From 03ed85decd2eacc908a0daeb3103f5c2b9be2085 Mon Sep 17 00:00:00 2001
From: James Rich <2199651+jamesarich@users.noreply.github.com>
Date: Wed, 10 Dec 2025 09:09:47 -0600
Subject: [PATCH] feat(navigation): Navigate back to list view on tab
 reselection (#3948)

Signed-off-by: James Rich <2199651+jamesarich@users.noreply.github.com>
---
 .../java/com/geeksville/mesh/model/UIState.kt    | 12 +++++++-----
 .../mesh/ui/contact/AdaptiveContactsScreen.kt    | 16 ++++++++++++++++
 .../mesh/ui/node/AdaptiveNodeListScreen.kt       | 15 +++++++++++++++
 3 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/app/src/main/java/com/geeksville/mesh/model/UIState.kt b/app/src/main/java/com/geeksville/mesh/model/UIState.kt
index da04eecd4..bdf9be6f5 100644
--- a/app/src/main/java/com/geeksville/mesh/model/UIState.kt
+++ b/app/src/main/java/com/geeksville/mesh/model/UIState.kt
@@ -28,19 +28,20 @@ import androidx.navigation.NavHostController
 import com.geeksville.mesh.repository.radio.MeshActivity
 import com.geeksville.mesh.repository.radio.RadioInterfaceService
 import dagger.hilt.android.lifecycle.HiltViewModel
-import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.channels.BufferOverflow
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharedFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asSharedFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.mapNotNull
 import kotlinx.coroutines.flow.onEach
-import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.flow.shareIn
 import org.jetbrains.compose.resources.getString
 import org.meshtastic.core.analytics.platform.PlatformAnalytics
@@ -131,11 +132,12 @@ constructor(
     val meshActivity: SharedFlow<MeshActivity> =
         radioInterfaceService.meshActivity.shareIn(viewModelScope, SharingStarted.Eagerly, 0)
 
-    private val scrollToTopEventChannel = Channel<ScrollToTopEvent>(capacity = Channel.CONFLATED)
-    val scrollToTopEventFlow: Flow<ScrollToTopEvent> = scrollToTopEventChannel.receiveAsFlow()
+    private val _scrollToTopEventFlow =
+        MutableSharedFlow<ScrollToTopEvent>(extraBufferCapacity = 1, onBufferOverflow = BufferOverflow.DROP_OLDEST)
+    val scrollToTopEventFlow: Flow<ScrollToTopEvent> = _scrollToTopEventFlow.asSharedFlow()
 
     fun emitScrollToTopEvent(event: ScrollToTopEvent) {
-        scrollToTopEventChannel.trySend(event)
+        _scrollToTopEventFlow.tryEmit(event)
     }
 
     data class AlertData(
diff --git a/app/src/main/java/com/geeksville/mesh/ui/contact/AdaptiveContactsScreen.kt b/app/src/main/java/com/geeksville/mesh/ui/contact/AdaptiveContactsScreen.kt
index 03e984917..9996ec1e1 100644
--- a/app/src/main/java/com/geeksville/mesh/ui/contact/AdaptiveContactsScreen.kt
+++ b/app/src/main/java/com/geeksville/mesh/ui/contact/AdaptiveContactsScreen.kt
@@ -77,6 +77,22 @@ fun AdaptiveContactsScreen(
             navigator.navigateTo(ListDetailPaneScaffoldRole.Detail, initialContactKey)
         }
     }
+
+    LaunchedEffect(scrollToTopEvents) {
+        scrollToTopEvents.collect { event ->
+            if (
+                event is ScrollToTopEvent.ConversationsTabPressed &&
+                navigator.currentDestination?.pane == ListDetailPaneScaffoldRole.Detail
+            ) {
+                if (navigator.canNavigateBack(backNavigationBehavior)) {
+                    navigator.navigateBack(backNavigationBehavior)
+                } else {
+                    navigator.navigateTo(ListDetailPaneScaffoldRole.List)
+                }
+            }
+        }
+    }
+
     ListDetailPaneScaffold(
         directive = navigator.scaffoldDirective,
         value = navigator.scaffoldValue,
diff --git a/app/src/main/java/com/geeksville/mesh/ui/node/AdaptiveNodeListScreen.kt b/app/src/main/java/com/geeksville/mesh/ui/node/AdaptiveNodeListScreen.kt
index f4db4c311..5b76a9425 100644
--- a/app/src/main/java/com/geeksville/mesh/ui/node/AdaptiveNodeListScreen.kt
+++ b/app/src/main/java/com/geeksville/mesh/ui/node/AdaptiveNodeListScreen.kt
@@ -77,6 +77,21 @@ fun AdaptiveNodeListScreen(
         }
     }
 
+    LaunchedEffect(scrollToTopEvents) {
+        scrollToTopEvents.collect { event ->
+            if (
+                event is ScrollToTopEvent.NodesTabPressed &&
+                navigator.currentDestination?.pane == ListDetailPaneScaffoldRole.Detail
+            ) {
+                if (navigator.canNavigateBack(backNavigationBehavior)) {
+                    navigator.navigateBack(backNavigationBehavior)
+                } else {
+                    navigator.navigateTo(ListDetailPaneScaffoldRole.List)
+                }
+            }
+        }
+    }
+
     ListDetailPaneScaffold(
         directive = navigator.scaffoldDirective,
         value = navigator.scaffoldValue,