[FEATURE] Proper drag-n-drop from file manager to windows explorer #3

Title

Proper drag-n-drop from file manager to windows explorer

Platform

Desktop App - Windows

Is it related to an issue?

Dragging the file out from the file manager to windows explorer popping out the windows save as dialog. While this is acceptable, this is unconventional.

The Solution

The options is kinda limited, since the client is electron(?) app, but there is still:

Option 1: Native C++ Addon (Virtual Files / OLE Streams)

Instead of using Electron's startDrag(), you build a native Node.js C++ addon (node-addon-api) implementing Windows COM drag-and-drop interfaces (IDataObject).

• How it works:
  • You provide Windows Explorer with virtual file metadata via CFSTR_FILEDESCRIPTOR and data streams via CFSTR_FILECONTENTS (IStream).
  • You implement IDataObjectAsyncCapability so large transfers won't freeze the Explorer UI.
  • When the user drops the item, Explorer creates the file and pulls chunks through IStream::Read. Your addon fetches those chunks on-the-fly via SFTP and streams them directly to disk.
• Pros: Clean architecture, no background hooks, Explorer shows its native copy/progress dialog.
• Cons: Requires writing custom C++ Win32/COM code.

Option 2: Shell Extension DLL (The FileZilla / WinSCP Trick)

This is the workaround traditionally used by desktop FTP/SFTP clients.

• How it works:
  • You build a C++ Windows Shell Extension DLL and register it in the system registry (regsvr32) during app installation. The DLL runs directly inside the explorer.exe process.
  • In Electron, you drag a lightweight "dummy/placeholder" file.
  • When dropped, your DLL inside Explorer intercepts the drop event, extracts the actual destination folder path (e.g., D:\Downloads), and sends it back to your Electron app via IPC (like a Named Pipe).
  • Your app then downloads the real file via SFTP straight into that target path, replacing the dummy file.
• Pros: Proven, battle-tested approach by legacy FTP tools.
• Cons: Requires admin rights for registration, extra installer setup, and injecting a DLL into the user's Windows Shell.

Additional Context

No response