<NME> MultiRendererLayer.java
<BEF> ADDFILE
<MSG> Allow the user to display a combination of all available offline Map files if more than one is inside the maps folder.

<DFF> @@ -0,0 +1,67 @@
+package cgeo.geocaching.maps.mapsforge.v6.layers;
+
+import java.util.List;
+
+import org.mapsforge.core.graphics.GraphicFactory;
+import org.mapsforge.map.datastore.MultiMapDataStore;
+import org.mapsforge.map.layer.Layer;
+import org.mapsforge.map.layer.cache.TileCache;
+import org.mapsforge.map.layer.renderer.TileRendererLayer;
+import org.mapsforge.map.model.IMapViewPosition;
+import org.mapsforge.map.reader.MapFile;
+
+
+public class MultiRendererLayer implements ITileLayer {
+    private final MultiMapDataStore mapDataStore;
+    private final TileRendererLayer tileLayer;
+    private byte zoomLevelMin = 0;
+    private byte zoomLevelMax = 21;
+
+
+    public MultiRendererLayer(final TileCache tileCache, final List<MapFile> mapFiles, final IMapViewPosition mapViewPosition, final boolean isTransparent, final boolean renderLabels, final boolean cacheLabels, final GraphicFactory graphicFactory) {
+        this.mapDataStore = new MultiMapDataStore(MultiMapDataStore.DataPolicy.RETURN_ALL);
+
+        for (MapFile f : mapFiles) {
+            mapDataStore.addMapDataStore(f, false, false);
+            zoomLevelMin = (byte) Math.max(f.getMapFileHeader().getMapFileInfo().zoomLevelMin, zoomLevelMin);
+            zoomLevelMax = (byte) Math.min(f.getMapFileHeader().getMapFileInfo().zoomLevelMax, zoomLevelMax);
+        }
+
+        tileLayer = new TileRendererLayer(tileCache, mapDataStore, mapViewPosition, isTransparent, renderLabels, cacheLabels, graphicFactory);
+    }
+
+    @Override
+    public Layer getTileLayer() {
+        return tileLayer;
+    }
+
+    @Override
+    public boolean hasThemes() {
+        return true;
+    }
+
+    @Override
+    public void onResume() {
+
+    }
+
+    @Override
+    public void onPause() {
+
+    }
+
+    @Override
+    public int getFixedTileSize() {
+        return 0;
+    }
+
+    @Override
+    public byte getZoomLevelMin() {
+        return zoomLevelMin;
+    }
+
+    @Override
+    public byte getZoomLevelMax() {
+        return zoomLevelMax;
+    }
+}

Allow the user to display a combination of all available offline Map files if more than one is inside the maps folder.