ANDROID: Wrap JNI code in a class

6 files changed, 265 insertions, 183 deletions

diff --git a/backends/platform/android/android.cpp b/backends/platform/android/android.cpp
index f2c9a7407d..9437bf540c 100644
--- a/backends/platform/android/android.cpp
+++ b/backends/platform/android/android.cpp
@@ -98,8 +98,6 @@ static inline T scalef(T in, float numerator, float denominator) {
 	return static_cast<float>(in) * numerator / denominator;
 }
 
-OSystem_Android *g_sys = 0;
-
 OSystem_Android::OSystem_Android(jobject am) :
 	_screen_changeid(0),
 	_force_redraw(false),
@@ -166,7 +164,7 @@ void *OSystem_Android::timerThreadFunc(void *arg) {
 	OSystem_Android *system = (OSystem_Android *)arg;
 	DefaultTimerManager *timer = (DefaultTimerManager *)(system->_timer);
 
-	JNU_AttachThread();
+	JNI::attachThread();
 
 	struct timespec tv;
 	tv.tv_sec = 0;
@@ -177,7 +175,7 @@ void *OSystem_Android::timerThreadFunc(void *arg) {
 		nanosleep(&tv, 0);
 	}
 
-	JNU_DetachThread();
+	JNI::detachThread();
 
 	return 0;
 }
@@ -185,7 +183,7 @@ void *OSystem_Android::timerThreadFunc(void *arg) {
 void OSystem_Android::initBackend() {
 	ENTER();
 
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 
 	ConfMan.setInt("autosave_period", 0);
 	ConfMan.setInt("FM_medium_quality", true);
@@ -235,10 +233,10 @@ void OSystem_Android::initBackend() {
 void OSystem_Android::addPluginDirectories(Common::FSList &dirs) const {
 	ENTER();
 
-	JNIEnv *env = JNU_GetEnv();
-
+	JNIEnv *env = JNI::getEnv();
 	jobjectArray array =
 		(jobjectArray)env->CallObjectMethod(back_ptr, MID_getPluginDirectories);
+
 	if (env->ExceptionCheck()) {
 		warning("Error finding plugin directories");
 
@@ -477,7 +475,7 @@ void OSystem_Android::quit() {
 void OSystem_Android::setWindowCaption(const char *caption) {
 	ENTER("%s", caption);
 
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 	jstring java_caption = env->NewStringUTF(caption);
 	env->CallVoidMethod(back_ptr, MID_setWindowCaption, java_caption);
 
@@ -494,9 +492,8 @@ void OSystem_Android::setWindowCaption(const char *caption) {
 void OSystem_Android::displayMessageOnOSD(const char *msg) {
 	ENTER("%s", msg);
 
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 	jstring java_msg = env->NewStringUTF(msg);
-
 	env->CallVoidMethod(back_ptr, MID_displayMessageOnOSD, java_msg);
 
 	if (env->ExceptionCheck()) {
@@ -512,8 +509,7 @@ void OSystem_Android::displayMessageOnOSD(const char *msg) {
 void OSystem_Android::showVirtualKeyboard(bool enable) {
 	ENTER("%d", enable);
 
-	JNIEnv *env = JNU_GetEnv();
-
+	JNIEnv *env = JNI::getEnv();
 	env->CallVoidMethod(back_ptr, MID_showVirtualKeyboard, enable);
 
 	if (env->ExceptionCheck()) {
@@ -560,8 +556,7 @@ void OSystem_Android::addSysArchivesToSearchSet(Common::SearchSet &s,
 												int priority) {
 	s.add("ASSET", _asset_archive, priority, false);
 
-	JNIEnv *env = JNU_GetEnv();
-
+	JNIEnv *env = JNI::getEnv();
 	jobjectArray array =
 		(jobjectArray)env->CallObjectMethod(back_ptr, MID_getSysArchives);
 
@@ -606,7 +601,7 @@ void OSystem_Android::logMessage(LogMessageType::Type type, const char *message)
 
