From 2d3cd9a3b3f3fb10394f7eb88e8e1490324d0684 Mon Sep 17 00:00:00 2001
From: pa <maplenagisa@gmail.com>
Date: Mon, 19 Jan 2026 14:02:48 +0900
Subject: [PATCH] sidebar virtual dom and textfield row sizing

---
 .../input-group/InputGroupTextareaField.vue   |   1 +
 src/components/ui/textarea/Textarea.vue       |  11 +-
 src/views/Sidebar/Sidebar.vue                 |   2 +-
 .../Sidebar/components/FriendsSidebar.vue     | 536 ++++++++++++------
 .../Sidebar/components/GroupsSidebar.vue      | 179 +++++-
 5 files changed, 529 insertions(+), 200 deletions(-)

diff --git a/src/components/ui/input-group/InputGroupTextareaField.vue b/src/components/ui/input-group/InputGroupTextareaField.vue
index d10aad38..04da6bd9 100644
--- a/src/components/ui/input-group/InputGroupTextareaField.vue
+++ b/src/components/ui/input-group/InputGroupTextareaField.vue
@@ -81,6 +81,7 @@
         delete rest.onChange;
         return {
             ...rest,
+            ...(autosizeConfig.value ? { 'data-autosize': 'true' } : {}),
             maxlength: maxLength.value
         };
     });
diff --git a/src/components/ui/textarea/Textarea.vue b/src/components/ui/textarea/Textarea.vue
index 0562cbfc..7535f15c 100644
--- a/src/components/ui/textarea/Textarea.vue
+++ b/src/components/ui/textarea/Textarea.vue
@@ -1,4 +1,5 @@
 <script setup>
+    import { computed, useAttrs } from 'vue';
     import { cn } from '@/lib/utils';
     import { useVModel } from '@vueuse/core';
 
@@ -9,11 +10,18 @@
     });
 
     const emits = defineEmits(['update:modelValue']);
+    const attrs = useAttrs();
 
     const modelValue = useVModel(props, 'modelValue', emits, {
         passive: true,
         defaultValue: props.defaultValue
     });
+
+    const autosizeClass = computed(() => {
+        const raw = attrs['data-autosize'];
+        const isAutosize = raw === '' || raw === true || raw === 'true';
+        return isAutosize ? 'field-sizing-content' : '[field-sizing:fixed]';
+    });
 </script>
 
