Add a code load status snackbar for iOS frontend

samples/emoji-search/ios-shared/src/commonMain/kotlin/com/example/redwood/emojisearch/ios/EmojiSearchLauncher.kt

@@ -30,6 +30,7 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.MainScope
 import kotlinx.coroutines.flow.flowOf
 import platform.Foundation.NSLog
+import platform.Foundation.NSOperationQueue
 import platform.Foundation.NSURLSession
 
 class EmojiSearchLauncher(
@@ -40,7 +41,7 @@ class EmojiSearchLauncher(
   private val manifestUrl = "http://localhost:8080/manifest.zipline.json"
 
   @Suppress("unused") // Invoked in Swift.
-  fun createTreehouseApp(): TreehouseApp<EmojiSearchPresenter> {
+  fun createTreehouseApp(listener: EmojiSearchEventListener): TreehouseApp<EmojiSearchPresenter> {
     val ziplineHttpClient = nsurlSession.asZiplineHttpClient()
 
     val treehouseAppFactory = TreehouseAppFactory(
@@ -49,10 +50,16 @@ class EmojiSearchLauncher(
       eventListener = object : EventListener() {
         override fun codeLoadFailed(app: TreehouseApp<*>, manifestUrl: String?, exception: Exception, startValue: Any?) {
           NSLog("Treehouse: codeLoadFailed: $exception")
+          NSOperationQueue.mainQueue.addOperationWithBlock {
+            listener.codeLoadFailed()
+          }
         }
 
         override fun codeLoadSuccess(app: TreehouseApp<*>, manifestUrl: String?, manifest: ZiplineManifest, zipline: Zipline, startValue: Any?) {
           NSLog("Treehouse: codeLoadSuccess")
+          NSOperationQueue.mainQueue.addOperationWithBlock {
+            listener.codeLoadSuccess()
+          }
         }
       },
     )
@@ -73,3 +80,8 @@ class EmojiSearchLauncher(
     return treehouseApp
   }
 }
+
+interface EmojiSearchEventListener {
+  fun codeLoadFailed()
+  fun codeLoadSuccess()
+}

samples/emoji-search/ios-uikit/EmojiSearchApp.xcodeproj/project.pbxproj

@@ -3,7 +3,7 @@
 	archiveVersion = 1;
 	classes = {
 	};
-	objectVersion = 50;
+	objectVersion = 52;
 	objects = {
 
