Merge pull request #17 from futuredapp/feature/predictive-back-gesture

Predictive back gesture and navigation update

app/build.gradle.kts

@@ -160,8 +160,7 @@ dependencies {
     implementation(Dependencies.Compose.animation)
     implementation(Dependencies.Compose.foundation)
     implementation(Dependencies.Compose.foundation_layout)
-    implementation(Dependencies.Compose.material)
-    implementation(Dependencies.Compose.material_icons_extended)
+    implementation(Dependencies.Compose.material3)
     implementation(Dependencies.Compose.runtime_livedata)
     implementation(Dependencies.Compose.runtime)
     implementation(Dependencies.Compose.ui)

app/src/main/AndroidManifest.xml

@@ -1,13 +1,16 @@
-<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+<manifest xmlns:tools="http://schemas.android.com/tools"
+    xmlns:android="http://schemas.android.com/apk/res/android">
 
     <application
         android:name=".App"
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"
+        android:enableOnBackInvokedCallback="true"
         android:theme="@style/Theme.App"
-        android:supportsRtl="true">
+        android:supportsRtl="true"
+        tools:targetApi="tiramisu">
 
         <activity
             android:name=".AppActivity"

app/src/main/kotlin/app/futured/androidprojecttemplate/App.kt

@@ -3,6 +3,7 @@ package app.futured.androidprojecttemplate
 import android.app.Application
 import android.os.Bundle
 import androidx.activity.compose.setContent
+import androidx.activity.enableEdgeToEdge
 import androidx.appcompat.app.AppCompatActivity
 import app.futured.androidprojecttemplate.ui.AppUI
 import dagger.hilt.android.AndroidEntryPoint
@@ -23,6 +24,7 @@ class App : Application() {
 class AppActivity : AppCompatActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+        enableEdgeToEdge()
         setContent {
             AppUI()
         }

app/src/main/kotlin/app/futured/androidprojecttemplate/navigation/Destinations.kt

@@ -1,6 +1,7 @@
 package app.futured.androidprojecttemplate.navigation
 
 import androidx.compose.animation.AnimatedContentScope
+import androidx.compose.animation.AnimatedVisibilityScope
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.window.DialogProperties
 import androidx.navigation.NamedNavArgument
@@ -11,19 +12,35 @@ import androidx.navigation.NavType
 import androidx.navigation.compose.composable
 import androidx.navigation.compose.dialog
 import androidx.navigation.navArgument
+import app.futured.androidprojecttemplate.ui.screens.detail.DetailScreen
+import app.futured.androidprojecttemplate.ui.screens.home.HomeScreen
 
 typealias DestinationArgumentKey = String
 typealias DestinationArgumentValue = String
 
+internal val screens = listOf(
+    Destination.Home,
+    Destination.Detail,
+)
+
+internal val dialogs = listOf<Destination>()
+
 sealed class Destination(
     val route: String,
     val arguments: List<NamedNavArgument> = emptyList(),
     val deepLinks: List<NavDeepLink> = emptyList(),
+    val destinationScreen: @Composable (router: NavRouter) -> Unit,
 ) {
-    data object Home : Destination(route = "home")
+    data object Home : Destination(
+        route = "home",
+        destinationScreen = { HomeScreen(navigation = it) },
+    )
+
     data object Detail : Destination(
         route = "detail/{title}?subtitle={subtitle}?value={value}",
-        arguments = listOf(
+        destinationScreen = { DetailScreen(navigation = it) },
+        arguments =
+        listOf(
             navArgument("title") {
                 type = NavType.StringType
             },
@@ -47,7 +64,7 @@ sealed class Destination(
 /**
  * Registers provided [destination] as a composable in [NavGraphBuilder].
  */
-fun NavGraphBuilder.composable(
+fun NavGraphBuilder.composableScreen(
     destination: Destination,
     content: @Composable AnimatedContentScope.(NavBackStackEntry) -> Unit,
 ) = composable(

app/src/main/kotlin/app/futured/androidprojecttemplate/navigation/NavRouter.kt

@@ -0,0 +1,12 @@
+package app.futured.androidprojecttemplate.navigation
+
+interface NavRouter {
+    fun popBackStack()
+    fun navigateBack(popUpToDestination: Destination, inclusive: Boolean = false)
+
+    fun navigateToDetail(title: String, subtitle: String? = null, value: String? = null)
+
+    fun <T> navigateBackWithResult(key: String, value: T)
+    fun <T> setCurrentResult(key: String, value: T)
+    fun <T> subscribeForResult(key: String, callback: (T) -> Unit)
+}

app/src/main/kotlin/app/futured/androidprojecttemplate/navigation/NavRouterImpl.kt

