✨ [Compose Multiplatform] When you tap the action label on the snack bar that appears when you don't have permission to access the calendar, the iOS Settings app will now open.

app-ios-shared/src/commonMain/composeResources/values-ja/strings.xml

@@ -1,4 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <string name="permission_required">セッションを予定として追加するには、カレンダーへのアクセス権限が必要です。</string>
+    <string name="open_settings">設定を開く</string>
 </resources>

app-ios-shared/src/commonMain/composeResources/values/strings.xml

@@ -1,4 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <string name="permission_required">To add a session as a scheduled event, you need access permission to the calendar.</string>
+    <string name="open_settings">Open settings.</string>
 </resources>

app-ios-shared/src/commonMain/kotlin/io/github/droidkaigi/confsched/shared/IosComposeKaigiApp.kt

@@ -10,6 +10,7 @@ import androidx.compose.material3.windowsizeclass.WindowSizeClass
 import androidx.compose.material3.windowsizeclass.calculateWindowSizeClass
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Modifier
@@ -22,6 +23,7 @@ import androidx.navigation.NavHostController
 import androidx.navigation.compose.rememberNavController
 import co.touchlab.kermit.Logger
 import conference_app_2024.app_ios_shared.generated.resources.permission_required
+import conference_app_2024.app_ios_shared.generated.resources.open_settings
 import io.github.droidkaigi.confsched.about.aboutScreen
 import io.github.droidkaigi.confsched.about.aboutScreenRoute
 import io.github.droidkaigi.confsched.about.navigateAboutScreen
@@ -93,11 +95,13 @@ import platform.Foundation.NSDate
 import platform.Foundation.NSURL
 import platform.Foundation.dateWithTimeIntervalSince1970
 import platform.UIKit.UIApplication
+import platform.UIKit.UIApplicationOpenSettingsURLString
 import platform.UIKit.UIViewController
 import platform.darwin.NSObject
 
 data class IosComposeKaigiAppUiState(
     val userMessageStateHolder: UserMessageStateHolder,
+    val shouldGoToSettingsApp: Boolean,
 )
 
 @OptIn(ExperimentalMaterial3WindowSizeClassApi::class)
@@ -142,6 +146,7 @@ fun KaigiApp(
     snackbarHostState: SnackbarHostState,
     onLicenseScreenRequest: () -> Unit,
     modifier: Modifier = Modifier,
+    externalNavController: ExternalNavController = rememberExternalNavController(),
 ) {
     val eventFlow = rememberEventFlow<IosComposeKaigiAppEvent>()
     val uiState = iosComposeKaigiAppPresenter(events = eventFlow)
@@ -151,6 +156,13 @@ fun KaigiApp(
         userMessageStateHolder = uiState.userMessageStateHolder,
     )
 
+    LaunchedEffect(uiState.shouldGoToSettingsApp) {
+        if (uiState.shouldGoToSettingsApp) {
+            eventFlow.tryEmit(IosComposeKaigiAppEvent.SettingsAppNavigated)
+            externalNavController.navigateToSettingsApp()
+        }
+    }
+
     KaigiTheme(
         fontFamily = fontFamily,
     ) {
@@ -159,13 +171,17 @@ fun KaigiApp(
             color = MaterialTheme.colorScheme.background,
         ) {
             val snackbarMessage = stringResource(AppIosSharedRes.string.permission_required)
+            val snackbarActionLabel = stringResource(AppIosSharedRes.string.open_settings)
+
             KaigiNavHost(
                 windowSize = windowSize,
+                externalNavController = externalNavController,
                 onLicenseScreenRequest = onLicenseScreenRequest,
                 onAccessCalendarIsDenied = {
                     eventFlow.tryEmit(
                         IosComposeKaigiAppEvent.ShowRequiresAuthorization(
                             snackbarMessage = snackbarMessage,
+                            actionLabel = snackbarActionLabel,
                         )
                     )
                 }
@@ -177,10 +193,10 @@ fun KaigiApp(
 @Composable
 private fun KaigiNavHost(
     windowSize: WindowSizeClass,
+    externalNavController: ExternalNavController,
     onLicenseScreenRequest: () -> Unit,
     onAccessCalendarIsDenied: () -> Unit,
     navController: NavHostController = rememberNavController(),
-    externalNavController: ExternalNavController = rememberExternalNavController(),
 ) {
     NavHostWithSharedAxisX(navController = navController, startDestination = mainScreenRoute) {
         mainScreen(
@@ -357,7 +373,7 @@ private fun rememberExternalNavController(): ExternalNavController {
     }
 }
 
