implement result API based on NavBackStackEntry

navigator/runtime-compose/build.gradle

@@ -59,7 +59,7 @@ dependencies {
     implementation "androidx.compose.runtime:runtime:1.1.1"
     implementation "androidx.lifecycle:lifecycle-runtime:2.4.1"
     implementation "androidx.lifecycle:lifecycle-runtime-ktx:2.4.1"
+    implementation "androidx.savedstate:savedstate-ktx:1.1.0"
     implementation "androidx.navigation:navigation-compose:2.4.1"
     implementation "com.google.accompanist:accompanist-navigation-material:0.23.1"
-
 }

navigator/runtime-compose/src/main/java/com/freeletics/mad/navigator/compose/NavigationSetup.kt

@@ -3,6 +3,7 @@ package com.freeletics.mad.navigator.compose
 import android.app.Activity
 import android.content.Context
 import android.content.ContextWrapper
+import android.os.Parcelable
 import androidx.activity.compose.LocalOnBackPressedDispatcherOwner
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.ActivityResultLauncher
@@ -11,9 +12,12 @@ import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalLifecycleOwner
+import androidx.lifecycle.Observer
 import androidx.lifecycle.flowWithLifecycle
+import androidx.navigation.NavController
 import com.freeletics.mad.navigator.ActivityResultRequest
 import com.freeletics.mad.navigator.NavEventNavigator
+import com.freeletics.mad.navigator.NavigationResultRequest
 import com.freeletics.mad.navigator.PermissionsResultRequest
 import com.freeletics.mad.navigator.internal.RequestPermissionsContract
 import com.freeletics.mad.navigator.internal.navigate
@@ -34,6 +38,10 @@ public fun NavigationSetup(navigator: NavEventNavigator) {
         rememberResultLaunchers(it)
     }
 
+    navigator.navigationResultRequests.forEach {
+        ResultEffect(it, controller)
+    }
+
     val backDispatcher = LocalOnBackPressedDispatcherOwner.current!!.onBackPressedDispatcher
     DisposableEffect(lifecycleOwner, backDispatcher, navigator) {
         backDispatcher.addCallback(lifecycleOwner, navigator.onBackPressedCallback)
@@ -77,3 +85,25 @@ private fun Context.findActivity(): Activity {
     }
     throw IllegalStateException("Permissions should be called in the context of an Activity")
 }
+
+@Composable
+private fun <O : Parcelable> ResultEffect(
+    request: NavigationResultRequest<O>,
+    controller: NavController,
+) {
+    DisposableEffect(request, controller) {
+        val liveData = controller.getBackStackEntry(request.key.destinationId).savedStateHandle
+            .getLiveData<Parcelable>(request.key.requestKey)
+
+        val observer = Observer<Parcelable> { result ->
+            @Suppress("UNCHECKED_CAST")
+            request.handleResult(result as O)
+        }
+
+        liveData.observeForever(observer)
+
+        onDispose {
+            liveData.removeObserver(observer)
+        }
+    }
+}

navigator/runtime-fragment/api/runtime-fragment.api

@@ -1,19 +1,9 @@
-public abstract class com/freeletics/mad/navigator/fragment/FragmentNavEventNavigator : com/freeletics/mad/navigator/NavEventNavigator {
-	public fun <init> ()V
-	public final fun getResultEvents ()Lkotlinx/coroutines/flow/Flow;
-	public final fun navigateBackWithResult (Ljava/lang/String;Landroid/os/Parcelable;)V
-	public final fun registerForFragmentResult (Ljava/lang/String;)Lcom/freeletics/mad/navigator/fragment/FragmentResultRequest;
-}
-
-public final class com/freeletics/mad/navigator/fragment/FragmentResultRequest : com/freeletics/mad/navigator/ResultOwner {
-}
-
 public final class com/freeletics/mad/navigator/fragment/FragmentRouteKt {
 	public static final fun requireRoute (Landroidx/fragment/app/Fragment;)Lcom/freeletics/mad/navigator/BaseRoute;
 }
 
 public final class com/freeletics/mad/navigator/fragment/HandleNavigationKt {
-	public static final fun handleNavigation (Landroidx/fragment/app/Fragment;Lcom/freeletics/mad/navigator/fragment/FragmentNavEventNavigator;)V
+	public static final fun handleNavigation (Landroidx/fragment/app/Fragment;Lcom/freeletics/mad/navigator/NavEventNavigator;)V
 }
 
 public abstract interface class com/freeletics/mad/navigator/fragment/NavDestination {

navigator/runtime-fragment/src/main/java/com/freeletics/mad/navigator/fragment/HandleNavigation.kt

