Add component tree expansion hook

src/components/molecules/ComponentTree.tsx

@@ -1,9 +1,9 @@
-import { useState, useCallback } from 'react'
 import { UIComponent } from '@/types/json-ui'
 import { ScrollArea } from '@/components/ui/scroll-area'
 import { ComponentTreeHeader } from '@/components/molecules/component-tree/ComponentTreeHeader'
 import { ComponentTreeEmptyState } from '@/components/molecules/component-tree/ComponentTreeEmptyState'
 import { ComponentTreeNodes } from '@/components/molecules/component-tree/ComponentTreeNodes'
+import { useComponentTreeExpansion } from '@/hooks/use-component-tree-expansion'
 
 interface ComponentTreeProps {
   components: UIComponent[]
@@ -34,42 +34,8 @@ export function ComponentTree({
   onDragLeave,
   onDrop,
 }: ComponentTreeProps) {
-  const [expandedIds, setExpandedIds] = useState<Set<string>>(new Set())
-
-  const getAllComponentIds = useCallback((comps: UIComponent[]): string[] => {
-    const ids: string[] = []
-    const traverse = (nodes: UIComponent[]) => {
-      nodes.forEach((comp) => {
-        if (Array.isArray(comp.children) && comp.children.length > 0) {
-          ids.push(comp.id)
-          traverse(comp.children)
-        }
-      })
-    }
-    traverse(comps)
-    return ids
-  }, [])
-
-  const handleExpandAll = useCallback(() => {
-    const allIds = getAllComponentIds(components)
-    setExpandedIds(new Set(allIds))
-  }, [components, getAllComponentIds])
-
-  const handleCollapseAll = useCallback(() => {
-    setExpandedIds(new Set())
-  }, [])
-
-  const toggleExpand = useCallback((id: string) => {
-    setExpandedIds((prev) => {
-      const next = new Set(prev)
-      if (next.has(id)) {
-        next.delete(id)
-      } else {
-        next.add(id)
-      }
-      return next
-    })
-  }, [])
+  const { expandedIds, handleExpandAll, handleCollapseAll, toggleExpand } =
+    useComponentTreeExpansion(components)
 
   return (
     <div className="h-full flex flex-col">

src/hooks/use-component-tree-expansion.ts

@@ -0,0 +1,58 @@
+import { useCallback, useMemo, useState } from 'react'
+import { UIComponent } from '@/types/json-ui'
+
+interface ComponentTreeExpansionState {
+  expandedIds: Set<string>
+  handleExpandAll: () => void
+  handleCollapseAll: () => void
+  toggleExpand: (id: string) => void
+}
+
+const getExpandableIds = (components: UIComponent[]): string[] => {
+  const ids: string[] = []
+  const traverse = (nodes: UIComponent[]) => {
+    nodes.forEach((component) => {
+      if (Array.isArray(component.children) && component.children.length > 0) {
+        ids.push(component.id)
+        traverse(component.children)
+      }
+    })
+  }
+  traverse(components)
+  return ids
+}
+
+export function useComponentTreeExpansion(
+  components: UIComponent[],
+): ComponentTreeExpansionState {
+  const [expandedIds, setExpandedIds] = useState<Set<string>>(new Set())
+
+  const expandableIds = useMemo(() => getExpandableIds(components), [components])
+
+  const handleExpandAll = useCallback(() => {
+    setExpandedIds(new Set(expandableIds))
+  }, [expandableIds])
+
+  const handleCollapseAll = useCallback(() => {
+    setExpandedIds(new Set())
+  }, [])
+
+  const toggleExpand = useCallback((id: string) => {
+    setExpandedIds((prev) => {
+      const next = new Set(prev)
+      if (next.has(id)) {
+        next.delete(id)
+      } else {
+        next.add(id)
+      }
+      return next
+    })
+  }, [])
+
+  return {
+    expandedIds,
+    handleExpandAll,
+    handleCollapseAll,
+    toggleExpand,
+  }
+}