fixes external resource handling

packages/studio/core/src/ui/clipboard/ClipboardUtils.ts

@@ -15,12 +15,14 @@ export namespace ClipboardUtils {
 
     export const serializeBoxes = (boxes: ReadonlyArray<Box>,
                                    metadata: ArrayBufferLike = new ArrayBuffer(0)): ArrayBufferLike => {
+        const uniqueBoxes = UUID.newSet<Box>(box => box.address.uuid)
+        boxes.forEach(box => uniqueBoxes.add(box))
         const typeCounts = new Map<string, number>()
-        boxes.forEach(box => typeCounts.set(box.name, (typeCounts.get(box.name) ?? 0) + 1))
+        uniqueBoxes.forEach(box => typeCounts.set(box.name, (typeCounts.get(box.name) ?? 0) + 1))
         const types = [...typeCounts.entries()].map(([type, count]) => `${type}: ${count}`).join(", ")
         const clipboardGraph = new BoxGraph<BoxIO.TypeMap>(Option.wrap(BoxIO.create))
         clipboardGraph.beginTransaction()
-        boxes.forEach(sourceBox => {
+        uniqueBoxes.forEach(sourceBox => {
             const input = new ByteArrayInput(sourceBox.toArrayBuffer())
             clipboardGraph.createBox(sourceBox.name as keyof BoxIO.TypeMap, sourceBox.address.uuid, box => box.read(input))
         })
@@ -50,7 +52,21 @@ export namespace ClipboardUtils {
         input.readBytes(graphData)
         const clipboardGraph = new BoxGraph<BoxIO.TypeMap>(Option.wrap(BoxIO.create))
         clipboardGraph.fromArrayBuffer(graphData.buffer)
-        const sourceBoxes = clipboardGraph.boxes().filter(box => !options.excludeBox?.(box))
+        const skippedExternalUuids = UUID.newSet<UUID.Bytes>(uuid => uuid)
+        clipboardGraph.boxes().forEach(box => {
+            if (box.resource === "external" && targetGraph.findBox(box.address.uuid).nonEmpty()) {
+                skippedExternalUuids.add(box.address.uuid)
+            }
+        })
+        const shouldSkipBox = (box: Box): boolean => {
+            if (options.excludeBox?.(box)) {return true}
+            if (box.resource === "external" && skippedExternalUuids.hasKey(box.address.uuid)) {return true}
+            for (const [, targetAddress] of box.outgoingEdges()) {
+                if (skippedExternalUuids.hasKey(targetAddress.uuid) && !targetAddress.isBox()) {return true}
+            }
+            return false
+        }
+        const sourceBoxes = clipboardGraph.boxes().filter(box => !shouldSkipBox(box))
         const typeCounts = new Map<string, number>()
         sourceBoxes.forEach(box => typeCounts.set(box.name, (typeCounts.get(box.name) ?? 0) + 1))
         console.debug("Clipboard paste:", [...typeCounts.entries()].map(([type, count]) => `${type}: ${count}`).join(", "))
@@ -59,6 +75,7 @@ export namespace ClipboardUtils {
             const isExternal = box.resource === "external"
             uuidMap.add({source: box.address.uuid, target: isExternal ? box.address.uuid : UUID.generate()})
         })
+        skippedExternalUuids.forEach(uuid => uuidMap.add({source: uuid, target: uuid}))
         const result: Array<T> = []
         PointerField.decodeWith({
             map: (pointer, address) => {
@@ -68,8 +85,6 @@ export namespace ClipboardUtils {
                 return options.mapPointer(pointer, address)
             }
         }, () => sourceBoxes.forEach(sourceBox => {
-            const isExternal = sourceBox.resource === "external"
-            if (isExternal && targetGraph.findBox(sourceBox.address.uuid).nonEmpty()) {return}
             const inputStream = new ByteArrayInput(sourceBox.toArrayBuffer())
             const targetUuid = uuidMap.get(sourceBox.address.uuid).target
             targetGraph.createBox(sourceBox.name as keyof BoxIO.TypeMap, targetUuid, box => {

