refactor backend Adapter classes

vtm-android/src/org/oscim/android/AndroidAssets.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2013 Hannes Janetzek
+ *
+ * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
+ *
+ * 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.oscim.android;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.oscim.backend.AssetAdapter;
+
+import android.content.Context;
+
+public class AndroidAssets extends AssetAdapter {
+	Context mContext;
+
+	public static void init(Context ctx) {
+		g = new AndroidAssets(ctx);
+	}
+
+	private AndroidAssets(Context ctx) {
+		mContext = ctx;
+	}
+
+	@Override
+	public InputStream openFileAsStream(String fileName) {
+		try {
+			return mContext.getAssets().open(fileName);
+		} catch (IOException e) {
+			e.printStackTrace();
+			return null;
+		}
+	}
+}