actuallyIntersecting || preIntersecting, actuallyIntersecting });
 }
 
 /**
@@ -40,9 +36,9 @@ export function isIntersecting(regionTop: number, regionBottom: number, windowTo
   );
 }
 
-export function calculateMonthGroupIntersecting(
-  timelineManager: TimelineManager,
-  monthGroup: MonthGroup,
+export function calculateSegmentIntersecting(
+  timelineManager: PhotostreamManager,
+  monthGroup: PhotostreamSegment,
   expandTop: number,
   expandBottom: number,
 ) {
@@ -58,7 +54,7 @@ export function calculateMonthGroupIntersecting(
  * Calculate intersection for viewer assets with additional parameters like header height and scroll compensation
  */
 export function calculateViewerAssetIntersecting(
-  timelineManager: TimelineManager,
+  timelineManager: PhotostreamManager,
   positionTop: number,
   positionHeight: number,
   expandTop: number = INTERSECTION_EXPAND_TOP,

web/src/lib/managers/timeline-manager/internal/layout-support.svelte.ts

@@ -1,8 +1,14 @@
+import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
+import type { PhotostreamSegment } from '$lib/managers/photostream-manager/PhotostreamSegment.svelte';
+import type { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
 import type { MonthGroup } from '../month-group.svelte';
-import type { TimelineManager } from '../timeline-manager.svelte';
 import type { UpdateGeometryOptions } from '../types';
 
-export function updateGeometry(timelineManager: TimelineManager, month: MonthGroup, options: UpdateGeometryOptions) {
+export function updateGeometry(
+  timelineManager: PhotostreamManager,
+  month: PhotostreamSegment,
+  options: UpdateGeometryOptions,
+) {
   const { invalidateHeight, noDefer = false } = options;
   if (invalidateHeight) {
     month.isHeightActual = false;
@@ -17,7 +23,7 @@ export function updateGeometry(timelineManager: TimelineManager, month: MonthGro
     }
     return;
   }
-  layoutMonthGroup(timelineManager, month, noDefer);
+  month.layout(noDefer);
 }
 
 export function layoutMonthGroup(timelineManager: TimelineManager, month: MonthGroup, noDefer: boolean = false) {

web/src/lib/managers/timeline-manager/internal/operations-support.svelte.ts

@@ -25,8 +25,7 @@ export function addAssetsToMonthGroups(
     let month = getMonthGroupByDate(timelineManager, asset.localDateTime);
 
     if (!month) {
-      month = new MonthGroup(timelineManager, asset.localDateTime, 1, options.order);
-      month.isLoaded = true;
+      month = new MonthGroup(timelineManager, asset.localDateTime, 1, true, options.order);
       timelineManager.months.push(month);
     }
 

web/src/lib/managers/timeline-manager/month-group.svelte.ts

@@ -1,22 +1,26 @@
 import { AssetOrder, type TimeBucketAssetResponseDto } from '@immich/sdk';
 
-import { CancellableTask } from '$lib/utils/cancellable-task';
-import { handleError } from '$lib/utils/handle-error';
 import {
   formatGroupTitle,
+  formatGroupTitleFull,
   formatMonthGroupTitle,
   fromTimelinePlainDate,
   fromTimelinePlainDateTime,
   fromTimelinePlainYearMonth,
+  getSegmentIdentifier,
   getTimes,
   setDifference,
   type TimelineDateTime,
   type TimelineYearMonth,
 } from '$lib/utils/timeline-util';
 
-import { t } from 'svelte-i18n';
-import { get } from 'svelte/store';
+import { layoutMonthGroup, updateGeometry } from '$lib/managers/timeline-manager/internal/layout-support.svelte';
+import { loadFromTimeBuckets } from '$lib/managers/timeline-manager/internal/load-support.svelte';
 
+import {
+  PhotostreamSegment,
+  type SegmentIdentifier,
+} from '$lib/managers/photostream-manager/PhotostreamSegment.svelte';
 import { SvelteSet } from 'svelte/reactivity';
 import { DayGroup } from './day-group.svelte';
 import { GroupInsertionCache } from './group-insertion-cache.svelte';
@@ -24,71 +28,49 @@ import type { TimelineManager } from './timeline-manager.svelte';
 import type { AssetDescriptor, AssetOperation, Direction, MoveAsset, TimelineAsset } from './types';
 import { ViewerAsset } from './viewer-asset.svelte';
 
-export class MonthGroup {
-  #intersecting: boolean = $state(false);
-  actuallyIntersecting: boolean = $state(false);
-  isLoaded: boolean = $state(false);
+export class MonthGroup extends PhotostreamSegment {
   dayGroups: DayGroup[] = $state([]);
-  readonly timelineManager: TimelineManager;
 
-  #height: number = $state(0);
-  #top: number = $state(0);
-
-  #initialCount: number = 0;
   #sortOrder: AssetOrder = AssetOrder.Desc;
-  percent: number = $state(0);
-
-  assetsCount: number = $derived(
-    this.isLoaded
-      ? this.dayGroups.reduce((accumulator, g) => accumulator + g.viewerAssets.length, 0)
-      : this.#initialCount,
-  );
-  loader: CancellableTask | undefined;
-  isHeightActual: boolean = $state(false);
+  #yearMonth: TimelineYearMonth;
+  #identifier: SegmentIdentifier;
+  #timelineManager: TimelineManager;
 
   readonly monthGroupTitle: string;
-  readonly yearMonth: TimelineYearMonth;
 
   constructor(
-    store: TimelineManager,
+    timelineManager: TimelineManager,
     yearMonth: TimelineYearMonth,
     initialCount: number,
+    loaded: boolean,
     order: AssetOrder = AssetOrder.Desc,
   ) {
-    this.timelineManager = store;
-    this.#initialCount = initialCount;
+    super();
+    this.initialCount = initialCount;
+    this.#yearMonth = yearMonth;
+    this.#identifier = getSegmentIdentifier(yearMonth);
+    this.#timelineManager = timelineManager;
     this.#sortOrder = order;
-
-    this.yearMonth = yearMonth;
     this.monthGroupTitle = formatMonthGroupTitle(fromTimelinePlainYearMonth(yearMonth));
-
-    this.loader = new CancellableTask(
-      () => {
-        this.isLoaded = true;
-      },
-      () => {
-        this.dayGroups = [];
-        this.isLoaded = false;
-      },
-      this.#handleLoadError,
-    );
-  }
-
-  set intersecting(newValue: boolean) {
-    const old = this.#intersecting;
-    if (old === newValue) {
-      return;
-    }
-    this.#intersecting = newValue;
-    if (newValue) {
-      void this.timelineManager.loadMonthGroup(this.yearMonth);
-    } else {
-      this.cancel();
+    if (loaded) {
+      this.markLoaded();
     }
   }
 
