Support re-ordering between sections. Add additional validation and reading options for re-order events. Improve Identifier to aid in type safety when creating and reading identifiers. See #292 for all changes and discussion.

Author: kyleve

BlueprintUILists/Sources/BlueprintItemContent.swift

@@ -15,13 +15,14 @@ import ListableUI
 /// you instead provide Blueprint elements, and `Listable` handles mapping this to an underlying `BlueprintView`.
 ///
 /// A `BlueprintItemContent` that displays text might look like this:
-/// ```
+/// ```swift
 /// struct MyItemContent : BlueprintItemContent, Equatable
 /// {
 ///     var text : String
+///     var id : UUID
 ///
-///     var identifier: Identifier<MyItemContent> {
-///         return .init(self.text)
+///     var identifier: String {
+///         self.id
 ///     }
 ///
 ///     func element(with info : ApplyItemContentInfo) -> Element

BlueprintUILists/Sources/Item.swift

@@ -41,7 +41,7 @@ extension Item
     ///     item.selectionStyle = .tappable
     /// }
     /// ```
-    public init<Represented, IDType:Hashable>(
+    public init<Represented, IDType>(
         _ representing : Represented,
 
         identifier : KeyPath<Represented, IDType>,
@@ -99,7 +99,7 @@ extension Item
     ///     item.selectionStyle = .tappable
     /// }
     /// ```
-    public init<Represented, IDType:Hashable>(
+    public init<Represented, IDType>(
         _ representing : Represented,
 
         identifier : KeyPath<Represented, IDType>,
@@ -142,8 +142,8 @@ public struct BlueprintItemContentWrapper<Represented, IDType:Hashable> : Bluepr
     let backgroundProvider : (Represented, ApplyItemContentInfo) -> Element?
     let selectedBackgroundProvider : (Represented, ApplyItemContentInfo) -> Element?
 
-    public var identifier: Identifier<Self> {
-        .init(self.representing[keyPath: self.identifierKeyPath])
+    public var identifier: IDType {
+        self.representing[keyPath: self.identifierKeyPath]
     }
 
     public func isEquivalent(to other: Self) -> Bool {

BlueprintUILists/Sources/ListReorderGesture.swift

@@ -31,7 +31,7 @@ import ListableUI
 ///         row.add(child: ListReorderGesture(actions: info.actions, wrapping: MyReorderGrabber()))
 ///
 ///         // Could also be written as:
-///         row.add(child: MyReorderGrabber().listReorderGesture(with: info.reordering))
+///         row.add(child: MyReorderGrabber().listReorderGesture(with: info.reorderingActions))
 ///     }
 /// }
 /// ```
@@ -43,14 +43,7 @@ public struct ListReorderGesture : Element
     /// If the gesture is enabled or not.
     public var isEnabled : Bool
 
-    typealias OnStart = () -> Bool
-    var onStart : OnStart
-    
-    typealias OnMove = (UIPanGestureRecognizer) -> ()
-    var onMove : OnMove
-    
-    typealias OnDone = () -> ()
-    var onDone : OnDone
+    let actions : ReorderingActions
 
     /// Creates a new re-order gesture which wraps the provided element.
     /// 
@@ -63,9 +56,7 @@ public struct ListReorderGesture : Element
     ) {
         self.isEnabled =  isEnabled
 
-        self.onStart = { actions.beginMoving() }
-        self.onMove = { actions.moved(with: $0) }
-        self.onDone = { actions.end() }
+        self.actions = actions
 
         self.element = element
     }
@@ -80,17 +71,15 @@ public struct ListReorderGesture : Element
 
     public func backingViewDescription(bounds: CGRect, subtreeExtent: CGRect?) -> ViewDescription?
     {
-        return ViewDescription(WrapperView.self) { config in
+        return ViewDescription(View.self) { config in
             config.builder = {
-                WrapperView(frame: bounds, wrapping: self)
+                View(frame: bounds, wrapping: self)
             }
 
             config.apply { view in
                 view.recognizer.isEnabled = self.isEnabled
 