plans/copy-and-paste-regions.md

@@ -60,6 +60,30 @@ subscribeDeletion(listener: Exec): Subscription {
 }
 ```
 
+```typescript
+// packages/lib/box/src/graph.ts
+readonly #deletionListeners: SortedSet<Readonly<Uint8Array>, { uuid: UUID.Bytes, listeners: Set<Exec> }>
+
+subscribeDeletion(uuid: UUID.Bytes, listener: Exec): Subscription {
+    const entry = this.#deletionListeners.getOrCreate(uuid, () => ({uuid, listeners: new Set()}))
+    entry.listeners.add(listener)
+    return {
+        terminate: () => {
+            entry.listeners.delete(listener)
+            if (entry.listeners.size === 0) {
+                this.#deletionListeners.removeByKey(uuid)
+            }
+        }
+    }
+}
+
+unstageBox(box: Box): void {
+    // ... existing code ...
+    this.#deletionListeners.removeByKeyIfExist(box.address.uuid)?.listeners.forEach(listener => listener())
+    // ... rest of method ...
+}
+```
+
 Deletion listeners are stored in `BoxGraph.#deletionListeners` and notified during `unstageBox()`.
 
 ---
@@ -381,6 +405,39 @@ const pasteRegions = (
 - Silently skip entire paste
 - No partial pastes to avoid orphaned dependency boxes
 
+### External Resource Handling (AudioFileBox)
+
+External resources like `AudioFileBox` require special handling during paste:
+
+1. **UUID Preservation**: External resources keep their original UUID (not regenerated)
+2. **Skip if exists**: If the external resource already exists in the target graph, don't create a duplicate
+3. **Skip field-level children**: Boxes that point to fields within an existing external resource (e.g., `TransientMarkerBox` pointing to `AudioFileBox.transientMarkers`) are skipped to avoid duplicates
+
+```typescript
+// In ClipboardUtils.deserializeBoxes
+const skippedExternalUuids = UUID.newSet<UUID.Bytes>(uuid => uuid)
+clipboardGraph.boxes().forEach(box => {
+    if (box.resource === "external" && targetGraph.findBox(box.address.uuid).nonEmpty()) {
+        skippedExternalUuids.add(box.address.uuid)
+    }
+})
+
+const shouldSkipBox = (box: Box): boolean => {
+    if (options.excludeBox?.(box)) {return true}
+    // Skip external resources that already exist
+    if (box.resource === "external" && skippedExternalUuids.hasKey(box.address.uuid)) {return true}
+    // Skip boxes pointing to FIELDS within skipped external resources (children like TransientMarkerBox)
+    for (const [, targetAddress] of box.outgoingEdges()) {
+        if (skippedExternalUuids.hasKey(targetAddress.uuid) && !targetAddress.isBox()) {return true}
+    }
+    return false
+}
+```
+
+The `!targetAddress.isBox()` check distinguishes between:
+- `AudioRegionBox` → `AudioFileBox` (box-level reference, allowed)
+- `TransientMarkerBox` → `AudioFileBox.transientMarkers` (field-level reference, skipped)
+
 ### Audio File Not in Project
 - AudioFileBox created with same UUID
 - Audio won't play until file is available
@@ -429,6 +486,7 @@ packages/studio/core/src/ui/timeline/TimelineFocus.ts
 packages/studio/core/src/project/Project.ts - added timelineFocus
 packages/lib/box/src/box.ts - added subscribeDeletion()
 packages/lib/box/src/graph.ts - added #deletionListeners and subscribeDeletion()
+packages/studio/core/src/ui/clipboard/ClipboardUtils.ts - external resource handling, skip field-level children
 packages/app/studio/src/ui/timeline/tracks/audio-unit/regions/RegionsArea.tsx - focus handling, clipboard integration
 packages/app/studio/src/ui/timeline/tracks/audio-unit/regions/RegionLane.tsx - focus visual feedback
 packages/app/studio/src/ui/timeline/tracks/audio-unit/regions/RegionLane.sass - .focused styling