@@ -1,37 +1,41 @@
 package com.freeletics.mad.navigator.fragment
 
-import android.annotation.SuppressLint
 import android.app.Activity
 import android.os.Bundle
+import android.os.Parcelable
 import androidx.activity.result.ActivityResultCaller
 import androidx.activity.result.ActivityResultLauncher
 import androidx.fragment.app.Fragment
-import androidx.fragment.app.FragmentResultOwner
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.LifecycleOwner
+import androidx.lifecycle.Observer
 import androidx.lifecycle.coroutineScope
 import androidx.lifecycle.repeatOnLifecycle
+import androidx.navigation.NavController
 import androidx.navigation.fragment.findNavController
 import com.freeletics.mad.navigator.ActivityResultRequest
+import com.freeletics.mad.navigator.NavEventNavigator
+import com.freeletics.mad.navigator.NavigationResultRequest
 import com.freeletics.mad.navigator.PermissionsResultRequest
 import com.freeletics.mad.navigator.internal.RequestPermissionsContract
 import com.freeletics.mad.navigator.internal.navigate
 import kotlinx.coroutines.launch
 
 /**
- * Handles the [FragmentNavEventNavigator] events while the Fragment's lifecycle is at least
+ * Handles the [NavEventNavigator] events while the Fragment's lifecycle is at least
  * started.
  */
-public fun handleNavigation(fragment: Fragment, navigator: FragmentNavEventNavigator) {
+public fun handleNavigation(fragment: Fragment, navigator: NavEventNavigator) {
     val activityLaunchers = navigator.activityResultRequests.associateWith {
         it.registerIn(fragment)
     }
     val permissionLaunchers = navigator.permissionsResultRequests.associateWith {
         it.registerIn(fragment, fragment.requireActivity())
     }
 
-    navigator.fragmentResultRequests.forEach {
-        it.registerIn(fragment.parentFragmentManager, fragment)
+    val controller = fragment.findNavController()
+    navigator.navigationResultRequests.forEach {
+        it.registerIn(controller, fragment)
     }
 
     val dispatcher = fragment.requireActivity().onBackPressedDispatcher
@@ -45,13 +49,6 @@ public fun handleNavigation(fragment: Fragment, navigator: FragmentNavEventNavig
             }
         }
     }
-    lifecycle.coroutineScope.launch {
-        lifecycle.repeatOnLifecycle(Lifecycle.State.STARTED) {
-            navigator.resultEvents.collect { event ->
-                navigate(fragment, event)
-            }
-        }
-    }
 }
 
 private fun <I, O> ActivityResultRequest<I, O>.registerIn(
@@ -69,22 +66,19 @@ private fun PermissionsResultRequest.registerIn(
     }
 }
 
-@SuppressLint("VisibleForTests") // it's ok to use onResult internally
-private fun <O> FragmentResultRequest<O>.registerIn(
-    fragmentResultOwner: FragmentResultOwner,
-    lifecycleOwner: LifecycleOwner
+private fun <O : Parcelable> NavigationResultRequest<O>.registerIn(
+    controller: NavController,
+    lifecycleOwner: LifecycleOwner,
 ) {
-    fragmentResultOwner.setFragmentResultListener(requestKey, lifecycleOwner) { _, bundle ->
-        onResult(bundle.getParcelable(KEY_FRAGMENT_RESULT)!!)
-    }
-}
+    val liveData = controller.getBackStackEntry(key.destinationId).savedStateHandle
+        .getLiveData<Parcelable>(key.requestKey)
 
-private fun navigate(fragment: Fragment, event: FragmentResultEvent) {
-    val result = Bundle(1).apply {
-        putParcelable(KEY_FRAGMENT_RESULT, event.result)
+    val observer = Observer<Parcelable> { result ->
+        @Suppress("UNCHECKED_CAST")
+        handleResult(result as O)
     }
-    fragment.parentFragmentManager.setFragmentResult(event.requestKey, result)
-    fragment.findNavController().popBackStack()
+
+    liveData.observe(lifecycleOwner, observer)
 }
 