 #ifdef DYNAMIC_MODULES
 void AndroidPluginProvider::addCustomDirectories(Common::FSList &dirs) const {
-	g_sys->addPluginDirectories(dirs);
+	((OSystem_Android *)g_system)->addPluginDirectories(dirs);
 }
 #endif
 
diff --git a/backends/platform/android/android.h b/backends/platform/android/android.h
index da487c5ceb..0ccf57e7c1 100644
--- a/backends/platform/android/android.h
+++ b/backends/platform/android/android.h
@@ -36,6 +36,7 @@
 #include "backends/plugins/posix/posix-provider.h"
 #include "backends/fs/posix/posix-fs-factory.h"
 
+#include "backends/platform/android/jni.h"
 #include "backends/platform/android/texture.h"
 
 #include <pthread.h>
@@ -81,13 +82,6 @@ extern void checkGlError(const char *expr, const char *file, int line);
 // back pointer to (java) peer instance
 extern jobject back_ptr;
 
-extern JNIEnv *JNU_GetEnv();
-extern void JNU_AttachThread();
-extern void JNU_DetachThread();
-
-class OSystem_Android;
-extern OSystem_Android *g_sys;
-
 #ifdef DYNAMIC_MODULES
 class AndroidPluginProvider : public POSIXPluginProvider {
 protected:
diff --git a/backends/platform/android/asset-archive.cpp b/backends/platform/android/asset-archive.cpp
index 71ce25aa72..eb2530823d 100644
--- a/backends/platform/android/asset-archive.cpp
+++ b/backends/platform/android/asset-archive.cpp
@@ -36,10 +36,9 @@
 #include "common/archive.h"
 #include "common/debug.h"
 
+#include "backends/platform/android/jni.h"
 #include "backends/platform/android/asset-archive.h"
 
-extern JNIEnv *JNU_GetEnv();
-
 // Must match android.content.res.AssetManager.ACCESS_*
 const jint ACCESS_UNKNOWN = 0;
 const jint ACCESS_RANDOM = 1;
@@ -124,7 +123,7 @@ JavaInputStream::JavaInputStream(JNIEnv *env, jobject is) :
 }
 
 JavaInputStream::~JavaInputStream() {
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 	close(env);
 
 	env->DeleteGlobalRef(_buf);
@@ -139,7 +138,7 @@ void JavaInputStream::close(JNIEnv *env) {
 }
 
 uint32 JavaInputStream::read(void *dataPtr, uint32 dataSize) {
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 
 	if (_buflen < jint(dataSize)) {
 		_buflen = dataSize;
@@ -171,7 +170,7 @@ uint32 JavaInputStream::read(void *dataPtr, uint32 dataSize) {
 }
 
 bool JavaInputStream::seek(int32 offset, int whence) {
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 	uint32 newpos;
 
 	switch (whence) {
@@ -318,7 +317,7 @@ AssetFdReadStream::AssetFdReadStream(JNIEnv *env, jobject assetfd) :
 }
 
 AssetFdReadStream::~AssetFdReadStream() {
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 	env->CallVoidMethod(_assetfd, MID_close);
 
 	if (env->ExceptionCheck())
@@ -369,7 +368,7 @@ bool AssetFdReadStream::seek(int32 offset, int whence) {
 }
 
 AndroidAssetArchive::AndroidAssetArchive(jobject am) {
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 	_am = env->NewGlobalRef(am);
 
 	jclass cls = env->GetObjectClass(_am);
@@ -387,12 +386,12 @@ AndroidAssetArchive::AndroidAssetArchive(jobject am) {
 }
 
 AndroidAssetArchive::~AndroidAssetArchive() {
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 	env->DeleteGlobalRef(_am);
 }
 
 bool AndroidAssetArchive::hasFile(const Common::String &name) {
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 	jstring path = env->NewStringUTF(name.c_str());
 	jobject result = env->CallObjectMethod(_am, MID_open, path, ACCESS_UNKNOWN);
 	if (env->ExceptionCheck()) {
@@ -412,7 +411,7 @@ bool AndroidAssetArchive::hasFile(const Common::String &name) {
 }
 
 int AndroidAssetArchive::listMembers(Common::ArchiveMemberList &member_list) {
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 	Common::List<Common::String> dirlist;
 	dirlist.push_back("");
 
