Query rendered features
QueryRenderedFeatureActivity.kt
package com.mapbox.maps.compose.testapp.examples.basic
import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberCoroutineScope
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import com.mapbox.geojson.Point
import com.mapbox.geojson.Polygon
import com.mapbox.maps.RenderedQueryGeometry
import com.mapbox.maps.RenderedQueryOptions
import com.mapbox.maps.Style
import com.mapbox.maps.compose.testapp.ExampleScaffold
import com.mapbox.maps.compose.testapp.examples.utils.CityLocations
import com.mapbox.maps.compose.testapp.ui.theme.MapboxMapComposeTheme
import com.mapbox.maps.extension.compose.MapState
import com.mapbox.maps.extension.compose.MapboxMap
import com.mapbox.maps.extension.compose.animation.viewport.rememberMapViewportState
import com.mapbox.maps.extension.compose.annotation.generated.PolygonAnnotation
import com.mapbox.maps.extension.compose.rememberMapState
import com.mapbox.maps.extension.compose.style.MapStyle
import com.mapbox.maps.logD
import com.mapbox.maps.plugin.gestures.generated.GesturesSettings
import kotlinx.coroutines.flow.first
import kotlinx.coroutines.launch
/**
* Example to showcase usage of query rendered features.
*/
public class QueryRenderedFeatureActivity : ComponentActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContent {
val mapState = rememberMapState {
gesturesSettings = GesturesSettings {
doubleTapToZoomInEnabled = false
quickZoomEnabled = false
doubleTouchToZoomOutEnabled = false
pinchToZoomEnabled = false
}
}
var highlightedBuilding by remember {
mutableStateOf(emptyList<List<Point>>())
}
LaunchedEffect(Unit) {
with(mapState) {
// wait and suspend for the first ever map idle event, meaning map is rendered.
mapIdleEvents.first()
highlightedBuilding =
queryBuildingCoordinatesAt(CityLocations.HELSINKI)
}
}
MapboxMapComposeTheme {
ExampleScaffold {
val coroutineScope = rememberCoroutineScope()
MapboxMap(
Modifier.fillMaxSize(),
mapViewportState = rememberMapViewportState {
setCameraOptions {
zoom(ZOOM)
center(CityLocations.HELSINKI)
}
},
style = {
MapStyle(style = Style.MAPBOX_STREETS)
},
onMapClickListener = {
coroutineScope.launch {
highlightedBuilding = mapState.queryBuildingCoordinatesAt(it)
}
false
},
mapState = mapState
) {
PolygonAnnotation(highlightedBuilding) {
fillColor = Color.Red
fillOpacity = 0.5
}
}
}
}
}
}
private suspend fun MapState.queryBuildingCoordinatesAt(point: Point): List<List<Point>> =
queryRenderedFeatures(
RenderedQueryGeometry(pixelForCoordinate(point)),
RenderedQueryOptions(listOf("building"), null)
).value?.let { list ->
list.firstNotNullOfOrNull {
logD(TAG, "Feature properties: ${it.queriedFeature.feature.properties()}")
(it.queriedFeature.feature.geometry() as? Polygon)?.coordinates()?.toList()
} ?: emptyList()
} ?: emptyList()
private companion object {
const val TAG = "QRFActivity"
const val ZOOM: Double = 15.5
}
}
この{Type}は役に立ちましたか？