 <template>
@@ -22,7 +30,8 @@
         data-slot="textarea"
         :class="
             cn(
-                'border-input placeholder:text-muted-foreground focus-visible:border-ring focus-visible:ring-ring/50 aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 aria-invalid:border-destructive dark:bg-input/30 flex field-sizing-content min-h-16 w-full rounded-md border bg-transparent px-3 py-2 text-base shadow-xs transition-[color,box-shadow] outline-none focus-visible:ring-[3px] disabled:cursor-not-allowed disabled:opacity-50 md:text-sm',
+                'border-input placeholder:text-muted-foreground focus-visible:border-ring focus-visible:ring-ring/50 aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 aria-invalid:border-destructive dark:bg-input/30 flex min-h-16 w-full rounded-md border bg-transparent px-3 py-2 text-base shadow-xs transition-[color,box-shadow] outline-none focus-visible:ring-[3px] disabled:cursor-not-allowed disabled:opacity-50 md:text-sm',
+                autosizeClass,
                 props.class
             )
         " />
diff --git a/src/views/Sidebar/Sidebar.vue b/src/views/Sidebar/Sidebar.vue
index e6943f70..a7402b06 100644
--- a/src/views/Sidebar/Sidebar.vue
+++ b/src/views/Sidebar/Sidebar.vue
@@ -104,7 +104,7 @@
             <template #groups>
                 <div class="h-full overflow-hidden">
                     <ScrollArea ref="groupsScrollAreaRef" class="h-full">
-                        <GroupsSidebar :group-instances="groupInstances" :group-order="inGameGroupOrder" />
+                        <GroupsSidebar :group-order="inGameGroupOrder" />
                     </ScrollArea>
                     <BackToTop :target="groupsScrollTarget" :bottom="20" :right="20" :teleport="false" />
                 </div>
diff --git a/src/views/Sidebar/components/FriendsSidebar.vue b/src/views/Sidebar/components/FriendsSidebar.vue
index 1be0bb4f..a03391da 100644
--- a/src/views/Sidebar/components/FriendsSidebar.vue
+++ b/src/views/Sidebar/components/FriendsSidebar.vue
@@ -1,173 +1,92 @@
 <template>
-    <div class="x-friend-list" style="padding: 10px 5px">
-        <div
-            class="x-friend-group cursor-pointer flex items-center"
-            style="padding: 0 0 5px"
-            @click="
-                isFriendsGroupMe = !isFriendsGroupMe;
-                saveFriendsGroupStates();
-            ">
-            <ChevronDown class="rotation-transition" :class="{ 'is-rotated': !isFriendsGroupMe }" />
-            <span style="margin-left: 5px">{{ t('side_panel.me') }}</span>
-        </div>
-        <div v-show="isFriendsGroupMe">
-            <div class="x-friend-item" @click="showUserDialog(currentUser.id)">
-                <div class="avatar" :class="userStatusClass(currentUser)">
-                    <img :src="userImage(currentUser)" loading="lazy" />
-                </div>
-                <div class="detail">
-                    <span class="name" :style="{ color: currentUser.$userColour }">{{ currentUser.displayName }}</span>
-                    <Location
-                        v-if="isGameRunning && !gameLogDisabled"
-                        class="text-xs"
-                        :location="lastLocation.location"
-                        :traveling="lastLocationDestination"
-                        :link="false" />
-                    <Location
-                        v-else-if="
-                            isRealInstance(currentUser.$locationTag) || isRealInstance(currentUser.$travelingToLocation)
-                        "
-                        class="text-xs"
-                        :location="currentUser.$locationTag"
-                        :traveling="currentUser.$travelingToLocation"
-                        :link="false" />
-
-                    <span v-else class="text-xs">{{ currentUser.statusDescription }}</span>
-                </div>
-            </div>
-        </div>
-        <div
-            v-show="vipFriendsDisplayNumber"
-            class="x-friend-group cursor-pointer flex items-center"
-            @click="
-                isVIPFriends = !isVIPFriends;
-                saveFriendsGroupStates();
-            ">
-            <ChevronDown class="rotation-transition" :class="{ 'is-rotated': !isVIPFriends }" />
-            <span style="margin-left: 5px">
-                {{ t('side_panel.favorite') }} &horbar;
-                {{ vipFriendsDisplayNumber }}
-            </span>
-        </div>
-        <div v-show="isVIPFriends">
-            <template v-if="isSidebarDivideByFriendGroup">
-                <div v-for="group in vipFriendsDivideByGroup" :key="group[0].key">
-                    <transition name="el-fade-in-linear">
-                        <div v-show="group[0].groupName !== ''" style="margin-bottom: 3px">
-                            <span class="text-xs">{{ group[0].groupName }}</span>
-                            <span class="text-xs" style="margin-left: 5px">{{ `(${group.length})` }}</span>
+    <div ref="listRootRef" class="x-friend-list" style="padding: 10px 5px">
+        <div v-if="virtualRows.length" class="friend-sidebar__virtual" :style="virtualContainerStyle">
+            <template v-for="item in virtualItems" :key="String(item.virtualItem.key)">
+                <div
+                    v-if="item.row"
+                    class="friend-sidebar__virtual-row"
+                    :class="`friend-sidebar__virtual-row--${item.row.type}`"
+                    :data-index="item.virtualItem.index"
+                    :ref="virtualizer.measureElement"
+                    :style="rowStyle(item)">
+                    <template v-if="item.row.type === 'toggle-header'">
+                        <div
+                            class="x-friend-group cursor-pointer flex items-center"
+                            :style="item.row.headerPadding ? { padding: item.row.headerPadding } : undefined"
+                            @click="item.row.onClick && item.row.onClick()">
+                            <ChevronDown class="rotation-transition" :class="{ 'is-rotated': !item.row.expanded }" />
+                            <span style="margin-left: 5px">
+                                {{ item.row.label }}
+                                <template v-if="item.row.count !== null && item.row.count !== undefined">
+                                    &horbar; {{ item.row.count }}
+                                </template>
+                            </span>
                         </div>
-                    </transition>
-                    <div v-if="group.length" style="margin-bottom: 10px">
+                    </template>
+
+                    <template v-else-if="item.row.type === 'me-item'">
+                        <div class="x-friend-item" @click="showUserDialog(currentUser.id)">
+                            <div class="avatar" :class="userStatusClass(currentUser)">
+                                <img :src="userImage(currentUser)" loading="lazy" />
+                            </div>
+                            <div class="detail">
+                                <span class="name" :style="{ color: currentUser.$userColour }">{{
+                                    currentUser.displayName