@@ -469,7 +468,7 @@ Common::ArchiveMemberPtr AndroidAssetArchive::getMember(const Common::String &na
 }
 
 Common::SeekableReadStream *AndroidAssetArchive::createReadStreamForMember(const Common::String &path) const {
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 	jstring jpath = env->NewStringUTF(path.c_str());
 
 	// Try openFd() first ...
diff --git a/backends/platform/android/gfx.cpp b/backends/platform/android/gfx.cpp
index 2b730385e6..2370958d30 100644
--- a/backends/platform/android/gfx.cpp
+++ b/backends/platform/android/gfx.cpp
@@ -62,7 +62,7 @@ int OSystem_Android::getGraphicsMode() const {
 void OSystem_Android::setupScummVMSurface() {
 	ENTER();
 
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 	env->CallVoidMethod(back_ptr, MID_setupScummVMSurface);
 
 	if (env->ExceptionCheck())
@@ -116,7 +116,7 @@ void OSystem_Android::setupScummVMSurface() {
 }
 
 void OSystem_Android::destroyScummVMSurface() {
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 	env->CallVoidMethod(back_ptr, MID_destroyScummVMSurface);
 	// Can't use OpenGLES functions after this
 }
@@ -261,7 +261,7 @@ void OSystem_Android::updateScreen() {
 
 	GLCALL(glPopMatrix());
 
-	JNIEnv *env = JNU_GetEnv();
+	JNIEnv *env = JNI::getEnv();
 	if (!env->CallBooleanMethod(back_ptr, MID_swapBuffers)) {
 		// Context lost -> need to reinit GL
 		destroyScummVMSurface();
diff --git a/backends/platform/android/jni.cpp b/backends/platform/android/jni.cpp
index b81587b3ba..4fa08ef7ab 100644
--- a/backends/platform/android/jni.cpp
+++ b/backends/platform/android/jni.cpp
@@ -30,28 +30,116 @@
 
 #include "backends/platform/android/android.h"
 
-// Fix JNIEXPORT declaration to actually do something useful
-#undef JNIEXPORT
-#define JNIEXPORT __attribute__ ((visibility("default")))
-
 jobject back_ptr;
 