-                view.recognizer.onStart = self.onStart
-                view.recognizer.onMove = self.onMove
-                view.recognizer.onDone = self.onDone
+                view.recognizer.apply(actions: self.actions)
             }
         }
     }
@@ -109,50 +98,13 @@ public extension Element
 
 fileprivate extension ListReorderGesture
 {
-    private final class GestureRecognizer : UIPanGestureRecognizer
-    {
-        public var onStart : OnStart? = nil
-        public var onMove : OnMove? = nil
-        public var onDone : OnDone? = nil
-        
-        override init(target: Any?, action: Selector?)
-        {
-            super.init(target: target, action: action)
-            
-            self.addTarget(self, action: #selector(updated))
-            
-            self.minimumNumberOfTouches = 1
-            self.maximumNumberOfTouches = 1
-        }
-                
-        @objc func updated()
-        {
-            switch self.state {
-            case .possible: break
-            case .began:
-                let canStart = self.onStart?()
-                
-                if canStart == false {
-                    self.state = .cancelled
-                }
-            case .changed:
-                self.onMove?(self)
-
-            case .ended: self.onDone?()
-            case .cancelled, .failed: self.onDone?()
-                
-            @unknown default: listableFatal()
-            }
-        }
-    }
-    
-    private final class WrapperView : UIView
+    private final class View : UIView
     {
-        let recognizer : GestureRecognizer
+        let recognizer : ItemReordering.GestureRecognizer
 
         init(frame: CGRect, wrapping : ListReorderGesture)
         {
-            self.recognizer = GestureRecognizer()
+            self.recognizer = .init()
 
             super.init(frame: frame)
 

BlueprintUILists/Tests/ListTests.swift

@@ -91,8 +91,8 @@ fileprivate struct TestItemContent : BlueprintItemContent {
 
     var wasCalled : () -> ()
 
-    var identifier: Identifier<TestItemContent> {
-        .init()
+    var identifier: String {
+        ""
     }
 
     func element(with info: ApplyItemContentInfo) -> Element {

CHANGELOG.md

@@ -4,10 +4,22 @@
 
 ### Added
 
+- [Reordering between multiple sections is now supported](https://github.com/kyleve/Listable/pull/292).
+- [Introduced type safe access to `Section` content following reorder events](https://github.com/kyleve/Listable/pull/292). See `Section.filtered`.
+- [`ListStateObserver.onItemReordered` was added](https://github.com/kyleve/Listable/pull/292) to observe reorder events at a list-wide level.
+- [`ListLayout` was extended](https://github.com/kyleve/Listable/pull/292) to allow customization of in-progress moves. Note that `ListLayout` is not yet public.
+
 ### Removed
 
 ### Changed
 
+- [`Reordering` has been renamed to `ItemReordering`, and a new `SectionReordering` has been introduced](https://github.com/kyleve/Listable/pull/292). This allows finer-grained control over validating reorder events at both the item level and section level.
+- [`ListReorderGesture` and `ItemReordering.GestureRecognizer` have been heavily refactored](https://github.com/kyleve/Listable/pull/292) to reduce visibility of internal state concerns.
+- [`Item.identifier` has been renamed to `Item.anyIdentifier`](https://github.com/kyleve/Listable/pull/292). The new `Item.identifier` property is now a fully type safe identifier.
+- [`ReorderingActions` was refactored](https://github.com/kyleve/Listable/pull/292) to expose less public state and ease use in UIView-backed list elements.
+- [`Identifier<Represented>` is now `Identifier<Represented, Value>`; eg `Identifier<MyContent, UUID>`](https://github.com/kyleve/Listable/pull/292). This is done to support reacting to reordering events in a more type safe manner, and to make `Identifier` creation more type safe. This is a large breaking change.
+- [Changed how `identifier`s for `ItemContent` are represented](https://github.com/kyleve/Listable/pull/292). `ItemContent` now returns a an identifier of a specific `IdentifierType` (eg, `String`, `UUID`, etc), which is then assembled into an `Identifier` by the containing item. Additional APIs have been added for creating `Identifier`s in a more type safe manner. This is a large breaking change.
+
 ### Misc
 
