Added within expression filter example

MapboxAndroidDemo/src/global/java/com/mapbox/mapboxandroiddemo/MainActivity.java

@@ -41,6 +41,7 @@
 import com.mapbox.mapboxandroiddemo.examples.dds.CircleToIconTransitionActivity;
 import com.mapbox.mapboxandroiddemo.examples.dds.PropertyIconDeterminationActivity;
 import com.mapbox.mapboxandroiddemo.examples.camera.ZoomToShowClusterLeavesActivity;
+import com.mapbox.mapboxandroiddemo.examples.dds.WithinExpressionActivity;
 import com.mapbox.mapboxandroiddemo.examples.javaservices.DirectionsProfileToggleActivity;
 import com.mapbox.mapboxandroiddemo.examples.javaservices.KotlinBorderedCircleActivity;
 import com.mapbox.mapboxandroiddemo.examples.dds.CreateHotspotsActivity;
@@ -1605,6 +1606,14 @@ private void initializeModels() {
       null,
       R.string.activity_dds_circle_icon_toggle_on_click_url, true, BuildConfig.MIN_SDK_VERSION));
 
+    exampleItemModels.add(new ExampleItemModel(
+        R.id.nav_dds,
+        R.string.activity_dds_within_expression_title,
+        R.string.activity_dds_within_expression_description,
+        null,
+        new Intent(MainActivity.this, WithinExpressionActivity.class),
+        R.string.activity_dds_within_expression_url, true, BuildConfig.MIN_SDK_VERSION));
+
     exampleItemModels.add(new ExampleItemModel(
       R.id.nav_basics,
       R.string.activity_basic_simple_mapview_title,

MapboxAndroidDemo/src/main/AndroidManifest.xml

@@ -924,6 +924,13 @@
                 android:name="android.support.PARENT_ACTIVITY"
                 android:value="com.mapbox.mapboxandroiddemo.MainActivity" />
         </activity>
+        <activity
+            android:name=".examples.dds.WithinExpressionActivity"
+            android:label="@string/activity_dds_within_expression_title">
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.mapbox.mapboxandroiddemo.MainActivity" />
+        </activity>
         <activity
             android:name=".examples.extrusions.MarathonExtrusionActivity"
             android:label="@string/activity_extrusions_catalina_marathon_extrusions_title">

MapboxAndroidDemo/src/main/java/com/mapbox/mapboxandroiddemo/examples/dds/WithinExpressionActivity.kt

@@ -0,0 +1,267 @@
+package com.mapbox.mapboxandroiddemo.examples.dds
+
+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.mapboxandroiddemo.R
+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 kotlinx.android.synthetic.main.activity_dds_within_expression.*
+
+/**
+ * Use 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_dds_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, 1500)
+                    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 = retrieveBufferLineStringGeometry(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() {
+        mapboxMap.getStyle {
+            // Add FillLayer to represent a buffered LineString
+            it.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 = it.getLayer("poi-label") as SymbolLayer
+            symbolLayer.setFilter(
+                    within(
+                            retrieveBufferLineStringGeometry()
+                    )
+            )
+
+            // Hide other types of labels to highlight POI labels
+            (it.getLayer("road-label") as SymbolLayer).setProperties(visibility(NONE))
+            (it.getLayer("transit-label") as SymbolLayer).setProperties(visibility(NONE))
+            (it.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 retrieveBufferLineStringGeometry(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"
+    }
+}

MapboxAndroidDemo/src/main/res/layout/activity_dds_within_expression.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:mapbox="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <com.mapbox.mapboxsdk.maps.MapView
+        android:id="@+id/mapView"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent" />
+
+</FrameLayout>

MapboxAndroidDemo/src/main/res/values/descriptions_strings.xml

@@ -68,6 +68,7 @@
     <string name="activity_dds_circle_to_icon_smooth_transition_description">Use expressions to create a smooth visual transition from circles to icons.</string>
     <string name="activity_dds_property_icon_switch_description">Create a SymbolLayer and set the iconId to be dependent on each Feature\'s property key/value pair. </string>
     <string name="activity_dds_circle_icon_toggle_on_click_description">Use layer filters and feature properties to create the visual effect of toggling between circles and icons when they\'re tapped on.</string>
+    <string name="activity_dds_within_expression_description">Check whether or not a feature is fully within the bounds of a GeoJSON polygon.</string>
     <string name="activity_styles_text_field_formatting_description">Adjust the color, size, and fonts of SymbolLayer text fields.</string>
     <string name="activity_camera_animate_description">"Animate the map's camera position, tilt, bearing, and zoom."</string>
     <string name="activity_camera_bounding_box_description">Position the camera so that all the given markers are in view.</string>

MapboxAndroidDemo/src/main/res/values/titles_strings.xml

@@ -69,6 +69,7 @@
     <string name="activity_dds_polygon_revealed_hole_outline_title">Outlined polygon hole</string>
     <string name="activity_dds_property_icon_switch_title">Icon setting based on Feature property</string>
     <string name="activity_dds_circle_icon_toggle_on_click_title">Circle icon toggle</string>
+    <string name="activity_dds_within_expression_title">Within filter</string>
     <string name="activity_camera_animate_title">Animate the map camera</string>
     <string name="activity_camera_bounding_box_title">Fit camera in bounding box</string>
     <string name="activity_camera_restrict_title">Restrict map panning</string>

MapboxAndroidDemo/src/main/res/values/urls_strings.xml

@@ -66,6 +66,7 @@
     <string name="activity_dds_circle_to_icon_smooth_transition_url" translatable="false">https://i.imgur.com/LYmENg3.png</string>
     <string name="activity_dds_property_icon_switch_url" translatable="false">https://i.imgur.com/GE1DZMp.png</string>
     <string name="activity_dds_circle_icon_toggle_on_click_url" translatable="false">https://i.imgur.com/5ewVbqM.png</string>
+    <string name="activity_dds_within_expression_url" translatable="false">https://i.imgur.com/9kChmHL.png</string>
     <string name="activity_styles_text_field_formatting_url" translatable="false">https://i.imgur.com/MSoIYmU.png</string>
     <string name="activity_camera_animate_url" translatable="false">http://i.imgur.com/PN3vyNJ.jpg</string>
     <string name="activity_camera_bounding_box_url" translatable="false">http://i.imgur.com/A0JL21Q.png</string>