-static JavaVM *cached_jvm;
+__attribute__ ((visibility("default")))
+jint JNICALL JNI_OnLoad(JavaVM *vm, void *) {
+	return JNI::onLoad(vm);
+}
+
+JavaVM *JNI::_vm = 0;
+jobject JNI::_jobj = 0;
+OSystem_Android *JNI::_system = 0;
+
+jfieldID JNI::_FID_Event_type = 0;
+jfieldID JNI::_FID_Event_synthetic = 0;
+jfieldID JNI::_FID_Event_kbd_keycode = 0;
+jfieldID JNI::_FID_Event_kbd_ascii = 0;
+jfieldID JNI::_FID_Event_kbd_flags = 0;
+jfieldID JNI::_FID_Event_mouse_x = 0;
+jfieldID JNI::_FID_Event_mouse_y = 0;
+jfieldID JNI::_FID_Event_mouse_relative = 0;
+jfieldID JNI::_FID_ScummVM_nativeScummVM = 0;
+
+const JNINativeMethod JNI::_natives[] = {
+	{ "create", "(Landroid/content/res/AssetManager;)V",
+		(void *)JNI::create },
+	{ "nativeDestroy", "()V",
+		(void *)JNI::destroy },
+	{ "scummVMMain", "([Ljava/lang/String;)I",
+	 	(void *)JNI::main },
+	{ "pushEvent", "(Lorg/inodes/gus/scummvm/Event;)V",
+		(void *)JNI::pushEvent },
+	{ "audioMixCallback", "([B)V",
+		(void *)JNI::audioMixCallback },
+	{ "setConfMan", "(Ljava/lang/String;I)V",
+		(void *)JNI::setConfManInt },
+	{ "setConfMan", "(Ljava/lang/String;Ljava/lang/String;)V",
+		(void *)JNI::setConfManString },
+	{ "enableZoning", "(Z)V",
+		(void *)JNI::enableZoning },
+	{ "setSurfaceSize", "(II)V",
+		(void *)JNI::setSurfaceSize },
+};
+
+JNI::JNI() {
+}
+
+JNI::~JNI() {
+}
+
+jint JNI::onLoad(JavaVM *vm) {
+	_vm = vm;
+
+	JNIEnv *env;
+
+	if (_vm->GetEnv((void **)&env, JNI_VERSION_1_2))
+		return JNI_ERR;
+
+	jclass cls = env->FindClass("org/inodes/gus/scummvm/ScummVM");
+	if (cls == 0)
+		return JNI_ERR;
+
+	if (env->RegisterNatives(cls, _natives, ARRAYSIZE(_natives)) < 0)
+		return JNI_ERR;
+
+	_FID_ScummVM_nativeScummVM = env->GetFieldID(cls, "nativeScummVM", "J");
+	if (_FID_ScummVM_nativeScummVM == 0)
+		return JNI_ERR;
+
+	jclass event = env->FindClass("org/inodes/gus/scummvm/Event");
+	if (event == 0)
+		return JNI_ERR;
+
+	_FID_Event_type = env->GetFieldID(event, "type", "I");
+	if (_FID_Event_type == 0)
+		return JNI_ERR;
+
+	_FID_Event_synthetic = env->GetFieldID(event, "synthetic", "Z");
+	if (_FID_Event_synthetic == 0)
+		return JNI_ERR;
+
+	_FID_Event_kbd_keycode = env->GetFieldID(event, "kbd_keycode", "I");
+	if (_FID_Event_kbd_keycode == 0)
+		return JNI_ERR;
+
+	_FID_Event_kbd_ascii = env->GetFieldID(event, "kbd_ascii", "I");
+	if (_FID_Event_kbd_ascii == 0)
+		return JNI_ERR;
+
+	_FID_Event_kbd_flags = env->GetFieldID(event, "kbd_flags", "I");
+	if (_FID_Event_kbd_flags == 0)
+		return JNI_ERR;
+
+	_FID_Event_mouse_x = env->GetFieldID(event, "mouse_x", "I");
+	if (_FID_Event_mouse_x == 0)
+		return JNI_ERR;
+
+	_FID_Event_mouse_y = env->GetFieldID(event, "mouse_y", "I");
+	if (_FID_Event_mouse_y == 0)
+		return JNI_ERR;
+
+	_FID_Event_mouse_relative = env->GetFieldID(event, "mouse_relative", "Z");
+	if (_FID_Event_mouse_relative == 0)
+		return JNI_ERR;
 
-static jfieldID FID_Event_type;
-static jfieldID FID_Event_synthetic;
-static jfieldID FID_Event_kbd_keycode;
-static jfieldID FID_Event_kbd_ascii;
-static jfieldID FID_Event_kbd_flags;
-static jfieldID FID_Event_mouse_x;
-static jfieldID FID_Event_mouse_y;
-static jfieldID FID_Event_mouse_relative;
-static jfieldID FID_ScummVM_nativeScummVM;
+	return JNI_VERSION_1_2;
+}
 
-JNIEnv *JNU_GetEnv() {
+JNIEnv *JNI::getEnv() {
 	JNIEnv *env = 0;
 
-	jint res = cached_jvm->GetEnv((void **)&env, JNI_VERSION_1_2);
+	jint res = _vm->GetEnv((void **)&env, JNI_VERSION_1_2);
 
 	if (res != JNI_OK) {
 		LOGE("GetEnv() failed: %d", res);
@@ -61,9 +149,10 @@ JNIEnv *JNU_GetEnv() {
 	return env;
 }
 
