Implemented drag-n-drop task reordering

ReSwift-Todo.xcodeproj/project.pbxproj

@@ -71,6 +71,9 @@
 		507347901D7FFE8B00ACFD0D /* StreamReader.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5073478F1D7FFE8B00ACFD0D /* StreamReader.swift */; };
 		507347921D7FFFBD00ACFD0D /* ErrorHelpers.swift in Sources */ = {isa = PBXBuildFile; fileRef = 507347911D7FFFBD00ACFD0D /* ErrorHelpers.swift */; };
 		507347941D8001A200ACFD0D /* String+ReSwiftTodo.swift in Sources */ = {isa = PBXBuildFile; fileRef = 507347931D8001A200ACFD0D /* String+ReSwiftTodo.swift */; };
+		6972332A240708A500E91FBA /* ToDoPasteboardWriter.swift in Sources */ = {isa = PBXBuildFile; fileRef = 697233282407084100E91FBA /* ToDoPasteboardWriter.swift */; };
+		6972332C24070EDE00E91FBA /* ToDoSerializer.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6972332B24070EDE00E91FBA /* ToDoSerializer.swift */; };
+		6972332E2407679800E91FBA /* Array+ReSwiftTodo.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6972332D2407679800E91FBA /* Array+ReSwiftTodo.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -164,6 +167,9 @@
 		5073478F1D7FFE8B00ACFD0D /* StreamReader.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = StreamReader.swift; sourceTree = "<group>"; };
 		507347911D7FFFBD00ACFD0D /* ErrorHelpers.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ErrorHelpers.swift; sourceTree = "<group>"; };
 		507347931D8001A200ACFD0D /* String+ReSwiftTodo.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; lineEnding = 0; path = "String+ReSwiftTodo.swift"; sourceTree = "<group>"; xcLanguageSpecificationIdentifier = xcode.lang.swift; };
+		697233282407084100E91FBA /* ToDoPasteboardWriter.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; name = ToDoPasteboardWriter.swift; path = "ReSwift-Todo/ToDoPasteboardWriter.swift"; sourceTree = SOURCE_ROOT; };
+		6972332B24070EDE00E91FBA /* ToDoSerializer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ToDoSerializer.swift; sourceTree = "<group>"; };
+		6972332D2407679800E91FBA /* Array+ReSwiftTodo.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Array+ReSwiftTodo.swift"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -208,6 +214,7 @@
 		504CDFDD1D8A6DA800D16314 /* Util */ = {
 			isa = PBXGroup;
 			children = (
+				6972332D2407679800E91FBA /* Array+ReSwiftTodo.swift */,
 				50703B461D7EF83D001DAF45 /* CollectionType+ReSwiftTodo.swift */,
 				507347931D8001A200ACFD0D /* String+ReSwiftTodo.swift */,
 			);
@@ -350,6 +357,7 @@
 				50703B311D7EB736001DAF45 /* ToDoListWindowController.swift */,
 				50703B441D7EF590001DAF45 /* ToDoTableDataSource.swift */,
 				50703B3A1D7EE569001DAF45 /* ToDoListViewModel.swift */,
+				697233282407084100E91FBA /* ToDoPasteboardWriter.swift */,
 				504CDFFD1D8ADF3400D16314 /* KeyboardEventHandler.swift */,
 				50703B3C1D7EE581001DAF45 /* To-Do Item */,
 				504CDFFC1D8ADF2400D16314 /* Components */,
@@ -408,6 +416,7 @@
 				502C04841D8850D00032B7F3 /* ToDoLineTokenizer.swift */,
 				5073478F1D7FFE8B00ACFD0D /* StreamReader.swift */,
 				502C046E1D87D9580032B7F3 /* ToDoListSerializer.swift */,
+				6972332B24070EDE00E91FBA /* ToDoSerializer.swift */,
 			);
 			name = Persistence;
 			sourceTree = "<group>";
@@ -555,12 +564,14 @@
 				50703AE91D7EACB8001DAF45 /* ToDoDocument.swift in Sources */,
 				502C04801D880C2A0032B7F3 /* DateConverter.swift in Sources */,
 				50703B0A1D7EAD09001DAF45 /* ToDoList.swift in Sources */,
+				6972332E2407679800E91FBA /* Array+ReSwiftTodo.swift in Sources */,
 				507347901D7FFE8B00ACFD0D /* StreamReader.swift in Sources */,
 				50703B371D7EBC76001DAF45 /* ToDoCellView.swift in Sources */,
 				504CDFE71D8A721D00D16314 /* UndoActionContext.swift in Sources */,
 				502C04851D8850D00032B7F3 /* ToDoLineTokenizer.swift in Sources */,
 				50703B0D1D7EAD09001DAF45 /* ToDoID.swift in Sources */,
 				504CDFE31D8A6F2D00D16314 /* UndoCommand.swift in Sources */,
+				6972332C24070EDE00E91FBA /* ToDoSerializer.swift in Sources */,
 				50703B4E1D7F1407001DAF45 /* ToDoListImporter.swift in Sources */,
 				504CDFE11D8A6E7300D16314 /* NotUndoable.swift in Sources */,
 				504CDFF71D8ADB3D00D16314 /* ToDoTableView.swift in Sources */,
@@ -585,6 +596,7 @@
 				504CDFEE1D8A8E1300D16314 /* SelectionState.swift in Sources */,
 				502C046F1D87D9580032B7F3 /* ToDoListSerializer.swift in Sources */,
 				50703B2C1D7EB2E7001DAF45 /* LoggingMiddleware.swift in Sources */,
+				6972332A240708A500E91FBA /* ToDoPasteboardWriter.swift in Sources */,
 				50703B341D7EB838001DAF45 /* ToDoListPresenter.swift in Sources */,
 				50703B301D7EB60F001DAF45 /* ToDoListState.swift in Sources */,
 				502C04731D87DF040032B7F3 /* ErrorHandling.swift in Sources */,

