#import "MGLFeature.h"
#import "MGLFoundation.h"
#import "MGLTileSource.h"
NS_ASSUME_NONNULL_BEGIN
/**
`MGLVectorTileSource` is a map content source that supplies tiled vector data
in Mapbox Vector Tile format
to be shown on the map. The location of and metadata about the tiles are
defined either by an option dictionary or by an external file that conforms to
the
TileJSON specification.
A vector tile source is added to an `MGLStyle` object along with one or more
`MGLVectorStyleLayer` objects. A vector style layer defines the appearance of
any content supplied by the vector tile source.
`MGLVectorTileSource` is optimized for data sets that are too large to fit
completely in memory, such as vector tile sets or data sets managed in
Mapbox Studio. For
GeoJSON data, use the `MGLShapeSource`
class. For tiled data that changes dynamically, the `MGLComputedShapeSource`
class may be a suitable alternative.
Each
vector
source defined by the style JSON file is represented at runtime by an
`MGLVectorTileSource` object that you can use to initialize new style layers.
You can also add and remove sources dynamically using methods such as
`-[MGLStyle addSource:]` and `-[MGLStyle sourceWithIdentifier:]`.
Within each vector tile, each geometric coordinate must lie between
−1 × extent and
(extent × 2) − 1, inclusive. Any vector style
layer initialized with a vector tile source must have a non-`nil` value in its
`sourceLayerIdentifier` property.
Commonly used vector tile sources include
Mapbox Streets,
Mapbox Terrain,
and
Mapbox Traffic.
### Example
```swift
let source = MGLVectorTileSource(identifier: "pois", tileURLTemplates: ["https://example.com/vector-tiles/{z}/{x}/{y}.mvt"], options: [
.minimumZoomLevel: 9,
.maximumZoomLevel: 16,
.attributionInfos: [
MGLAttributionInfo(title: NSAttributedString(string: "© Mapbox"), url: URL(string: "https://mapbox.com"))
]
])
mapView.style?.addSource(source)
```
#### Related examples
See the
Data-driven circles example to learn how to add data to your map using
an `MGLVectorTileSource` object.
*/
MGL_EXPORT
@interface MGLVectorTileSource : MGLTileSource
#pragma mark Initializing a Source
/**
Returns a vector tile source initialized with an identifier and configuration
URL.
After initializing and configuring the source, add it to a map view’s style
using the `-[MGLStyle addSource:]` method.
The URL may be a full HTTP or HTTPS URL or, for tile sets hosted by Mapbox, a
Mapbox URL indicating a map identifier (`mapbox://`). The URL should
point to a JSON file that conforms to the
TileJSON specification.
@param identifier A string that uniquely identifies the source in the style to
which it is added.
@param configurationURL A URL to a TileJSON configuration file describing the
source’s contents and other metadata.
@return An initialized vector tile source.
*/
- (instancetype)initWithIdentifier:(NSString *)identifier configurationURL:(NSURL *)configurationURL NS_DESIGNATED_INITIALIZER;
/**
Returns a vector tile source initialized an identifier, tile URL templates, and
options.
Tile URL templates are strings that specify the URLs of the vector tiles to
load. See the “Tile URL Templates”
guide for information about the format of a tile URL template.
After initializing and configuring the source, add it to a map view’s style
using the `-[MGLStyle addSource:]` method.
@param identifier A string that uniquely identifies the source in the style to
which it is added.
@param tileURLTemplates An array of tile URL template strings. Only the first
string is used; any additional strings are ignored.
@param options A dictionary containing configuration options. See
`MGLTileSourceOption` for available keys and values. Pass in `nil` to use
the default values.
@return An initialized tile source.
*/
- (instancetype)initWithIdentifier:(NSString *)identifier tileURLTemplates:(NSArray *)tileURLTemplates options:(nullable NSDictionary *)options NS_DESIGNATED_INITIALIZER;
#pragma mark Accessing a Source’s Content
/**
Returns an array of map features loaded by this source, restricted to the given
source layers and filtered by the given predicate.
Each object in the returned array represents a feature loaded by the source and
provides access to attributes specified as part of the loaded feature. The
source loads a feature if the source is added to an `MGLMapView`’s style; that
style has a layer that uses the source; and the map view has recently scrolled
to the region containing the feature.
Features come from tiled vector data that is converted to tiles internally, so
feature geometries are clipped at tile boundaries and features may appear
duplicated across tiles. For example, suppose part of a lengthy polyline
representing a road has recently scrolled into view. The resulting array
includes those parts of the road that lie within the map tiles that the source
has loaded, even if the road extends into other tiles. The portion of the road
within each map tile is included individually.
Returned features may not necessarily be visible to the user at the time they
are loaded: the style may contain a layer that forces the source’s tiles to
load but filters out the features in question, preventing them from being
drawn. To obtain only _visible_ features, use the
`-[MGLMapView visibleFeaturesAtPoint:inStyleLayersWithIdentifiers:predicate:]`
or
`-[MGLMapView visibleFeaturesInRect:inStyleLayersWithIdentifiers:predicate:]`
method.
@param sourceLayerIdentifiers The source layers to include in the query. Only
the features contained in these source layers are included in the returned
array. This array may not be empty.
@param predicate A predicate to filter the returned features. Use `nil` to
include all loaded features.
@return An array of objects conforming to the `MGLFeature` protocol that
represent features loaded by the source that match the predicate.
*/
- (NSArray> *)featuresInSourceLayersWithIdentifiers:(NSSet *)sourceLayerIdentifiers predicate:(nullable NSPredicate *)predicate NS_SWIFT_NAME(features(sourceLayerIdentifiers:predicate:));
@end
NS_ASSUME_NONNULL_END