-void JNU_AttachThread() {
+void JNI::attachThread() {
 	JNIEnv *env = 0;
-	jint res = cached_jvm->AttachCurrentThread(&env, 0);
+
+	jint res = _vm->AttachCurrentThread(&env, 0);
 
 	if (res != JNI_OK) {
 		LOGE("AttachCurrentThread() failed: %d", res);
@@ -71,8 +160,8 @@ void JNU_AttachThread() {
 	}
 }
 
-void JNU_DetachThread() {
-	jint res = cached_jvm->DetachCurrentThread();
+void JNI::detachThread() {
+	jint res = _vm->DetachCurrentThread();
 
 	if (res != JNI_OK) {
 		LOGE("DetachCurrentThread() failed: %d", res);
@@ -80,7 +169,7 @@ void JNU_DetachThread() {
 	}
 }
 
-static void JNU_ThrowByName(JNIEnv *env, const char *name, const char *msg) {
+void JNI::throwByName(JNIEnv *env, const char *name, const char *msg) {
 	jclass cls = env->FindClass(name);
 
 	// if cls is 0, an exception has already been thrown
@@ -90,49 +179,50 @@ static void JNU_ThrowByName(JNIEnv *env, const char *name, const char *msg) {
 	env->DeleteLocalRef(cls);
 }
 
-static void ScummVM_create(JNIEnv *env, jobject self, jobject am) {
-	assert(!g_system);
+void JNI::create(JNIEnv *env, jobject self, jobject am) {
+	assert(!_system);
 
-	g_sys = new OSystem_Android(am);
-	assert(g_sys);
+	_system = new OSystem_Android(am);
+	assert(_system);
 
 	// weak global ref to allow class to be unloaded
 	// ... except dalvik implements NewWeakGlobalRef only on froyo
-	//back_ptr = env->NewWeakGlobalRef(self);
-	back_ptr = env->NewGlobalRef(self);
+	//_jobj = env->NewWeakGlobalRef(self);
+	_jobj = env->NewGlobalRef(self);
+	back_ptr = _jobj;
 
 	// Exception already thrown by initJavaHooks?
-	if (!g_sys->initJavaHooks(env))
+	if (!_system->initJavaHooks(env))
 		return;
 
-	env->SetLongField(self, FID_ScummVM_nativeScummVM, (jlong)g_sys);
+	env->SetLongField(self, _FID_ScummVM_nativeScummVM, (jlong)_system);
 
-	g_system = g_sys;
+	g_system = _system;
 }
 
-static void ScummVM_nativeDestroy(JNIEnv *env, jobject self) {
-	assert(g_sys);
+void JNI::destroy(JNIEnv *env, jobject self) {
+	assert(_system);
 
-	OSystem_Android *tmp = g_sys;
+	OSystem_Android *tmp = _system;
 	g_system = 0;
-	g_sys = 0;
+	_system = 0;
 	delete tmp;
 
 	// see above
-	//JNU_GetEnv()->DeleteWeakGlobalRef(back_ptr);
-	JNU_GetEnv()->DeleteGlobalRef(back_ptr);
+	//JNI::getEnv()->DeleteWeakGlobalRef(_jobj);
+	JNI::getEnv()->DeleteGlobalRef(_jobj);
 }
 
-static jint ScummVM_scummVMMain(JNIEnv *env, jobject self, jobjectArray args) {
-	assert(g_sys);
+jint JNI::main(JNIEnv *env, jobject self, jobjectArray args) {
+	assert(_system);
 
 	const int MAX_NARGS = 32;
 	int res = -1;
 
 	int argc = env->GetArrayLength(args);
 	if (argc > MAX_NARGS) {
-		JNU_ThrowByName(env, "java/lang/IllegalArgumentException",
-						"too many arguments");
+		throwByName(env, "java/lang/IllegalArgumentException",
+					"too many arguments");
 		return 0;
 	}
 
