[testapp] - add example using within expression (#288)

MapboxGLAndroidSDKTestApp/src/main/AndroidManifest.xml

@@ -998,6 +998,17 @@
                     android:name="android.support.PARENT_ACTIVITY"
                     android:value=".activity.FeatureOverviewActivity" />
         </activity>
+        <activity
+            android:name=".activity.turf.WithinExpressionActivity"
+            android:description="@string/description_within"
+            android:label="@string/activity_within">
+            <meta-data
+                android:name="@string/category"
+                android:value="@string/category_style" />
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value=".activity.FeatureOverviewActivity" />
+        </activity>
         <!-- For Instrumentation tests -->
         <activity
             android:name=".activity.style.RuntimeStyleTimingTestActivity"

MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/turf/WithinExpressionActivity.kt

@@ -0,0 +1,268 @@
+package com.mapbox.mapboxsdk.testapp.activity.turf
+
+import android.graphics.Color
+import android.os.Bundle
+import android.os.Handler
+import android.os.PersistableBundle
+import androidx.appcompat.app.AppCompatActivity
+import com.mapbox.geojson.*
+import com.mapbox.mapboxsdk.camera.CameraPosition
+import com.mapbox.mapboxsdk.camera.CameraUpdateFactory
+import com.mapbox.mapboxsdk.geometry.LatLng
+import com.mapbox.mapboxsdk.maps.MapView
+import com.mapbox.mapboxsdk.maps.MapboxMap
+import com.mapbox.mapboxsdk.maps.Style
+import com.mapbox.mapboxsdk.style.expressions.Expression.within
+import com.mapbox.mapboxsdk.style.layers.CircleLayer
+import com.mapbox.mapboxsdk.style.layers.FillLayer
+import com.mapbox.mapboxsdk.style.layers.LineLayer
+import com.mapbox.mapboxsdk.style.layers.Property.NONE
+import com.mapbox.mapboxsdk.style.layers.PropertyFactory.*
+import com.mapbox.mapboxsdk.style.layers.SymbolLayer
+import com.mapbox.mapboxsdk.style.sources.GeoJsonOptions
+import com.mapbox.mapboxsdk.style.sources.GeoJsonSource
+import com.mapbox.mapboxsdk.testapp.R
+import kotlinx.android.synthetic.main.activity_physical_circle.*
+
+/**
+ * An Activity that showcases the within expression to filter features outside a geometry
+ */
+class WithinExpressionActivity : AppCompatActivity() {
+
+  private lateinit var mapboxMap: MapboxMap
+  private val handler: Handler = Handler()
+  private val runnable: Runnable = Runnable {
+    optimizeStyle()
+  }
+
+  override fun onCreate(savedInstanceState: Bundle?) {
+    super.onCreate(savedInstanceState)
+    setContentView(R.layout.activity_within_expression)
+
+    mapView.onCreate(savedInstanceState)
+    mapView.getMapAsync { map ->
+      mapboxMap = map
+
+      // Setup camera position above Georgetown
+      mapboxMap.cameraPosition = CameraPosition.Builder()
+        .target(LatLng(38.90628988399711, -77.06574689337494))
+        .zoom(15.5)
+        .build()
+
+      // Wait for the map to become idle before manipulating the style and camera of the map
+      mapView.addOnDidBecomeIdleListener(object : MapView.OnDidBecomeIdleListener {
+        override fun onDidBecomeIdle() {
+          handler.postDelayed(runnable, 2500)
+          mapView.removeOnDidBecomeIdleListener(this)
+        }
+      })
+
+      // Load mapbox streets and add lines and circles
+      setupStyle()
+    }
+  }
+
+  private fun setupStyle() {
+    // 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
+      )
+    )
+
+    // Convert to a LineString
+    val routeLineString = LineString.fromLngLats(coordinates)
+
+    // Create buffer around linestring
+    val bufferedRouteGeometry = bufferLineStringGeometry(routeLineString)
+
+    // Setup style with additional layers,
+    // using Style.MAPBOX_STREETS as a base style
+    mapboxMap.setStyle(
+      Style.Builder()
+        .fromUri(Style.MAPBOX_STREETS)
+        .withSources(
+          GeoJsonSource(
+            POINT_ID, LineString.fromLngLats(coordinates)
+          ),
+          GeoJsonSource(
+            FILL_ID,
