adding example of removing feature visibility with layer filter (#1308)

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

@@ -39,6 +39,7 @@
 import com.mapbox.mapboxandroiddemo.examples.dds.CircleLayerClusteringActivity;
 import com.mapbox.mapboxandroiddemo.examples.dds.CircleRadiusActivity;
 import com.mapbox.mapboxandroiddemo.examples.dds.CircleToIconTransitionActivity;
+import com.mapbox.mapboxandroiddemo.examples.dds.KotlinFilterFeaturesActivity;
 import com.mapbox.mapboxandroiddemo.examples.dds.PropertyIconDeterminationActivity;
 import com.mapbox.mapboxandroiddemo.examples.camera.ZoomToShowClusterLeavesActivity;
 import com.mapbox.mapboxandroiddemo.examples.dds.WithinExpressionActivity;
@@ -1678,6 +1679,14 @@ private void initializeModels() {
         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_dds,
+      R.string.activity_dds_filter_features_title,
+      R.string.activity_dds_filter_features_description,
+      null,
+      new Intent(MainActivity.this, KotlinFilterFeaturesActivity.class),
+      R.string.activity_dds_filter_features_url, false, BuildConfig.MIN_SDK_VERSION));
+
     exampleItemModels.add(new ExampleItemModel(
       R.id.nav_basics,
       R.string.activity_basic_simple_mapview_title,

MapboxAndroidDemo/src/main/AndroidManifest.xml

@@ -97,6 +97,13 @@
                 android:name="android.support.PARENT_ACTIVITY"
                 android:value="com.mapbox.mapboxandroiddemo.MainActivity" />
         </activity>
+        <activity
+            android:name=".examples.dds.KotlinFilterFeaturesActivity"
+            android:label="@string/activity_dds_filter_features_title">
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.mapbox.mapboxandroiddemo.MainActivity" />
+        </activity>
         <activity
             android:name=".examples.javaservices.MultipleGeometriesDirectionsRouteActivity"
             android:label="@string/activity_java_services_multiple_geometries_from_directions_route_title">

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

@@ -0,0 +1,103 @@
+package com.mapbox.mapboxandroiddemo.examples.dds
+
+import android.os.Bundle
+import android.widget.Toast
+import androidx.appcompat.app.AppCompatActivity
+import com.mapbox.mapboxandroiddemo.R
+import com.mapbox.mapboxsdk.Mapbox
+import com.mapbox.mapboxsdk.maps.Style
+import com.mapbox.mapboxsdk.style.expressions.Expression.*
+import com.mapbox.mapboxsdk.style.layers.SymbolLayer
+import kotlinx.android.synthetic.main.activity_dds_filter_feature.*
+
+/**
+ * Use filters to toggle the visibility of specific features. In this example, specific
+ * country labels are filtered out from a single layer.
+ */
+class KotlinFilterFeaturesActivity : AppCompatActivity() {
+
+    private var specificCountryLabelsHidden = false
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        // Mapbox access token is configured here. This needs to be called either in your application
+        // object or in the same activity which contains the mapview.
+        Mapbox.getInstance(this, getString(R.string.access_token))
+
+        // This contains the MapView in XML and needs to be called after the access token is configured.
+        setContentView(R.layout.activity_dds_filter_feature)
+        mapView?.onCreate(savedInstanceState)
+        mapView?.getMapAsync { mapboxMap ->
+
+            mapboxMap.uiSettings.setAllGesturesEnabled(false)
+
+            mapboxMap.setStyle(Style.MAPBOX_STREETS) {
+
+                toggle_feature_filter_visibility_fab.setOnClickListener {
+
+                    mapboxMap.getStyle {
+                        if (it.getLayer("country-label") != null) {
+                            it.getLayerAs<SymbolLayer>("country-label")?.setFilter(
+                                    if (specificCountryLabelsHidden) all() else
+                                        match(
+                                                get("name_en"),
+                                                all(
+                                                        literal("Libya"),
+                                                        literal("Austria"),
+                                                        literal("Spain"),
+                                                        literal("Mali"),
+                                                        literal("Syria"),
+                                                        literal("Tunisia"),
+                                                        literal("Denmark")
+                                                ),
+                                                literal(false), literal(true)
+                                        )
+                            )
+                            specificCountryLabelsHidden = !specificCountryLabelsHidden
+                            Toast.makeText(this, if (specificCountryLabelsHidden)
+                                R.string.filtering_countries else
+                                R.string.showing_all_country_labels, Toast.LENGTH_SHORT).show()
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    // Add the mapView lifecycle to the activity's lifecycle methods
+    public override fun onResume() {
+        super.onResume()
+        mapView?.onResume()
+    }
+
+    override fun onStart() {
+        super.onStart()
+        mapView?.onStart()
+    }
+
+    override fun onStop() {
+        super.onStop()
+        mapView?.onStop()
+    }
+
+    public override fun onPause() {
+        super.onPause()
+        mapView?.onPause()
+    }
+
+    override fun onLowMemory() {
+        super.onLowMemory()
+        mapView?.onLowMemory()
+    }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        mapView?.onDestroy()
+    }
+
+    override fun onSaveInstanceState(outState: Bundle) {
+        super.onSaveInstanceState(outState)
+        mapView?.onSaveInstanceState(outState)
+    }
+}

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

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    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"
+        mapbox:mapbox_cameraTargetLat="17.184917"
+        mapbox:mapbox_cameraTargetLng="9.386903"
+        mapbox:mapbox_cameraZoom="2" />
+
+    <com.google.android.material.floatingactionbutton.FloatingActionButton
+        android:id="@+id/toggle_feature_filter_visibility_fab"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="end|bottom"
+        android:layout_margin="16dp"
+        android:tint="@android:color/white"
+        app:backgroundTint="@color/colorPrimary"
+        app:srcCompat="@drawable/ic_cycle_through" />
+
+</androidx.coordinatorlayout.widget.CoordinatorLayout>

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

@@ -9,7 +9,6 @@
         android:id="@+id/mapView"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        mapbox:mapbox_cameraTargetLng="-43.334931"
         mapbox:mapbox_cameraZoom="0.346515"
          />
 

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

@@ -491,4 +491,8 @@
     <string name="duration">Duration:</string>
     <string name="color">Color:</string>
     <string name="select">Select</string>
+
+    <!-- Feature filter  -->
+    <string name="showing_all_country_labels">Showing all country labels</string>
+    <string name="filtering_countries">Match filter using "name_en", applied to layer to hide some countries\' labels</string>
 </resources>

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

@@ -70,6 +70,7 @@
     <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_dds_filter_features_description">Use filters to toggle the visibility of specific features. In this example, specific country labels are filtered out from a single layer.</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

@@ -71,6 +71,7 @@
     <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_dds_filter_features_title">Filter specific features</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

@@ -68,6 +68,7 @@
     <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_dds_filter_features_url" translatable="false">https://i.imgur.com/fnn6RMI.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>