-  get intersecting() {
-    return this.#intersecting;
+  get identifier() {
+    return this.#identifier;
+  }
+
+  get timelineManager() {
+    return this.#timelineManager;
+  }
+
+  get yearMonth() {
+    return this.#yearMonth;
+  }
+
+  fetch(signal: AbortSignal): Promise<void> {
+    return loadFromTimeBuckets(this.timelineManager, this, this.timelineManager.options, signal);
   }
 
   get lastDayGroup() {
@@ -99,9 +81,9 @@ export class MonthGroup {
     return this.dayGroups[0]?.getFirstAsset();
   }
 
-  getAssets() {
+  get viewerAssets() {
     // eslint-disable-next-line unicorn/no-array-reduce
-    return this.dayGroups.reduce((accumulator: TimelineAsset[], g: DayGroup) => accumulator.concat(g.getAssets()), []);
+    return this.dayGroups.reduce((accumulator: ViewerAsset[], g: DayGroup) => accumulator.concat(g.viewerAssets), []);
   }
 
   sortDayGroups() {
@@ -222,7 +204,8 @@ export class MonthGroup {
       addContext.setDayGroup(dayGroup, localDateTime);
     } else {
       const groupTitle = formatGroupTitle(fromTimelinePlainDate(localDateTime));
-      dayGroup = new DayGroup(this, this.dayGroups.length, localDateTime.day, groupTitle);
+      const groupTitleFull = formatGroupTitleFull(fromTimelinePlainDate(localDateTime));
+      dayGroup = new DayGroup(this, this.dayGroups.length, localDateTime.day, groupTitle, groupTitleFull);
       this.dayGroups.push(dayGroup);
       addContext.setDayGroup(dayGroup, localDateTime);
       addContext.newDayGroups.add(dayGroup);
@@ -242,67 +225,15 @@ export class MonthGroup {
     return this.getRandomDayGroup()?.getRandomAsset()?.asset;
   }
 
+  get id() {
+    return this.viewId;
+  }
+
   get viewId() {
     const { year, month } = this.yearMonth;
     return year + '-' + month;
   }
 
-  set height(height: number) {
-    if (this.#height === height) {
-      return;
-    }
-    const { timelineManager: store, percent } = this;
-    const index = store.months.indexOf(this);
-    const heightDelta = height - this.#height;
-    this.#height = height;
-    const prevMonthGroup = store.months[index - 1];
-    if (prevMonthGroup) {
-      const newTop = prevMonthGroup.#top + prevMonthGroup.#height;
-      if (this.#top !== newTop) {
-        this.#top = newTop;
-      }
-    }
-    for (let cursor = index + 1; cursor < store.months.length; cursor++) {
-      const monthGroup = this.timelineManager.months[cursor];
-      const newTop = monthGroup.#top + heightDelta;
-      if (monthGroup.#top !== newTop) {
-        monthGroup.#top = newTop;
-      }
-    }
-    if (store.topIntersectingMonthGroup) {
-      const currentIndex = store.months.indexOf(store.topIntersectingMonthGroup);
-      if (currentIndex > 0) {
-        if (index < currentIndex) {
-          store.scrollCompensation = {
-            heightDelta,
-            scrollTop: undefined,
-            monthGroup: this,
-          };
-        } else if (percent > 0) {
-          const top = this.top + height * percent;
-          store.scrollCompensation = {
-            heightDelta: undefined,
-            scrollTop: top,
-            monthGroup: this,
-          };
-        }
-      }
-    }
-  }
-
-  get height() {
-    return this.#height;
-  }
-
-  get top(): number {
-    return this.#top + this.timelineManager.topSectionHeight;
-  }
-
-  #handleLoadError(error: unknown) {
-    const _$t = get(t);
-    handleError(error, _$t('errors.failed_to_load_assets'));
-  }
-
   findDayGroupForAsset(asset: TimelineAsset) {
     for (const group of this.dayGroups) {
       if (group.viewerAssets.some((viewerAsset) => viewerAsset.id === asset.id)) {
@@ -316,7 +247,7 @@ export class MonthGroup {
   }
 
   findAssetAbsolutePosition(assetId: string) {
-    this.timelineManager.clearDeferredLayout(this);
+    this.#clearDeferredLayout();
     for (const group of this.dayGroups) {
       const viewerAsset = group.viewerAssets.find((viewAsset) => viewAsset.id === assetId);
       if (viewerAsset) {
@@ -374,4 +305,26 @@ export class MonthGroup {
   cancel() {
     this.loader?.cancel();
   }
+
+  layout(noDefer: boolean) {
+    layoutMonthGroup(this.timelineManager, this, noDefer);
+  }
+
+  #clearDeferredLayout() {
+    const hasDeferred = this.dayGroups.some((group) => group.deferredLayout);
+    if (hasDeferred) {
+      updateGeometry(this.timelineManager, this, { invalidateHeight: true, noDefer: true });
+      for (const group of this.dayGroups) {
+        group.deferredLayout = false;
+      }
+    }
+  }
+
+  updateIntersection({ intersecting, actuallyIntersecting }: { intersecting: boolean; actuallyIntersecting: boolean }) {
+    this.intersecting = intersecting;
+    this.actuallyIntersecting = actuallyIntersecting;
+    if (intersecting) {
+      this.#clearDeferredLayout();
+    }
+  }
 }

