Group layer implementation, closes mapsforge#860

docs/Changelog.md

@@ -2,6 +2,7 @@
 
 ## New since 0.6.1
 
+- Group layer implementation [#860](https://github.com/mapsforge/mapsforge/issues/860)
 - Allow resources without location prefixes in render themes [#847](https://github.com/mapsforge/mapsforge/issues/847)
 - SVG symbols customization [#858](https://github.com/mapsforge/mapsforge/issues/858)
 - Deprecate water tiles rendering [#640](https://github.com/mapsforge/mapsforge/issues/640)

mapsforge-map/src/main/java/org/mapsforge/map/layer/GroupLayer.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright 2016 devemux86
+ *
+ * This program is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.mapsforge.map.layer;
+
+import org.mapsforge.core.graphics.Canvas;
+import org.mapsforge.core.model.BoundingBox;
+import org.mapsforge.core.model.LatLong;
+import org.mapsforge.core.model.Point;
+import org.mapsforge.map.model.DisplayModel;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A layer which is a group of other layers.
+ */
+public class GroupLayer extends Layer {
+
+    /**
+     * The group of other layers.
+     */
+    public final List<Layer> layers = new ArrayList<>();
+
+    public GroupLayer() {
+        super();
+    }
+
+    @Override
+    public void draw(BoundingBox boundingBox, byte zoomLevel, Canvas canvas, Point topLeftPoint) {
+        for (Layer layer : layers) {
+            layer.draw(boundingBox, zoomLevel, canvas, topLeftPoint);
+        }
+    }
+
+    @Override
+    public void onDestroy() {
+        for (Layer layer : layers) {
+            layer.onDestroy();
+        }
+    }
+
+    @Override
+    public boolean onLongPress(LatLong tapLatLong, Point layerXY, Point tapXY) {
+        for (int i = layers.size() - 1; i >= 0; i--) {
+            Layer layer = layers.get(i);
+            if (layer.onLongPress(tapLatLong, layerXY, tapXY)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public boolean onTap(LatLong tapLatLong, Point layerXY, Point tapXY) {
+        for (int i = layers.size() - 1; i >= 0; i--) {
+            Layer layer = layers.get(i);
+            if (layer.onTap(tapLatLong, layerXY, tapXY)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public synchronized void setDisplayModel(DisplayModel displayModel) {
+        super.setDisplayModel(displayModel);
+        for (Layer layer : layers) {
+            layer.setDisplayModel(displayModel);
+        }
+    }
+}

mapsforge-samples-android/src/main/java/org/mapsforge/samples/android/PoiSearchViewer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 devemux86
+ * Copyright 2015-2016 devemux86
  *
  * This program is free software: you can redistribute it and/or modify it under the
  * terms of the GNU Lesser General Public License as published by the Free Software
@@ -25,6 +25,7 @@
 import org.mapsforge.core.model.LatLong;
 import org.mapsforge.core.model.Point;
 import org.mapsforge.map.android.graphics.AndroidGraphicFactory;
+import org.mapsforge.map.layer.GroupLayer;
 import org.mapsforge.map.layer.Layer;
 import org.mapsforge.map.layer.Layers;
 import org.mapsforge.map.layer.overlay.Circle;
@@ -47,7 +48,7 @@
  */
 public class PoiSearchViewer extends RenderTheme4 {
     private static final String POI_FILE = Environment.getExternalStorageDirectory() + "/germany.poi";
-    private static final String POI_CATEGORY = "Embassies";
+    private static final String POI_CATEGORY = "Restaurants";
 
     private static final Paint CIRCLE = Utils.createPaint(AndroidGraphicFactory.INSTANCE.createColor(128, 255, 0, 0), 0, Style.FILL);
 
@@ -71,7 +72,7 @@ private void onLongPress() {
         // Clear overlays
         Layers layers = this.mapView.getLayerManager().getLayers();
         for (Layer layer : layers) {
-            if (layer instanceof Circle) {
+            if (layer instanceof GroupLayer) {
                 layers.remove(layer);
             }
         }
@@ -120,19 +121,23 @@ protected void onPostExecute(Collection<PointOfInterest> pointOfInterests) {
                 return;
             }
 
+            GroupLayer groupLayer = new GroupLayer();
             for (final PointOfInterest pointOfInterest : pointOfInterests) {
-                Circle circle = new FixedPixelCircle(pointOfInterest.getLatLong(), 16, CIRCLE, null) {
+                final Circle circle = new FixedPixelCircle(pointOfInterest.getLatLong(), 16, CIRCLE, null) {
                     @Override
                     public boolean onTap(LatLong tapLatLong, Point layerXY, Point tapXY) {
-                        if (this.contains(layerXY, tapXY)) {
+                        // GroupLayer does not have a position!
+                        Point circleXY = activity.mapView.getMapViewProjection().toPixels(getPosition());
+                        if (this.contains(circleXY, tapXY)) {
                             Toast.makeText(activity, pointOfInterest.getName(), Toast.LENGTH_SHORT).show();
                             return true;
                         }
                         return false;
                     }
                 };
-                activity.mapView.getLayerManager().getLayers().add(circle);
+                groupLayer.layers.add(circle);
             }
+            activity.mapView.getLayerManager().getLayers().add(groupLayer);
             activity.redrawLayers();
         }
     }