feat(app): implement shared transition for search functionality in HomeTopBar and HomeSearchFullScreen

app/src/main/java/hu/bbara/purefin/PurefinActivity.kt

@@ -6,6 +6,8 @@ import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import androidx.compose.animation.core.tween
+import androidx.compose.animation.ExperimentalSharedTransitionApi
+import androidx.compose.animation.SharedTransitionLayout
 import androidx.compose.animation.fadeIn
 import androidx.compose.animation.fadeOut
 import androidx.compose.animation.togetherWith
@@ -41,6 +43,7 @@ import hu.bbara.purefin.jellyfin.JellyfinAuthInterceptor
 import hu.bbara.purefin.data.UserSessionRepository
 import hu.bbara.purefin.navigation.LocalNavigationBackStack
 import hu.bbara.purefin.navigation.LocalNavigationManager
+import hu.bbara.purefin.navigation.LocalSharedTransitionScope
 import hu.bbara.purefin.navigation.NavigationCommand
 import hu.bbara.purefin.navigation.NavigationManager
 import hu.bbara.purefin.navigation.Route
@@ -131,6 +134,7 @@ class PurefinActivity : ComponentActivity() {
         return (applicationInfo.flags and ApplicationInfo.FLAG_DEBUGGABLE) != 0
     }
 
+    @OptIn(ExperimentalSharedTransitionApi::class)
     @Composable
     fun MainApp(
         userSessionRepository: UserSessionRepository,
@@ -172,9 +176,11 @@ class PurefinActivity : ComponentActivity() {
                 }
             }
 
+            SharedTransitionLayout {
                 CompositionLocalProvider(
                     LocalNavigationManager provides navigationManager,
-                LocalNavigationBackStack provides backStack.toList()
+                    LocalNavigationBackStack provides backStack.toList(),
+                    LocalSharedTransitionScope provides this
                 ) {
                     NavDisplay(
                         backStack = backStack,
@@ -212,6 +218,7 @@ class PurefinActivity : ComponentActivity() {
                         entryProvider = appEntryProvider
                     )
                 }
+            }
         } else {
             LoginScreen()
         }

app/src/main/java/hu/bbara/purefin/navigation/NavigationLocals.kt

@@ -1,5 +1,8 @@
 package hu.bbara.purefin.navigation
 
+import androidx.compose.animation.AnimatedVisibilityScope
+import androidx.compose.animation.ExperimentalSharedTransitionApi
+import androidx.compose.animation.SharedTransitionScope
 import androidx.compose.runtime.ProvidableCompositionLocal
 import androidx.compose.runtime.compositionLocalOf
 import androidx.compose.runtime.staticCompositionLocalOf
@@ -8,3 +11,11 @@ val LocalNavigationManager: ProvidableCompositionLocal<NavigationManager> =
     staticCompositionLocalOf { error("NavigationManager not provided") }
 
 val LocalNavigationBackStack = compositionLocalOf<List<Route>> { emptyList() }
+
+@OptIn(ExperimentalSharedTransitionApi::class)
+val LocalSharedTransitionScope = compositionLocalOf<SharedTransitionScope?> { null }
+
+val LocalNavSharedAnimatedVisibilityScope =
+    compositionLocalOf<AnimatedVisibilityScope?> { null }
+
+const val HOME_SEARCH_SHARED_BOUNDS_KEY = "home_search_shared_bounds"

app/src/main/java/hu/bbara/purefin/navigation/RouteEntryBuilder.kt

@@ -1,6 +1,8 @@
 package hu.bbara.purefin.navigation
 
+import androidx.compose.runtime.CompositionLocalProvider
 import androidx.navigation3.runtime.EntryProviderScope
+import androidx.navigation3.ui.LocalNavAnimatedContentScope
 import hu.bbara.purefin.ui.screen.library.LibraryScreen
 import hu.bbara.purefin.ui.screen.login.LoginScreen
 import hu.bbara.purefin.ui.screen.AppScreen
@@ -11,11 +13,19 @@ import hu.bbara.purefin.ui.screen.series.SeriesScreen
 
 fun EntryProviderScope<Route>.appRouteEntryBuilder() {
     entry<Route.Home> {
+        CompositionLocalProvider(
+            LocalNavSharedAnimatedVisibilityScope provides LocalNavAnimatedContentScope.current
+        ) {
             AppScreen()
         }
+    }
     entry<Route.HomeSearchRoute> {
+        CompositionLocalProvider(
+            LocalNavSharedAnimatedVisibilityScope provides LocalNavAnimatedContentScope.current
+        ) {
             HomeSearchFullScreen()
         }
+    }
     entry<Route.MovieRoute> {
         MovieScreen(movie = it.item)
     }

