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fix: stop syncing gesture positions back to mapProvider

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Removed the updateCamera() call from onPositionChanged. Previously,
every gesture-driven pan/zoom frame updated the provider state, which
triggered ref.listen to call _mapController.move() redundantly.
This caused flutter_map's TileLayer to cancel in-flight tile loads
on every frame — producing partially-rendered maps and crashes when
zooming out during tile loading.

The ref.listen now only fires for programmatic changes (locateUser,
zoomIn/zoomOut), which are infrequent single-shot moves.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
Shautvast 2026-04-04 16:15:02 +02:00
parent 578d2d24ed
commit a3aaf1b6de
1 changed files with 11 additions and 17 deletions
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26
mobile/lib/features/map/presentation/screens/map_screen.dart
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@ -41,20 +41,14 @@ class _MapScreenState extends ConsumerState<MapScreen> {
final apiClient = ref.watch(apiClientProvider);
final styleAsync = ref.watch(mapStyleProvider(apiClient.baseUrl));
// Listen for zoom/center changes from the provider and move the map.
// Skip the move if the map controller is already at the target position
// (meaning the state change came from a user gesture via onPositionChanged).
// Without this guard, every gesture-driven pan calls _mapController.move()
// with the position the map is already at, which triggers a tile
// recalculation that cancels in-flight tile loads and produces a
// partially-rendered (diagonal) map.
// Move the map only for programmatic state changes (locateUser,
// zoomIn/zoomOut). Gesture-driven pans no longer call updateCamera(),
// so this listener only fires for intentional moves and won't interfere
// with the TileLayer's in-flight tile loads.
ref.listen<MapState>(mapProvider, (previous, next) {
if (previous?.center != next.center || previous?.zoom != next.zoom) {
final camera = _mapController.camera;
if (camera.center != next.center || camera.zoom != next.zoom) {
_mapController.move(next.center, next.zoom);
}
}
});
return Scaffold(
@ -69,12 +63,12 @@ class _MapScreenState extends ConsumerState<MapScreen> {
minZoom: 0,
maxZoom: 18,
onPositionChanged: (position, hasGesture) {
if (hasGesture) {
ref.read(mapProvider.notifier).updateCamera(
position.center,
position.zoom,
);
}
// Intentionally not syncing gesture-driven position changes
// back to the provider. Doing so caused ref.listen to call
// _mapController.move() on every pan/zoom frame, which made
// flutter_map's TileLayer cancel in-flight tile loads —
// producing a partially-rendered (diagonal) map and crashes
// when zooming out during tile loading.
},
onTap: (tapPosition, point) {
ref.read(mapProvider.notifier).clearSelectedPlace();