+                                }}</span>
+                                <Location
+                                    v-if="isGameRunning && !gameLogDisabled"
+                                    class="text-xs"
+                                    :location="lastLocation.location"
+                                    :traveling="lastLocationDestination"
+                                    :link="false" />
+                                <Location
+                                    v-else-if="
+                                        isRealInstance(currentUser.$locationTag) ||
+                                        isRealInstance(currentUser.$travelingToLocation)
+                                    "
+                                    class="text-xs"
+                                    :location="currentUser.$locationTag"
+                                    :traveling="currentUser.$travelingToLocation"
+                                    :link="false" />
+
+                                <span v-else class="text-xs">{{ currentUser.statusDescription }}</span>
+                            </div>
+                        </div>
+                    </template>
+
+                    <template v-else-if="item.row.type === 'vip-subheader'">
+                        <div>
+                            <span class="text-xs">{{ item.row.label }}</span>
+                            <span class="text-xs" style="margin-left: 5px">{{ `(${item.row.count})` }}</span>
+                        </div>
+                    </template>
+
+                    <template v-else-if="item.row.type === 'instance-header'">
+                        <div class="mb-1 flex items-center">
+                            <Location class="text-xs" :location="item.row.location" style="display: inline" />
+                            <span class="text-xs" style="margin-left: 5px">{{ `(${item.row.count})` }}</span>
+                        </div>
+                    </template>
+
+                    <template v-else-if="item.row.type === 'friend-item'">
                         <friend-item
-                            v-for="friend in group"
-                            :key="friend.id"
-                            :friend="friend"
-                            @confirm-delete-friend="confirmDeleteFriend"></friend-item>
-                    </div>
+                            :friend="item.row.friend"
+                            :style="item.row.itemStyle"
+                            :is-group-by-instance="item.row.isGroupByInstance"
+                            @confirm-delete-friend="confirmDeleteFriend" />
+                    </template>
                 </div>
             </template>
-            <template v-else>
-                <friend-item
-                    v-for="friend in vipFriendsByGroupStatus"
-                    :key="friend.id"
-                    :friend="friend"
-                    @confirm-delete-friend="confirmDeleteFriend">
-                </friend-item>
-            </template>
-        </div>
-
-        <template v-if="isSidebarGroupByInstance && friendsInSameInstance.length">
-            <div class="x-friend-group cursor-pointer flex items-center" @click="toggleSwitchGroupByInstanceCollapsed">
-                <ChevronDown class="rotation-transition" :class="{ 'is-rotated': isSidebarGroupByInstanceCollapsed }" />
-                <span style="margin-left: 5px"
-                    >{{ t('side_panel.same_instance') }} &horbar; {{ friendsInSameInstance.length }}</span
-                >
-            </div>
-
-            <div v-show="!isSidebarGroupByInstanceCollapsed">
-                <div v-for="friendArr in friendsInSameInstance" :key="friendArr[0].ref.$location.tag">
-                    <div class="mb-1 flex items-center">
-                        <Location
-                            class="text-xs text-muted-foreground"
-                            :location="getFriendsLocations(friendArr)"
-                            style="display: inline" />
-                        <span class="text-xs" style="margin-left: 5px">{{ `(${friendArr.length})` }}</span>
-                    </div>
-                    <div v-if="friendArr && friendArr.length">
-                        <friend-item
-                            v-for="(friend, idx) in friendArr"
-                            :key="friend.id"
-                            :friend="friend"
-                            is-group-by-instance
-                            :style="{ 'margin-bottom': idx === friendArr.length - 1 ? '5px' : undefined }"
-                            @confirm-delete-friend="confirmDeleteFriend">
-                        </friend-item>
-                    </div>
-                </div>
-            </div>
-        </template>
-        <div
-            v-show="onlineFriendsByGroupStatus.length"
-            class="x-friend-group cursor-pointer flex items-center"
-            @click="
-                isOnlineFriends = !isOnlineFriends;
-                saveFriendsGroupStates();
-            ">
-            <ChevronDown class="rotation-transition" :class="{ 'is-rotated': !isOnlineFriends }" />
-            <span style="margin-left: 5px"
-                >{{ t('side_panel.online') }} &horbar; {{ onlineFriendsByGroupStatus.length }}</span
-            >
-        </div>
-        <div v-show="isOnlineFriends">
-            <friend-item
-                v-for="friend in onlineFriendsByGroupStatus"
-                :key="friend.id"
-                :friend="friend"
-                @confirm-delete-friend="confirmDeleteFriend" />
-        </div>
-        <div
-            v-show="activeFriends.length"
-            class="x-friend-group cursor-pointer flex items-center"
-            @click="
-                isActiveFriends = !isActiveFriends;
-                saveFriendsGroupStates();
-            ">
-            <ChevronDown class="rotation-transition" :class="{ 'is-rotated': !isActiveFriends }" />
-            <span style="margin-left: 5px">{{ t('side_panel.active') }} &horbar; {{ activeFriends.length }}</span>
-        </div>
-        <div v-if="isActiveFriends">
-            <friend-item
-                v-for="friend in activeFriends"
-                :key="friend.id"
-                :friend="friend"
-                @confirm-delete-friend="confirmDeleteFriend"></friend-item>
-        </div>
-        <div
-            v-show="offlineFriends.length"
-            class="x-friend-group cursor-pointer flex items-center"
-            @click="
-                isOfflineFriends = !isOfflineFriends;
-                saveFriendsGroupStates();
-            ">
-            <ChevronDown class="rotation-transition" :class="{ 'is-rotated': !isOfflineFriends }" />
-            <span style="margin-left: 5px">{{ t('side_panel.offline') }} &horbar; {{ offlineFriends.length }}</span>
-        </div>
-        <div v-if="isOfflineFriends">
-            <friend-item
-                v-for="friend in offlineFriends"
-                :key="friend.id"
-                :friend="friend"
-                @confirm-delete-friend="confirmDeleteFriend"></friend-item>
         </div>
     </div>
 </template>
 
