diff --git a/autotests/jnisignaturetest.cpp b/autotests/jnisignaturetest.cpp
index f432201..6c72602 100644
--- a/autotests/jnisignaturetest.cpp
+++ b/autotests/jnisignaturetest.cpp
@@ -1,48 +1,55 @@
 /*
     Copyright (C) 2019 Volker Krause <vkrause@kde.org>
 
     This program is free software; you can redistribute it and/or modify it
     under the terms of the GNU Library General Public License as published by
     the Free Software Foundation; either version 2 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 Library General Public
     License for more details.
 
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
 #include <../src/kandroidextras/jnisignature.h>
 #include <../src/kandroidextras/jnitypes.h>
 
 #include <QtTest/qtest.h>
 
 using namespace KAndroidExtras;
 
 class JniSignatureTest : public QObject
 {
     Q_OBJECT
 private Q_SLOTS:
     void testSignature()
     {
         QCOMPARE((const char*)Jni::signature<bool>(), "Z");
+        QCOMPARE((const char*)Jni::signature<bool()>(), "()Z");
         QCOMPARE((const char*)Jni::signature<void(float[])>(), "([F)V");
         QCOMPARE((const char*)Jni::signature<void(java::lang::String)>(), "(Ljava/lang/String;)V");
         QCOMPARE((const char*)Jni::signature<java::lang::String()>(), "()Ljava/lang/String;");
         QCOMPARE((const char*)Jni::signature<android::content::Intent(java::lang::String, bool[])>(), "(Ljava/lang/String;[Z)Landroid/content/Intent;");
+        QCOMPARE((const char*)Jni::signature<android::database::Cursor(android::net::Uri, java::lang::String[], java::lang::String, java::lang::String[], java::lang::String)>(), "(Landroid/net/Uri;[Ljava/lang/String;Ljava/lang/String;[Ljava/lang/String;Ljava/lang/String;)Landroid/database/Cursor;");
+    }
+
+    void testTypeName()
+    {
+        QCOMPARE((const char*)Jni::typeName<android::provider::OpenableColumns>(), "android/provider/OpenableColumns");
     }
 
     void testImplementationDetails()
     {
         static_assert(Internal::static_strlen("Hello!") == 6, "");
         QCOMPARE(java::lang::String::jniName(), "java/lang/String");
         QCOMPARE(((const char*)Internal::staticStringFromJniType<java::lang::String, std::make_index_sequence<16>>::value()), "java/lang/String");
     }
 };
 
 QTEST_GUILESS_MAIN(JniSignatureTest)
 
 #include "jnisignaturetest.moc"
diff --git a/src/kandroidextras/jnitypes.h b/src/kandroidextras/jnitypes.h
index 7bfd8e9..b17a55f 100644
--- a/src/kandroidextras/jnitypes.h
+++ b/src/kandroidextras/jnitypes.h
@@ -1,58 +1,71 @@
 /*
     Copyright (C) 2019 Volker Krause <vkrause@kde.org>
 
     This program is free software; you can redistribute it and/or modify it
     under the terms of the GNU Library General Public License as published by
     the Free Software Foundation; either version 2 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 Library General Public
     License for more details.
 
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
 #ifndef KANDROIDEXTRAS_JNITYPES_H
 #define KANDROIDEXTRAS_JNITYPES_H
 
+namespace KAndroidExtras {
+
 // determine how many elements are in __VA_ARGS__
 #define PP_NARG(...) PP_NARG_(__VA_ARGS__, PP_RSEQ_N())
 #define PP_NARG_(...) PP_ARG_N(__VA_ARGS__)
 #define PP_ARG_N(_1, _2, _3, _4, _5, _6, _7, N, ...) N
 #define PP_RSEQ_N() 7, 6, 5, 4, 3, 2, 1, 0
 
 // preprocessor-level token concat
 #define PP_CONCAT(arg1, arg2) PP_CONCAT1(arg1, arg2)
 #define PP_CONCAT1(arg1, arg2) PP_CONCAT2(arg1, arg2)
 #define PP_CONCAT2(arg1, arg2) arg1##arg2
 
 // preprocessor "iteration"
 #define JNI_TYPE_1(name, type, ...) \
     struct type { static constexpr const char* jniName() { return name #type; } };
 #define JNI_TYPE_2(name, type, ...) \
     namespace type { JNI_TYPE_1(name #type "/", __VA_ARGS__) }
 #define JNI_TYPE_3(name, type, ...) \
     namespace type { JNI_TYPE_2(name #type "/", __VA_ARGS__) }
 #define JNI_TYPE_4(name, type, ...) \
     namespace type { JNI_TYPE_3(name #type "/", __VA_ARGS__) }
 #define JNI_TYPE_5(name, type, ...) \
     namespace type { JNI_TYPE_4(name #type "/", __VA_ARGS__) }
 #define JNI_TYPE_6(name, type, ...) \
     namespace type { JNI_TYPE_5(name #type "/", __VA_ARGS__) }
 #define JNI_TYPE_7(name, type, ...) \
     namespace type { JNI_TYPE_6(#type "/", __VA_ARGS__) }
 #define JNI_TYPE_(N, name, ...) PP_CONCAT(JNI_TYPE_, N)(name, __VA_ARGS__)
 
 /** Macro to define Java types with their corresponding JNI signature strings. */
 #define JNI_TYPE(...) JNI_TYPE_(PP_NARG(__VA_ARGS__), "", __VA_ARGS__)
 
 
 // type declarations
+JNI_TYPE(android, content, ContentResolver)
 JNI_TYPE(android, content, Intent)
+JNI_TYPE(android, database, Cursor)
 JNI_TYPE(android, net, Uri)
+JNI_TYPE(android, provider, OpenableColumns)
 JNI_TYPE(java, lang, String)
 
+namespace Jni
+{
+    /** Returns the JNI type name of the given template arugment. */
+    template <typename T> inline const char* typeName() { return T::jniName(); }
+}
+
+}
+
 #endif // KANDROIDEXTRAS_JNITYPES_H