Create a Toast message which shows from the bottom. (Very much an iOS equivalent of an Android toast)

Example/ViewControllers/MessageViewController.swift

@@ -13,7 +13,7 @@ class MessageViewController: UIViewController {
 
     private lazy var messageStackView: MessageStackView = {
         let messageStackView: MessageStackView = view.createMessageStackView()
-        messageStackView.messageConfiguation = MessageConfiguration(
+        messageStackView.messageConfiguration = MessageConfiguration(
             backgroundColor: .systemGroupedBackground,
             tintColor: .gray,
             shadow: true,

Example/ViewControllers/RootTableViewController.swift

@@ -24,7 +24,8 @@ class RootTableViewController: UITableViewController {
         ("Badge Message", BadgeMessageViewController.self, false),
         ("Message", MessageViewController.self, false),
         ("No Internet", NoInternetTabBarController.self, true),
-        ("Shadow", ShadowViewController.self, false)
+        ("Shadow", ShadowViewController.self, false),
+        ("Toast", ToastViewController.self, false)
     ]
 
     // MARK: - ViewController lifecycle

Example/ViewControllers/ToastViewController.swift

@@ -0,0 +1,52 @@
+//
+//  ToastViewController.swift
+//  Example
+//
+//  Created by Ben Shutt on 02/06/2021.
+//  Copyright © 2021 3 SIDED CUBE APP PRODUCTIONS LTD. All rights reserved.
+//
+
+import Foundation
+import UIKit
+import MessageStackView
+
+/// `UIViewController` to test `Toast`
+class ToastViewController: UIViewController {
+
+    /// `Toast` to post at the bottom of the screen
+    private lazy var toast = Toast()
+
+    // MARK: - ViewController lifecycle
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+
+        toast.addTo(
+            view: view,
+            layout: .bottom,
+            constrainToSafeArea: true
+        )
+    }
+
+    override func viewDidAppear(_ animated: Bool) {
+        super.viewDidAppear(animated)
+
+        toast.post(message: .shortMessage)
+        toast.postIfNotShowing(message: .shortMessage) // Shouldn't show
+        toast.post(message: .longMessage)
+    }
+}
+
+// MARK: - String + Text
+
+private extension String {
+
+    static let shortMessage = """
+        This is a toast!
+        """
+
+    static let longMessage = """
+        This is a long toast to test how the text wraps when the width \
+        of the text is greater than the width of the screen
+        """
+}