 /* Begin PBXBuildFile section */
@@ -16,6 +16,7 @@
 		AACC042628AC72AC00721342 /* RemoteImageLoader.swift in Sources */ = {isa = PBXBuildFile; fileRef = AACC042528AC72AC00721342 /* RemoteImageLoader.swift */; };
 		C2F7CE6628BEAB6C00A66A69 /* ImageBinding.swift in Sources */ = {isa = PBXBuildFile; fileRef = C2F7CE6528BEAB6C00A66A69 /* ImageBinding.swift */; };
 		C2F7FBA228BEB54200A66A69 /* TextInputBinding.swift in Sources */ = {isa = PBXBuildFile; fileRef = C2F7FBA128BEB54200A66A69 /* TextInputBinding.swift */; };
+		CB5D6B092AC5326B004BF9CB /* SnackBar in Frameworks */ = {isa = PBXBuildFile; productRef = CB5D6B082AC5326B004BF9CB /* SnackBar */; };
 		CB85C0B725AFE61A007A2CC7 /* EmojiSearchViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = CB85C0B625AFE61A007A2CC7 /* EmojiSearchViewController.swift */; };
 		CB9F76562810A8A8008CF457 /* IosHostApi.swift in Sources */ = {isa = PBXBuildFile; fileRef = CB9F76552810A8A8008CF457 /* IosHostApi.swift */; };
 /* End PBXBuildFile section */
@@ -42,6 +43,7 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				CB5D6B092AC5326B004BF9CB /* SnackBar in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -101,6 +103,9 @@
 			dependencies = (
 			);
 			name = EmojiSearchApp;
+			packageProductDependencies = (
+				CB5D6B082AC5326B004BF9CB /* SnackBar */,
+			);
 			productName = EmojiSearchApp;
 			productReference = 635661D121F12B7E00DD7240 /* EmojiSearchApp.app */;
 			productType = "com.apple.product-type.application";
@@ -130,6 +135,9 @@
 				Base,
 			);
 			mainGroup = 635661C821F12B7D00DD7240;
+			packageReferences = (
+				CB5D6B072AC5326B004BF9CB /* XCRemoteSwiftPackageReference "SnackBar" */,
+			);
 			productRefGroup = 635661D221F12B7E00DD7240 /* Products */;
 			projectDirPath = "";
 			projectRoot = "";
@@ -415,6 +423,25 @@
 			defaultConfigurationName = Release;
 		};
 /* End XCConfigurationList section */
+
+/* Begin XCRemoteSwiftPackageReference section */
+		CB5D6B072AC5326B004BF9CB /* XCRemoteSwiftPackageReference "SnackBar" */ = {
+			isa = XCRemoteSwiftPackageReference;
+			repositoryURL = "https://github.com/ahmedAlmasri/SnackBar.swift";
+			requirement = {
+				kind = upToNextMajorVersion;
+				minimumVersion = 0.1.2;
+			};
+		};
+/* End XCRemoteSwiftPackageReference section */
+
+/* Begin XCSwiftPackageProductDependency section */
+		CB5D6B082AC5326B004BF9CB /* SnackBar */ = {
+			isa = XCSwiftPackageProductDependency;
+			package = CB5D6B072AC5326B004BF9CB /* XCRemoteSwiftPackageReference "SnackBar" */;
+			productName = SnackBar;
+		};
+/* End XCSwiftPackageProductDependency section */
 	};
 	rootObject = 635661C921F12B7D00DD7240 /* Project object */;
 }

samples/emoji-search/ios-uikit/EmojiSearchApp/EmojiSearchViewController.swift

@@ -17,12 +17,14 @@
 import Foundation
 import UIKit
 import EmojiSearchKt
+import SnackBar
 
-class EmojiSearchViewController : UIViewController {
-
+class EmojiSearchViewController : UIViewController, EmojiSearchEventListener {
     // MARK: - Private Properties
 
     private let urlSession: URLSession = .init(configuration: .default)
+    private var success = true
+    private var snackBar: SnackBarPresentable? = nil
 
     // MARK: - UIViewController
 
@@ -34,7 +36,7 @@ class EmojiSearchViewController : UIViewController {
 
     override func loadView() {
         let emojiSearchLauncher = EmojiSearchLauncher(nsurlSession: urlSession, hostApi: IosHostApi())
-        let treehouseApp = emojiSearchLauncher.createTreehouseApp()
+        let treehouseApp = emojiSearchLauncher.createTreehouseApp(listener: self)
         let widgetSystem = EmojiSearchWidgetSystem(treehouseApp: treehouseApp)
         let treehouseView = TreehouseUIView(widgetSystem: widgetSystem)
         let content = treehouseApp.createContent(
@@ -44,6 +46,29 @@ class EmojiSearchViewController : UIViewController {
         ExposedKt.bindWhenReady(content: content, view: treehouseView)
         view = treehouseView.view
     }
+
+    func codeLoadFailed() {
+        if (success) {
+            // Only show the Snackbar on the first transition from success.
+            success = false
+            let snackBar = SnackBar.make(in: view, message: "Unable to load guest code from server", duration: SnackBar.Duration.infinite)
+                .setAction(with: "Dismiss", action: { self.maybeDismissSnackBar() })
+            snackBar.show()
+            self.snackBar = snackBar
+        }
+    }
+
+    func codeLoadSuccess() {
+        success = true
+        maybeDismissSnackBar()
+    }
+
+    private func maybeDismissSnackBar() {
+        if let snackBar = snackBar {
+            snackBar.dismiss()
+            self.snackBar = nil
+        }
+    }
 }
 
 class EmojiSearchContent : TreehouseContentSource {