updated

Author: flocked

Example/Example/Base.lproj/Main.storyboard

@@ -731,7 +731,7 @@
                                     <rect key="frame" x="0.0" y="0.0" width="220" height="376"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <subviews>
-                                        <outlineView verticalHuggingPriority="750" allowsExpansionToolTips="YES" columnAutoresizingStyle="lastColumnOnly" tableStyle="sourceList" selectionHighlightStyle="sourceList" columnReordering="NO" columnResizing="NO" autosaveColumns="NO" rowHeight="24" rowSizeStyle="automatic" viewBased="YES" indentationPerLevel="13" outlineTableColumn="dkC-fw-nsz" id="OL6-2g-mY0">
+                                        <outlineView verticalHuggingPriority="750" allowsExpansionToolTips="YES" columnAutoresizingStyle="lastColumnOnly" tableStyle="sourceList" selectionHighlightStyle="sourceList" columnReordering="NO" columnResizing="NO" autosaveColumns="NO" rowHeight="24" rowSizeStyle="automatic" viewBased="YES" floatsGroupRows="NO" indentationPerLevel="13" outlineTableColumn="dkC-fw-nsz" id="OL6-2g-mY0">
                                             <rect key="frame" x="0.0" y="0.0" width="220" height="376"/>
                                             <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                             <size key="intercellSpacing" width="3" height="0.0"/>

Example/Example/OutlineSidebarViewController.swift

@@ -32,7 +32,7 @@ class OutlineSidebarViewController: NSViewController {
         outlineView.dataSource = dataSource
 
         /// Enables reordering selected rows by dragging them.
-        dataSource.reorderingHandlers.canReorder = { _, _ in return true }
+        dataSource.reorderingHandlers.canReorder = { _,_ in return true }
 
         /// Enables deleting selected items via backspace key.
         dataSource.deletingHandlers.canDelete = { items in return items }

Sources/AdvancedCollectionTableView/Configuration/Extensions/NSTableView+/NSTableCellVew+.swift

@@ -84,10 +84,12 @@ extension NSTableCellView {
                 contentView = contentConfiguration.makeContentView()
                 translatesAutoresizingMaskIntoConstraints = false
                 addSubview(withConstraint: contentView!)
+                /*
                 if let contentView = contentView as? NSListContentView {
-                    // textField = contentView.textField
-                    // imageView = contentView.imageView
+                    textField = contentView.textField
+                    imageView = contentView.imageView
                 }
+                 */
             }
             setNeedsDisplay()
             contentView?.setNeedsDisplay()

Sources/AdvancedCollectionTableView/DiffableDataSource/NSOutlineView/OutlineViewDiffableDataSource.swift

@@ -31,12 +31,12 @@ import FZSwiftUtils
  To connect a diffable data source to a outline view, you create the diffable data source using its ``init(outlineView:cellProvider:)`` or ``init(outlineView:cellRegistration:)`` initializer, passing in the outline view you want to associate with that data source.
 
  ```swift
- outlineView.dataSource = OutlineViewDiffableDataSource<Section, Item>(outlineView: outlineView, cellRegistration: cellRegistration)
+ outlineView.dataSource = OutlineViewDiffableDataSource<Item>(outlineView: outlineView, cellRegistration: cellRegistration)
  ```
 
  Then, you generate the current state of the data and display the data in the UI by constructing and applying a snapshot. For more information, see `NSDiffableDataSourceSnapshot`.
 
- - Note: Each of your sections and items must have unique identifiers.
+ - Note: Each of your items must have unique identifiers.
 
  - Note: Don’t change the `dataSource` or `delegate` on the outline view after you configure it with a diffable data source. If the outline view needs a new data source after you configure it initially, create and configure a new outline view and diffable data source.
  */
@@ -431,7 +431,7 @@ public class OutlineViewDiffableDataSource<ItemIdentifierType: Hashable>: NSObje
      To connect a diffable data source to a outline view, you create the diffable data source using this initializer, passing in the outline view you want to associate with that data source. You also pass in a item provider, where you configure each of your cells to determine how to display your data in the UI.
 