web/src/lib/managers/timeline-manager/timeline-manager.svelte.spec.ts

@@ -1,7 +1,7 @@
 import { sdkMock } from '$lib/__mocks__/sdk.mock';
 import { getMonthGroupByDate } from '$lib/managers/timeline-manager/internal/search-support.svelte';
 import { AbortError } from '$lib/utils';
-import { fromISODateTimeUTCToObject } from '$lib/utils/timeline-util';
+import { fromISODateTimeUTCToObject, getSegmentIdentifier } from '$lib/utils/timeline-util';
 import { type AssetResponseDto, type TimeBucketAssetResponseDto } from '@immich/sdk';
 import { timelineAssetFactory, toResponseDto } from '@test-data/factories/asset-factory';
 import { TimelineManager } from './timeline-manager.svelte';
@@ -92,7 +92,7 @@ describe('TimelineManager', () => {
     });
   });
 
-  describe('loadMonthGroup', () => {
+  describe('loadSegment', () => {
     let timelineManager: TimelineManager;
     const bucketAssets: Record<string, TimelineAsset[]> = {
       '2024-01-03T00:00:00.000Z': timelineAssetFactory.buildList(1).map((asset) =>
@@ -128,48 +128,48 @@ describe('TimelineManager', () => {
     });
 
     it('loads a month', async () => {
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(0);
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.assets.length).toEqual(0);
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
       expect(sdkMock.getTimeBucket).toBeCalledTimes(1);
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(3);
+      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.assets.length).toEqual(3);
     });
 
     it('ignores invalid months', async () => {
-      await timelineManager.loadMonthGroup({ year: 2023, month: 1 });
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2023, month: 1 }));
       expect(sdkMock.getTimeBucket).toBeCalledTimes(0);
     });
 
     it('cancels month loading', async () => {
       const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })!;
-      void timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      void timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
       const abortSpy = vi.spyOn(month!.loader!.cancelToken!, 'abort');
       month?.cancel();
       expect(abortSpy).toBeCalledTimes(1);
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(3);
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
+      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.assets.length).toEqual(3);
     });
 
     it('prevents loading months multiple times', async () => {
       await Promise.all([
-        timelineManager.loadMonthGroup({ year: 2024, month: 1 }),
-        timelineManager.loadMonthGroup({ year: 2024, month: 1 }),
+        timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 })),
+        timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 })),
       ]);
       expect(sdkMock.getTimeBucket).toBeCalledTimes(1);
 
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
       expect(sdkMock.getTimeBucket).toBeCalledTimes(1);
     });
 
     it('allows loading a canceled month', async () => {
       const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })!;
-      const loadPromise = timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      const loadPromise = timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
 
       month.cancel();
       await loadPromise;
-      expect(month?.getAssets().length).toEqual(0);
+      expect(month?.assets.length).toEqual(0);
 
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
-      expect(month!.getAssets().length).toEqual(3);
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
+      expect(month!.assets.length).toEqual(3);
     });
   });
 
@@ -198,7 +198,7 @@ describe('TimelineManager', () => {
 
       expect(timelineManager.months.length).toEqual(1);
       expect(timelineManager.assetCount).toEqual(1);
-      expect(timelineManager.months[0].getAssets().length).toEqual(1);
+      expect(timelineManager.months[0].assets.length).toEqual(1);
       expect(timelineManager.months[0].yearMonth.year).toEqual(2024);
       expect(timelineManager.months[0].yearMonth.month).toEqual(1);
       expect(timelineManager.months[0].getFirstAsset().id).toEqual(asset.id);
@@ -215,7 +215,7 @@ describe('TimelineManager', () => {
 
       expect(timelineManager.months.length).toEqual(1);
       expect(timelineManager.assetCount).toEqual(2);
-      expect(timelineManager.months[0].getAssets().length).toEqual(2);
+      expect(timelineManager.months[0].assets.length).toEqual(2);
       expect(timelineManager.months[0].yearMonth.year).toEqual(2024);
       expect(timelineManager.months[0].yearMonth.month).toEqual(1);
     });
@@ -240,10 +240,10 @@ describe('TimelineManager', () => {
 
       const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 1 });
       expect(month).not.toBeNull();
-      expect(month?.getAssets().length).toEqual(3);
-      expect(month?.getAssets()[0].id).toEqual(assetOne.id);
-      expect(month?.getAssets()[1].id).toEqual(assetThree.id);
-      expect(month?.getAssets()[2].id).toEqual(assetTwo.id);
+      expect(month?.assets.length).toEqual(3);
+      expect(month?.assets[0].id).toEqual(assetOne.id);
+      expect(month?.assets[1].id).toEqual(assetThree.id);
+      expect(month?.assets[2].id).toEqual(assetTwo.id);
     });
 
     it('orders months by descending date', () => {
@@ -341,14 +341,14 @@ describe('TimelineManager', () => {
       timelineManager.addAssets([asset]);
       expect(timelineManager.months.length).toEqual(1);
       expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })).not.toBeUndefined();
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(1);
+      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.assets.length).toEqual(1);
 
       timelineManager.updateAssets([updatedAsset]);
       expect(timelineManager.months.length).toEqual(2);
       expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })).not.toBeUndefined();
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(0);
+      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.assets.length).toEqual(0);
       expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 3 })).not.toBeUndefined();
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 3 })?.getAssets().length).toEqual(1);
+      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 3 })?.assets.length).toEqual(1);
     });
   });
 
@@ -374,7 +374,7 @@ describe('TimelineManager', () => {
 
       expect(timelineManager.assetCount).toEqual(2);
       expect(timelineManager.months.length).toEqual(1);
-      expect(timelineManager.months[0].getAssets().length).toEqual(2);
+      expect(timelineManager.months[0].assets.length).toEqual(2);
     });
 
     it('removes asset from month', () => {
@@ -388,7 +388,7 @@ describe('TimelineManager', () => {
 
       expect(timelineManager.assetCount).toEqual(1);
       expect(timelineManager.months.length).toEqual(1);
-      expect(timelineManager.months[0].getAssets().length).toEqual(1);
+      expect(timelineManager.months[0].assets.length).toEqual(1);
     });
 
     it('does not remove month when empty', () => {
@@ -477,45 +477,45 @@ describe('TimelineManager', () => {
     });
 
     it('returns previous assetId', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
       const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 1 });
 
