modifications based on Akwizgran's comments

briar-android/src/org/briarproject/android/controller/ConfigControllerImpl.java

@@ -0,0 +1,41 @@
+package org.briarproject.android.controller;
+
+import android.content.SharedPreferences;
+
+import org.briarproject.api.db.DatabaseConfig;
+
+import javax.inject.Inject;
+
+public class ConfigControllerImpl implements ConfigController {
+
+	private final static String PREF_DB_KEY = "key";
+
+	@Inject
+	protected SharedPreferences briarPrefs;
+	@Inject
+	protected volatile DatabaseConfig databaseConfig;
+
+	@Inject
+	public ConfigControllerImpl() {
+
+	}
+
+	public String getEncryptedDatabaseKey() {
+		return briarPrefs.getString(PREF_DB_KEY, null);
+	}
+
+	public void clearPrefs() {
+		SharedPreferences.Editor editor = briarPrefs.edit();
+		editor.clear();
+		editor.apply();
+	}
+
+	@Override
+	public boolean initialized() {
+		String hex = getEncryptedDatabaseKey();
+		if (hex != null && databaseConfig.databaseExists()) {
+			return true;
+		}
+		return false;
+	}
+}