draggable(_:id:containerNamespace:_:)

Declaration

nonisolated func draggable<Item, ItemID>(_ itemType: Item.Type = Item.self, id: KeyPath<Item, ItemID>, containerNamespace: Namespace.ID? = nil, _ payload: @escaping () -> Item?) -> some View where Item : Transferable, ItemID : Hashable, ItemID : Sendable

Parameters

• itemType:

  A type of the dragged item.

• id:

  An key path of the identifier of an item.

• containerNamespace:

  A namespace of the associated drag container.

• payload:

  A closure that returns a single instance or a value conforming to Transferable that represents the draggable data from this view.

Return Value

A view that activates this view as the source of a drag and drop operation, beginning with user gesture input.

Discussion

Applying the draggable(_:id:containerNamespace:_:) modifier adds the appropriate gestures for drag and drop to this view. When a drag operation begins, a rendering of this view is generated and used as the preview image.

   var fruits: [Fruit]

   var body: some View {
       ScrollView {
           VStack {
               ForEach(fruits) { fruit in
                   FruitView(fruit)
                       .draggable(Fruit.self, id: \.dragID) {
                           fruit.supportsDrag ? fruit : nil
                       }
               }
           }
       }
   }

   struct Fruit: Transferable {
       var supportsDrag: Bool
       var dragID: UUID
   }

If the draggable view is enclosed in a container, it participates in container drag-and-drop sessions:

   var fruits: [Fruit]
   var selectedFruits: [UUID]

   var body: some View {
       ScrollView {
           VStack {
               ForEach(fruits) { fruit in
                   FruitView(fruit)
                       .draggable(Fruit.self, id: \.dragID) {
                           fruit.supportsDrag ? fruit : nil
                       }
               }
           }
       }
       .dragContainer(for: Fruit.self) { identifiers in
           fruits(with: identifiers)
       }
       .dragContainerSelection(selectedFruits)
   }

   func fruits(with: [UUID]) -> [Fruit] { ... }