-      const a = month!.getAssets()[0];
-      const b = month!.getAssets()[1];
+      const a = month!.assets[0];
+      const b = month!.assets[1];
       const previous = await timelineManager.getLaterAsset(b);
       expect(previous).toEqual(a);
     });
 
     it('returns previous assetId spanning multiple months', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 2 });
-      await timelineManager.loadMonthGroup({ year: 2024, month: 3 });
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 2 }));
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 3 }));
 
       const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 2 });
       const previousMonth = getMonthGroupByDate(timelineManager, { year: 2024, month: 3 });
-      const a = month!.getAssets()[0];
-      const b = previousMonth!.getAssets()[0];
+      const a = month!.assets[0];
+      const b = previousMonth!.assets[0];
       const previous = await timelineManager.getLaterAsset(a);
       expect(previous).toEqual(b);
     });
 
     it('loads previous month', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 2 });
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 2 }));
       const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 2 });
       const previousMonth = getMonthGroupByDate(timelineManager, { year: 2024, month: 3 });
       const a = month!.getFirstAsset();
       const b = previousMonth!.getFirstAsset();
-      const loadMonthGroupSpy = vi.spyOn(month!.loader!, 'execute');
+      const loadSegmentSpy = vi.spyOn(month!.loader!, 'execute');
       const previousMonthSpy = vi.spyOn(previousMonth!.loader!, 'execute');
       const previous = await timelineManager.getLaterAsset(a);
       expect(previous).toEqual(b);
-      expect(loadMonthGroupSpy).toBeCalledTimes(0);
+      expect(loadSegmentSpy).toBeCalledTimes(0);
       expect(previousMonthSpy).toBeCalledTimes(0);
     });
 
     it('skips removed assets', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
-      await timelineManager.loadMonthGroup({ year: 2024, month: 2 });
-      await timelineManager.loadMonthGroup({ year: 2024, month: 3 });
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 2 }));
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 3 }));
 
       const [assetOne, assetTwo, assetThree] = await getAssets(timelineManager);
       timelineManager.removeAssets([assetTwo.id]);
@@ -523,7 +523,7 @@ describe('TimelineManager', () => {
     });
 
     it('returns null when no more assets', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 3 });
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 3 }));
       expect(await timelineManager.getLaterAsset(timelineManager.months[0].getFirstAsset())).toBeUndefined();
     });
   });

web/src/lib/managers/timeline-manager/timeline-manager.svelte.ts

@@ -3,14 +3,18 @@ import { AssetOrder, getAssetInfo, getTimeBuckets } from '@immich/sdk';
 import { authManager } from '$lib/managers/auth-manager.svelte';
 
 import { CancellableTask } from '$lib/utils/cancellable-task';
-import { toTimelineAsset, type TimelineDateTime, type TimelineYearMonth } from '$lib/utils/timeline-util';
+import {
+  getSegmentIdentifier,
+  toTimelineAsset,
+  type TimelineDateTime,
+  type TimelineYearMonth,
+} from '$lib/utils/timeline-util';
 
-import { clamp, debounce, isEqual } from 'lodash-es';
+import { isEqual } from 'lodash-es';
 import { SvelteDate, SvelteMap, SvelteSet } from 'svelte/reactivity';
 
-import { updateIntersectionMonthGroup } from '$lib/managers/timeline-manager/internal/intersection-support.svelte';
+import { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
 import { updateGeometry } from '$lib/managers/timeline-manager/internal/layout-support.svelte';
-import { loadFromTimeBuckets } from '$lib/managers/timeline-manager/internal/load-support.svelte';
 import {
   addAssetsToMonthGroups,
   runAssetOperation,
@@ -32,29 +36,14 @@ import type {
   Direction,
   ScrubberMonth,
   TimelineAsset,
-  TimelineManagerLayoutOptions,
   TimelineManagerOptions,
-  Viewport,
 } from './types';
 
-export class TimelineManager {
-  isInitialized = $state(false);
-  months: MonthGroup[] = $state([]);
-  topSectionHeight = $state(0);
-  timelineHeight = $derived(this.months.reduce((accumulator, b) => accumulator + b.height, 0) + this.topSectionHeight);
-  assetCount = $derived(this.months.reduce((accumulator, b) => accumulator + b.assetsCount, 0));
-
+export class TimelineManager extends PhotostreamManager {
   albumAssets: Set<string> = new SvelteSet();
-
   scrubberMonths: ScrubberMonth[] = $state([]);
   scrubberTimelineHeight: number = $state(0);
-
-  topIntersectingMonthGroup: MonthGroup | undefined = $state();
-
-  visibleWindow = $derived.by(() => ({
-    top: this.#scrollTop,
-    bottom: this.#scrollTop + this.viewportHeight,
-  }));
+  #months: MonthGroup[] = $state([]);
 
   initTask = new CancellableTask(
     () => {
@@ -72,121 +61,16 @@ export class TimelineManager {
   );
 
   static #INIT_OPTIONS = {};
-  #viewportHeight = $state(0);
-  #viewportWidth = $state(0);
-  #scrollTop = $state(0);
+
   #websocketSupport: WebsocketSupport | undefined;
-
-  #rowHeight = $state(235);
-  #headerHeight = $state(48);
-  #gap = $state(12);
-
   #options: TimelineManagerOptions = TimelineManager.#INIT_OPTIONS;
 
