From f109253bbabd0a7d3d066f29f1172b61b8d48b73 Mon Sep 17 00:00:00 2001
From: Shadowfacts <me@shadowfacts.net>
Date: Sun, 15 Aug 2021 18:19:25 -0400
Subject: [PATCH] Show toast when there are no new posts

---
 .../TimelineTableViewController.swift         | 12 ++++
 Tusker/Views/Toast/ToastConfiguration.swift   |  2 +
 Tusker/Views/Toast/ToastView.swift            | 70 ++++++++++++++-----
 .../Views/Toast/ToastableViewController.swift | 14 ++++
 4 files changed, 79 insertions(+), 19 deletions(-)

diff --git a/Tusker/Screens/Timeline/TimelineTableViewController.swift b/Tusker/Screens/Timeline/TimelineTableViewController.swift
index 06806332..254bd845 100644
--- a/Tusker/Screens/Timeline/TimelineTableViewController.swift
+++ b/Tusker/Screens/Timeline/TimelineTableViewController.swift
@@ -236,6 +236,18 @@ class TimelineTableViewController: DiffableTimelineLikeTableViewController<Timel
                         snapshot.appendItems(newIdentifiers, toSection: .statuses)
                     }
                     completion(.success(snapshot))
+                    
+                    if statuses.isEmpty {
+                        DispatchQueue.main.async {
+                            var config = ToastConfiguration(title: "You're all caught up")
+                            config.edge = .top
+                            config.dismissAutomaticallyAfter = 2
+                            config.action = { (toast) in
+                                toast.dismissToast(animated: true)
+                            }
+                            self.showToast(configuration: config, animated: true)
+                        }
+                    }
                 }
             }
         }
diff --git a/Tusker/Views/Toast/ToastConfiguration.swift b/Tusker/Views/Toast/ToastConfiguration.swift
index 524c05d4..f55beb27 100644
--- a/Tusker/Views/Toast/ToastConfiguration.swift
+++ b/Tusker/Views/Toast/ToastConfiguration.swift
@@ -10,6 +10,7 @@ import UIKit
 
 struct ToastConfiguration {
     var systemImageName: String?
+    var titleFont: UIFont = .boldSystemFont(ofSize: 14)
     var title: String
     var subtitle: String?
     var actionTitle: String?
@@ -17,6 +18,7 @@ struct ToastConfiguration {
     var edgeSpacing: CGFloat = 8
     var edge: Edge = .automatic
     var dismissOnScroll = true
+    var dismissAutomaticallyAfter: TimeInterval? = nil
     
     init(title: String) {
         self.title = title
diff --git a/Tusker/Views/Toast/ToastView.swift b/Tusker/Views/Toast/ToastView.swift
index dd71096e..d8431194 100644
--- a/Tusker/Views/Toast/ToastView.swift
+++ b/Tusker/Views/Toast/ToastView.swift
@@ -14,6 +14,8 @@ class ToastView: UIView {
     
     private var shrinkAnimator: UIViewPropertyAnimator?
     private var recognizedGesture = false
+    private var shouldDismissOnScroll = false
+    private(set) var shouldDismissAutomatically = true
     
     private var offscreenTranslation: CGFloat {
         var translation = bounds.height + configuration.edgeSpacing
@@ -62,7 +64,7 @@ class ToastView: UIView {
         let titleLabel = UILabel()
         titleLabel.text = configuration.title
         titleLabel.textColor = .white
-        titleLabel.font = .boldSystemFont(ofSize: 14)
+        titleLabel.font = configuration.titleFont
         titleLabel.adjustsFontSizeToFitWidth = true
         
         if let subtitle = configuration.subtitle {
@@ -109,10 +111,40 @@ class ToastView: UIView {
         layer.shadowPath = CGPath(roundedRect: bounds, cornerWidth: layer.cornerRadius, cornerHeight: layer.cornerRadius, transform: nil)
     }
     
