| // Copyright 2018 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| part of google_maps_flutter; |
| |
| /// [Polyline] update events to be applied to the [GoogleMap]. |
| /// |
| /// Used in [GoogleMapController] when the map is updated. |
| class _PolylineUpdates { |
| /// Computes [_PolylineUpdates] given previous and current [Polyline]s. |
| _PolylineUpdates.from(Set<Polyline> previous, Set<Polyline> current) { |
| if (previous == null) { |
| previous = Set<Polyline>.identity(); |
| } |
| |
| if (current == null) { |
| current = Set<Polyline>.identity(); |
| } |
| |
| final Map<PolylineId, Polyline> previousPolylines = |
| _keyByPolylineId(previous); |
| final Map<PolylineId, Polyline> currentPolylines = |
| _keyByPolylineId(current); |
| |
| final Set<PolylineId> prevPolylineIds = previousPolylines.keys.toSet(); |
| final Set<PolylineId> currentPolylineIds = currentPolylines.keys.toSet(); |
| |
| Polyline idToCurrentPolyline(PolylineId id) { |
| return currentPolylines[id]; |
| } |
| |
| final Set<PolylineId> _polylineIdsToRemove = |
| prevPolylineIds.difference(currentPolylineIds); |
| |
| final Set<Polyline> _polylinesToAdd = currentPolylineIds |
| .difference(prevPolylineIds) |
| .map(idToCurrentPolyline) |
| .toSet(); |
| |
| /// Returns `true` if [current] is not equals to previous one with the |
| /// same id. |
| bool hasChanged(Polyline current) { |
| final Polyline previous = previousPolylines[current.polylineId]; |
| return current != previous; |
| } |
| |
| final Set<Polyline> _polylinesToChange = currentPolylineIds |
| .intersection(prevPolylineIds) |
| .map(idToCurrentPolyline) |
| .where(hasChanged) |
| .toSet(); |
| |
| polylinesToAdd = _polylinesToAdd; |
| polylineIdsToRemove = _polylineIdsToRemove; |
| polylinesToChange = _polylinesToChange; |
| } |
| |
| Set<Polyline> polylinesToAdd; |
| Set<PolylineId> polylineIdsToRemove; |
| Set<Polyline> polylinesToChange; |
| |
| Map<String, dynamic> _toMap() { |
| final Map<String, dynamic> updateMap = <String, dynamic>{}; |
| |
| void addIfNonNull(String fieldName, dynamic value) { |
| if (value != null) { |
| updateMap[fieldName] = value; |
| } |
| } |
| |
| addIfNonNull('polylinesToAdd', _serializePolylineSet(polylinesToAdd)); |
| addIfNonNull('polylinesToChange', _serializePolylineSet(polylinesToChange)); |
| addIfNonNull('polylineIdsToRemove', |
| polylineIdsToRemove.map<dynamic>((PolylineId m) => m.value).toList()); |
| |
| return updateMap; |
| } |
| |
| @override |
| bool operator ==(Object other) { |
| if (identical(this, other)) return true; |
| if (other.runtimeType != runtimeType) return false; |
| final _PolylineUpdates typedOther = other; |
| return setEquals(polylinesToAdd, typedOther.polylinesToAdd) && |
| setEquals(polylineIdsToRemove, typedOther.polylineIdsToRemove) && |
| setEquals(polylinesToChange, typedOther.polylinesToChange); |
| } |
| |
| @override |
| int get hashCode => |
| hashValues(polylinesToAdd, polylineIdsToRemove, polylinesToChange); |
| |
| @override |
| String toString() { |
| return '_PolylineUpdates{polylinesToAdd: $polylinesToAdd, ' |
| 'polylineIdsToRemove: $polylineIdsToRemove, ' |
| 'polylinesToChange: $polylinesToChange}'; |
| } |
| } |