 <script setup>
-    import { computed, ref, watch } from 'vue';
+    import { computed, nextTick, onMounted, ref, watch } from 'vue';
     import { ChevronDown } from 'lucide-vue-next';
     import { storeToRefs } from 'pinia';
     import { useI18n } from 'vue-i18n';
+    import { useVirtualizer } from '@tanstack/vue-virtual';
 
     import {
         useAdvancedSettingsStore,
@@ -180,9 +99,9 @@
     } from '../../../stores';
     import { isRealInstance, userImage, userStatusClass } from '../../../shared/utils';
     import { getFriendsLocations } from '../../../shared/utils/location.js';
-    import { watchState } from '../../../service/watchState';
 
     import FriendItem from './FriendItem.vue';
+    import Location from '../../../components/Location.vue';
     import configRepository from '../../../service/config';
 
     const emit = defineEmits(['confirm-delete-friend']);
@@ -203,18 +122,11 @@
     const isFriendsGroupMe = ref(true);
     const isVIPFriends = ref(true);
     const isOnlineFriends = ref(true);
-    const isActiveFriends = ref(false);
-    const isOfflineFriends = ref(false);
+    const isActiveFriends = ref(true);
+    const isOfflineFriends = ref(true);
     const isSidebarGroupByInstanceCollapsed = ref(false);
-
-    watch(
-        () => watchState.isFriendsLoaded,
-        (isFriendsLoaded) => {
-            if (isFriendsLoaded) {
-                isOfflineFriends.value = offlineFriends.value.length < 10 ? true : false;
-            }
-        }
-    );
+    const listRootRef = ref(null);
+    const scrollViewportRef = ref(null);
 
     loadFriendsGroupStates();
 
@@ -281,6 +193,235 @@
             : vipFriendsByGroupStatus.value.length;
     });
 