-  #scrolling = $state(false);
-  #suspendTransitions = $state(false);
-  #resetScrolling = debounce(() => (this.#scrolling = false), 1000);
-  #resetSuspendTransitions = debounce(() => (this.suspendTransitions = false), 1000);
-  scrollCompensation: {
-    heightDelta: number | undefined;
-    scrollTop: number | undefined;
-    monthGroup: MonthGroup | undefined;
-  } = $state({
-    heightDelta: 0,
-    scrollTop: 0,
-    monthGroup: undefined,
-  });
-
-  constructor() {}
-
-  setLayoutOptions({ headerHeight = 48, rowHeight = 235, gap = 12 }: TimelineManagerLayoutOptions) {
-    let changed = false;
-    changed ||= this.#setHeaderHeight(headerHeight);
-    changed ||= this.#setGap(gap);
-    changed ||= this.#setRowHeight(rowHeight);
-    if (changed) {
-      this.refreshLayout();
-    }
+  get months() {
+    return this.#months;
   }
 
-  #setHeaderHeight(value: number) {
-    if (this.#headerHeight == value) {
-      return false;
-    }
-    this.#headerHeight = value;
-    return true;
-  }
-
-  get headerHeight() {
-    return this.#headerHeight;
-  }
-
-  #setGap(value: number) {
-    if (this.#gap == value) {
-      return false;
-    }
-    this.#gap = value;
-    return true;
-  }
-
-  get gap() {
-    return this.#gap;
-  }
-
-  #setRowHeight(value: number) {
-    if (this.#rowHeight == value) {
-      return false;
-    }
-    this.#rowHeight = value;
-    return true;
-  }
-
-  get rowHeight() {
-    return this.#rowHeight;
-  }
-
-  set scrolling(value: boolean) {
-    this.#scrolling = value;
-    if (value) {
-      this.suspendTransitions = true;
-      this.#resetScrolling();
-    }
-  }
-
-  get scrolling() {
-    return this.#scrolling;
-  }
-
-  set suspendTransitions(value: boolean) {
-    this.#suspendTransitions = value;
-    if (value) {
-      this.#resetSuspendTransitions();
-    }
-  }
-
-  get suspendTransitions() {
-    return this.#suspendTransitions;
-  }
-
-  set viewportWidth(value: number) {
-    const changed = value !== this.#viewportWidth;
-    this.#viewportWidth = value;
-    this.suspendTransitions = true;
-    void this.#updateViewportGeometry(changed);
-  }
-
-  get viewportWidth() {
-    return this.#viewportWidth;
-  }
-
-  set viewportHeight(value: number) {
-    this.#viewportHeight = value;
-    this.#suspendTransitions = true;
-    void this.#updateViewportGeometry(false);
-  }
-
-  get viewportHeight() {
-    return this.#viewportHeight;
+  get options() {
+    return this.#options;
   }
 
   async *assetsIterator(options?: {
@@ -198,7 +82,7 @@ export class TimelineManager {
     const direction = options?.direction ?? 'earlier';
     let { startDayGroup, startAsset } = options ?? {};
     for (const monthGroup of this.monthGroupIterator({ direction, startMonthGroup: options?.startMonthGroup })) {
-      await this.loadMonthGroup(monthGroup.yearMonth, { cancelable: false });
+      await this.loadSegment(monthGroup.identifier, { cancelable: false });
       yield* monthGroup.assetsIterator({ startDayGroup, startAsset, direction });
       startDayGroup = startAsset = undefined;
     }
@@ -234,75 +118,24 @@ export class TimelineManager {
     this.#websocketSupport = undefined;
   }
 
-  updateSlidingWindow(scrollTop: number) {
-    if (this.#scrollTop !== scrollTop) {
-      this.#scrollTop = scrollTop;
-      this.updateIntersections();
-    }
-  }
-
-  clearScrollCompensation() {
-    this.scrollCompensation = {
-      heightDelta: undefined,
-      scrollTop: undefined,
-      monthGroup: undefined,
-    };
-  }
-
-  updateIntersections() {
-    if (!this.isInitialized || this.visibleWindow.bottom === this.visibleWindow.top) {
-      return;
-    }
-    let topIntersectingMonthGroup = undefined;
-    for (const month of this.months) {
-      updateIntersectionMonthGroup(this, month);
-      if (!topIntersectingMonthGroup && month.actuallyIntersecting) {
-        topIntersectingMonthGroup = month;
-      }
-    }
-    if (topIntersectingMonthGroup !== undefined && this.topIntersectingMonthGroup !== topIntersectingMonthGroup) {
-      this.topIntersectingMonthGroup = topIntersectingMonthGroup;
-    }
-    for (const month of this.months) {
-      if (month === this.topIntersectingMonthGroup) {
-        this.topIntersectingMonthGroup.percent = clamp(
-          (this.visibleWindow.top - this.topIntersectingMonthGroup.top) / this.topIntersectingMonthGroup.height,
-          0,
-          1,
-        );
-      } else {
-        month.percent = 0;
-      }
-    }
-  }
-
-  clearDeferredLayout(month: MonthGroup) {
-    const hasDeferred = month.dayGroups.some((group) => group.deferredLayout);
-    if (hasDeferred) {
-      updateGeometry(this, month, { invalidateHeight: true, noDefer: true });
-      for (const group of month.dayGroups) {
-        group.deferredLayout = false;
-      }
-    }
-  }
-
   async #initializeMonthGroups() {
     const timebuckets = await getTimeBuckets({
       ...authManager.params,
       ...this.#options,
     });
 
-    this.months = timebuckets.map((timeBucket) => {
+    this.#months = timebuckets.map((timeBucket) => {
       const date = new SvelteDate(timeBucket.timeBucket);
       return new MonthGroup(
         this,
         { year: date.getUTCFullYear(), month: date.getUTCMonth() + 1 },
         timeBucket.count,
+        false,
         this.#options.order,
       );
     });
     this.albumAssets.clear();
-    this.#updateViewportGeometry(false);
+    this.updateViewportGeometry(false);
   }
 
   async updateOptions(options: TimelineManagerOptions) {
@@ -313,16 +146,16 @@ export class TimelineManager {
       return;
     }
     await this.initTask.reset();
-    await this.#init(options);
-    this.#updateViewportGeometry(false);
+    this.#options = options;
+    await this.init();
+    this.updateViewportGeometry(false);
   }
 