 # Past Releases
@@ -59,7 +71,7 @@ Example usage:
 
 ```
 listActions.scrolling.scrollToSection(
-  with: Identifier<Section>(id),
+  with: MyItem.identifier(with: id),
   sectionPosition: .top,
   scrollPosition: ScrollPosition(position: .centered)
 )

Demo/Demo.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		0A02B2F42675E14600B3501B /* PaymentTypesViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0A02B2F32675E14600B3501B /* PaymentTypesViewController.swift */; };
 		0A07119324BA798400CDF65D /* ListStateViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0A07119224BA798400CDF65D /* ListStateViewController.swift */; };
 		0A0E070423870A5700DDD27D /* README.md in Resources */ = {isa = PBXBuildFile; fileRef = 0A0E070323870A5700DDD27D /* README.md */; };
 		0A49210424E5E11300D17038 /* AccordionViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0A49210324E5E11300D17038 /* AccordionViewController.swift */; };
@@ -50,6 +51,7 @@
 
 /* Begin PBXFileReference section */
 		06908B38E59ACD7502B5332F /* Pods-Demo.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-Demo.release.xcconfig"; path = "Target Support Files/Pods-Demo/Pods-Demo.release.xcconfig"; sourceTree = "<group>"; };
+		0A02B2F32675E14600B3501B /* PaymentTypesViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PaymentTypesViewController.swift; sourceTree = "<group>"; };
 		0A07119224BA798400CDF65D /* ListStateViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ListStateViewController.swift; sourceTree = "<group>"; };
 		0A0E070323870A5700DDD27D /* README.md */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = net.daringfireball.markdown; name = README.md; path = ../README.md; sourceTree = "<group>"; };
 		0A49210324E5E11300D17038 /* AccordionViewController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AccordionViewController.swift; sourceTree = "<group>"; };
@@ -152,6 +154,7 @@
 				0AD6767925423BE500A49315 /* MultiSelectViewController.swift */,
 				0AC2A1952489F93E00779459 /* PagedViewController.swift */,
 				0AA4D9B7248064A300CF95A5 /* ReorderingViewController.swift */,
+				0A02B2F32675E14600B3501B /* PaymentTypesViewController.swift */,
 				1F46FB6A26010F4900760961 /* RefreshControlOffsetAdjustmentViewController.swift */,
 				0AA4D9AA248064A200CF95A5 /* ScrollViewEdgesPlaygroundViewController.swift */,
 				0A793B5724E4B53500850139 /* ManualSelectionManagementViewController.swift */,
@@ -292,7 +295,7 @@
 			isa = PBXProject;
 			attributes = {
 				LastSwiftUpdateCheck = 1110;
-				LastUpgradeCheck = 1210;
+				LastUpgradeCheck = 1220;
 				ORGANIZATIONNAME = "Kyle Van Essen";
 				TargetAttributes = {
 					0AE8554D2390933100F2E245 = {
@@ -464,6 +467,7 @@
 				0AA4D9C7248064A300CF95A5 /* CollectionViewDictionaryDemoViewController.swift in Sources */,
 				0ADC3B3524907C80008DF2C0 /* XcodePreviewDemo.swift in Sources */,
 				0AD6767A25423BE500A49315 /* MultiSelectViewController.swift in Sources */,
+				0A02B2F42675E14600B3501B /* PaymentTypesViewController.swift in Sources */,
 				0AA4D9C4248064A300CF95A5 /* ItemizationEditorViewController.swift in Sources */,
 				0A5F5CCF257EC2D7003CCE2C /* LocalizedCollationViewController.swift in Sources */,
 				0AA4D9BA248064A300CF95A5 /* FlowLayoutViewController.swift in Sources */,

Demo/Demo.xcodeproj/xcshareddata/xcschemes/Demo.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1210"
+   LastUpgradeVersion = "1220"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"

Demo/Resources/Assets.xcassets/ReorderControl.imageset/Contents.json

@@ -0,0 +1,23 @@
+{
+  "images" : [
+    {
+      "filename" : "ReorderControl.png",
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "filename" : "[email protected]",
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "filename" : "[email protected]",
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

Demo/Resources/Assets.xcassets/ReorderControl.imageset/ReorderControl.png

@@ -80,8 +80,8 @@ fileprivate struct AccordionRow : BlueprintItemContent, Equatable
 {
     var text : String
 
-    var identifier: Identifier<AccordionRow> {
-        .init(text)
+    var identifier: String {
+        self.text
     }
 
