[android] - add example of camera zoom function on a symbol layer.

platform/android/MapboxGLAndroidSDKTestApp/src/main/AndroidManifest.xml

@@ -626,12 +626,12 @@
                 android:value=".activity.FeatureOverviewActivity"/>
         </activity>
         <activity
-            android:name=".activity.annotation.AddRemoveMarkerActivity"
+            android:name=".activity.style.ZoomFunctionSymbolLayerActivity"
             android:description="@string/description_add_remove_markers"
             android:label="@string/activity_add_remove_markers">
             <meta-data
                 android:name="@string/category"
-                android:value="@string/category_annotation"/>
+                android:value="@string/category_style"/>
             <meta-data
                 android:name="android.support.PARENT_ACTIVITY"
                 android:value=".activity.FeatureOverviewActivity"/>

platform/android/MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/style/ZoomFunctionSymbolLayerActivity.java

@@ -0,0 +1,123 @@
+package com.mapbox.mapboxsdk.testapp.activity.style;
+
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.support.v7.app.AppCompatActivity;
+
+import com.mapbox.mapboxsdk.maps.MapView;
+import com.mapbox.mapboxsdk.maps.MapboxMap;
+import com.mapbox.mapboxsdk.maps.OnMapReadyCallback;
+import com.mapbox.mapboxsdk.style.layers.SymbolLayer;
+import com.mapbox.mapboxsdk.style.sources.GeoJsonSource;
+import com.mapbox.mapboxsdk.testapp.R;
+
+import java.net.MalformedURLException;
+import java.net.URL;
+
+import timber.log.Timber;
+
+import static com.mapbox.mapboxsdk.style.functions.Function.zoom;
+import static com.mapbox.mapboxsdk.style.functions.stops.Stop.stop;
+import static com.mapbox.mapboxsdk.style.functions.stops.Stops.interval;
+import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.iconAllowOverlap;
+import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.iconImage;
+
+public class ZoomFunctionSymbolLayerActivity extends AppCompatActivity {
+
+  private static final String SOURCE_URL = "https://gist.githubusercontent.com/anonymous/"
+    + "70ddad0e58520307cd1699e704f4b626/raw/a5deaccdc4517c12d63b1f8abcb7becf5e36506a/map.geojson";
+  private static final String LAYER_ID = "symbolLayer";
+  private static final String SOURCE_ID = "poiSource";
+  private static final String BUS_MAKI_ICON_ID = "bus-11";
+  private static final String CAFE_MAKI_ICON_ID = "cafe-11";
+  private static final float ZOOM_STOP_MIN_VALUE = 7.0f;
+  private static final float ZOOM_STOP_MAX_VALUE = 12.0f;
+
+  private MapView mapView;
+  private MapboxMap mapboxMap;
+  private GeoJsonSource source;
+
+  @Override
+  public void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    setContentView(R.layout.activity_zoom_symbol_layer);
+
+    mapView = (MapView) findViewById(R.id.mapView);
+    mapView.onCreate(savedInstanceState);
+    mapView.getMapAsync(new OnMapReadyCallback() {
+      @Override
+      public void onMapReady(@NonNull final MapboxMap map) {
+        mapboxMap = map;
+        addSource();
+        addLayer();
+      }
+    });
+  }
+
+  private void addSource() {
+    try {
+      source = new GeoJsonSource(SOURCE_ID, new URL(SOURCE_URL));
+    } catch (MalformedURLException exception) {
+      Timber.e(exception, "That's not an url... ");
+    }
+    mapboxMap.addSource(source);
+  }
+
+  private void addLayer() {
+    SymbolLayer layer = new SymbolLayer(LAYER_ID, SOURCE_ID);
+    layer.setProperties(
+      iconImage(
+        zoom(
+          interval(
+            stop(ZOOM_STOP_MIN_VALUE, iconImage(BUS_MAKI_ICON_ID)),
+            stop(ZOOM_STOP_MAX_VALUE, iconImage(CAFE_MAKI_ICON_ID))
+          )
+        )
+      ),
+      iconAllowOverlap(true)
+    );
+    mapboxMap.addLayer(layer);
+  }
+
+  @Override
+  protected void onStart() {
+    super.onStart();
+    mapView.onStart();
+  }
+
+  @Override
+  protected void onResume() {
+    super.onResume();
+    mapView.onResume();
+  }
+
+  @Override
+  protected void onPause() {
+    super.onPause();
+    mapView.onPause();
+  }
+
+  @Override
+  protected void onStop() {
+    super.onStop();
+    mapView.onStop();
+  }
+
+  @Override
+  public void onSaveInstanceState(Bundle outState) {
+    super.onSaveInstanceState(outState);
+    mapView.onSaveInstanceState(outState);
+  }
+
+  @Override
+  public void onLowMemory() {
+    super.onLowMemory();
+    mapView.onLowMemory();
+  }
+
+  @Override
+  public void onDestroy() {
+    super.onDestroy();
+    mapView.onDestroy();
+  }
+}

platform/android/MapboxGLAndroidSDKTestApp/src/main/res/layout/activity_zoom_symbol_layer.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+                xmlns:app="http://schemas.android.com/apk/res-auto"
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"
+                android:orientation="vertical">
+
+    <com.mapbox.mapboxsdk.maps.MapView
+        android:id="@id/mapView"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        app:mapbox_cameraTargetLat="40.730648"
+        app:mapbox_cameraTargetLng="-73.993619"
+        app:mapbox_cameraZoom="11"
+        app:mapbox_styleUrl="@string/mapbox_style_light"/>
+
+</RelativeLayout>

platform/android/MapboxGLAndroidSDKTestApp/src/main/res/values/dimens.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <dimen name="circle_size">24dp</dimen>
     <dimen name="fab_margin">16dp</dimen>
     <dimen name="attr_margin">10dp</dimen>
     <dimen name="map_padding_left">96dp</dimen>

platform/android/MapboxGLAndroidSDKTestApp/src/main/res/values/strings.xml

@@ -13,7 +13,7 @@
     <string name="activity_polygon">Polygon</string>
     <string name="activity_press_for_marker">Press Map For Marker</string>
     <string name="activity_view_marker">View Marker API</string>
-    <string name="activity_add_remove_markers">Add/Remove marker</string>
+    <string name="activity_add_remove_markers">Zoom function with SymbolLayer</string>
     <string name="activity_info_window">Standard InfoWindow</string>
     <string name="activity_infowindow_adapter">Custom InfoWindow</string>
     <string name="activity_dynamic_infowindow_adapter">Custom Dynamic InfoWindow</string>
@@ -114,7 +114,7 @@
     <string name="description_simple_map">Shows a simple map</string>
     <string name="description_map_change">Logs map change events to Logcat</string>
     <string name="description_visibility_map">Changes visibility of map and view parent</string>
-    <string name="description_add_remove_markers">Based on zoom level</string>
+    <string name="description_add_remove_markers">Change Symbol icon when zoom levels changes</string>
     <string name="description_style_file">Use a local file as the style</string>
     <string name="description_map_in_dialog">Display a map inside a dialog fragment</string>
     <string name="description_marker_view_rectangle">Marker Views within a rectangle</string>