-  async #init(options: TimelineManagerOptions) {
+  async init() {
     this.isInitialized = false;
-    this.months = [];
+    this.#months = [];
     this.albumAssets.clear();
     await this.initTask.execute(async () => {
-      this.#options = options;
       await this.#initializeMonthGroups();
     }, true);
   }
@@ -332,36 +165,8 @@ export class TimelineManager {
     this.isInitialized = false;
   }
 
-  async updateViewport(viewport: Viewport) {
-    if (viewport.height === 0 && viewport.width === 0) {
-      return;
-    }
-
-    if (this.viewportHeight === viewport.height && this.viewportWidth === viewport.width) {
-      return;
-    }
-
-    if (!this.initTask.executed) {
-      await (this.initTask.loading ? this.initTask.waitUntilCompletion() : this.#init(this.#options));
-    }
-
-    const changedWidth = viewport.width !== this.viewportWidth;
-    this.viewportHeight = viewport.height;
-    this.viewportWidth = viewport.width;
-    this.#updateViewportGeometry(changedWidth);
-  }
-
-  #updateViewportGeometry(changedWidth: boolean) {
-    if (!this.isInitialized) {
-      return;
-    }
-    if (this.viewportWidth === 0 || this.viewportHeight === 0) {
-      return;
-    }
-    for (const month of this.months) {
-      updateGeometry(this, month, { invalidateHeight: changedWidth });
-    }
-    this.updateIntersections();
+  updateViewportGeometry(changedWidth: boolean) {
+    super.updateViewportGeometry(changedWidth);
     this.#createScrubberMonths();
   }
 
@@ -376,39 +181,6 @@ export class TimelineManager {
     this.scrubberTimelineHeight = this.timelineHeight;
   }
 
-  createLayoutOptions() {
-    const viewportWidth = this.viewportWidth;
-
-    return {
-      spacing: 2,
-      heightTolerance: 0.15,
-      rowHeight: this.#rowHeight,
-      rowWidth: Math.floor(viewportWidth),
-    };
-  }
-
-  async loadMonthGroup(yearMonth: TimelineYearMonth, options?: { cancelable: boolean }): Promise<void> {
-    let cancelable = true;
-    if (options) {
-      cancelable = options.cancelable;
-    }
-    const monthGroup = getMonthGroupByDate(this, yearMonth);
-    if (!monthGroup) {
-      return;
-    }
-
-    if (monthGroup.loader?.executed) {
-      return;
-    }
-
-    const result = await monthGroup.loader?.execute(async (signal: AbortSignal) => {
-      await loadFromTimeBuckets(this, monthGroup, this.#options, signal);
-    }, cancelable);
-    if (result === 'LOADED') {
-      updateIntersectionMonthGroup(this, monthGroup);
-    }
-  }
-
   addAssets(assets: TimelineAsset[]) {
     const assetsToUpdate = assets.filter((asset) => !this.isExcluded(asset));
     const notUpdated = this.updateAssets(assetsToUpdate);
@@ -442,7 +214,7 @@ export class TimelineManager {
   }
 
   async #loadMonthGroupAtTime(yearMonth: TimelineYearMonth, options?: { cancelable: boolean }) {
-    await this.loadMonthGroup(yearMonth, options);
+    await this.loadSegment(getSegmentIdentifier(yearMonth), options);
     return getMonthGroupByDate(this, yearMonth);
   }
 
@@ -454,7 +226,7 @@ export class TimelineManager {
   async getRandomMonthGroup() {
     const random = Math.floor(Math.random() * this.months.length);
     const month = this.months[random];
-    await this.loadMonthGroup(month.yearMonth, { cancelable: false });
+    await this.loadSegment(getSegmentIdentifier(month.yearMonth), { cancelable: false });
     return month;
   }
 
@@ -527,7 +299,7 @@ export class TimelineManager {
     if (!monthGroup) {
       return;
     }
-    await this.loadMonthGroup(dateTime, { cancelable: false });
+    await this.loadSegment(getSegmentIdentifier(dateTime), { cancelable: false });
     const asset = monthGroup.findClosest(dateTime);
     if (asset) {
       return asset;

web/src/lib/managers/timeline-manager/types.ts

@@ -35,7 +35,7 @@ export type TimelineAsset = {
   longitude?: number | null;
 };
 
-export type AssetOperation = (asset: TimelineAsset) => { remove: boolean };
+export type AssetOperation = (asset: TimelineAsset) => { remove: boolean } | void;
 
 export type MoveAsset = { asset: TimelineAsset; date: TimelineDate };
 

web/src/lib/utils/actions.ts

@@ -21,15 +21,15 @@ export type OnSetVisibility = (ids: string[]) => void;
 
 export const deleteAssets = async (
   force: boolean,
-  onAssetDelete: OnDelete,
+  onAssetDelete: OnDelete | undefined,
   assets: TimelineAsset[],
-  onUndoDelete: OnUndoDelete | undefined = undefined,
+  onUndoDelete: OnUndoDelete | undefined,
 ) => {
   const $t = get(t);
   try {
     const ids = assets.map((a) => a.id);
     await deleteBulk({ assetBulkDeleteDto: { ids, force } });
-    onAssetDelete(ids);
+    onAssetDelete?.(ids);
 
     notificationController.show({
       message: force

web/src/lib/utils/asset-utils.ts

@@ -513,7 +513,7 @@ export const selectAllAssets = async (timelineManager: TimelineManager, assetInt
 
   try {
     for (const monthGroup of timelineManager.months) {
-      await timelineManager.loadMonthGroup(monthGroup.yearMonth);
+      await timelineManager.loadSegment(monthGroup.identifier);
 
       if (!get(isSelectingAllAssets)) {
         assetInteraction.clearMultiselect();

web/src/lib/utils/timeline-util.ts

@@ -1,3 +1,4 @@
+import type { MonthGroup } from '$lib/managers/timeline-manager/month-group.svelte';
 import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
 import { locale } from '$lib/stores/preferences.store';
 import { getAssetRatio } from '$lib/utils/asset-utils';
@@ -23,11 +24,11 @@ export type TimelineDateTime = TimelineDate & {
   millisecond: number;
 };
 