+    const buildToggleRow = ({
+        key,
+        label,
+        count = null,
+        expanded = true,
+        headerPadding = null,
+        paddingBottom = null,
+        onClick = null
+    }) => ({
+        type: 'toggle-header',
+        key,
+        label,
+        count,
+        expanded,
+        headerPadding,
+        paddingBottom,
+        onClick
+    });
+    const buildFriendRow = (friend, key, options = {}) => ({
+        type: 'friend-item',
+        key,
+        friend,
+        isGroupByInstance: options.isGroupByInstance,
+        paddingBottom: options.paddingBottom,
+        itemStyle: options.itemStyle
+    });
+    const buildVipSubheaderRow = (label, count, key) => ({
+        type: 'vip-subheader',
+        key,
+        label,
+        count,
+        paddingBottom: 4
+    });
+    const buildInstanceHeaderRow = (location, count, key) => ({
+        type: 'instance-header',
+        key,
+        location,
+        count,
+        paddingBottom: 4
+    });
+
+    const virtualRows = computed(() => {
+        const rows = [];
+
+        rows.push(
+            buildToggleRow({
+                key: 'me-header',
+                label: t('side_panel.me'),
+                expanded: isFriendsGroupMe.value,
+                headerPadding: '0 0 5px',
+                onClick: toggleFriendsGroupMe
+            })
+        );
+
+        if (isFriendsGroupMe.value) {
+            rows.push({ type: 'me-item', key: `me:${currentUser.value?.id ?? 'me'}` });
+        }
+
+        if (vipFriendsDisplayNumber.value) {
+            rows.push(
+                buildToggleRow({
+                    key: 'vip-header',
+                    label: t('side_panel.favorite'),
+                    count: vipFriendsDisplayNumber.value,
+                    expanded: isVIPFriends.value,
+                    onClick: toggleVIPFriends
+                })
+            );
+        }
+
+        if (isVIPFriends.value) {
+            if (isSidebarDivideByFriendGroup.value) {
+                vipFriendsDivideByGroup.value.forEach((group, groupIndex) => {
+                    const groupName = group?.[0]?.groupName ?? '';
+                    const groupKey = group?.[0]?.key ?? groupIndex;
+                    if (groupName) {
+                        rows.push(buildVipSubheaderRow(groupName, group.length, `vip-subheader:${groupKey}`));
+                    }
+                    group.forEach((friend, idx) => {
+                        rows.push(
+                            buildFriendRow(friend, `vip:${groupKey}:${friend?.id ?? idx}`, {
+                                paddingBottom: idx === group.length - 1 ? 10 : undefined
+                            })
+                        );
+                    });
+                });
+            } else {
+                vipFriendsByGroupStatus.value.forEach((friend, idx) => {
+                    rows.push(buildFriendRow(friend, `vip:${friend?.id ?? idx}`));
+                });
+            }
+        }
+
+        if (isSidebarGroupByInstance.value && friendsInSameInstance.value.length) {
+            rows.push(
+                buildToggleRow({
+                    key: 'same-instance-header',
+                    label: t('side_panel.same_instance'),
+                    count: friendsInSameInstance.value.length,
+                    expanded: !isSidebarGroupByInstanceCollapsed.value,
+                    onClick: toggleSwitchGroupByInstanceCollapsed,
+                    paddingBottom: 4
+                })
+            );
+
+            if (!isSidebarGroupByInstanceCollapsed.value) {
+                friendsInSameInstance.value.forEach((friendArr, groupIndex) => {
+                    if (!friendArr || !friendArr.length) return;
+                    const groupKey = friendArr?.[0]?.ref?.$location?.tag ?? `group-${groupIndex}`;
+                    rows.push(
+                        buildInstanceHeaderRow(getFriendsLocations(friendArr), friendArr.length, `instance:${groupKey}`)
+                    );
+                    friendArr.forEach((friend, idx) => {
+                        rows.push(
+                            buildFriendRow(friend, `instance:${groupKey}:${friend?.id ?? idx}`, {
+                                isGroupByInstance: true,
+                                paddingBottom: idx === friendArr.length - 1 ? 5 : undefined,
+                                itemStyle: idx === friendArr.length - 1 ? { marginBottom: '5px' } : undefined
+                            })
+                        );
+                    });
+                });
+            }
+        }
+
+        if (onlineFriendsByGroupStatus.value.length) {
+            rows.push(
+                buildToggleRow({
+                    key: 'online-header',
+                    label: t('side_panel.online'),
+                    count: onlineFriendsByGroupStatus.value.length,
+                    expanded: isOnlineFriends.value,
+                    onClick: toggleOnlineFriends
+                })
+            );
+        }
+
+        if (isOnlineFriends.value) {
+            onlineFriendsByGroupStatus.value.forEach((friend, idx) => {
+                rows.push(buildFriendRow(friend, `online:${friend?.id ?? idx}`));
+            });
+        }
+
+        if (activeFriends.value.length) {
+            rows.push(
+                buildToggleRow({
+                    key: 'active-header',
+                    label: t('side_panel.active'),
+                    count: activeFriends.value.length,
+                    expanded: isActiveFriends.value,
+                    onClick: toggleActiveFriends
+                })
+            );
+        }
+
+        if (isActiveFriends.value) {
+            activeFriends.value.forEach((friend, idx) => {
+                rows.push(buildFriendRow(friend, `active:${friend?.id ?? idx}`));
+            });
+        }
+
+        if (offlineFriends.value.length) {
+            rows.push(
+                buildToggleRow({
+                    key: 'offline-header',
+                    label: t('side_panel.offline'),
+                    count: offlineFriends.value.length,
+                    expanded: isOfflineFriends.value,
+                    onClick: toggleOfflineFriends
+                })
+            );
+        }
+
+        if (isOfflineFriends.value) {
+            offlineFriends.value.forEach((friend, idx) => {
+                rows.push(buildFriendRow(friend, `offline:${friend?.id ?? idx}`));
+            });
+        }
+
+        return rows;
+    });
+
+    const estimateRowSize = (row) => {
+        if (!row) {
+            return 44;
+        }
+        if (row.type === 'toggle-header') {
+            return 28 + (row.paddingBottom || 0);
+        }
+        if (row.type === 'vip-subheader') {
+            return 24 + (row.paddingBottom || 0);
+        }
+        if (row.type === 'instance-header') {
+            return 26 + (row.paddingBottom || 0);
+        }
+        return 52 + (row.paddingBottom || 0);
+    };
+
+    const virtualizer = useVirtualizer(
+        computed(() => ({
+            count: virtualRows.value.length,
+            getScrollElement: () => scrollViewportRef.value,
+            estimateSize: (index) => estimateRowSize(virtualRows.value[index]),
+            getItemKey: (index) => virtualRows.value[index]?.key ?? index,
+            overscan: 6
+        }))
+    );
+
+    const virtualItems = computed(() => {
+        const items = virtualizer.value?.getVirtualItems?.() ?? [];
+        return items.map((virtualItem) => ({
+            virtualItem,
+            row: virtualRows.value[virtualItem.index]
+        }));
+    });
+
+    const virtualContainerStyle = computed(() => ({
+        height: `${virtualizer.value?.getTotalSize?.() ?? 0}px`,
+        width: '100%'
+    }));
+
+    const rowStyle = (item) => {
+        const paddingBottom = item?.row?.paddingBottom;
+        return {
+            transform: `translateY(${item.virtualItem.start}px)`,
+            ...(paddingBottom ? { paddingBottom: `${paddingBottom}px` } : {})
+        };
+    };
+
     function saveFriendsGroupStates() {
         configRepository.setBool('VRCX_isFriendsGroupMe', isFriendsGroupMe.value);
         configRepository.setBool('VRCX_isFriendsGroupFavorites', isVIPFriends.value);
@@ -304,9 +445,47 @@
         configRepository.setBool('VRCX_sidebarGroupByInstanceCollapsed', isSidebarGroupByInstanceCollapsed.value);
     }
 
