Refactor MainActivity to use compose as basis

app/src/main/java/org/jellyfin/androidtv/ui/browsing/MainActivity.kt

@@ -6,7 +6,7 @@ import android.view.KeyEvent
 import android.view.MotionEvent
 import android.view.View
 import android.view.WindowManager
-import androidx.activity.OnBackPressedCallback
+import androidx.activity.compose.setContent
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.FragmentActivity
 import androidx.lifecycle.Lifecycle
@@ -20,11 +20,11 @@ import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.launch
 import org.jellyfin.androidtv.auth.repository.SessionRepository
 import org.jellyfin.androidtv.auth.repository.UserRepository
-import org.jellyfin.androidtv.databinding.ActivityMainBinding
 import org.jellyfin.androidtv.integration.LeanbackChannelWorker
 import org.jellyfin.androidtv.ui.InteractionTrackerViewModel
 import org.jellyfin.androidtv.ui.background.AppBackground
-import org.jellyfin.androidtv.ui.navigation.NavigationAction
+import org.jellyfin.androidtv.ui.base.JellyfinTheme
+import org.jellyfin.androidtv.ui.composable.compat.AppNavigationHost
 import org.jellyfin.androidtv.ui.navigation.NavigationRepository
 import org.jellyfin.androidtv.ui.screensaver.InAppScreensaver
 import org.jellyfin.androidtv.ui.settings.compat.MainActivitySettings
@@ -42,14 +42,6 @@ class MainActivity : FragmentActivity() {
 	private val interactionTrackerViewModel by viewModel<InteractionTrackerViewModel>()
 	private val workManager by inject<WorkManager>()
 
-	private lateinit var binding: ActivityMainBinding
-
-	private val backPressedCallback = object : OnBackPressedCallback(false) {
-		override fun handleOnBackPressed() {
-			if (navigationRepository.canGoBack) navigationRepository.goBack()
-		}
-	}
-
 	override fun onCreate(savedInstanceState: Bundle?) {
 		applyTheme()
 
@@ -63,22 +55,24 @@ class MainActivity : FragmentActivity() {
 				else window.clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
 			}.launchIn(lifecycleScope)
 
-		onBackPressedDispatcher.addCallback(this, backPressedCallback)
 		if (savedInstanceState == null && navigationRepository.canGoBack) navigationRepository.reset(clearHistory = true)
 
 		navigationRepository.currentAction
 			.flowWithLifecycle(lifecycle, Lifecycle.State.STARTED)
-			.onEach { action ->
-				handleNavigationAction(action)
-				backPressedCallback.isEnabled = navigationRepository.canGoBack
+			.onEach {
 				interactionTrackerViewModel.notifyInteraction(canCancel = false, userInitiated = false)
 			}.launchIn(lifecycleScope)
 
-		binding = ActivityMainBinding.inflate(layoutInflater)
-		binding.background.setContent { AppBackground() }
-		binding.settings.setContent { MainActivitySettings() }
-		binding.screensaver.setContent { InAppScreensaver() }
-		setContentView(binding.root)
+		setContent {
+			JellyfinTheme {
+				AppBackground()
+				AppNavigationHost(
+					navigationRepository = navigationRepository,
+				)
+				InAppScreensaver()
+				MainActivitySettings()
+			}
+		}
 	}
 
 	override fun onResume() {
@@ -119,17 +113,6 @@ class MainActivity : FragmentActivity() {
 		}
 	}
 
-	private fun handleNavigationAction(action: NavigationAction) {
-		interactionTrackerViewModel.notifyInteraction(canCancel = true, userInitiated = false)
-
-		when (action) {
-			is NavigationAction.NavigateFragment -> binding.contentView.navigate(action)
-			NavigationAction.GoBack -> binding.contentView.goBack()
-
-			NavigationAction.Nothing -> Unit
-		}
-	}
-
 	// Forward key events to fragments
 	private fun Fragment.onKeyEvent(keyCode: Int, event: KeyEvent?): Boolean {
 		var result = childFragmentManager.fragments.any { it.onKeyEvent(keyCode, event) }

app/src/main/java/org/jellyfin/androidtv/ui/composable/compat/AppNavigationHost.kt

@@ -0,0 +1,59 @@
+package org.jellyfin.androidtv.ui.composable.compat
+
+import android.content.Context
+import android.view.View
+import androidx.activity.compose.BackHandler
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.viewinterop.AndroidView
+import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.flow.map
+import org.jellyfin.androidtv.ui.browsing.DestinationFragmentView
+import org.jellyfin.androidtv.ui.navigation.NavigationAction
+import org.jellyfin.androidtv.ui.navigation.NavigationRepository
+import org.koin.compose.koinInject
+
+@Composable
+fun AppNavigationHost(
+	modifier: Modifier = Modifier,
+	navigationRepository: NavigationRepository = koinInject(),
+) {
+	val factory = remember { AppNavigationHostViewFactory() }
+
+	val currentAction by navigationRepository.currentAction.collectAsState(NavigationAction.Nothing)
+	val canGoBack by remember {
+		navigationRepository.currentAction.map { navigationRepository.canGoBack }.distinctUntilChanged()
+	}.collectAsState(navigationRepository.canGoBack)
+
+	BackHandler(canGoBack) { navigationRepository.goBack() }
+
+	AndroidView(
+		factory = factory,
+		modifier = modifier,
+	)
+
+	LaunchedEffect(currentAction) {
+		when (val currentAction = currentAction) {
+			is NavigationAction.NavigateFragment -> factory.view.navigate(currentAction)
+			NavigationAction.GoBack -> factory.view.goBack()
+
+			NavigationAction.Nothing -> Unit
+		}
+	}
+}
+
+private class AppNavigationHostViewFactory : (Context) -> View {
+	private var _view: DestinationFragmentView? = null
+
+	val view get() = requireNotNull(_view)
+
+	override operator fun invoke(
+		context: Context
+	): View = DestinationFragmentView(context).also { view ->
+		_view = view
+	}
+}

app/src/main/res/layout/activity_main.xml

@@ -1,30 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:tools="http://schemas.android.com/tools"
-    android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    android:fitsSystemWindows="true"
-    tools:context=".ui.startup.MainActivity">
-
-    <androidx.compose.ui.platform.ComposeView
-        android:id="@+id/background"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent"
-        android:descendantFocusability="blocksDescendants"
-        android:focusable="false" />
-
-    <org.jellyfin.androidtv.ui.browsing.DestinationFragmentView
-        android:id="@+id/content_view"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent" />
-
-    <androidx.compose.ui.platform.ComposeView
-        android:id="@+id/settings"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent" />
-
-    <androidx.compose.ui.platform.ComposeView
-        android:id="@+id/screensaver"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent" />
-</RelativeLayout>