macOS: work on drop destination

macos/Sources/Features/Splits/TerminalSplitTreeView.swift

@@ -32,8 +32,14 @@ struct TerminalSplitSubtreeView: View {
             Ghostty.InspectableSurface(
                 surfaceView: leafView,
                 isSplit: !isRoot)
-                .accessibilityElement(children: .contain)
-                .accessibilityLabel("Terminal pane")
+            .dropDestination(for: Ghostty.SurfaceView.self) { views, point in
+                Ghostty.logger.warning("BABY WHAT!")
+                return false
+            } isTargeted: { targeted in
+                Ghostty.logger.warning("BABY TARGETED=\(targeted)")
+            }
+            .accessibilityElement(children: .contain)
+            .accessibilityLabel("Terminal pane")
 
         case .split(let split):
             let splitViewDirection: SplitViewDirection = switch (split.direction) {

macos/Sources/Ghostty/Surface View/SurfaceView+Transferable.swift

@@ -1,3 +1,4 @@
+import AppKit
 import CoreTransferable
 import UniformTypeIdentifiers
 
@@ -6,12 +7,40 @@ extension Ghostty.SurfaceView: Transferable {
         DataRepresentation(contentType: .ghosttySurfaceId) { surface in
             withUnsafeBytes(of: surface.id.uuid) { Data($0) }
         } importing: { data in
-            throw TransferError.importNotSupported
+            guard data.count == 16 else {
+                throw TransferError.invalidData
+            }
+
+            let uuid = data.withUnsafeBytes {
+                $0.load(as: UUID.self)
+            }
+            
+            guard let imported = await Self.find(uuid: uuid) else {
+                throw TransferError.invalidData
+            }
+            
+            return imported
         }
     }
 
     enum TransferError: Error {
-        case importNotSupported
+        case invalidData
+    }
+    
+    @MainActor
+    static func find(uuid: UUID) -> Self? {
+        for window in NSApp.windows {
+            guard let controller = window.windowController as? BaseTerminalController else {
+                continue
+            }
+            for surface in controller.surfaceTree {
+                if surface.id == uuid {
+                    return surface as? Self
+                }
+            }
+        }
+        
+        return nil
     }
 }