-export type ScrubberListener = (
-  scrubberMonth: { year: number; month: number },
-  overallScrollPercent: number,
-  scrubberMonthScrollPercent: number,
-) => void | Promise<void>;
+export type ScrubberListener = (scrubberData: {
+  scrubberMonth: { year: number; month: number };
+  overallScrollPercent: number;
+  scrubberMonthScrollPercent: number;
+}) => void | Promise<void>;
 
 // used for AssetResponseDto.dateTimeOriginal, amongst others
 export const fromISODateTime = (isoDateTime: string, timeZone: string): DateTime<true> =>
@@ -151,6 +152,14 @@ export function formatGroupTitle(_date: DateTime): string {
   return getDateLocaleString(date, { locale: get(locale) });
 }
 
+export const formatGroupTitleFull = (_date: DateTime): string => {
+  if (!_date.isValid) {
+    return _date.toString();
+  }
+  const date = _date as DateTime<true>;
+  return getDateLocaleString(date);
+};
+
 export const getDateLocaleString = (date: DateTime, opts?: LocaleOptions): string =>
   date.toLocaleString(DateTime.DATE_MED_WITH_WEEKDAY, opts);
 
@@ -234,3 +243,11 @@ export function setDifference<T>(setA: Set<T>, setB: Set<T>): SvelteSet<T> {
   }
   return result;
 }
+
+export const getSegmentIdentifier = (yearMonth: TimelineYearMonth | TimelineDateTime) => ({
+  matches(segment: MonthGroup) {
+    return (
+      segment.yearMonth && segment.yearMonth.year === yearMonth.year && segment.yearMonth.month === yearMonth.month
+    );
+  },
+});

web/src/routes/(user)/albums/[albumId=id]/[[photos=photos]]/[[assetId=id]]/+page.svelte

@@ -34,7 +34,6 @@
   import { AlbumPageViewMode, AppRoute } from '$lib/constants';
   import { activityManager } from '$lib/managers/activity-manager.svelte';
   import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
-  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
   import AlbumOptionsModal from '$lib/modals/AlbumOptionsModal.svelte';
   import AlbumShareModal from '$lib/modals/AlbumShareModal.svelte';
   import AlbumUsersModal from '$lib/modals/AlbumUsersModal.svelte';
@@ -262,18 +261,15 @@
     }
   };
 
-  const handleSetVisibility = (assetIds: string[]) => {
-    timelineManager.removeAssets(assetIds);
+  const handleSetVisibility = () => {
     assetInteraction.clearMultiselect();
   };
 
-  const handleRemoveAssets = async (assetIds: string[]) => {
-    timelineManager.removeAssets(assetIds);
+  const handleRemoveAssets = async () => {
     await refreshAlbum();
   };
 
-  const handleUndoRemoveAssets = async (assets: TimelineAsset[]) => {
-    timelineManager.addAssets(assets);
+  const handleUndoRemoveAssets = async () => {
     await refreshAlbum();
   };
 
@@ -572,14 +568,7 @@
           <AddToAlbum shared />
         </ButtonContextMenu>
         {#if assetInteraction.isAllUserOwned}
-          <FavoriteAction
-            removeFavorite={assetInteraction.isAllFavorite}
-            onFavorite={(ids, isFavorite) =>
-              timelineManager.updateAssetOperation(ids, (asset) => {
-                asset.isFavorite = isFavorite;
-                return { remove: false };
-              })}
-          ></FavoriteAction>
+          <FavoriteAction removeFavorite={assetInteraction.isAllFavorite} manager={timelineManager}></FavoriteAction>
         {/if}
         <ButtonContextMenu icon={mdiDotsVertical} title={$t('menu')} offset={{ x: 175, y: 25 }}>
           <DownloadAction menuItem filename="{album.albumName}.zip" />
@@ -594,7 +583,7 @@
                 onClick={() => updateThumbnailUsingCurrentSelection()}
               />
             {/if}
-            <ArchiveAction menuItem unarchive={assetInteraction.isAllArchived} />
+            <ArchiveAction menuItem unarchive={assetInteraction.isAllArchived} manager={timelineManager} />
             <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
           {/if}
 
@@ -606,7 +595,12 @@
             <RemoveFromAlbum menuItem bind:album onRemove={handleRemoveAssets} />
           {/if}
           {#if assetInteraction.isAllUserOwned}
-            <DeleteAssets menuItem onAssetDelete={handleRemoveAssets} onUndoDelete={handleUndoRemoveAssets} />
+            <DeleteAssets
+              menuItem
+              onAssetDelete={handleRemoveAssets}
+              onUndoDelete={handleUndoRemoveAssets}
+              manager={timelineManager}
+            />
           {/if}
         </ButtonContextMenu>
       </AssetSelectControlBar>

web/src/routes/(user)/archive/[[photos=photos]]/[[assetId=id]]/+page.svelte

@@ -65,32 +65,18 @@
     assets={assetInteraction.selectedAssets}
     clearSelect={() => assetInteraction.clearMultiselect()}
   >
-    <ArchiveAction
-      unarchive
-      onArchive={(ids, visibility) =>
-        timelineManager.updateAssetOperation(ids, (asset) => {
-          asset.visibility = visibility;
-          return { remove: false };
-        })}
-    />
+    <ArchiveAction unarchive manager={timelineManager} />
     <CreateSharedLink />
     <SelectAllAssets {timelineManager} {assetInteraction} />
     <ButtonContextMenu icon={mdiPlus} title={$t('add_to')}>
       <AddToAlbum />
       <AddToAlbum shared />
     </ButtonContextMenu>
-    <FavoriteAction
-      removeFavorite={assetInteraction.isAllFavorite}
-      onFavorite={(ids, isFavorite) =>
-        timelineManager.updateAssetOperation(ids, (asset) => {
-          asset.isFavorite = isFavorite;
-          return { remove: false };
-        })}
-    />
+    <FavoriteAction removeFavorite={assetInteraction.isAllFavorite} manager={timelineManager} />
     <ButtonContextMenu icon={mdiDotsVertical} title={$t('menu')}>
       <DownloadAction menuItem />
       <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
-      <DeleteAssets menuItem onAssetDelete={(assetIds) => timelineManager.removeAssets(assetIds)} />
+      <DeleteAssets menuItem manager={timelineManager} />
     </ButtonContextMenu>
   </AssetSelectControlBar>
 {/if}