-private class ExternalNavController(
+class ExternalNavController(
     private val shareNavigator: ShareNavigator,
     private val coroutineScope: CoroutineScope,
 ) {
@@ -430,6 +446,13 @@ private class ExternalNavController(
         }
     }
 
+    fun navigateToSettingsApp() {
+        val settingsUrl = NSURL.URLWithString(UIApplicationOpenSettingsURLString)
+        if (settingsUrl != null) {
+            UIApplication.sharedApplication.openURL(settingsUrl)
+        }
+    }
+
     fun onShareClick(timetableItem: TimetableItem) {
         shareNavigator.share(
             "[${timetableItem.room.name.currentLangTitle}] ${timetableItem.startsTimeString} - ${timetableItem.endsTimeString}\n" +

app-ios-shared/src/commonMain/kotlin/io/github/droidkaigi/confsched/shared/IosComposeKaigiAppPresenter.kt

@@ -1,34 +1,51 @@
 package io.github.droidkaigi.confsched.shared
 
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import io.github.droidkaigi.confsched.compose.EventEffect
 import io.github.droidkaigi.confsched.compose.EventFlow
+import io.github.droidkaigi.confsched.droidkaigiui.UserMessageResult.ActionPerformed
 import io.github.droidkaigi.confsched.droidkaigiui.providePresenterDefaults
+import io.github.droidkaigi.confsched.shared.IosComposeKaigiAppEvent.SettingsAppNavigated
 import io.github.droidkaigi.confsched.shared.IosComposeKaigiAppEvent.ShowRequiresAuthorization
 
 sealed interface IosComposeKaigiAppEvent {
-    val snackbarMessage: String
-
     data class ShowRequiresAuthorization(
-        override val snackbarMessage: String,
+        val snackbarMessage: String,
+        val actionLabel: String,
     ) : IosComposeKaigiAppEvent
+
+    data object SettingsAppNavigated : IosComposeKaigiAppEvent
 }
 
 @Composable
 fun iosComposeKaigiAppPresenter(
     events: EventFlow<IosComposeKaigiAppEvent>
 ) : IosComposeKaigiAppUiState = providePresenterDefaults { userMessageStateHolder ->
+    var shouldGoToSettingsApp by remember { mutableStateOf(false) }
+
     EventEffect(events) { event ->
         when (event) {
             is ShowRequiresAuthorization -> {
-                userMessageStateHolder.showMessage(
+                val result = userMessageStateHolder.showMessage(
                     message = event.snackbarMessage,
-                    // TODO Add code to transition to the settings screen when the action button is pressed.
-                    // TODO Perhaps UIApplication.openSettingsURLString can be used to achieve this.
-                    actionLabel = null,
+                    actionLabel = event.actionLabel,
                 )
+                if (result == ActionPerformed) {
+                    shouldGoToSettingsApp = true
+                }
+            }
+
+            SettingsAppNavigated -> {
+                shouldGoToSettingsApp = false
             }
         }
     }
-    IosComposeKaigiAppUiState(userMessageStateHolder)
+    IosComposeKaigiAppUiState(
+        userMessageStateHolder = userMessageStateHolder,
+        shouldGoToSettingsApp = shouldGoToSettingsApp,
+    )
 }