MessageStackView.xcodeproj/project.pbxproj

@@ -29,6 +29,9 @@
 		B81AEE5024FFF27A0068CE23 /* ShadowLayer.swift in Sources */ = {isa = PBXBuildFile; fileRef = B81AEE4F24FFF27A0068CE23 /* ShadowLayer.swift */; };
 		B81AEE5224FFFB2E0068CE23 /* ParentShadowLayer.swift in Sources */ = {isa = PBXBuildFile; fileRef = B81AEE5124FFFB2E0068CE23 /* ParentShadowLayer.swift */; };
 		B81AEE5425003F270068CE23 /* ShadowViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = B81AEE5325003F270068CE23 /* ShadowViewController.swift */; };
+		B83CACB12667D5CE008FB755 /* Order.swift in Sources */ = {isa = PBXBuildFile; fileRef = B83CACB02667D5CE008FB755 /* Order.swift */; };
+		B83CACB32667D97E008FB755 /* Toast.swift in Sources */ = {isa = PBXBuildFile; fileRef = B83CACB22667D97E008FB755 /* Toast.swift */; };
+		B83CACB52667DA8A008FB755 /* ToastViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = B83CACB42667DA8A008FB755 /* ToastViewController.swift */; };
 		B872BE8725A3874C0031D619 /* UIImageView+Hidden.swift in Sources */ = {isa = PBXBuildFile; fileRef = B872BE8625A3874C0031D619 /* UIImageView+Hidden.swift */; };
 		B872BE9125A387570031D619 /* UILabel+Hidden.swift in Sources */ = {isa = PBXBuildFile; fileRef = B872BE9025A387570031D619 /* UILabel+Hidden.swift */; };
 		B875C98925126EB200FA05B5 /* UIViewController+System.swift in Sources */ = {isa = PBXBuildFile; fileRef = B875C98825126EB200FA05B5 /* UIViewController+System.swift */; };
@@ -172,6 +175,9 @@
 		B81AEE4F24FFF27A0068CE23 /* ShadowLayer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ShadowLayer.swift; sourceTree = "<group>"; };
 		B81AEE5124FFFB2E0068CE23 /* ParentShadowLayer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ParentShadowLayer.swift; sourceTree = "<group>"; };
 		B81AEE5325003F270068CE23 /* ShadowViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ShadowViewController.swift; sourceTree = "<group>"; };
+		B83CACB02667D5CE008FB755 /* Order.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Order.swift; sourceTree = "<group>"; };
+		B83CACB22667D97E008FB755 /* Toast.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Toast.swift; sourceTree = "<group>"; };
+		B83CACB42667DA8A008FB755 /* ToastViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ToastViewController.swift; sourceTree = "<group>"; };
 		B872BE8625A3874C0031D619 /* UIImageView+Hidden.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UIImageView+Hidden.swift"; sourceTree = "<group>"; };
 		B872BE9025A387570031D619 /* UILabel+Hidden.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UILabel+Hidden.swift"; sourceTree = "<group>"; };
 		B875C98825126EB200FA05B5 /* UIViewController+System.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UIViewController+System.swift"; sourceTree = "<group>"; };
@@ -369,6 +375,7 @@
 				B8BB087924C4BC46000E2E87 /* MessageViewController.swift */,
 				B87CC99C24CC263E002B697C /* NoInternetTabBarController.swift */,
 				B81AEE5325003F270068CE23 /* ShadowViewController.swift */,
+				B83CACB42667DA8A008FB755 /* ToastViewController.swift */,
 			);
 			path = ViewControllers;
 			sourceTree = "<group>";
@@ -519,6 +526,7 @@
 				OBJ_54 /* PostAnimation.swift */,
 				OBJ_55 /* Queue.swift */,
 				B80B92AA2527324400F97364 /* Vector3.swift */,
+				B83CACB02667D5CE008FB755 /* Order.swift */,
 			);
 			path = Models;
 			sourceTree = "<group>";
@@ -595,6 +603,7 @@
 				OBJ_74 /* MessageStackView.swift */,
 				OBJ_75 /* PostView.swift */,
 				B8F1C76224D8198E007C2712 /* ApplicationPostView.swift */,
+				B83CACB22667D97E008FB755 /* Toast.swift */,
 			);
 			path = PostView;
 			sourceTree = "<group>";
@@ -812,6 +821,7 @@
 				B8BB088424C4BC46000E2E87 /* WindowViewController.swift in Sources */,
 				B8BB088724C4BC46000E2E87 /* MessageViewController.swift in Sources */,
 				B8BB088224C4BC46000E2E87 /* RootTableViewController.swift in Sources */,
+				B83CACB52667DA8A008FB755 /* ToastViewController.swift in Sources */,
 				B87CC99D24CC263E002B697C /* NoInternetTabBarController.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -854,6 +864,7 @@
 				OBJ_99 /* DispatchQueue+Extensions.swift in Sources */,
 				OBJ_100 /* String+Extensions.swift in Sources */,
 				OBJ_101 /* UIApplication+StatusBar.swift in Sources */,
+				B83CACB32667D97E008FB755 /* Toast.swift in Sources */,
 				OBJ_102 /* UIEdgeInsets+Extensions.swift in Sources */,
 				OBJ_103 /* UIView+Animation.swift in Sources */,
 				B8BCDA8C24CDB55B0067F26C /* UIViewController+Lifecycle.m in Sources */,
@@ -874,6 +885,7 @@
 				B8F1C76324D8198E007C2712 /* ApplicationPostView.swift in Sources */,
 				B81727F024D6CC9F0062282B /* PostViewController.swift in Sources */,
 				B8E1CEEF2500F88C002BFE77 /* NeuomorphicShadow.swift in Sources */,
+				B83CACB12667D5CE008FB755 /* Order.swift in Sources */,
 				OBJ_115 /* BadgeMessageView.swift in Sources */,
 				OBJ_116 /* BadgeMessageViewable.swift in Sources */,
 				OBJ_117 /* Poster+BadgeMessage.swift in Sources */,

