feat: [US-021] - Add dialogue node from toolbar

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package-lock.json

@@ -10,6 +10,7 @@
       "dependencies": {
         "@supabase/ssr": "^0.8.0",
         "@supabase/supabase-js": "^2.91.0",
+        "nanoid": "^5.1.6",
         "next": "16.1.4",
         "react": "19.2.3",
         "react-dom": "19.2.3",
@@ -5511,9 +5512,9 @@
       "license": "MIT"
     },
     "node_modules/nanoid": {
-      "version": "3.3.11",
-      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.11.tgz",
-      "integrity": "sha512-N8SpfPUnUp1bK+PMYW8qSWdl9U+wwNWI4QKxOYDy9JAro3WMX7p2OeVRF9v+347pnakNevPmiHhNmZ2HbFA76w==",
+      "version": "5.1.6",
+      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-5.1.6.tgz",
+      "integrity": "sha512-c7+7RQ+dMB5dPwwCp4ee1/iV/q2P6aK1mTZcfr1BTuVlyW9hJYiMPybJCcnBlQtuSmTIWNeazm/zqNoZSSElBg==",
       "funding": [
         {
           "type": "github",
@@ -5522,10 +5523,10 @@
       ],
       "license": "MIT",
       "bin": {
-        "nanoid": "bin/nanoid.cjs"
+        "nanoid": "bin/nanoid.js"
       },
       "engines": {
-        "node": "^10 || ^12 || ^13.7 || ^14 || >=15.0.1"
+        "node": "^18 || >=20"
       }
     },
     "node_modules/napi-postinstall": {
@@ -5604,6 +5605,24 @@
         }
       }
     },
+    "node_modules/next/node_modules/nanoid": {
+      "version": "3.3.11",
+      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.11.tgz",
+      "integrity": "sha512-N8SpfPUnUp1bK+PMYW8qSWdl9U+wwNWI4QKxOYDy9JAro3WMX7p2OeVRF9v+347pnakNevPmiHhNmZ2HbFA76w==",
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/ai"
+        }
+      ],
+      "license": "MIT",
+      "bin": {
+        "nanoid": "bin/nanoid.cjs"
+      },
+      "engines": {
+        "node": "^10 || ^12 || ^13.7 || ^14 || >=15.0.1"
+      }
+    },
     "node_modules/next/node_modules/postcss": {
       "version": "8.4.31",
       "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.4.31.tgz",
@@ -5928,6 +5947,25 @@
         "node": "^10 || ^12 || >=14"
       }
     },
+    "node_modules/postcss/node_modules/nanoid": {
+      "version": "3.3.11",
+      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.11.tgz",
+      "integrity": "sha512-N8SpfPUnUp1bK+PMYW8qSWdl9U+wwNWI4QKxOYDy9JAro3WMX7p2OeVRF9v+347pnakNevPmiHhNmZ2HbFA76w==",
+      "dev": true,
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/ai"
+        }
+      ],
+      "license": "MIT",
+      "bin": {
+        "nanoid": "bin/nanoid.cjs"
+      },
+      "engines": {
+        "node": "^10 || ^12 || ^13.7 || ^14 || >=15.0.1"
+      }
+    },
     "node_modules/prelude-ls": {
       "version": "1.2.1",
       "resolved": "https://registry.npmjs.org/prelude-ls/-/prelude-ls-1.2.1.tgz",

package.json

@@ -12,6 +12,7 @@
   "dependencies": {
     "@supabase/ssr": "^0.8.0",
     "@supabase/supabase-js": "^2.91.0",
+    "nanoid": "^5.1.6",
     "next": "16.1.4",
     "react": "19.2.3",
     "react-dom": "19.2.3",

src/app/editor/[projectId]/FlowchartEditor.tsx

@@ -7,12 +7,15 @@ import ReactFlow, {
   Controls,
   useNodesState,
   useEdgesState,
+  useReactFlow,
+  ReactFlowProvider,
   addEdge,
   Connection,
   Node,
   Edge,
   NodeTypes,
 } from 'reactflow'
+import { nanoid } from 'nanoid'
 import 'reactflow/dist/style.css'
 import Toolbar from '@/components/editor/Toolbar'
 import DialogueNode from '@/components/editor/nodes/DialogueNode'
@@ -45,9 +48,8 @@ function toReactFlowEdges(edges: FlowchartEdge[]): Edge[] {
   }))
 }
 
-export default function FlowchartEditor({
-  initialData,
-}: FlowchartEditorProps) {
+// Inner component that uses useReactFlow hook
+function FlowchartEditorInner({ initialData }: FlowchartEditorProps) {
   // Define custom node types - memoized to prevent re-renders
   const nodeTypes: NodeTypes = useMemo(
     () => ({
@@ -56,6 +58,8 @@ export default function FlowchartEditor({
     []
   )
 
+  const { getViewport } = useReactFlow()
+
   const [nodes, setNodes, onNodesChange] = useNodesState(
     toReactFlowNodes(initialData.nodes)
   )
@@ -68,10 +72,27 @@ export default function FlowchartEditor({
     [setEdges]
   )
 
-  // Placeholder handlers - functionality will be added in future stories
+  // Get center position of current viewport for placing new nodes
+  const getViewportCenter = useCallback(() => {
+    const viewport = getViewport()
+    // Calculate center based on viewport dimensions (assume ~800x600 visible area)
+    // Adjust based on zoom level
+    const centerX = (-viewport.x + 400) / viewport.zoom
+    const centerY = (-viewport.y + 300) / viewport.zoom
+    return { x: centerX, y: centerY }
+  }, [getViewport])
+
+  // Add dialogue node at viewport center
   const handleAddDialogue = useCallback(() => {
-    // TODO: Implement in US-021
-  }, [])
+    const position = getViewportCenter()
+    const newNode: Node = {
+      id: nanoid(),
+      type: 'dialogue',
+      position,
+      data: { speaker: '', text: '' },
+    }
+    setNodes((nodes) => [...nodes, newNode])
+  }, [getViewportCenter, setNodes])
 
   const handleAddChoice = useCallback(() => {
     // TODO: Implement in US-023
@@ -120,3 +141,12 @@ export default function FlowchartEditor({
     </div>
   )
 }
+
+// Outer wrapper component with ReactFlowProvider
+export default function FlowchartEditor(props: FlowchartEditorProps) {
+  return (
+    <ReactFlowProvider>
+      <FlowchartEditorInner {...props} />
+    </ReactFlowProvider>
+  )
+}