Within expression
package com.mapbox.maps.testapp.examples
import android.graphics.Color
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import com.mapbox.geojson.*
import com.mapbox.maps.CameraOptions
import com.mapbox.maps.MapView
import com.mapbox.maps.Style
import com.mapbox.maps.extension.style.expressions.dsl.generated.within
import com.mapbox.maps.extension.style.layers.addLayerBelow
import com.mapbox.maps.extension.style.layers.generated.SymbolLayer
import com.mapbox.maps.extension.style.layers.generated.fillLayer
import com.mapbox.maps.extension.style.layers.generated.lineLayer
import com.mapbox.maps.extension.style.layers.getLayer
import com.mapbox.maps.extension.style.layers.properties.generated.Visibility
import com.mapbox.maps.extension.style.sources.generated.geoJsonSource
import com.mapbox.maps.extension.style.style
import com.mapbox.maps.plugin.animation.MapAnimationOptions.Companion.mapAnimationOptions
import com.mapbox.maps.plugin.animation.camera
/**
* An Activity that showcases the within expression to filter features outside a geometry
*/
class WithinExpressionActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
val mapView = MapView(this)
setContentView(mapView)
val center = Point.fromLngLat(LON, LAT)
// Setup camera position above Georgetown
mapView.mapboxMap.setCamera(
CameraOptions.Builder()
.center(center)
.zoom(15.5)
.build()
)
// Assume the route is represented by an array of coordinates.
val coordinates = listOf<Point>(
Point.fromLngLat(
-77.06866264343262,
38.90506061276737
),
Point.fromLngLat(
-77.06283688545227,
38.905194197410545
),
Point.fromLngLat(
-77.06285834312439,
38.906429843444094
),
Point.fromLngLat(
-77.0630407333374,
38.90680554236621
)
)
// Create buffer around linestring
val bufferedRouteGeometry = bufferLineStringGeometry()
mapView.mapboxMap.loadStyle(
style(Style.MAPBOX_STREETS) {
+geoJsonSource(POINT_ID) {
geometry(LineString.fromLngLats(coordinates))
}
+geoJsonSource(FILL_ID) {
featureCollection(FeatureCollection.fromFeature(Feature.fromGeometry(bufferedRouteGeometry)))
buffer(0)
tolerance(0.0)
}
+layerAtPosition(
lineLayer(LINE_ID, POINT_ID) {
lineWidth(7.5)
lineColor(Color.LTGRAY)
},
below = POI_LABEL
)
}
) { // Add fill layer to represent buffered LineString
it.addLayerBelow(
fillLayer(FILL_ID, FILL_ID) {
fillOpacity(0.12)
fillColor(Color.YELLOW)
},
LINE_ID
)
// Move to a new camera position
mapView.camera.easeTo(
CameraOptions.Builder()
.zoom(16.0)
.center(Point.fromLngLat(-77.06535338052844, 38.905156245642814))
.bearing(80.68015859462369)
.pitch(55.0)
.build(),
mapAnimationOptions {
duration(1750)
startDelay(2000)
}
)
// Show only POI labels inside geometry using within expression
val symbolLayer = it.getLayer(POI_LABEL) as SymbolLayer
symbolLayer.filter(within(bufferedRouteGeometry))
// Hide other types of labels to highlight POI labels
(it.getLayer(ROAD_LABEL) as SymbolLayer).visibility(
Visibility.NONE
)
(it.getLayer(TRANSIT_LABEL) as SymbolLayer).visibility(
Visibility.NONE
)
(it.getLayer(ROAD_NUMBER_SHIELD) as SymbolLayer).visibility(
Visibility.NONE
)
}
}
private fun bufferLineStringGeometry(): Polygon {
// TODO replace static data by Turf#Buffer: mapbox-java/issues/987
return FeatureCollection.fromJson(
"""
{
"type": "FeatureCollection",
"features": [
{
"type": "Feature",
"properties": {},
"geometry": {
"type": "Polygon",
"coordinates": [
[
[
-77.06867337226866,
38.90467655551809
],
[
-77.06233263015747,
38.90479344272695
],
[
-77.06234335899353,
38.906463238984344
],
[
-77.06290125846863,
38.907206285691615
],
[
-77.06364154815674,
38.90684728656818
],
[
-77.06326603889465,
38.90637140121084
],
[
-77.06321239471436,
38.905561553883246
],
[
-77.0691454410553,
38.905436318935635
],
[
-77.06912398338318,
38.90466820642439
],
[
-77.06867337226866,
38.90467655551809
]
]
]
}
}
]
}
""".trimIndent()
).features()!![0].geometry() as Polygon
}
companion object {
const val POINT_ID = "point"
const val FILL_ID = "fill"
const val LINE_ID = "line"
const val LAT = 38.90628988399711
const val LON = -77.06574689337494
const val POI_LABEL = "poi-label"
const val ROAD_LABEL = "road-label"
const val TRANSIT_LABEL = "transit-label"
const val ROAD_NUMBER_SHIELD = "road-number-shield"
}
}
この{Type}は役に立ちましたか?