@@ -0,0 +1,54 @@
+package app.futured.androidprojecttemplate.navigation
+
+import androidx.navigation.NavController
+import app.futured.androidprojecttemplate.tools.extensions.subscribeForResult
+import timber.log.Timber
+
+/**
+ * Class that triggers navigation actions on provided [navController].
+ */
+class NavRouterImpl(private val navController: NavController) : NavRouter {
+    override fun popBackStack() {
+        navController.navigateUp()
+    }
+
+    override fun navigateBack(popUpToDestination: Destination, inclusive: Boolean) {
+        navController.popBackStack(route = popUpToDestination.route, inclusive = inclusive)
+    }
+
+    override fun navigateToDetail(title: String, subtitle: String?, value: String?) =
+        Destination.Detail.buildRoute(title, subtitle, value).execute()
+
+    override fun <T> navigateBackWithResult(key: String, value: T) {
+        navController.previousBackStackEntry?.savedStateHandle?.also {
+            it[key] = value
+            navController.popBackStack()
+        }
+    }
+
+    override fun <T> setCurrentResult(key: String, value: T) {
+        navController.currentBackStackEntry?.savedStateHandle?.also {
+            it[key] = value
+        }
+    }
+
+    override fun <T> subscribeForResult(key: String, callback: (T) -> Unit) {
+        navController.currentBackStackEntry?.savedStateHandle?.subscribeForResult<T>(key) { callback(it) }
+    }
+
+    private fun String.execute(
+        popUpToDestinationRoute: String? = null,
+        isInclusive: Boolean = true,
+    ) {
+        Timber.d("## Navigate to $this, popupTo $popUpToDestinationRoute, inclusive $isInclusive")
+        if (popUpToDestinationRoute != null) {
+            navController.navigate(this) {
+                popUpTo(popUpToDestinationRoute) {
+                    inclusive = isInclusive
+                }
+            }
+        } else {
+            navController.navigate(this)
+        }
+    }
+}

app/src/main/kotlin/app/futured/androidprojecttemplate/tools/extensions/GeneralExtensions.kt

@@ -0,0 +1,28 @@
+package app.futured.androidprojecttemplate.tools.extensions
+
+inline fun <T> T?.ifNull(defaultValue: () -> T): T = this ?: defaultValue.invoke()
+
+inline fun <T> withValue(receiver: T, block: T.() -> Unit) {
+    receiver.block()
+}
+
+inline fun <reified T : Any> withNonNullValue(receiver: T?, block: (T) -> Unit) {
+    if (receiver != null) block(receiver)
+}
+
+inline fun <T> safe(block: () -> T): T? {
+    return try {
+        block()
+    } catch (e: Exception) {
+        e.printStackTrace()
+        null
+    }
+}
+
+fun <T> T?.orThrow(): T = this ?: error("UnexpectedError") // Dev error
+
+inline fun <reified T> ifElseNull(predicate: Boolean, block: () -> T?) = if (predicate) block.invoke() else null
+
+inline fun <T> T.runWith(block: (T) -> Unit) {
+    block(this)
+}

app/src/main/kotlin/app/futured/androidprojecttemplate/tools/extensions/SavedStateHandleExtensions.kt