web/src/routes/(user)/favorites/[[photos=photos]]/[[assetId=id]]/+page.svelte

@@ -71,7 +71,7 @@
     assets={assetInteraction.selectedAssets}
     clearSelect={() => assetInteraction.clearMultiselect()}
   >
-    <FavoriteAction removeFavorite onFavorite={(assetIds) => timelineManager.removeAssets(assetIds)} />
+    <FavoriteAction removeFavorite manager={timelineManager} />
     <CreateSharedLink />
     <SelectAllAssets {timelineManager} {assetInteraction} />
     <ButtonContextMenu icon={mdiPlus} title={$t('add_to')}>
@@ -83,20 +83,12 @@
       <ChangeDate menuItem />
       <ChangeDescription menuItem />
       <ChangeLocation menuItem />
-      <ArchiveAction
-        menuItem
-        unarchive={assetInteraction.isAllArchived}
-        onArchive={(assetIds) => timelineManager.removeAssets(assetIds)}
-      />
+      <ArchiveAction menuItem unarchive={assetInteraction.isAllArchived} manager={timelineManager} />
       {#if $preferences.tags.enabled}
         <TagAction menuItem />
       {/if}
       <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
-      <DeleteAssets
-        menuItem
-        onAssetDelete={(assetIds) => timelineManager.removeAssets(assetIds)}
-        onUndoDelete={(assets) => timelineManager.addAssets(assets)}
-      />
+      <DeleteAssets menuItem manager={timelineManager} />
     </ButtonContextMenu>
   </AssetSelectControlBar>
 {/if}

web/src/routes/(user)/people/[personId]/[[photos=photos]]/[[assetId=id]]/+page.svelte

@@ -349,15 +349,8 @@
     }
   };
 
-  const handleDeleteAssets = async (assetIds: string[]) => {
-    timelineManager.removeAssets(assetIds);
-    await updateAssetCount();
-  };
-
-  const handleUndoDeleteAssets = async (assets: TimelineAsset[]) => {
-    timelineManager.addAssets(assets);
-    await updateAssetCount();
-  };
+  const handleDeleteAssets = async () => await updateAssetCount();
+  const handleUndoDeleteAssets = async () => await updateAssetCount();
 
   let person = $derived(data.person);
 
@@ -511,14 +504,7 @@
         <AddToAlbum />
         <AddToAlbum shared />
       </ButtonContextMenu>
-      <FavoriteAction
-        removeFavorite={assetInteraction.isAllFavorite}
-        onFavorite={(ids, isFavorite) =>
-          timelineManager.updateAssetOperation(ids, (asset) => {
-            asset.isFavorite = isFavorite;
-            return { remove: false };
-          })}
-      />
+      <FavoriteAction removeFavorite={assetInteraction.isAllFavorite} manager={timelineManager} />
       <ButtonContextMenu icon={mdiDotsVertical} title={$t('menu')}>
         <DownloadAction menuItem filename="{person.name || 'immich'}.zip" />
         <MenuOption
@@ -529,19 +515,16 @@
         <ChangeDate menuItem />
         <ChangeDescription menuItem />
         <ChangeLocation menuItem />
-        <ArchiveAction
-          menuItem
-          unarchive={assetInteraction.isAllArchived}
-          onArchive={(assetIds) => timelineManager.removeAssets(assetIds)}
-        />
+        <ArchiveAction menuItem unarchive={assetInteraction.isAllArchived} manager={timelineManager} />
         {#if $preferences.tags.enabled && assetInteraction.isAllUserOwned}
           <TagAction menuItem />
         {/if}
         <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
         <DeleteAssets
           menuItem
-          onAssetDelete={(assetIds) => handleDeleteAssets(assetIds)}
-          onUndoDelete={(assets) => handleUndoDeleteAssets(assets)}
+          manager={timelineManager}
+          onAssetDelete={handleDeleteAssets}
+          onUndoDelete={handleUndoDeleteAssets}
         />
       </ButtonContextMenu>
     </AssetSelectControlBar>

web/src/routes/(user)/photos/[[assetId=id]]/+page.svelte

@@ -118,14 +118,7 @@
       <AddToAlbum />
       <AddToAlbum shared />
     </ButtonContextMenu>
-    <FavoriteAction
-      removeFavorite={assetInteraction.isAllFavorite}
-      onFavorite={(ids, isFavorite) =>
-        timelineManager.updateAssetOperation(ids, (asset) => {
-          asset.isFavorite = isFavorite;
-          return { remove: false };
-        })}
-    ></FavoriteAction>
+    <FavoriteAction removeFavorite={assetInteraction.isAllFavorite} manager={timelineManager}></FavoriteAction>
     <ButtonContextMenu icon={mdiDotsVertical} title={$t('menu')}>
       <DownloadAction menuItem />
       {#if assetInteraction.selectedAssets.length > 1 || isAssetStackSelected}
@@ -146,15 +139,11 @@
       <ChangeDate menuItem />
       <ChangeDescription menuItem />
       <ChangeLocation menuItem />
-      <ArchiveAction menuItem onArchive={(assetIds) => timelineManager.removeAssets(assetIds)} />
+      <ArchiveAction menuItem manager={timelineManager} />
       {#if $preferences.tags.enabled}
         <TagAction menuItem />
       {/if}
-      <DeleteAssets
-        menuItem
-        onAssetDelete={(assetIds) => timelineManager.removeAssets(assetIds)}
-        onUndoDelete={(assets) => timelineManager.addAssets(assets)}
-      />
+      <DeleteAssets menuItem manager={timelineManager} />
       <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
       <hr />
       <AssetJobActions />