Our Final Cut Pro workflow extension built with ProExtensionHost framework uses an advanced NSPasteboardItemDataProvider system with multi-version FCPXML support (1.9, 1.10, 1.13) and proper relative path UIDs for Motion templates. We've implemented clip wrapper approach with placeholder assets and <clip> elements containing <filter-video> effects to enable direct timeline drag functionality. However, drag and drop from our Final Cut Pro workflow extension directly to timeline is still not working despite proper <clip> element structure in our FCPXML. Our implementation creates valid clip elements with effects applied, but Final Cut Pro timeline doesn't accept them during drag operations from our ProExtensionHost-based workflow extension. Steps to Reproduce:
- Create Final Cut Pro workflow extension using ProExtensionHost framework with NSPasteboardItemDataProvider implementation
- Generate FCPXML with proper <clip> element structure:
<clip id="r123456" name="Effect Applied" ref="r789012" duration="300/30s" start="0s"> <filter-video ref="r111111" name="Effect Name"/> </clip> 3. Register multiple FCPXML pasteboard types (v1.9, v1.10, v1.13, generic) in workflow extension 4. Use relative path UIDs for Motion template references 5. Attempt to drag clip element from Final Cut Pro workflow extension directly to Final Cut Pro timeline 6. Timeline does not accept the drop operation despite valid clip structure
Expected Result: Clip should be accepted by timeline and effect applied from workflow extension Actual Result: Timeline rejects drag operation from ProExtensionHost-based workflow extension Question: Are there additional requirements or ProExtensionHost API calls needed beyond standard NSPasteboardItemDataProvider for Final Cut Pro workflow extension timeline drag functionality?