     func element(with info: ApplyItemContentInfo) -> Element {

Demo/Resources/Assets.xcassets/ReorderControl.imageset/[email protected]

@@ -34,8 +34,8 @@ struct AutoLayoutContent : ItemContent, Equatable {
     var header : String
     var detail : String
 
-    var identifier: Identifier<AutoLayoutContent> {
-        .init(header + detail)
+    var identifier: String {
+        header + detail
     }
 
     var defaultItemProperties: DefaultItemProperties<Self> {

Demo/Resources/Assets.xcassets/ReorderControl.imageset/[email protected]

@@ -18,7 +18,7 @@ final class AutoScrollingViewController : UIViewController
 {
     let list = ListView()
 
-    private var items: [BottomPinnedItem] = []
+    private var items: [Item<BottomPinnedItem>] = []
 
     override func loadView()
     {
@@ -41,11 +41,11 @@ final class AutoScrollingViewController : UIViewController
 
     @objc private func addItem()
     {
-        let last = items.last?.identifier
+        let last = items.last
 
-        items.append(BottomPinnedItem(text: "Item \(items.count)"))
+        items.append(Item(BottomPinnedItem(text: "Item \(items.count)")))
 
-        updateItems(autoScrollIfVisible: last)
+        updateItems(autoScrollIfVisible: last?.identifier)
     }
 
     @objc private func removeItem()
@@ -62,10 +62,9 @@ final class AutoScrollingViewController : UIViewController
             list.appearance = .demoAppearance
             list.layout = .demoLayout
 
-            let items = self.items.map { Item($0) }
-            list += Section("items", items: items)
+            list += Section("items", items: self.items)
 
-            if let last = items.last {
+            if let last = self.items.last {
 
                 list.autoScrollAction = .scrollTo(
                     .lastItem,
@@ -102,8 +101,8 @@ struct BottomPinnedItem : BlueprintItemContent, Equatable
 {
     var text : String
 
-    var identifier: Identifier<BottomPinnedItem> {
-        return .init(self.text)
+    var identifier: String {
+        self.text
     }
 
     func element(with info : ApplyItemContentInfo) -> Element

Demo/Sources/Demos/Demo Screens/AccordionViewController.swift

@@ -85,17 +85,33 @@ struct DemoItem : BlueprintItemContent, Equatable, LocalizedCollatableItemConten
 {
     var text : String
 
-    var identifier: Identifier<DemoItem> {
-        return .init(self.text)
+    var identifier: String {
+        return self.text
     }
 
     typealias SwipeActionsView = DefaultSwipeActionsView
 
     func element(with info : ApplyItemContentInfo) -> Element
     {
-        Label(text: self.text) {
-            $0.font = .systemFont(ofSize: 16.0, weight: .medium)
-            $0.color = info.state.isActive ? .white : .darkGray
+        Row { row in
+            row.verticalAlignment = .center
+            
+            row.add(child: Label(text: self.text) {
+                $0.font = .systemFont(ofSize: 16.0, weight: .medium)
+                $0.color = info.state.isActive ? .white : .darkGray
+            })
+            
+            row.addFlexible(child: Spacer(width: 1.0))
+            
+            if info.isReorderable {
+                row.addFixed(
+                    child: Image(
+                        image: UIImage(named: "ReorderControl"),
+                        contentMode: .center
+                    )
+                        .listReorderGesture(with: info.reorderingActions)
+                )
+            }
         }
         .inset(horizontal: 15.0, vertical: 10.0)
         .accessibility(label: self.text, traits: [.button])
@@ -106,7 +122,12 @@ struct DemoItem : BlueprintItemContent, Equatable, LocalizedCollatableItemConten
         Box(
             backgroundColor: .white,
             cornerStyle: .rounded(radius: 8.0),
-            shadowStyle: .simple(radius: 2.0, opacity: 0.15, offset: .init(width: 0.0, height: 1.0), color: .black)
+            shadowStyle: .simple(
+                radius: info.state.isReordering ? 5.0 : 2.0,
+                opacity: info.state.isReordering ? 0.5 : 0.15,
+                offset: .init(width: 0.0, height: 1.0),
+                color: .black
+            )
         )
     }