Sources/Constraints/MessageLayout.swift

@@ -21,6 +21,19 @@ public enum MessageLayout: Int {
     case bottom
 }
 
+// MARK: - Order
+
+public extension MessageLayout {
+
+    /// Map to `Order`
+    func toOrder() -> Order {
+        switch self {
+        case .top: return .topToBottom
+        case .bottom: return .bottomToTop
+        }
+    }
+}
+
 // MARK: - NSLayoutConstraint
 
 public extension MessageLayout {

Sources/Models/Order.swift

@@ -0,0 +1,35 @@
+//
+//  Order.swift
+//  MessageStackView
+//
+//  Created by Ben Shutt on 02/06/2021.
+//  Copyright © 2021 3 SIDED CUBE APP PRODUCTIONS LTD. All rights reserved.
+//
+
+import Foundation
+
+/// How posted `UIView`s are ordered.
+/// E.g. the order of the `arrangedSubviews`.
+public enum Order {
+
+    /// Natural order of `UIStackView`s. Posted `UIView`s get appended to the
+    /// `arrangedSubviews` array appearing below/after the previous.
+    case topToBottom
+
+    /// Reverse order of `UIStackView`s. Posted `UIView`s get inserted at the start of the
+    /// `arrangedSubviews` array appearing above/before the previous.
+    case bottomToTop
+}
+
+// MARK: - Extensions
+
+public extension Order {
+
+    /// Other `Order` (opposite direction)
+    var switched: Self {
+        switch self {
+        case .topToBottom: return .bottomToTop
+        case .bottomToTop: return .topToBottom
+        }
+    }
+}

Sources/PostManager/PostGestureManager.swift

@@ -30,7 +30,7 @@ protocol PostGestureManagerDelegate: AnyObject {
 
 /// Manage gestures for posted `UIView`s to trigger a removal of that posted `UIView`.
 /// 
-/// E.g. The user pans a view off the top wanting for it to be dimissed.
+/// E.g. The user pans a view off of the top wanting for it to be dismissed.
 /// E.g. T user tapped to dismiss
 public class PostGestureManager {
 
@@ -43,6 +43,12 @@ public class PostGestureManager {
     /// Map `UIView`s to their "pan to dismiss" `UIPanGestureRecognizer`
     private var panGestureMap = [UIView: UIPanGestureRecognizer]()
 
+    /// `Order` to configure which direction the user is allowed to pan.
+    ///
+    /// - When `.topToBottom`, the user can pan/swipe up to dismiss
+    /// - When `.bottomToTop`, the user can pan/swipe down to dismiss
+    var order: Order = .topToBottom
+
     // MARK: - Deinit
 
     deinit {
@@ -51,6 +57,7 @@ public class PostGestureManager {
 
     // MARK: - Invalidate
 
+    /// Invalidate maps
     func invalidate() {
         tapGestureMap.forEach {
             $0.key.removeGestureRecognizer($0.value)
@@ -152,19 +159,15 @@ public class PostGestureManager {
 
         // Pan did update
         case .changed:
-            view.transform = CGAffineTransform(
-                translationX: 0,
-                y: min(0, sender.translation(in: view.superview).y)
-            )
+            let ty = sender.translation(in: view.superview).y
+            let y = order.translationY(ty)
+            view.transform = CGAffineTransform(translationX: 0, y: y)
             return
 
