perf: virtualize FormDropdownMenu to reduce DOM nodes and image requests

- Integrate VirtualGrid into FormDropdownMenu for virtualized rendering
- Only render visible items (~20-30) instead of all items (100+)
- Add computed properties for grid configuration per layout mode
- Extend VirtualGrid slot to provide original item index
- Change container from max-h to fixed h for proper virtualization

Amp-Thread-ID: https://ampcode.com/threads/T-019c0ca8-be8d-770e-ab31-349937cd2acf
Co-authored-by: Amp <amp@ampcode.com>

src/components/common/VirtualGrid.vue

@@ -6,12 +6,12 @@
     <div :style="topSpacerStyle" />
     <div :style="mergedGridStyle">
       <div
-        v-for="item in renderedItems"
+        v-for="(item, i) in renderedItems"
         :key="item.key"
         class="transition-[width] duration-150 ease-out"
         data-virtual-grid-item
       >
-        <slot name="item" :item="item" />
+        <slot name="item" :item="item" :index="state.start + i" />
       </div>
     </div>
     <div :style="bottomSpacerStyle" />

src/renderer/extensions/vueNodes/widgets/components/form/dropdown/FormDropdownMenu.vue

@@ -1,7 +1,8 @@
 <script setup lang="ts">
-import type { MaybeRefOrGetter } from 'vue'
+import type { CSSProperties, MaybeRefOrGetter } from 'vue'
+import { computed } from 'vue'
 
-import { cn } from '@/utils/tailwindUtil'
+import VirtualGrid from '@/components/common/VirtualGrid.vue'
 
 import FormDropdownMenuActions from './FormDropdownMenuActions.vue'
 import FormDropdownMenuFilter from './FormDropdownMenuFilter.vue'
@@ -26,7 +27,7 @@ interface Props {
   updateKey?: MaybeRefOrGetter<unknown>
 }
 
-defineProps<Props>()
+const props = defineProps<Props>()
 const emit = defineEmits<{
   (e: 'item-click', item: DropdownItem, index: number): void
 }>()
@@ -37,12 +38,70 @@ const layoutMode = defineModel<LayoutMode>('layoutMode')
 const sortSelected = defineModel<OptionId>('sortSelected')
 const searchQuery = defineModel<string>('searchQuery')
 
-// Handle item selection
+// VirtualGrid configuration based on layout mode
+const maxColumns = computed(() => {
+  switch (layoutMode.value) {
+    case 'grid':
+      return 4
+    case 'list':
+    case 'list-small':
+      return 1
+    default:
+      return 4
+  }
+})
+
+const defaultItemHeight = computed(() => {
+  switch (layoutMode.value) {
+    case 'grid':
+      return 120
+    case 'list':
+      return 64
+    case 'list-small':
+      return 40
+    default:
+      return 120
+  }
+})
+
+const defaultItemWidth = computed(() => {
+  switch (layoutMode.value) {
+    case 'grid':
+      return 89
+    case 'list':
+    case 'list-small':
+      return 380
+    default:
+      return 89
+  }
+})
+
+const gridStyle = computed<CSSProperties>(() => ({
+  display: 'grid',
+  gridTemplateColumns:
+    layoutMode.value === 'grid' ? 'repeat(4, 1fr)' : 'repeat(1, 1fr)',
+  gap:
+    layoutMode.value === 'grid'
+      ? '1rem 0.5rem'
+      : layoutMode.value === 'list'
+        ? '0.5rem'
+        : '0.25rem',
+  padding: '1rem',
+  width: '100%'
+}))
+
+type VirtualDropdownItem = DropdownItem & { key: string }
+const virtualItems = computed<VirtualDropdownItem[]>(() =>
+  props.items.map((item) => ({
+    ...item,
+    key: String(item.id)
+  }))
+)
 </script>
 
 <template>
   <div
-    class="flex max-h-[640px] w-103 flex-col rounded-lg bg-component-node-background pt-4 outline outline-offset-[-1px] outline-node-component-border"
+    class="flex h-[640px] w-103 flex-col rounded-lg bg-component-node-background pt-4 outline outline-offset-[-1px] outline-node-component-border"
   >
     <!-- Filter -->
     <FormDropdownMenuFilter
@@ -59,45 +118,44 @@ const searchQuery = defineModel<string>('searchQuery')
       :searcher
       :update-key="updateKey"
     />
-    <!-- List -->
-    <div class="relative flex h-full mt-2 overflow-y-scroll">
+    <!-- List Container -->
+    <div class="relative mt-2 min-h-0 flex-1">
+      <!-- Empty State -->
       <div
-        :class="
-          cn(
-            'h-full max-h-full grid gap-x-2 gap-y-4 overflow-y-auto px-4 pt-4 pb-4 w-full',
-            {
-              'grid-cols-4': layoutMode === 'grid',
-              'grid-cols-1 gap-y-2': layoutMode === 'list',
-              'grid-cols-1 gap-y-1': layoutMode === 'list-small'
-            }
-          )
-        "
+        v-if="items.length === 0"
+        class="flex h-50 items-center justify-center"
       >
-        <div class="pointer-events-none absolute inset-x-3 top-0 z-10 h-5" />
-        <div
-          v-if="items.length === 0"
-          class="h-50 col-span-full flex items-center justify-center"
-        >
-          <i
-            :title="$t('g.noItems')"
-            :aria-label="$t('g.noItems')"
-            class="icon-[lucide--circle-off] size-30 text-zinc-500/20"
-          />
-        </div>
-        <!-- Item -->
-        <FormDropdownMenuItem
-          v-for="(item, index) in items"
-          :key="item.id"
-          :index="index"
-          :selected="isSelected(item, index)"
-          :media-src="item.mediaSrc"
-          :name="item.name"
-          :label="item.label"
-          :metadata="item.metadata"
-          :layout="layoutMode"
-          @click="emit('item-click', item, index)"
+        <i
+          :title="$t('g.noItems')"
+          :aria-label="$t('g.noItems')"
+          class="icon-[lucide--circle-off] size-30 text-zinc-500/20"
         />
       </div>
+      <!-- Virtualized Grid -->
+      <VirtualGrid
+        v-else
+        :key="layoutMode"
+        :items="virtualItems"
+        :grid-style="gridStyle"
+        :max-columns="maxColumns"
+        :default-item-height="defaultItemHeight"
+        :default-item-width="defaultItemWidth"
+        :buffer-rows="2"
+        class="h-full"
+      >
+        <template #item="{ item, index }">
+          <FormDropdownMenuItem
+            :index="index"
+            :selected="isSelected(item, index)"
+            :media-src="item.mediaSrc"
+            :name="item.name"
+            :label="item.label"
+            :metadata="item.metadata"
+            :layout="layoutMode"
+            @click="emit('item-click', item, index)"
+          />
+        </template>
+      </VirtualGrid>
     </div>
   </div>
 </template>