+    function toggleFriendsGroupMe() {
+        isFriendsGroupMe.value = !isFriendsGroupMe.value;
+        saveFriendsGroupStates();
+    }
+
+    function toggleVIPFriends() {
+        isVIPFriends.value = !isVIPFriends.value;
+        saveFriendsGroupStates();
+    }
+
+    function toggleOnlineFriends() {
+        isOnlineFriends.value = !isOnlineFriends.value;
+        saveFriendsGroupStates();
+    }
+
+    function toggleActiveFriends() {
+        isActiveFriends.value = !isActiveFriends.value;
+        saveFriendsGroupStates();
+    }
+
+    function toggleOfflineFriends() {
+        isOfflineFriends.value = !isOfflineFriends.value;
+        saveFriendsGroupStates();
+    }
+
     function confirmDeleteFriend(friend) {
         emit('confirm-delete-friend', friend);
     }
+
+    onMounted(() => {
+        scrollViewportRef.value = listRootRef.value?.closest('[data-slot="scroll-area-viewport"]') ?? null;
+        nextTick(() => {
+            virtualizer.value?.measure?.();
+        });
+    });
+
+    watch(virtualRows, () => {
+        nextTick(() => {
+            virtualizer.value?.measure?.();
+        });
+    });
 </script>
 
