[android] Bindings for Custom Geometry Sources

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/geometry/LatLngBounds.java

@@ -231,6 +231,25 @@ public class LatLngBounds implements Parcelable {
     return new LatLngBounds(latNorth, lonEast, latSouth, lonWest);
   }
 
+  private static double lat_(int z, int y) {
+    double n = Math.PI - 2.0 * Math.PI * y / Math.pow(2.0, z);
+    return Math.toDegrees(Math.atan(0.5 * (Math.exp(n) - Math.exp(-n))));
+  }
+
+  private static double lon_(int z, int x) {
+    return x / Math.pow(2.0, z) * 360.0 - GeoConstants.MAX_LONGITUDE;
+  }
+
+  /**
+   * Constructs a LatLngBounds from a Tile identifier.
+   * @param z Tile zoom level.
+   * @param x Tile X coordinate.
+   * @param y Tile Y coordinate.
+   */
+  public static LatLngBounds from(int z, int x, int y) {
+    return new LatLngBounds(lat_(z, y), lon_(z, x + 1), lat_(z, y + 1), lon_(z, x));
+  }
+
   /**
    * Constructs a LatLngBounds from current bounds with an additional latitude-longitude pair.
    *

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/sources/CustomGeometrySource.java

@@ -0,0 +1,203 @@
+package com.mapbox.mapboxsdk.style.sources;
+
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.annotation.UiThread;
+import android.support.annotation.WorkerThread;
+
+import com.mapbox.mapboxsdk.geometry.LatLngBounds;
+import com.mapbox.mapboxsdk.style.layers.Filter;
+import com.mapbox.services.commons.geojson.Feature;
+import com.mapbox.services.commons.geojson.FeatureCollection;
+
+import java.lang.ref.WeakReference;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * Custom Vector Source, allows using FeatureCollections.
+ *
+ */
+@UiThread
+public class CustomGeometrySource extends Source {
+  private ExecutorService executor;
+  private GeometryTileProvider provider;
+  private final Map<TileID, AtomicBoolean> cancelledTileRequests = new ConcurrentHashMap<>();
+
+  /**
+   * Create a CustomGeometrySource
+   *
+   * @param id The source id.
+   * @param provider The tile provider that returns geometry data for this source.
+   */
+  public CustomGeometrySource(String id, GeometryTileProvider provider) {
+    this(id, provider, new GeoJsonOptions());
+  }
+
+  /**
+   * Create a CustomGeometrySource with non-default GeoJsonOptions.
+   * <p>Supported options are minZoom, maxZoom, buffer, and tolerance.</p>
+   *
+   * @param id      The source id.
+   * @param provider The tile provider that returns geometry data for this source.
+   * @param options GeoJsonOptions.
+   */
+  public CustomGeometrySource(String id, GeometryTileProvider provider, GeoJsonOptions options) {
+    this.provider = provider;
+    executor = Executors.newFixedThreadPool(4);
+    initialize(this, id, options);
+  }
+
+  /**
+   *  Invalidate previously provided features within a given bounds at all zoom levels.
+   *  Invoking this method will result in new requests to `GeometryTileProvider` for regions
+   *  that contain, include, or intersect with the provided bounds.
+   *
+   * @param bounds The region in which features should be invalidated at all zoom levels
+   */
+  public void invalidateRegion(LatLngBounds bounds) {
+    nativeInvalidateBounds(bounds);
+  }
+
+  /**
+   * Invalidate the geometry contents of a specific tile. Invoking this method will result
+   * in new requests to `GeometryTileProvider` for visible tiles.
+   *
+   * @param zoomLevel Tile zoom level.
+   * @param x Tile X coordinate.
+   * @param y Tile Y coordinate.
+   */
+  public void invalidateTile(int zoomLevel, int x, int y) {
+    nativeInvalidateTile(zoomLevel, x, y);
+  }
+
+  /**
+   * Set or update geometry contents of a specific tile. Use this method to update tiles
+   * for which `GeometryTileProvider` was previously invoked. This method can be called from
+   * background threads.
+   *
+   * @param zoomLevel Tile zoom level.
+   * @param x Tile X coordinate.
+   * @param y Tile Y coordinate.
+   * @param data Feature collection for the tile.
+   */
+  public void setTileData(int zoomLevel, int x, int y, FeatureCollection data) {
+    nativeSetTileData(zoomLevel, x, y, data);
+  }
+
+  /**
+   * Queries the source for features.
+   *
+   * @param filter an optional filter statement to filter the returned Features
+   * @return the features
+   */
+  @NonNull
+  public List<Feature> querySourceFeatures(@Nullable Filter.Statement filter) {
+    Feature[] features = querySourceFeatures(filter != null ? filter.toArray() : null);
+    return features != null ? Arrays.asList(features) : new ArrayList<Feature>();
+  }
+
+  protected native void initialize(CustomGeometrySource self, String sourceId, Object options);
+
+  private native Feature[] querySourceFeatures(Object[] filter);
+
+  private native void nativeSetTileData(int z, int x, int y, FeatureCollection data);
+
+  private native void nativeInvalidateTile(int z, int x, int y);
+
+  private native void nativeInvalidateBounds(LatLngBounds bounds);
+
+  @Override
+  protected native void finalize() throws Throwable;
+
+  private void setTileData(TileID tileId, FeatureCollection data) {
+    cancelledTileRequests.remove(tileId);
+    nativeSetTileData(tileId.z, tileId.x, tileId.y, data);
+  }
+
+  @WorkerThread
+  private void fetchTile(int z, int x, int y) {
+    AtomicBoolean cancelFlag = new AtomicBoolean(false);
+    TileID tileID = new TileID(z, x, y);
+    cancelledTileRequests.put(tileID, cancelFlag);
+    GeometryTileRequest request = new GeometryTileRequest(tileID, provider, this, cancelFlag);
+    executor.submit(request);
+  }
+
+  @WorkerThread
+  private void cancelTile(int z, int x, int y) {
+    AtomicBoolean cancelFlag = cancelledTileRequests.get(new TileID(z, x, y));
+    if (cancelFlag != null) {
+      cancelFlag.compareAndSet(false, true);
+    }
+  }
+
+  private static class TileID {
+    public int z;
+    public int x;
+    public int y;
+
+    public TileID(int _z, int _x, int _y) {
+      z = _z;
+      x = _x;
+      y = _y;
+    }
+
+    public int hashCode() {
+      return Arrays.hashCode(new int[]{z, x, y});
+    }
+
+    public boolean equals(Object object) {
+      if (object == this) {
+        return true;
+      }
+
+      if (object == null || getClass() != object.getClass()) {
+        return false;
+      }
+
+      if (object instanceof TileID) {
+        TileID other = (TileID)object;
+        return this.z == other.z && this.x == other.x && this.y == other.y;
+      }
+      return false;
+    }
+  }
+
+  private static class GeometryTileRequest implements Runnable {
+    private TileID id;
+    private GeometryTileProvider provider;
+    private WeakReference<CustomGeometrySource> sourceRef;
+    private AtomicBoolean cancelled;
+
+    public GeometryTileRequest(TileID _id, GeometryTileProvider p,
+                               CustomGeometrySource _source, AtomicBoolean _cancelled) {
+      id = _id;
+      provider = p;
+      sourceRef = new WeakReference<>(_source);
+      cancelled = _cancelled;
+    }
+
+    public void run() {
+      if (isCancelled()) {
+        return;
+      }
+
+      FeatureCollection data = provider.getFeaturesForBounds(LatLngBounds.from(id.z, id.x, id.y), id.z);
+      CustomGeometrySource source = sourceRef.get();
+      if (!isCancelled() && source != null && !data.getFeatures().isEmpty())  {
+        source.setTileData(id, data);
+      }
+    }
+
+    private Boolean isCancelled() {
+      return cancelled.get();
+    }
+  }
+}