app/src/main/java/hu/bbara/purefin/ui/screen/home/components/HomeTopBar.kt

@@ -1,5 +1,9 @@
 package hu.bbara.purefin.ui.screen.home.components
 
+import androidx.compose.animation.ExperimentalSharedTransitionApi
+import androidx.compose.animation.SharedTransitionScope
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.shape.CircleShape
@@ -21,7 +25,11 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.unit.dp
+import hu.bbara.purefin.navigation.HOME_SEARCH_SHARED_BOUNDS_KEY
+import hu.bbara.purefin.navigation.LocalNavSharedAnimatedVisibilityScope
+import hu.bbara.purefin.navigation.LocalSharedTransitionScope
 
+@OptIn(ExperimentalSharedTransitionApi::class)
 @Composable
 fun HomeTopBar(
     onSearchClick: () -> Unit,
@@ -30,11 +38,34 @@ fun HomeTopBar(
     onLogoutClick: () -> Unit,
 ) {
     val scheme = MaterialTheme.colorScheme
+    val sharedTransitionScope = LocalSharedTransitionScope.current
+    val animatedVisibilityScope = LocalNavSharedAnimatedVisibilityScope.current
 
     var isProfileMenuExpanded by remember { mutableStateOf(false) }
 
     DefaultTopBar()
         {
+            val searchButtonModifier = if (
+                sharedTransitionScope != null &&
+                animatedVisibilityScope != null
+            ) {
+                with(sharedTransitionScope) {
+                    Modifier
+                        .sharedBounds(
+                            sharedContentState = rememberSharedContentState(
+                                key = HOME_SEARCH_SHARED_BOUNDS_KEY
+                            ),
+                            animatedVisibilityScope = animatedVisibilityScope,
+                            enter = fadeIn(),
+                            exit = fadeOut(),
+                            resizeMode = SharedTransitionScope.ResizeMode.scaleToBounds()
+                        )
+                        .size(50.dp)
+                }
+            } else {
+                Modifier.size(50.dp)
+            }
+
             IconButton(
                 onClick = onSearchClick,
                 colors = IconButtonColors(
@@ -43,7 +74,7 @@ fun HomeTopBar(
                     disabledContainerColor = scheme.surface,
                     disabledContentColor = scheme.onSurface
                 ),
-                modifier = Modifier.size(50.dp),
+                modifier = searchButtonModifier,
             ) {
                 Icon(
                     imageVector = Icons.Outlined.Search,

app/src/main/java/hu/bbara/purefin/ui/screen/home/components/search/HomeSearchFullScreen.kt

@@ -1,5 +1,9 @@
 package hu.bbara.purefin.ui.screen.home.components.search
 
+import androidx.compose.animation.ExperimentalSharedTransitionApi
+import androidx.compose.animation.SharedTransitionScope
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
 import androidx.compose.foundation.BorderStroke
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Arrangement
@@ -51,17 +55,41 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import hu.bbara.purefin.ui.common.image.PurefinAsyncImage
 import hu.bbara.purefin.ui.common.image.PurefinLogo
+import hu.bbara.purefin.navigation.HOME_SEARCH_SHARED_BOUNDS_KEY
+import hu.bbara.purefin.navigation.LocalNavSharedAnimatedVisibilityScope
+import hu.bbara.purefin.navigation.LocalSharedTransitionScope
 import hu.bbara.purefin.ui.theme.AppTheme
 
-@OptIn(ExperimentalLayoutApi::class)
+@OptIn(ExperimentalLayoutApi::class, ExperimentalSharedTransitionApi::class)
 @Composable
 fun HomeSearchFullScreen(
     modifier: Modifier = Modifier
 ) {
     val scheme = MaterialTheme.colorScheme
+    val sharedTransitionScope = LocalSharedTransitionScope.current
+    val animatedVisibilityScope = LocalNavSharedAnimatedVisibilityScope.current
+    val sharedBoundsModifier = if (
+        sharedTransitionScope != null &&
+        animatedVisibilityScope != null
+    ) {
+        with(sharedTransitionScope) {
+            Modifier.sharedBounds(
+                sharedContentState = rememberSharedContentState(
+                    key = HOME_SEARCH_SHARED_BOUNDS_KEY
+                ),
+                animatedVisibilityScope = animatedVisibilityScope,
+                enter = fadeIn(),
+                exit = fadeOut(),
+                resizeMode = SharedTransitionScope.ResizeMode.scaleToBounds()
+            )
+        }
+    } else {
+        Modifier
+    }
 
     Column(
         modifier = modifier
+            .then(sharedBoundsModifier)
             .fillMaxSize()
             .background(scheme.background)
             .statusBarsPadding()