@@ -0,0 +1,44 @@
+package app.futured.androidprojecttemplate.tools.extensions
+
+import android.util.Base64.NO_PADDING
+import android.util.Base64.NO_WRAP
+import android.util.Base64.URL_SAFE
+import android.util.Base64.decode
+import android.util.Base64.encodeToString
+import androidx.lifecycle.Observer
+import androidx.lifecycle.SavedStateHandle
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+
+inline fun <reified T> SavedStateHandle.getSerializedArgument(key: String): T? = get<String>(key)?.deserializeFromNavArgument()
+
+inline fun <reified T> SavedStateHandle.getRequiredSerializedArgument(key: String): T =
+    getSerializedArgument(key) ?: error("Required parameter is not present")
+
+inline fun <reified T> SavedStateHandle.getArgument(key: String): T? = safe { get<T>(key) }
+
+inline fun <reified T> SavedStateHandle.getRequiredArgument(key: String): T =
+    getArgument(key) ?: getSerializedArgument(key) ?: error("Required parameter is not present")
+
+inline fun <reified T : Any> T.serializeAsNavArgument(): String? =
+    encodeToString(Json.encodeToString(this).encodeToByteArray(), NO_PADDING or NO_WRAP or URL_SAFE)
+
+inline fun <reified T> String.deserializeFromNavArgument(): T? =
+    safe { Json.decodeFromString(decode(this, NO_PADDING or NO_WRAP or URL_SAFE).decodeToString()) }
+
+fun <T> SavedStateHandle.subscribeForResult(key: String, callback: (T) -> Unit) {
+    val liveData = this.getLiveData<T>(key)
+    val observer = object : Observer<T> {
+        override fun onChanged(t: T) {
+            if (t != null) {
+                val value = remove<T>(key)
+                if (value != null) {
+                    callback(t)
+                }
+                liveData.removeObserver(this)
+                subscribeForResult(key, callback)
+            }
+        }
+    }
+    liveData.observeForever(observer)
+}

app/src/main/kotlin/app/futured/androidprojecttemplate/ui/NavGraph.kt

@@ -1,32 +1,40 @@
 package app.futured.androidprojecttemplate.ui
 
+import androidx.activity.compose.LocalOnBackPressedDispatcherOwner
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.remember
 import androidx.navigation.NavHostController
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.rememberNavController
 import app.futured.androidprojecttemplate.navigation.Destination
-import app.futured.androidprojecttemplate.navigation.NavigationDestinations
-import app.futured.androidprojecttemplate.navigation.NavigationDestinationsImpl
-import app.futured.androidprojecttemplate.navigation.composable
-import app.futured.androidprojecttemplate.ui.screens.detail.DetailScreen
-import app.futured.androidprojecttemplate.ui.screens.home.HomeScreen
+import app.futured.androidprojecttemplate.navigation.NavRouter
+import app.futured.androidprojecttemplate.navigation.NavRouterImpl
+import app.futured.androidprojecttemplate.navigation.composableDialog
+import app.futured.androidprojecttemplate.navigation.composableScreen
+import app.futured.androidprojecttemplate.navigation.dialogs
+import app.futured.androidprojecttemplate.navigation.screens
 
 @Composable
 fun NavGraph(
     navController: NavHostController = rememberNavController(),
-    navigation: NavigationDestinations = remember { NavigationDestinationsImpl(navController) },
+    navigation: NavRouter = remember { NavRouterImpl(navController) },
 ) {
+    LocalOnBackPressedDispatcherOwner.current?.onBackPressedDispatcher?.let {
+        navController.navigateUp()
+    }
+
     NavHost(
         navController = navController,
         startDestination = Destination.Home.route,
     ) {
-        composable(Destination.Home) {
-            HomeScreen(navigation)
+        // Destinations without navbar at the bottom
+        screens.forEach { destination ->
+            composableScreen(destination) { destination.destinationScreen(navigation) }
         }
 
-        composable(Destination.Detail) {
-            DetailScreen(navigation)
+        // Dialogs
+        dialogs.forEach { destination ->
+            composableDialog(destination) { destination.destinationScreen(navigation) }
         }
     }
 }

app/src/main/kotlin/app/futured/androidprojecttemplate/ui/components/AddFloatingActionButton.kt

@@ -1,9 +1,9 @@
 package app.futured.androidprojecttemplate.ui.components
 
-import androidx.compose.material.FloatingActionButton
-import androidx.compose.material.Icon
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Add
+import androidx.compose.material3.FloatingActionButton
+import androidx.compose.material3.Icon
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import app.futured.androidprojecttemplate.tools.compose.ComponentPreviews

app/src/main/kotlin/app/futured/androidprojecttemplate/ui/components/Showcase.kt

@@ -1,7 +1,7 @@
 package app.futured.androidprojecttemplate.ui.components
 
-import androidx.compose.material.MaterialTheme
-import androidx.compose.material.Surface
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import app.futured.androidprojecttemplate.ui.theme.AppTheme
@@ -12,7 +12,7 @@ import app.futured.androidprojecttemplate.ui.theme.AppTheme
 @Composable
 fun Showcase(modifier: Modifier = Modifier, content: @Composable () -> Unit) {
     AppTheme {
-        Surface(color = MaterialTheme.colors.background, modifier = modifier) {
+        Surface(color = MaterialTheme.colorScheme.background, modifier = modifier) {
             content()
         }
     }