ReSwift-Todo.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>

ReSwift-Todo/Array+ReSwiftTodo.swift

@@ -0,0 +1,29 @@
+//
+//  Array+ReSwiftTodo.swift
+//  ReSwift-Todo
+//
+//  Created by Jay Koutavas on 2/26/20.
+//  Copyright © 2020 ReSwift. All rights reserved.
+//
+
+import Foundation
+
+extension Array {
+    // These functions from sooop on GitHub
+    // https://gist.github.com/sooop/3c964900d429516ba48bd75050d0de0a
+    mutating func move(from start: Index, to end: Index) {
+        guard (0..<count) ~= start, (0...count) ~= end else { return }
+        if start == end { return }
+        let targetIndex = start < end ? end - 1 : end
+        insert(remove(at: start), at: targetIndex)
+    }
+
+    mutating func move(from indexes: IndexSet, to toIndex: Index) {
+        let movingData = indexes.map{ self[$0] }
+        let targetIndex = toIndex - indexes.filter{ $0 < toIndex }.count
+        for (i, e) in indexes.enumerated() {
+            remove(at: e - i)
+        }
+        insert(contentsOf: movingData, at: targetIndex)
+    }
+}

ReSwift-Todo/ToDoList.swift

@@ -6,6 +6,8 @@
 //  Copyright © 2016 ReSwift. All rights reserved.
 //
 
+import Foundation
+
 struct ToDoList {
 
     static var empty: ToDoList { return ToDoList(title: nil, items: []) }
@@ -39,6 +41,10 @@ struct ToDoList {
         }
     }
 
+    mutating func moveItems(from: Int, to: Int) {
+        items.move(from: from, to: to)
+    }
+
     func indexOf(toDoID: ToDoID) -> Int? {
 
         return items.firstIndex(where: { $0.toDoID == toDoID })

ReSwift-Todo/ToDoListActions.swift

@@ -104,3 +104,32 @@ struct RemoveTaskAction: UndoableAction, ToDoListAction {
         return InsertTaskAction(toDo: removingToDo.toDo, index: removingToDo.index)
     }
 }
+
+struct MoveTaskAction: UndoableAction, ToDoListAction {
+    let from: Int
+    let to: Int
+
+    init(from: Int, to: Int) {
+        self.from = from
+        self.to = to
+    }
+
+    func apply(oldToDoList: ToDoList) -> ToDoList {
+
+        var result = oldToDoList
+        result.moveItems(from: from, to: to)
+        return result
+    }
+
+    var name: String { return "Move Task" }
+    var isUndoable: Bool { return true }
+
+    func inverse(context: UndoActionContext) -> UndoableAction? {
+
+        let movedDown = self.to > self.from
+        let inversedFrom = movedDown ? self.to-1 : self.to
+        let inversedTo = movedDown ? self.from : self.from+1
+
+        return MoveTaskAction(from: inversedFrom, to: inversedTo)
+    }
+}

ReSwift-Todo/ToDoListSerializer.swift

@@ -34,8 +34,8 @@ enum SerializationError: Error {
 class ToDoListSerializer {
 
     init() { }
-
-    lazy var dateConverter: DateConverter = DateConverter()
+    
+    lazy var toDoSerializer = ToDoSerializer()
 
     func data(toDoList: ToDoList, encoding: String.Encoding = String.Encoding.utf8) -> Data? {
 
