Adds context menu to ArrivalDeparture rows in Stop Controller

Fixes #55 - Add support for context menus on iOS 13

OBAKit/ContextMenus/Previewable.swift

@@ -0,0 +1,13 @@
+//
+//  Previewable.swift
+//  OBAKit
+//
+//  Created by Aaron Brethorst on 4/12/20.
+//
+
+import UIKit
+
+protocol Previewable: NSObjectProtocol {
+    func enterPreviewMode()
+    func exitPreviewMode()
+}

OBAKit/Controls/ListKit/CollectionController.swift

@@ -16,7 +16,7 @@ public enum TableCollectionStyle {
 }
 
 /// Meant to be used as a child view controller. It hosts a `UICollectionView` plus all of the logic for using `IGListKit`.
-public class CollectionController: UIViewController {
+public class CollectionController: UIViewController, UICollectionViewDelegate {
     private let application: Application
     public let listAdapter: ListAdapter
     public let style: TableCollectionStyle
@@ -35,6 +35,7 @@ public class CollectionController: UIViewController {
 
         self.listAdapter.collectionView = collectionView
         self.listAdapter.dataSource = dataSource
+        self.listAdapter.collectionViewDelegate = self
     }
 
     required init?(coder aDecoder: NSCoder) {
@@ -120,4 +121,31 @@ public class CollectionController: UIViewController {
         collectionView.contentInset = UIEdgeInsets(top: collectionView.contentInset.top, left: 0, bottom: 0, right: 0)
         collectionView.scrollIndicatorInsets = collectionView.contentInset
     }
+
+    // MARK: - UICollectionViewDelegate
+
+    @available(iOS 13.0, *)
+    public func collectionView(_ collectionView: UICollectionView, contextMenuConfigurationForItemAt indexPath: IndexPath, point: CGPoint) -> UIContextMenuConfiguration? {
+        guard let provider = listAdapter.sectionController(forSection: indexPath.section) as? ContextMenuProvider else {
+            return nil
+        }
+
+        return provider.contextMenuConfiguration(forItemAt: indexPath)
+    }
+
+     @available(iOS 13.0, *)
+     public func collectionView(_ collectionView: UICollectionView, willPerformPreviewActionForMenuWith configuration: UIContextMenuConfiguration, animator: UIContextMenuInteractionCommitAnimating) {
+        guard
+            let viewController = animator.previewViewController,
+            let parent = parent
+        else { return }
+
+        animator.addCompletion {
+            if let previewable = viewController as? Previewable {
+                previewable.exitPreviewMode()
+            }
+
+            self.application.viewRouter.navigate(to: viewController, from: parent, animated: false)
+        }
+    }
 }

OBAKit/Controls/ListKit/OBAListSectionController.swift

@@ -9,10 +9,21 @@ import Foundation
 import IGListKit
 import OBAKitCore
 
+// MARK: - ContextMenuProvider
+
+@available(iOS 13.0, *)
+protocol ContextMenuProvider {
+    func contextMenuConfiguration(forItemAt indexPath: IndexPath) -> UIContextMenuConfiguration?
+}
+
+// MARK: - OBAListSectionControllerInitializer
+
 protocol OBAListSectionControllerInitializer {
     init(formatters: Formatters, style: TableCollectionStyle, hasVisualEffectBackground: Bool)
 }
 
+// MARK: - OBAListSectionController
+
 /// An OBAKit-specific subclass of `ListSectionController` meant to be overriden instead of `ListSectionController`.
 ///
 /// Provides easy access to the application-wide `formatters` object, along with the current view controller's table collection style.