 <style scoped>
@@ -316,4 +495,23 @@
     .rotation-transition {
         transition: transform 0.2s ease-in-out;
     }
+
+    .friend-sidebar__virtual {
+        width: 100%;
+        position: relative;
+        box-sizing: border-box;
+    }
+
+    .friend-sidebar__virtual-row {
+        width: 100%;
+        box-sizing: border-box;
+        position: absolute;
+        left: 0;
+        top: 0;
+    }
+
+    .friend-sidebar__virtual-row--toggle-header .x-friend-group {
+        padding: 16px 0 6px;
+        font-size: 12px;
+    }
 </style>
diff --git a/src/views/Sidebar/components/GroupsSidebar.vue b/src/views/Sidebar/components/GroupsSidebar.vue
index ea8b70ae..6c55d95c 100644
--- a/src/views/Sidebar/components/GroupsSidebar.vue
+++ b/src/views/Sidebar/components/GroupsSidebar.vue
@@ -1,49 +1,64 @@
 <template>
-    <div class="x-friend-list" style="padding: 10px 5px">
-        <template v-for="(group, index) in groupedGroupInstances" :key="getGroupId(group)">
-            <div class="x-friend-group cursor-pointer" :style="{ paddingTop: index === 0 ? '0px' : '10px' }">
-                <div @click="toggleGroupSidebarCollapse(getGroupId(group))" style="display: flex; align-items: center">
-                    <ChevronDown
-                        class="rotation-transition"
-                        :class="{ 'is-rotated': groupInstancesCfg[getGroupId(group)]?.isCollapsed }" />
-                    <span style="margin-left: 5px">{{ group[0].group.name }} – {{ group.length }}</span>
-                </div>
-            </div>
-
-            <template v-if="!groupInstancesCfg[getGroupId(group)]?.isCollapsed">
+    <div ref="listRootRef" class="x-friend-list" style="padding: 10px 5px">
+        <div v-if="virtualRows.length" class="group-sidebar__virtual" :style="virtualContainerStyle">
+            <template v-for="item in virtualItems" :key="String(item.virtualItem.key)">
                 <div
-                    v-for="ref in group"
-                    :key="ref.instance.id"
-                    class="x-friend-item"
-                    @click="showGroupDialog(ref.instance.ownerId)">
-                    <template v-if="isAgeGatedInstancesVisible || !(ref.ageGate || ref.location?.includes('~ageGate'))">
-                        <div class="avatar">
-                            <img :src="getSmallGroupIconUrl(ref.group.iconUrl)" loading="lazy" />
+                    v-if="item.row"
+                    class="group-sidebar__virtual-row"
+                    :class="`group-sidebar__virtual-row--${item.row.type}`"
+                    :data-index="item.virtualItem.index"
+                    :ref="virtualizer.measureElement"
+                    :style="rowStyle(item)">
+                    <template v-if="item.row.type === 'group-header'">
+                        <div
+                            class="x-friend-group cursor-pointer"
+                            :style="item.row.headerPaddingTop ? { paddingTop: item.row.headerPaddingTop } : undefined">
+                            <div
+                                @click="toggleGroupSidebarCollapse(item.row.groupId)"
+                                style="display: flex; align-items: center">
+                                <ChevronDown
+                                    class="rotation-transition"
+                                    :class="{ 'is-rotated': item.row.isCollapsed }" />
+                                <span style="margin-left: 5px"> {{ item.row.label }} – {{ item.row.count }} </span>
+                            </div>
                         </div>
-                        <div class="detail">
-                            <span class="name">
-                                <span v-text="ref.group.name"></span>
-                                <span style="font-weight: normal; margin-left: 5px"
-                                    >({{ ref.instance.userCount }}/{{ ref.instance.capacity }})</span
-                                >
-                            </span>
-                            <Location class="text-xs" :location="ref.instance.location" :link="false" />
+                    </template>
+
+                    <template v-else-if="item.row.type === 'group-item'">
+                        <div class="x-friend-item" @click="showGroupDialog(item.row.ownerId)">
+                            <template v-if="item.row.isVisible">
+                                <div class="avatar">
+                                    <img :src="getSmallGroupIconUrl(item.row.iconUrl)" loading="lazy" />
+                                </div>
+                                <div class="detail">
+                                    <span class="name">
+                                        <span v-text="item.row.name"></span>
+                                        <span style="font-weight: normal; margin-left: 5px"
+                                            >({{ item.row.userCount }}/{{ item.row.capacity }})</span
+                                        >
+                                    </span>
+                                    <Location class="text-xs" :location="item.row.location" :link="false" />
+                                </div>
+                            </template>
                         </div>
                     </template>
                 </div>
             </template>
-        </template>
+        </div>
     </div>
 </template>
 
 <script setup>
-    import { computed, ref } from 'vue';
+    import { computed, nextTick, onMounted, ref, watch } from 'vue';
     import { ChevronDown } from 'lucide-vue-next';
     import { storeToRefs } from 'pinia';
+    import { useVirtualizer } from '@tanstack/vue-virtual';
 
     import { useAppearanceSettingsStore, useGroupStore } from '../../../stores';
     import { convertFileUrlToImageUrl } from '../../../shared/utils';
 
