google_maps_cluster_manager
所属分类：云计算
开发工具：Dart
文件大小：0KB
下载次数：0
上传日期：2024-03-06 10:11:47
上 传 者：
sh-1993
说明： 谷歌地图集群管理器
(google maps cluster manager)
文件列表:
example/
lib/
test/
.metadata
CHANGELOG.md
LICENSE
pubspec.yaml
[](https://pub.dartlang.org/packages/google_maps_cluster_manager)
# Flutter Cluster Manager for Google Maps
A Flutter package to cluster items on a [Google Maps](https://pub.dev/packages/google_maps_flutter) widget based on Geohash. Highly inspired by [clustering_google_maps](https://pub.dev/packages/clustering_google_maps)
## Usage
To use this package, add `google_maps_cluster_manager` as a [dependency in your pubspec.yaml file](https://flutter.io/platform-plugins/).
### Getting Started
Your map items has to use `ClusterItem` as a mixin (or extends this class) and implements the `LatLng location` getter.
```dart
class Place with ClusterItem {
final String name;
final LatLng latLng;
Place({required this.name, required this.latLng});
@override
LatLng get location => latLng;
}
```
To start with Cluster Manager, you have to initialize a `ClusterManager` instance.
```dart
ClusterManager
(
_items, // Your items to be clustered on the map (of Place type for this example)
_updateMarkers, // Method to be called when markers are updated
markerBuilder: _markerBuilder, // Optional : Method to implement if you want to customize markers
levels: [1, 4.25, 6.75, 8.25, 11.5, 14.5, 16.0, 16.5, 20.0], // Optional : Configure this if you want to change zoom levels at which the clustering precision change
extraPercent: 0.2, // Optional : This number represents the percentage (0.2 for 20%) of latitude and longitude (in each direction) to be considered on top of the visible map bounds to render clusters. This way, clusters don't "pop out" when you cross the map.
stopClusteringZoom: 17.0 // Optional : The zoom level to stop clustering, so it's only rendering single item "clusters"
);
```
When your `GoogleMapController` is created, you have to set the `mapId` with the `setMapId` method :
```dart
_manager.setMapId(controller.mapId);
```
You are able to add an new item to the map by calling `addItem` method on your `ClusterManager` instance. You can also completely change the items on your maps by calling `setItems` method.
You can customize the icon of a cluster by using `Future Function(Cluster) markerBuilder` parameter.
```dart
static Future Function(Cluster) get markerBuilder => (cluster) async {
return Marker(
markerId: MarkerId(cluster.getId()),
position: cluster.location,
onTap: () {
print(cluster.items);
},
icon: await getClusterBitmap(cluster.isMultiple ? 125 : 75,
text: cluster.isMultiple? cluster.count.toString() : null),
);
};
static Future getClusterBitmap(int size, {String text?}) async {
final PictureRecorder pictureRecorder = PictureRecorder();
final Canvas canvas = Canvas(pictureRecorder);
final Paint paint1 = Paint()..color = Colors.red;
canvas.drawCircle(Offset(size / 2, size / 2), size / 2.0, paint1);
if (text != null) {
TextPainter painter = TextPainter(textDirection: TextDirection.ltr);
painter.text = TextSpan(
text: text,
style: TextStyle(
fontSize: size / 3,
color: Colors.white,
fontWeight: FontWeight.normal),
);
painter.layout();
painter.paint(
canvas,
Offset(size / 2 - painter.width / 2, size / 2 - painter.height / 2),
);
}
final img = await pictureRecorder.endRecording().toImage(size, size);
final data = await img.toByteData(format: ImageByteFormat.png);
return BitmapDescriptor.fromBytes(data.buffer.asUint8List());
}
```
Every cluster (even one item clusters) is rendered by the library as a `Cluster` object. You can differentiate single item clusters from multiple ones by using the `isMultiple` variable (or the `count` variable). This way, you can create different markers icon depending on the type of cluster.
You can create multiple managers for a single map, see the `multiple.dart` example.
## Complete Basic Example
See the `example` directory for a complete sample app.
近期下载者：
相关文件：
收藏者：