@@ -47,35 +47,14 @@ class ToDoListSerializer {
         guard !toDoList.isEmpty else { return "" }
 
         let title = toDoList.title.map { $0.appended(":") } ?? ""
-        let items = toDoList.items.map(itemRepresentation)
+        let items = toDoList.items.map(toDoSerializer.itemRepresentation)
 
         let lines = [title]
             .appendedContentsOf(items)
             .filter({ !$0.isEmpty }) // Remove empty title lines
 
         return lines.joined(separator: "\n").appended("\n")
     }
-
-    fileprivate func itemRepresentation(_ item: ToDo) -> String {
-
-        let body = "- \(item.title)"
-        let tags = item.tags.sorted().map { "@\($0)" }
-        let done: String? = {
-            switch item.completion {
-            case .unfinished: return nil
-            case .finished(when: let date):
-                guard let date = date else { return "@done" }
-
-                let dateString = dateConverter.string(date: date)
-                return "@done(\(dateString))"
-            }
-        }()
-
-        return [body]
-            .appendedContentsOf(tags)
-            .appendedContentsOf([done].compactMap(identity)) // remove nil
-            .joined(separator: " ")
-    }
 }
 
 func identity<T>(_ value: T?) -> T? {

ReSwift-Todo/ToDoListWindowController.swift

@@ -23,6 +23,7 @@ protocol ToDoTableDataSourceType {
     var toDoCount: Int { get }
 
     func updateContents(toDoListViewModel viewModel: ToDoListViewModel)
+    func setStore(toDoListStore: ToDoListStore?)
     func toDoCellView(tableView: NSTableView, row: Int, owner: AnyObject) -> ToDoCellView?
 }
 
@@ -64,6 +65,7 @@ class ToDoListWindowController: NSWindowController {
 
         didSet {
             keyboardEventHandler?.store = store
+            dataSource.setStore(toDoListStore: store)
         }
     }
 
@@ -86,6 +88,7 @@ class ToDoListWindowController: NSWindowController {
 
         tableView.dataSource = self.dataSource.tableDataSource
         tableView.delegate = self
+        tableView.registerForDraggedTypes([.todo, .tableViewIndex])
 
         keyboardEventHandler?.dataSource = self.dataSource
         keyboardEventHandler?.store = self.store
@@ -193,6 +196,12 @@ extension ToDoListWindowController: NSTableViewDelegate {
 
         dispatchAction(action)
     }
+
+    // Due to a bug with NSTableView, this method has to be implemented to get
+    // the draggingDestinationFeedbackStyle.gap animation to look right.
+    func tableView(_ tableView: NSTableView, heightOfRow row: Int) -> CGFloat {
+        return 30
+    }
 }
 
 extension ToDoListWindowController: ToDoItemChangeDelegate {

ReSwift-Todo/ToDoPasteboardWriter.swift

@@ -0,0 +1,50 @@
+//
+//  ToDoPasteboardWriter.swift
+//  ReSwift-TodoTests
+//
+//  Created by Jay Koutavas on 2/26/20.
+//  Copyright © 2020 ReSwift. All rights reserved.
+//
+
+import Cocoa
+
+class ToDoPasteboardWriter: NSObject, NSPasteboardWriting {
+    var todoViewModel: ToDoViewModel
+    var index: Int
+
+    init(todoViewModel: ToDoViewModel, at index: Int) {
+        self.todoViewModel = todoViewModel
+        self.index = index
+    }
+
+    func writableTypes(for pasteboard: NSPasteboard) -> [NSPasteboard.PasteboardType] {
+        return [.todo, .tableViewIndex]
+    }
+
+    func pasteboardPropertyList(forType type: NSPasteboard.PasteboardType) -> Any? {
+        switch type {
+        case .todo:
+            return todoViewModel.title
+        case .tableViewIndex:
+            return index
+        default:
+            return nil
+        }
+    }
+}
+
+extension NSPasteboard.PasteboardType {
+    static let todo = NSPasteboard.PasteboardType("com.heynow.todo")
+    static let tableViewIndex = NSPasteboard.PasteboardType("com.heynow.tableViewIndex")
+}
+
+extension NSPasteboardItem {
+    open func integer(forType type: NSPasteboard.PasteboardType) -> Int? {
+        guard let data = data(forType: type) else { return nil }
+        let plist = try? PropertyListSerialization.propertyList(
+            from: data,
+            options: .mutableContainers,
+            format: nil)
+        return plist as? Int
+    }
+}

ReSwift-Todo/ToDoSerializer.swift

@@ -0,0 +1,37 @@
+//
+//  ToDoSerializer.swift
+//  ReSwift-Todo
+//
+//  Created by Jay Koutavas on 2/26/20.
+//  Copyright © 2020 ReSwift. All rights reserved.
+//
+
+import Foundation
+
+class ToDoSerializer {
+
+init() { }
+
+    lazy var dateConverter: DateConverter = DateConverter()
+
+    func itemRepresentation(_ item: ToDo) -> String {
+
+        let body = "- \(item.title)"
+        let tags = item.tags.sorted().map { "@\($0)" }
+        let done: String? = {
+            switch item.completion {
+            case .unfinished: return nil
+            case .finished(when: let date):
+                guard let date = date else { return "@done" }
+
+                let dateString = dateConverter.string(date: date)
+                return "@done(\(dateString))"
+            }
+        }()
+
+        return [body]
+            .appendedContentsOf(tags)
+            .appendedContentsOf([done].compactMap(identity)) // remove nil
+            .joined(separator: " ")
+    }
+}