Don't reframe the route on ordinary arrivals polls (#1895) (#1896)

In stop + route focus, onArrivalsLoaded re-emits the selected route's
ShowRoute directive on every arrivals load with frameRoute derived only from
preserveViewport. On an ordinary poll preserveViewport is false, so frameRoute
was true — routing through RouteMapController.reframe -> host.frameRoute() and
snapping the camera back to the whole route's extent, discarding whatever the
rider had panned/zoomed to.

Frame the selected route only when the load is the initial (restore/deep-link)
focus establishment. On an ordinary poll refresh the ShowRoute re-emission now
carries frameRoute=false, so reframe() is a no-op (direction unchanged, no
focusTripId) and the camera stays put. The initial route selection still frames
via selectStopRoute's default frameRoute=true.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: bmander

onebusaway-android/src/main/java/org/onebusaway/android/ui/home/HomeViewModel.kt

@@ -297,6 +297,10 @@ class HomeViewModel @Inject constructor(
         focusedTrips = trips
         presentedRoutes = trips.mapTo(linkedSetOf(), FocusedTrip::routeDirection)
         val preserveViewport = pendingMapFocus && preserveViewportForPendingMapFocus
+        // Frame the selected route only when this load is the initial (restore/deep-link) focus
+        // establishment; an ordinary arrivals poll must refresh the presentation without reframing the
+        // camera to the whole route (#1895). A restore carrying a saved viewport already declines to frame.
+        val frameSelectedRoute = pendingMapFocus && !preserveViewportForPendingMapFocus
         if (pendingMapFocus) {
             pendingMapFocus = false
             preserveViewportForPendingMapFocus = false
@@ -323,7 +327,7 @@ class HomeViewModel @Inject constructor(
                 MapDirective.ShowRoute(
                     it.target(focus.stop.id).toRequest(),
                     stopScoped = true,
-                    frameRoute = !preserveViewport,
+                    frameRoute = frameSelectedRoute,
                 )
             )
         }

onebusaway-android/src/test/java/org/onebusaway/android/ui/home/HomeViewModelTest.kt

@@ -291,6 +291,32 @@ class HomeViewModelTest {
         mapJob.cancel()
     }
 
+    @Test
+    fun `an ordinary arrivals poll refreshes the selected route without reframing`() = runTest {
+        val vm = viewModel()
+        val map = MapDirectiveRecorder(vm)
+        val mapJob = launch { map.collect() }
+        advanceUntilIdle()
+        vm.onStopFocused(FocusedStop("stop", "Main St", "100", 47.6, -122.3))
+        advanceUntilIdle()
+        vm.selectArrivalRoute(
+            request = ShowRouteRequest("65", directionStopId = "stop", initialDirectionId = 0),
+            shortName = "65",
+            headsign = "Downtown",
+        )
+        advanceUntilIdle()
+        // Selecting the route frames it once.
+        assertEquals(true, map.routeCommands.single().frameRoute)
+        map.sent.clear()
+
+        // A subsequent arrivals poll (no pending focus) re-shows the selected route but must not reframe.
+        vm.onArrivalsLoaded(ObaStopElement("stop", 47.6, -122.3, "Main St", "100"), emptyList(), emptySet())
+        advanceUntilIdle()
+
+        assertEquals(false, map.routeCommands.single().frameRoute)
+        mapJob.cancel()
+    }
+
     @Test
     fun `drawer route selection and continuation remain subordinate to stop focus`() = runTest {
         val savedState = SavedStateHandle()