back-portable TableView DiffableDataSource

Sources/Internals.DiffableDataUIDispatcher.Changeset.swift

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+//
+//  Internals.DiffableDataUIDispatcher.Changeset.swift
+//  CoreStore
+//
+//  Copyright © 2018 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+#if canImport(UIKit) || canImport(AppKit)
+
+import Foundation
+
+
+// MARK: - Internals.DiffableDataUIDispatcher
+
+extension Internals.DiffableDataUIDispatcher {
+    
+    // MARK: - ChangeSet
+    
+    internal struct Changeset<C: Collection>: Equatable where C: Equatable {
+        
+        var data: C
+        var sectionDeleted: [Int]
+        var sectionInserted: [Int]
+        var sectionUpdated: [Int]
+        var sectionMoved: [(source: Int, target: Int)]
+
+        var elementDeleted: [ElementPath]
+        var elementInserted: [ElementPath]
+        var elementUpdated: [ElementPath]
+        var elementMoved: [(source: ElementPath, target: ElementPath)]
+
+        @inlinable
+        init(
+            data: C,
+            sectionDeleted: [Int] = [],
+            sectionInserted: [Int] = [],
+            sectionUpdated: [Int] = [],
+            sectionMoved: [(source: Int, target: Int)] = [],
+            elementDeleted: [ElementPath] = [],
+            elementInserted: [ElementPath] = [],
+            elementUpdated: [ElementPath] = [],
+            elementMoved: [(source: ElementPath, target: ElementPath)] = []
+        ) {
+            self.data = data
+            self.sectionDeleted = sectionDeleted
+            self.sectionInserted = sectionInserted
+            self.sectionUpdated = sectionUpdated
+            self.sectionMoved = sectionMoved
+            self.elementDeleted = elementDeleted
+            self.elementInserted = elementInserted
+            self.elementUpdated = elementUpdated
+            self.elementMoved = elementMoved
+        }
+
+        @inlinable
+        var sectionChangeCount: Int {
+            
+            return self.sectionDeleted.count
+                + self.sectionInserted.count
+                + self.sectionUpdated.count
+                + self.sectionMoved.count
+        }
+
+        @inlinable
+        var elementChangeCount: Int {
+            
+            return self.elementDeleted.count
+                + self.elementInserted.count
+                + self.elementUpdated.count
+                + self.elementMoved.count
+        }
+
+        @inlinable
+        var changeCount: Int {
+            
+            return self.sectionChangeCount + self.elementChangeCount
+        }
+
+        @inlinable
+        var hasSectionChanges: Bool {
+            
+            return self.sectionChangeCount > 0
+        }
+
+        @inlinable
+        var hasElementChanges: Bool {
+            
+            return self.elementChangeCount > 0
+        }
+
+        @inlinable
+        var hasChanges: Bool {
+            
+            return self.changeCount > 0
+        }
+        
+        
+        // MARK: Equatable
+        
+        static func == (lhs: Changeset, rhs: Changeset) -> Bool {
+            return lhs.data == rhs.data
+                && Set(lhs.sectionDeleted) == Set(rhs.sectionDeleted)
+                && Set(lhs.sectionInserted) == Set(rhs.sectionInserted)
+                && Set(lhs.sectionUpdated) == Set(rhs.sectionUpdated)
+                && Set(lhs.sectionMoved.map(HashablePair.init)) == Set(rhs.sectionMoved.map(HashablePair.init))
+                && Set(lhs.elementDeleted) == Set(rhs.elementDeleted)
+                && Set(lhs.elementInserted) == Set(rhs.elementInserted)
+                && Set(lhs.elementUpdated) == Set(rhs.elementUpdated)
+                && Set(lhs.elementMoved.map(HashablePair.init)) == Set(rhs.elementMoved.map(HashablePair.init))
+        }
+        
+        
+        // MARK: - HashablePair
+        
+        private struct HashablePair<H: Hashable>: Hashable {
+            
+            let first: H
+            let second: H
+        }
+    }
+}
+
+#endif