OBAKit/Stops/StopArrivalListItem.swift

@@ -16,8 +16,13 @@ final class ArrivalDepartureSectionData: NSObject, ListDiffable {
     let arrivalDeparture: ArrivalDeparture
     let isAlarmAvailable: Bool
     let selected: VoidBlock
+
     var onCreateAlarm: VoidBlock?
     var onShowOptions: VoidBlock?
+    var onAddBookmark: VoidBlock?
+    var onShareTrip: VoidBlock?
+
+    var previewDestination: (() -> UIViewController?)?
 
     init(arrivalDeparture: ArrivalDeparture, isAlarmAvailable: Bool = false, selected: @escaping VoidBlock) {
         self.arrivalDeparture = arrivalDeparture
@@ -37,7 +42,9 @@ final class ArrivalDepartureSectionData: NSObject, ListDiffable {
 
 // MARK: - Controller
 
-final class StopArrivalSectionController: OBAListSectionController<ArrivalDepartureSectionData>, SwipeCollectionViewCellDelegate {
+final class StopArrivalSectionController: OBAListSectionController<ArrivalDepartureSectionData>,
+    ContextMenuProvider,
+    SwipeCollectionViewCellDelegate {
 
     override func cellForItem(at index: Int) -> UICollectionViewCell {
         guard let object = sectionData else { fatalError() }
@@ -84,6 +91,49 @@ final class StopArrivalSectionController: OBAListSectionController<ArrivalDepart
 
         return actions
     }
+
+    // MARK: - Context Menu
+
+    @available(iOS 13.0, *)
+    func contextMenuConfiguration(forItemAt indexPath: IndexPath) -> UIContextMenuConfiguration? {
+        let previewProvider = { [weak self] () -> UIViewController? in
+            guard
+                let self = self,
+                let sectionData = self.sectionData
+            else { return nil }
+
+            return sectionData.previewDestination?()
+        }
+
+        return UIContextMenuConfiguration(identifier: nil, previewProvider: previewProvider) { [weak self] _ in
+            guard
+                let self = self,
+                let sectionData = self.sectionData
+            else { return nil }
+
+            var actions = [UIAction]()
+
+            if sectionData.isAlarmAvailable {
+                let alarm = UIAction(title: Strings.addAlarm, image: Icons.addAlarm) { _ in
+                    sectionData.onCreateAlarm?()
+                }
+                actions.append(alarm)
+            }
+
+            let addBookmark = UIAction(title: Strings.addBookmark, image: Icons.bookmark) { _ in
+                sectionData.onAddBookmark?()
+            }
+            actions.append(addBookmark)
+
+            let shareTrip = UIAction(title: Strings.shareTrip, image: UIImage(systemName: "square.and.arrow.up")) { _ in
+                sectionData.onShareTrip?()
+            }
+            actions.append(shareTrip)
+
+            // Create and return a UIMenu with all of the actions as children
+            return UIMenu(title: "", children: actions)
+        }
+    }
 }
 
 // MARK: - View

OBAKit/Stops/StopViewController.swift

@@ -20,9 +20,9 @@ public class StopViewController: UIViewController,
     AlarmBuilderDelegate,
     AppContext,
     BookmarkEditorDelegate,
+    Idleable,
     ListAdapterDataSource,
     ModalDelegate,
-    Idleable,
     StopPreferencesDelegate {
 
     public let application: Application
@@ -457,18 +457,33 @@ public class StopViewController: UIViewController,
     private func buildArrivalDepartureSectionData(arrivalDeparture: ArrivalDeparture) -> ArrivalDepartureSectionData {
         let alarmAvailable = canCreateAlarm(for: arrivalDeparture)
 
-        let data = ArrivalDepartureSectionData(
-            arrivalDeparture: arrivalDeparture,
-            isAlarmAvailable: alarmAvailable) { [weak self] in
+        let data = ArrivalDepartureSectionData(arrivalDeparture: arrivalDeparture, isAlarmAvailable: alarmAvailable) { [weak self] in
             guard let self = self else { return }
             self.application.viewRouter.navigateTo(arrivalDeparture: arrivalDeparture, from: self)
         }
 
