Merge remote-tracking branch 'origin/main' into claude/audio-rooms-android-ui-PIpFN

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/NavigationEffects.kt

@@ -34,19 +34,22 @@ import androidx.navigation.NavGraphBuilder
 import androidx.navigation.compose.composable
 import androidx.navigation.toRoute
 
-// Per-entry hint stored on NavBackStackEntry.savedStateHandle by
-// Nav.navBottomBar. When present, composableFromEnd skips the horizontal
-// slide so bottom-bar taps fall back to the NavHost-level fade.
-const val SKIP_SLIDE_ANIMATION_KEY = "skipSlideAnimation"
+// Per-entry hint stamped by Nav.navBottomBar marking that the entry was
+// reached via a bottom-nav tab. Used in two places:
+//   - composableFromEnd skips the horizontal slide on tab entries so
+//     bottom-bar taps fall back to the NavHost-level fade.
+//   - Nav.canPop hides the back arrow on tab roots even though Home
+//     sits below them in the stack.
+const val BOTTOM_NAV_ROOT_KEY = "bottomNavRoot"
 
-fun NavBackStackEntry.skipsSlideAnimation(): Boolean = savedStateHandle.get<Boolean>(SKIP_SLIDE_ANIMATION_KEY) == true
+fun NavBackStackEntry.isBottomNavRoot(): Boolean = savedStateHandle.get<Boolean>(BOTTOM_NAV_ROOT_KEY) == true
 
 inline fun <reified T : Any> NavGraphBuilder.composableFromEnd(noinline content: @Composable AnimatedContentScope.(NavBackStackEntry) -> Unit) {
     composable<T>(
-        enterTransition = { if (targetState.skipsSlideAnimation()) null else slideInHorizontallyFromEnd },
-        exitTransition = { if (targetState.skipsSlideAnimation()) null else scaleOut },
-        popEnterTransition = { if (initialState.skipsSlideAnimation()) null else scaleIn },
-        popExitTransition = { if (initialState.skipsSlideAnimation()) null else slideOutHorizontallyToEnd },
+        enterTransition = { if (targetState.isBottomNavRoot()) null else slideInHorizontallyFromEnd },
+        exitTransition = { if (targetState.isBottomNavRoot()) null else scaleOut },
+        popEnterTransition = { if (initialState.isBottomNavRoot()) null else scaleIn },
+        popExitTransition = { if (initialState.isBottomNavRoot()) null else slideOutHorizontallyToEnd },
         content = content,
     )
 }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/navs/Nav.kt

@@ -24,9 +24,9 @@ import android.annotation.SuppressLint
 import androidx.compose.material3.DrawerState
 import androidx.compose.material3.DrawerValue
 import androidx.compose.runtime.Stable
-import androidx.navigation.NavGraph.Companion.findStartDestination
 import androidx.navigation.NavHostController
-import com.vitorpamplona.amethyst.ui.navigation.SKIP_SLIDE_ANIMATION_KEY
+import com.vitorpamplona.amethyst.ui.navigation.BOTTOM_NAV_ROOT_KEY
+import com.vitorpamplona.amethyst.ui.navigation.isBottomNavRoot
 import com.vitorpamplona.amethyst.ui.navigation.routes.Route
 import com.vitorpamplona.amethyst.ui.navigation.routes.getRouteWithArguments
 import kotlinx.coroutines.CoroutineScope
@@ -79,22 +79,25 @@ class Nav(
     override fun navBottomBar(route: Route) {
         navigationScope.launch {
             controller.navigate(route) {
-                // Clear the back stack down to and including the graph's start
-                // destination so a bottom-nav tap leaves only the new route in
-                // the stack. Without inclusive=true, Home would remain below
-                // the new tab and canPop() would wrongly show a back arrow.
-                popUpTo(controller.graph.findStartDestination().id) {
-                    inclusive = true
+                // Clear sibling bottom-nav entries but keep Home (the start
+                // destination) below, so back-swipe from any tab returns to
+                // Home and back-swipe from Home leaves the app.
+                popUpTo(Route.Home) {
+                    inclusive = false
                 }
                 launchSingleTop = true
             }
-            // Stamp the entry so composableFromEnd's transition lambdas can
-            // skip the slide animation when this entry enters or exits.
-            controller.getBackStackEntry(route).savedStateHandle[SKIP_SLIDE_ANIMATION_KEY] = true
+            // Mark this entry as a tab root: hides the back arrow in canPop
+            // and skips the horizontal slide in composableFromEnd.
+            controller.getBackStackEntry(route).savedStateHandle[BOTTOM_NAV_ROOT_KEY] = true
         }
     }
 
-    override fun canPop(): Boolean = controller.previousBackStackEntry != null
+    override fun canPop(): Boolean {
+        val current = controller.currentBackStackEntry ?: return false
+        if (current.isBottomNavRoot()) return false
+        return controller.previousBackStackEntry != null
+    }
 
     override fun popBack() {
         navigationScope.launch {