         // Pan did finish
         case .ended:
             let translateY = view.transform.ty
-            let centerY = view.center.y
-
-            let finalY = centerY + translateY
-            if finalY < 0 {
+            if abs(translateY) > view.bounds.size.height * 0.5 {
                 requestRemove(view: view)
                 return
             }
@@ -220,3 +223,15 @@ private extension UIGestureRecognizer.State {
         }
     }
 }
+
+// MARK: - Order + Translation
+
+private extension Order {
+
+    func translationY(_ ty: CGFloat) -> CGFloat {
+        switch self {
+        case .topToBottom: return min(0, ty)
+        case .bottomToTop: return max(0, ty)
+        }
+    }
+}

Sources/PostManager/PostManager.swift

@@ -26,7 +26,7 @@ public class PostManager {
     /// `UIViewPoster` to handle the post and remove of a `PostRequest`
     private weak var poster: UIViewPoster?
 
-    /// `PostManagerDelegate` for `PostManager` delegate callabacks
+    /// `PostManagerDelegate` for `PostManager` delegate callbacks
     public weak var delegate: PostManagerDelegate?
 
     /// `PostGestureManager` to manage `UIGestureRecognizer` actions
@@ -48,7 +48,7 @@ public class PostManager {
 
     /// Should the posted `UIView`s be handled by a serial `Queue`, i.e. one at a time.
     /// If `true`, queued `PostRequest`s are stored in `queue`.
-    public var isSerialQueue: Bool = true {
+    public var isSerialQueue = true {
         didSet {
             guard !isSerialQueue else { return }
             while let postRequest = queue.dequeue() {
@@ -107,10 +107,10 @@ public class PostManager {
 
     /// Is the `PostManager` posting or scheduled to post
     public var isActive: Bool {
-        // A post is showing atm
+        // Is a post is showing at the moment
         let isPosting = !currentPostRequests.isEmpty
 
-        // A post is scheduled to show in the future
+        // Is a post is scheduled to show in the future
         let isQueued = !queue.isEmpty
 
         return isPosting || isQueued
@@ -157,7 +157,8 @@ public class PostManager {
             animated: postRequest.animated.contains(.onPost),
             completion: {
                 self.completePost(postRequest: postRequest)
-            })
+            }
+        )
     }
 
     /// Invoke on the completion of `poster` posting a `view` of a `postRequest`.
@@ -217,7 +218,7 @@ public class PostManager {
         )
     }
 
-    /// Remove (unpost) a posted `view` invalidatating appropriate properties.
+    /// Remove (un-post) a posted `view` invalidating appropriate properties.
     /// - Parameters:
     ///   - view: `UIView` to remove
     ///   - animated: Should the removal be animated

Sources/PostManager/UIView+Poster.swift

@@ -1,5 +1,5 @@
 //
-//  UIView+MessageStackView.swift
+//  UIView+Poster.swift
 //  MessageStackView
 //
 //  Created by Ben Shutt on 03/07/2020.
@@ -48,7 +48,7 @@ public extension UIView {
             layout: layout,
             constrainToSafeArea: constrainToSafeArea
         )
-        messageStackView.updateOrderForLayout(layout)
+        messageStackView.order = layout.toOrder()
         return messageStackView
     }
 

Sources/Reachability/ConnectivityManager+MessageManager.swift

@@ -21,7 +21,7 @@ public extension ConnectivityManager {
         /// `MessageStackView ` to post messages
         public private(set) lazy var messageStackView: MessageStackView = {
             let messageStackView = MessageStackView()
-            messageStackView.updateOrderForLayout(.bottom)
+            messageStackView.order = MessageLayout.bottom.toOrder()
             messageStackView.postManager.delegate = self
             return messageStackView
         }()

Sources/Reachability/ConnectivityViewController.swift

@@ -38,7 +38,7 @@ open class ConnectivityViewController: UIViewController, ConnectivityMessageable
             layout: messageLayout,
             constrainToSafeArea: false // Inset spaceView height
         )
-        messageStackView.updateOrderForLayout(messageLayout)
+        messageStackView.order = messageLayout.toOrder()
         view.setNeedsLayout()
     }