+    import Location from '../../../components/Location.vue';
+
     const { isAgeGatedInstancesVisible } = storeToRefs(useAppearanceSettingsStore());
     const { showGroupDialog, sortGroupInstancesByInGame } = useGroupStore();
     const { groupInstances } = storeToRefs(useGroupStore());
@@ -56,6 +71,8 @@
     });
 
     const groupInstancesCfg = ref({});
+    const listRootRef = ref(null);
+    const scrollViewportRef = ref(null);
 
     const groupedGroupInstances = computed(() => {
         const groupMap = new Map();
@@ -79,6 +96,78 @@
         return Array.from(groupMap.values()).sort(sortGroupInstancesByInGame);
     });
 
+    const buildGroupHeaderRow = (group, index) => ({
+        type: 'group-header',
+        key: `group-header:${getGroupId(group)}`,
+        groupId: getGroupId(group),
+        label: group[0]?.group?.name ?? '',
+        count: group.length,
+        isCollapsed: Boolean(groupInstancesCfg.value[getGroupId(group)]?.isCollapsed),
+        headerPaddingTop: index === 0 ? '0px' : '10px'
+    });
+
+    const buildGroupItemRow = (ref, index, groupId) => ({
+        type: 'group-item',
+        key: `group-item:${groupId}:${ref?.instance?.id ?? index}`,
+        ownerId: ref?.instance?.ownerId ?? '',
+        iconUrl: ref?.group?.iconUrl ?? '',
+        name: ref?.group?.name ?? '',
+        userCount: ref?.instance?.userCount ?? 0,
+        capacity: ref?.instance?.capacity ?? 0,
+        location: ref?.instance?.location ?? '',
+        isVisible: Boolean(isAgeGatedInstancesVisible.value || !(ref?.ageGate || ref?.location?.includes('~ageGate')))
+    });
+
+    const virtualRows = computed(() => {
+        const rows = [];
+        groupedGroupInstances.value.forEach((group, index) => {
+            if (!group?.length) return;
+            const groupId = getGroupId(group);
+            rows.push(buildGroupHeaderRow(group, index));
+            if (!groupInstancesCfg.value[groupId]?.isCollapsed) {
+                group.forEach((ref, idx) => {
+                    rows.push(buildGroupItemRow(ref, idx, groupId));
+                });
+            }
+        });
+        return rows;
+    });
+
+    const estimateRowSize = (row) => {
+        if (!row) return 44;
+        if (row.type === 'group-header') {
+            return 30;
+        }
+        return 52;
+    };
+
+    const virtualizer = useVirtualizer(
+        computed(() => ({
+            count: virtualRows.value.length,
+            getScrollElement: () => scrollViewportRef.value,
+            estimateSize: (index) => estimateRowSize(virtualRows.value[index]),
+            getItemKey: (index) => virtualRows.value[index]?.key ?? index,
+            overscan: 6
+        }))
+    );
+
+    const virtualItems = computed(() => {
+        const items = virtualizer.value?.getVirtualItems?.() ?? [];
+        return items.map((virtualItem) => ({
+            virtualItem,
+            row: virtualRows.value[virtualItem.index]
+        }));
+    });
+
+    const virtualContainerStyle = computed(() => ({
+        height: `${virtualizer.value?.getTotalSize?.() ?? 0}px`,
+        width: '100%'
+    }));
+
+    const rowStyle = (item) => ({
+        transform: `translateY(${item.virtualItem.start}px)`
+    });
+
     function getSmallGroupIconUrl(url) {
         return convertFileUrlToImageUrl(url);
     }
@@ -90,6 +179,19 @@
     function getGroupId(group) {
         return group[0]?.group?.groupId || '';
     }
+
+    onMounted(() => {
+        scrollViewportRef.value = listRootRef.value?.closest('[data-slot="scroll-area-viewport"]') ?? null;
+        nextTick(() => {
+            virtualizer.value?.measure?.();
+        });
+    });
+
+    watch(virtualRows, () => {
+        nextTick(() => {
+            virtualizer.value?.measure?.();
+        });
+    });
 </script>
 
 <style scoped>
@@ -99,4 +201,23 @@
     .rotation-transition {
         transition: transform 0.2s ease-in-out;
     }
+
+    .group-sidebar__virtual {
+        width: 100%;
+        position: relative;
+        box-sizing: border-box;
+    }
+
+    .group-sidebar__virtual-row {
+        width: 100%;
+        box-sizing: border-box;
+        position: absolute;
+        left: 0;
+        top: 0;
+    }
+
+    .group-sidebar__virtual-row--group-header .x-friend-group {
+        padding: 16px 0 5px;
+        font-size: 12px;
+    }
 </style>