      ```swift
-     dataSource = OutlineViewDiffableDataSource<Section, Item>(outlineView: outlineView, cellProvider: {
+     dataSource = OutlineViewDiffableDataSource<Item>(outlineView: outlineView, cellProvider: {
      (outlineView, tableColumn, item) in
      // configure and return cell
      })
@@ -459,7 +459,7 @@ public class OutlineViewDiffableDataSource<ItemIdentifierType: Hashable>: NSObje
      To connect a diffable data source to a outline view, you create the diffable data source using this initializer, passing in the outline view you want to associate with that data source. You also pass in a cell registration, where each of your cells gets determine how to display your data in the UI.
 
      ```swift
-     dataSource = OutlineViewDiffableDataSource<Section, Item>(outlineView: outlineView, cellRegistration: cellRegistration)
+     dataSource = OutlineViewDiffableDataSource<Item>(outlineView: outlineView, cellRegistration: cellRegistration)
      ```
 
      - Parameters:
@@ -485,15 +485,23 @@ public class OutlineViewDiffableDataSource<ItemIdentifierType: Hashable>: NSObje
      */
     public typealias CellProvider = (_ outlineView: NSOutlineView, _ tableColumn: NSTableColumn?, _ identifier: ItemIdentifierType) -> NSView
 
-    /**
-     Returns a representation of the current state of the data in the outline view.
-     
-     A snapshot containing section and item identifiers in the order that they appear in the UI.
-     */
+    /// Returns a representation of the current state of the data in the outline view.
     public func snapshot() -> OutlineViewDiffableDataSourceSnapshot<ItemIdentifierType> {
         currentSnapshot
     }
 
+    /// Returns a representation of the current state of the data in the specified item of the collection view.
+    public func snapshot(for item: ItemIdentifierType) -> OutlineViewDiffableDataSourceSnapshot<ItemIdentifierType> {
+        guard currentSnapshot.nodes[item] != nil else { return emptySnapshot() }
+        let current = snapshot()
+        var snapshot = emptySnapshot()
+        snapshot.nodes[item] = .init()
+        current.descendants(of: item).forEach({ snapshot.nodes[$0] = current.nodes[$0] })
+        current.children(of: item).forEach({ snapshot.nodes[$0]?.parent = item })
+        snapshot.updateOrderedItems()
+        return snapshot
+    }
+    
     /// Returns an empty snapshot.
     public func emptySnapshot() -> OutlineViewDiffableDataSourceSnapshot<ItemIdentifierType> {
         .init()
@@ -660,7 +668,7 @@ public class OutlineViewDiffableDataSource<ItemIdentifierType: Hashable>: NSObje
         if draggedParent == item as? ItemIdentifierType, let last = draggedIndexes.last, (draggedIndexes + [last+1]).contains(index) {
             return []
         }
-        if index == -1, delegate.outlineView(outlineView, isGroupItem: item) {
+        if index == -1, let item = item, delegate.outlineView(outlineView, isGroupItem: item) {
             return []
         }
         if let item = item as? ItemIdentifierType, draggedItems.contains(where: { currentSnapshot.isDescendant(item, of: $0) }) {

Sources/AdvancedCollectionTableView/DiffableDataSource/NSOutlineView/Snapshot/OutlineViewDiffableDataSourceSnapshot.swift

@@ -398,7 +398,7 @@ public struct OutlineViewDiffableDataSourceSnapshot<ItemIdentifierType: Hashable
     }
 
     /// All descendants of a given item in depth-first order.
-    private func descendants(of parent: ItemIdentifierType) -> [ItemIdentifierType] {
+    func descendants(of parent: ItemIdentifierType) -> [ItemIdentifierType] {
         var result: [ItemIdentifierType] = []
         var stack: [ItemIdentifierType] = [parent]
 

Sources/AdvancedCollectionTableView/DiffableDataSource/NSOutlineView/Snapshot/OutlineViewDiffableDataSourceTransaction.swift

@@ -7,6 +7,7 @@
 
 import Foundation
 
+/// A transaction that describes the changes after reordering the items of a outline view..
 public struct OutlineViewDiffableDataSourceTransaction<ItemIdentifierType: Hashable> {
     /// The section snapshot before the transaction occured.
     public let initialSnapshot: OutlineViewDiffableDataSourceSnapshot<ItemIdentifierType>