 /**

navigator/runtime/api/navigator-runtime.api

@@ -9,8 +9,10 @@ public class com/freeletics/mad/navigator/NavEventNavigator {
 	public fun <init> ()V
 	public final fun backPresses ()Lkotlinx/coroutines/flow/Flow;
 	public final fun backPresses (Ljava/lang/Object;)Lkotlinx/coroutines/flow/Flow;
+	public final fun deliverNavigationResult (Lcom/freeletics/mad/navigator/NavigationResultRequest$Key;Landroid/os/Parcelable;)V
 	public final fun getActivityResultRequests ()Ljava/util/List;
 	public final fun getNavEvents ()Lkotlinx/coroutines/flow/Flow;
+	public final fun getNavigationResultRequests ()Ljava/util/List;
 	public final fun getOnBackPressedCallback ()Landroidx/activity/OnBackPressedCallback;
 	public final fun getPermissionsResultRequests ()Ljava/util/List;
 	public final fun navigateBack ()V
@@ -33,6 +35,33 @@ public abstract interface class com/freeletics/mad/navigator/NavRoot : com/freel
 public abstract interface class com/freeletics/mad/navigator/NavRoute : com/freeletics/mad/navigator/BaseRoute {
 }
 
+public final class com/freeletics/mad/navigator/NavigationResultRequest : com/freeletics/mad/navigator/ResultOwner {
+	public final fun getKey ()Lcom/freeletics/mad/navigator/NavigationResultRequest$Key;
+}
+
+public final class com/freeletics/mad/navigator/NavigationResultRequest$Key : android/os/Parcelable {
+	public static final field CREATOR Lcom/freeletics/mad/navigator/NavigationResultRequest$Key$CREATOR;
+	public fun <init> (Landroid/os/Parcel;)V
+	public final fun component1 ()I
+	public final fun component2 ()Ljava/lang/String;
+	public final fun copy (ILjava/lang/String;)Lcom/freeletics/mad/navigator/NavigationResultRequest$Key;
+	public static synthetic fun copy$default (Lcom/freeletics/mad/navigator/NavigationResultRequest$Key;ILjava/lang/String;ILjava/lang/Object;)Lcom/freeletics/mad/navigator/NavigationResultRequest$Key;
+	public fun describeContents ()I
+	public fun equals (Ljava/lang/Object;)Z
+	public final fun getDestinationId ()I
+	public final fun getRequestKey ()Ljava/lang/String;
+	public fun hashCode ()I
+	public fun toString ()Ljava/lang/String;
+	public fun writeToParcel (Landroid/os/Parcel;I)V
+}
+
+public final class com/freeletics/mad/navigator/NavigationResultRequest$Key$CREATOR : android/os/Parcelable$Creator {
+	public fun createFromParcel (Landroid/os/Parcel;)Lcom/freeletics/mad/navigator/NavigationResultRequest$Key;
+	public synthetic fun createFromParcel (Landroid/os/Parcel;)Ljava/lang/Object;
+	public fun newArray (I)[Lcom/freeletics/mad/navigator/NavigationResultRequest$Key;
+	public synthetic fun newArray (I)[Ljava/lang/Object;
+}
+
 public final class com/freeletics/mad/navigator/PermissionsResultRequest : com/freeletics/mad/navigator/ResultOwner {
 }
 
@@ -45,7 +74,6 @@ public final class com/freeletics/mad/navigator/PermissionsResultRequest$Permiss
 }
 
 public abstract class com/freeletics/mad/navigator/ResultOwner {
-	public fun <init> ()V
 	public final fun getResults ()Lkotlinx/coroutines/flow/Flow;
 }
 

navigator/runtime/build.gradle

@@ -53,6 +53,7 @@ dependencies {
     implementation "androidx.core:core:1.7.0"
     implementation "androidx.navigation:navigation-common:2.4.1"
     implementation "androidx.navigation:navigation-runtime:2.4.1"
+    implementation "androidx.lifecycle:lifecycle-viewmodel-savedstate:2.4.1"
 
     testImplementation "junit:junit:4.13.2"
     testImplementation "com.google.truth:truth:1.1.3"