+    func dismissToast(animated: Bool) {
+        guard animated else {
+            removeFromSuperview()
+            return
+        }
+        UIView.animate(withDuration: 0.25, delay: 0, options: .curveEaseInOut) {
+            self.transform = CGAffineTransform(translationX: 0, y: self.offscreenTranslation)
+        } completion: { (_) in
+            self.removeFromSuperview()
+        }
+    }
+    
+    func animateAppearance() {
+        self.transform = CGAffineTransform(translationX: 0, y: offscreenTranslation)
+        let duration = 0.5
+        let velocity = 0.5
+        UIView.animate(withDuration: duration, delay: 0, usingSpringWithDamping: 0.65, initialSpringVelocity: velocity, options: []) {
+            self.transform = .identity
+        }
+    }
+    
+    func setupDismissOnScroll(connectedTo scrollView: UIScrollView) {
+        guard configuration.dismissOnScroll else { return }
+        scrollView.panGestureRecognizer.addTarget(self, action: #selector(scrollViewPanGestureRecognized))
+    }
+    
+    // MARK: - Interaction
+    
     override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
         super.touchesBegan(touches, with: event)
         
         recognizedGesture = false
+        shouldDismissAutomatically = false
+        
         shrinkAnimator = UIViewPropertyAnimator(duration: 0.1, curve: .easeInOut) {
             self.transform = CGAffineTransform(scaleX: 0.95, y: 0.95)
         }
@@ -145,6 +177,7 @@ class ToastView: UIView {
         switch recognizer.state {
         case .began:
             recognizedGesture = true
+            shouldDismissAutomatically = false
             UIView.animate(withDuration: 0.1, delay: 0, options: [.curveEaseInOut, .allowUserInteraction]) {
                 self.transform = .identity
             }
@@ -199,24 +232,23 @@ class ToastView: UIView {
         }
     }
     
-    func dismissToast(animated: Bool) {
-        guard animated else {
-            removeFromSuperview()
-            return
-        }
-        UIView.animate(withDuration: 0.25, delay: 0, options: .curveEaseInOut) {
-            self.transform = CGAffineTransform(translationX: 0, y: self.offscreenTranslation)
-        } completion: { (_) in
-            self.removeFromSuperview()
-        }
-    }
-    
-    func animateAppearance() {
-        self.transform = CGAffineTransform(translationX: 0, y: offscreenTranslation)
-        let duration = 0.5
-        let velocity = 0.5
-        UIView.animate(withDuration: duration, delay: 0, usingSpringWithDamping: 0.65, initialSpringVelocity: velocity, options: []) {
-            self.transform = .identity
+    @objc private func scrollViewPanGestureRecognized(_ recognizer: UIPanGestureRecognizer) {
+        switch recognizer.state {
+        case .began:
+            shouldDismissOnScroll = true
+            
+        case .changed:
+            let translation = recognizer.translation(in: recognizer.view).y
+            if shouldDismissOnScroll && abs(translation) > 50 {
+                dismissToast(animated: true)
+                shouldDismissOnScroll = false
+            }
+            
+        case .ended, .cancelled:
+            shouldDismissOnScroll = false
+            
+        default:
+            break
         }
     }
     
diff --git a/Tusker/Views/Toast/ToastableViewController.swift b/Tusker/Views/Toast/ToastableViewController.swift
index d5a71759..e7d900f5 100644
--- a/Tusker/Views/Toast/ToastableViewController.swift
+++ b/Tusker/Views/Toast/ToastableViewController.swift
@@ -11,6 +11,7 @@ import UIKit
 protocol ToastableViewController: UIViewController {
     
     var toastParentView: UIView { get }
+    var toastScrollView: UIScrollView? { get }
     
 }
 
@@ -33,6 +34,7 @@ extension ToastableViewController {
     }
     
     var toastParentView: UIView { view }
+    var toastScrollView: UIScrollView? { view as? UIScrollView }
     
     func showToast(configuration config: ToastConfiguration, animated: Bool) {
         currentToast?.dismissToast(animated: false)
@@ -67,6 +69,18 @@ extension ToastableViewController {
         if animated {
             toast.animateAppearance()
         }
+        
+        if config.dismissOnScroll,
+           let scrollView = toastScrollView {
+            toast.setupDismissOnScroll(connectedTo: scrollView)
+        }
+        
+        if let time = config.dismissAutomaticallyAfter {
+            DispatchQueue.main.asyncAfter(deadline: .now() + time) { [weak toast] in
+                guard let toast = toast, toast.shouldDismissAutomatically else { return }
+                toast.dismissToast(animated: true)
+            }
+        }
     }
     
     private func effectiveEdge(edge: ToastConfiguration.Edge) -> ToastConfiguration.Edge {