+        data.previewDestination = { [weak self] in
+            guard let self = self else { return nil }
+            let controller = TripViewController(application: self.application, arrivalDeparture: arrivalDeparture)
+            controller.enterPreviewMode()
+            return controller
+        }
+
         data.onCreateAlarm = { [weak self] in
             guard let self = self else { return }
             self.addAlarm(arrivalDeparture: arrivalDeparture)
         }
 
+        data.onAddBookmark = { [weak self] in
+            guard let self = self else { return }
+            self.addBookmark(arrivalDeparture: arrivalDeparture)
+        }
+
+        data.onShareTrip = { [weak self] in
+            guard let self = self else { return }
+            self.shareTripStatus(arrivalDeparture: arrivalDeparture)
+        }
+
         data.onShowOptions = { [weak self] in
             guard let self = self else { return }
             self.showMoreOptions(arrivalDeparture: arrivalDeparture)
@@ -645,13 +660,13 @@ public class StopViewController: UIViewController,
     public func showMoreOptions(arrivalDeparture: ArrivalDeparture) {
         let actionSheet = UIAlertController(title: nil, message: nil, preferredStyle: .actionSheet)
 
-        actionSheet.addAction(title: OBALoc("stop_controller.add_bookmark", value: "Add Bookmark", comment: "Action sheet button title for adding a bookmark")) { [weak self] _ in
+        actionSheet.addAction(title: Strings.addBookmark) { [weak self] _ in
             guard let self = self else { return }
             self.addBookmark(arrivalDeparture: arrivalDeparture)
         }
 
         if application.features.deepLinking == .running {
-            actionSheet.addAction(title: OBALoc("stop_controller.share_trip", value: "Share Trip", comment: "Action sheet button title for sharing the status of your trip (i.e. location, arrival time, etc.)")) { [weak self] _ in
+            actionSheet.addAction(title: Strings.shareTrip) { [weak self] _ in
                 guard let self = self else { return }
                 self.shareTripStatus(arrivalDeparture: arrivalDeparture)
             }

OBAKit/Trip/TripViewController.swift

@@ -11,34 +11,16 @@ import FloatingPanel
 import OBAKitCore
 
 class TripViewController: UIViewController,
+    AppContext,
     FloatingPanelControllerDelegate,
     Idleable,
     MKMapViewDelegate,
-    AppContext {
+    Previewable {
 
     public let application: Application
 
     private let tripConvertible: TripConvertible
 
-    public var selectedStopTime: TripStopTime? {
-        didSet {
-            var animated = true
-            if isFirstStopTimeLoad {
-                animated = false
-                isFirstStopTimeLoad.toggle()
-            }
-            self.mapView.deselectAnnotation(oldValue, animated: animated)
-
-            guard
-                oldValue != self.selectedStopTime,
-                let selectedStopTime = self.selectedStopTime
-            else { return }
-
-            self.mapView.selectAnnotation(selectedStopTime, animated: animated)
-        }
-    }
-    private var isFirstStopTimeLoad = true
-
     init(application: Application, tripConvertible: TripConvertible) {
         self.application = application
         self.tripConvertible = tripConvertible
@@ -82,7 +64,9 @@ class TripViewController: UIViewController,
 
         loadData()
 
-        floatingPanel.addPanel(toParent: self)
+        if !isBeingPreviewed {
+            floatingPanel.addPanel(toParent: self)
+        }
     }
 
     override func viewWillAppear(_ animated: Bool) {
@@ -111,6 +95,24 @@ class TripViewController: UIViewController,
         self.userActivity = activity
     }
 