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/sources/GeoJsonOptions.java

@@ -10,6 +10,17 @@ import java.util.HashMap;
  */
 public class GeoJsonOptions extends HashMap<String, Object> {
 
+  /**
+   * Maximum zoom level at which to create vector tiles (higher means greater detail at high zoom levels).
+   *
+   * @param maxZoom the maximum zoom - Defaults to 18.
+   * @return the current instance for chaining
+   */
+  public GeoJsonOptions withMinZoom(int minZoom) {
+    this.put("minzoom", minZoom);
+    return this;
+  }
+
   /**
    * Maximum zoom level at which to create vector tiles (higher means greater detail at high zoom levels).
    *

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/sources/GeometryTileProvider.java

@@ -0,0 +1,22 @@
+package com.mapbox.mapboxsdk.style.sources;
+
+import android.support.annotation.WorkerThread;
+
+import com.mapbox.mapboxsdk.geometry.LatLngBounds;
+import com.mapbox.services.commons.geojson.FeatureCollection;
+
+/**
+ * Interface that defines methods for working with {@link CustomGeometrySource}.
+ */
+public interface GeometryTileProvider {
+
+  /***
+   * Interface method called by {@link CustomGeometrySource} to request features for a tile.
+   *
+   * @param bounds {@link LatLngBounds} of the tile.
+   * @param zoomLevel Tile zoom level.
+   * @return Return a @{link FeatureCollection} to be displayed in the requested tile.
+   */
+  @WorkerThread
+  FeatureCollection getFeaturesForBounds(LatLngBounds bounds, int zoomLevel);
+}