aves/lib/widgets/common/map/zoomed_bounds.dart
Thibault Deckers c63de86c78 minor fixes
2021-10-07 15:55:55 +09:00

81 lines
2.1 KiB
Dart

import 'dart:math';
import 'package:aves/utils/geo_utils.dart';
import 'package:equatable/equatable.dart';
import 'package:flutter/foundation.dart';
import 'package:latlong2/latlong.dart';
@immutable
class ZoomedBounds extends Equatable {
final LatLng sw, ne;
final double zoom, rotation;
// returns [southwestLng, southwestLat, northeastLng, northeastLat], as expected by Fluster
List<double> get boundingBox => [sw.longitude, sw.latitude, ne.longitude, ne.latitude];
LatLng get center => GeoUtils.getLatLngCenter([sw, ne]);
@override
List<Object?> get props => [sw, ne, zoom, rotation];
const ZoomedBounds({
required this.sw,
required this.ne,
required this.zoom,
required this.rotation,
});
static const _collocationMaxDeltaThreshold = 360 / (2 << 19);
factory ZoomedBounds.fromPoints({
required Set<LatLng> points,
double collocationZoom = 20,
}) {
var west = .0, south = .0, east = .0, north = .0;
var zoom = collocationZoom;
if (points.isNotEmpty) {
final first = points.first;
west = first.longitude;
south = first.latitude;
east = first.longitude;
north = first.latitude;
for (var point in points) {
final lng = point.longitude;
final lat = point.latitude;
if (lng < west) west = lng;
if (lat < south) south = lat;
if (lng > east) east = lng;
if (lat > north) north = lat;
}
final boundsDelta = max(north - south, east - west);
if (boundsDelta > _collocationMaxDeltaThreshold) {
zoom = max(1, log(360) / ln2 - log(boundsDelta) / ln2);
}
}
return ZoomedBounds(
sw: LatLng(south, west),
ne: LatLng(north, east),
zoom: zoom,
rotation: 0,
);
}
ZoomedBounds copyWith({
LatLng? sw,
LatLng? ne,
double? zoom,
double? rotation,
}) {
return ZoomedBounds(
sw: sw ?? this.sw,
ne: ne ?? this.ne,
zoom: zoom ?? this.zoom,
rotation: rotation ?? this.rotation,
);
}
bool contains(LatLng point) => GeoUtils.contains(sw, ne, point);
}