+    // MARK: Previewable
+
+    /// Set this to `true` before `viewDidLoad` to present the UI in a stripped-down 'preview mode'
+    /// suitable for display in a context menu.
+    var isBeingPreviewed = false
+
+    func enterPreviewMode() {
+        isBeingPreviewed = true
+    }
+
+    func exitPreviewMode() {
+        isBeingPreviewed = false
+
+        if isViewLoaded, floatingPanel.parent == nil {
+            floatingPanel.addPanel(toParent: self)
+        }
+    }
+
     // MARK: - Idle Timer
 
     public var idleTimerFailsafe: Timer?
@@ -355,4 +357,25 @@ class TripViewController: UIViewController,
         default: return nil
         }
     }
+
+    public var selectedStopTime: TripStopTime? {
+        didSet {
+            guard !isBeingPreviewed else { return }
+
+            var animated = true
+            if isFirstStopTimeLoad {
+                animated = false
+                isFirstStopTimeLoad.toggle()
+            }
+            self.mapView.deselectAnnotation(oldValue, animated: animated)
+
+            guard
+                oldValue != self.selectedStopTime,
+                let selectedStopTime = self.selectedStopTime
+            else { return }
+
+            self.mapView.selectAnnotation(selectedStopTime, animated: animated)
+        }
+    }
+    private var isFirstStopTimeLoad = true
 }

OBAKit/ViewRouting/Router.swift

@@ -53,10 +53,11 @@ public class ViewRouter: NSObject, UINavigationControllerDelegate {
     /// - Parameters:
     ///   - viewController: The 'to' view controller.
     ///   - fromController: The 'from' view controller.
-    public func navigate(to viewController: UIViewController, from fromController: UIViewController) {
+    ///   - animated: Is the transition animated or not.
+    public func navigate(to viewController: UIViewController, from fromController: UIViewController, animated: Bool = true) {
         assert(fromController.navigationController != nil)
         viewController.hidesBottomBarWhenPushed = true
-        fromController.navigationController?.pushViewController(viewController, animated: true)
+        fromController.navigationController?.pushViewController(viewController, animated: animated)
     }
 
     public func navigateTo(stop: Stop, from fromController: UIViewController, bookmark: Bookmark? = nil) {

Tutorials/ContextMenus.md

@@ -0,0 +1,33 @@
+# Adding a Context Menu to a Collection Cell
+
+This guide is about implementing an iOS 13 `UIContextMenu`, which replaced 3D Touch/Force Touch.
+
+Kyle Bashour, a software engineer, [wrote a very helpful guide about how this feature works](https://kylebashour.com/posts/context-menu-guide). I found Kyle's guide to be invaluable to my understanding of the feature. This guide, in contrast, is strictly about OBA's implementation of `UIContextMenu`s.
+
+## Dependence on CollectionController
+
+This feature only works as described if your user interface is hosted within an instance of `CollectionController`.
+
+## IGListKit Components
+
+Implement the following method in your `OBAListSectionController` subclass:
+
+    func contextMenuConfiguration(forItemAt indexPath: IndexPath) -> UIContextMenuConfiguration? {
+        // TODO!
+    }
+
+Potientally add one or more blocks to your `ListDiffable`-implementing class (i.e. the view model) for a `UIViewController` preview and for each `UIMenu`action that you will support in the `UIContextMenu`.
+
+## Hosting View Controller
+
+A `UIContextMenu` is presented from a view controller. This view controller, referred to here as the hosting view controller, is responsible for:
+
+* Attaching blocks to your view models, which will trigger actions. (e.g. an 'Add Bookmark' context menu item would trigger the presentation of the `AddBookmarkViewController` from the hosting view controller.)
+* From your `UIViewController` preview block (attached to the view model), the hosting view controller should include code to toggle the previewed view controller into preview mode.
+
+## Previewed View Controller
+
+This view controller should be conform to the `Previewable` protocol and implement its required methods.
+
+* `enterPreviewMode()` - configure your view controller UI to be in a 'bare bones' preview state. Show a small, glanceable UI here.
+* `exitPreviewMode()` - configure your view controller UI to be presented in a full screen normal mode. Unhide all of the UI you disabled in `enterPreviewMode().`