+            FeatureCollection.fromFeature(Feature.fromGeometry(bufferedRouteGeometry)),
+            GeoJsonOptions().withBuffer(0).withTolerance(0.0f)
+          )
+        )
+        .withLayerBelow(
+          LineLayer(LINE_ID, POINT_ID)
+            .withProperties(lineWidth(7.5f), lineColor(Color.LTGRAY)),
+          "poi-label"
+        )
+        .withLayerBelow(
+          CircleLayer(POINT_ID, POINT_ID)
+            .withProperties(
+              circleRadius(7.5f),
+              circleColor(Color.DKGRAY),
+              circleOpacity(0.75f)
+            ), "poi-label"
+        )
+    )
+  }
+
+  private fun optimizeStyle() {
+    val style = mapboxMap.style!!
+
+    // Add fill layer to represent buffered LineString
+    mapboxMap.style!!.addLayerBelow(
+      FillLayer(FILL_ID, FILL_ID)
+        .withProperties(
+          fillOpacity(0.12f),
+          fillColor(Color.YELLOW)
+        ), LINE_ID
+    )
+
+    // Move to a new camera position
+    mapboxMap.easeCamera(
+      CameraUpdateFactory.newCameraPosition(
+        CameraPosition.Builder()
+          .zoom(16.0)
+          .target(LatLng(38.905156245642814, -77.06535338052844))
+          .bearing(80.68015859462369)
+          .tilt(55.0)
+          .build()
+      ), 1750
+    )
+
+    // Show only POI labels inside geometry using within expression
+    val symbolLayer = style.getLayer("poi-label") as SymbolLayer
+    symbolLayer.setFilter(
+      within(
+        bufferLineStringGeometry()
+      )
+    )
+
+    // Hide other types of labels to highlight POI labels
+    (style.getLayer("road-label") as SymbolLayer).setProperties(visibility(NONE))
+    (style.getLayer("transit-label") as SymbolLayer).setProperties(visibility(NONE))
+    (style.getLayer("road-number-shield") as SymbolLayer).setProperties(visibility(NONE))
+  }
+
+  override fun onStart() {
+    super.onStart()
+    mapView.onStart()
+  }
+
+  override fun onResume() {
+    super.onResume()
+    mapView.onResume()
+  }
+
+  override fun onPause() {
+    super.onPause()
+    mapView.onPause()
+  }
+
+  override fun onStop() {
+    super.onStop()
+    mapView.onStop()
+  }
+
+  override fun onLowMemory() {
+    super.onLowMemory()
+    mapView.onLowMemory()
+  }
+
+  override fun onDestroy() {
+    super.onDestroy()
+    handler.removeCallbacks(runnable)
+    mapView.onDestroy()
+  }
+
+  override fun onSaveInstanceState(outState: Bundle?, outPersistentState: PersistableBundle?) {
+    super.onSaveInstanceState(outState, outPersistentState)
+    outState?.let {
+      mapView.onSaveInstanceState(it)
+    }
+  }
+
+  private fun bufferLineStringGeometry(lineString: LineString? = null): 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"
+  }
+}

MapboxGLAndroidSDKTestApp/src/main/res/layout/activity_within_expression.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".activity.style.DraggableMarkerActivity">
+
+    <com.mapbox.mapboxsdk.maps.MapView
+        android:id="@+id/mapView"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent" />
+
+</RelativeLayout>

MapboxGLAndroidSDKTestApp/src/main/res/values/descriptions.xml

@@ -19,6 +19,7 @@
     <string name="description_debug_mode">Debug Mode</string>
     <string name="description_offline">Offline Map example</string>
     <string name="description_region">Download an offline region.</string>
+    <string name="description_within">Usage of the within expression on a buffered geometry</string>
     <string name="description_update_metadata">Update metadata example</string>
     <string name="description_offline_region_delete">Delete region example</string>
     <string name="description_change_resources_cache_path">Change resources cache path example</string>

MapboxGLAndroidSDKTestApp/src/main/res/values/titles.xml

@@ -87,4 +87,5 @@
     <string name="activity_performance_measurement">Performance Measurement</string>
     <string name="activity_physical_circle">Physical Unit Circle</string>
     <string name="activity_region">Download region</string>
+    <string name="activity_within">Within expression</string>
 </resources>