@@ -169,7 +259,7 @@ static jint ScummVM_scummVMMain(JNIEnv *env, jobject self, jobjectArray args) {
 
 	LOGI("Exiting scummvm_main");
 
-	g_sys->quit();
+	_system->quit();
 
 cleanup:
 	nargs--;
@@ -191,25 +281,25 @@ cleanup:
 	return res;
 }
 
-static void ScummVM_pushEvent(JNIEnv *env, jobject self, jobject java_event) {
-	assert(g_sys);
+void JNI::pushEvent(JNIEnv *env, jobject self, jobject java_event) {
+	assert(_system);
 
 	Common::Event event;
 	event.type = (Common::EventType)env->GetIntField(java_event,
-														FID_Event_type);
+														_FID_Event_type);
 
 	event.synthetic =
-		env->GetBooleanField(java_event, FID_Event_synthetic);
+		env->GetBooleanField(java_event, _FID_Event_synthetic);
 
 	switch (event.type) {
 	case Common::EVENT_KEYDOWN:
 	case Common::EVENT_KEYUP:
 		event.kbd.keycode = (Common::KeyCode)env->GetIntField(
-			java_event, FID_Event_kbd_keycode);
+			java_event, _FID_Event_kbd_keycode);
 		event.kbd.ascii = static_cast<int>(env->GetIntField(
-			java_event, FID_Event_kbd_ascii));
+			java_event, _FID_Event_kbd_ascii));
 		event.kbd.flags = static_cast<int>(env->GetIntField(
-			java_event, FID_Event_kbd_flags));
+			java_event, _FID_Event_kbd_flags));
 		break;
 	case Common::EVENT_MOUSEMOVE:
 	case Common::EVENT_LBUTTONDOWN:
@@ -221,25 +311,24 @@ static void ScummVM_pushEvent(JNIEnv *env, jobject self, jobject java_event) {
 	case Common::EVENT_MBUTTONDOWN:
 	case Common::EVENT_MBUTTONUP:
 		event.mouse.x =
-			env->GetIntField(java_event, FID_Event_mouse_x);
+			env->GetIntField(java_event, _FID_Event_mouse_x);
 		event.mouse.y =
-			env->GetIntField(java_event, FID_Event_mouse_y);
+			env->GetIntField(java_event, _FID_Event_mouse_y);
 		// This is a terrible hack.	 We stash "relativeness"
 		// in the kbd.flags field until pollEvent() can work
 		// it out.
 		event.kbd.flags = env->GetBooleanField(
-			java_event, FID_Event_mouse_relative) ? 1 : 0;
+			java_event, _FID_Event_mouse_relative) ? 1 : 0;
 		break;
 	default:
 		break;
 	}
 
-	g_sys->pushEvent(event);
+	_system->pushEvent(event);
 }
 
-static void ScummVM_audioMixCallback(JNIEnv *env, jobject self,
-										jbyteArray jbuf) {
-	assert(g_sys);
+void JNI::audioMixCallback(JNIEnv *env, jobject self, jbyteArray jbuf) {
+	assert(_system);
 
 	jsize len = env->GetArrayLength(jbuf);
 	jbyte *buf = env->GetByteArrayElements(jbuf, 0);
@@ -250,15 +339,14 @@ static void ScummVM_audioMixCallback(JNIEnv *env, jobject self,
 	}
 
 	Audio::MixerImpl *mixer =
-		static_cast<Audio::MixerImpl *>(g_sys->getMixer());
+		static_cast<Audio::MixerImpl *>(_system->getMixer());
 	assert(mixer);
 	mixer->mixCallback(reinterpret_cast<byte *>(buf), len);
 
 	env->ReleaseByteArrayElements(jbuf, buf, 0);
 }
 
-static void ScummVM_setConfManInt(JNIEnv *env, jclass cls,
-									jstring key_obj, jint value) {
+void JNI::setConfManInt(JNIEnv *env, jclass cls, jstring key_obj, jint value) {
 	ENTER("%p, %d", key_obj, (int)value);
 
 	const char *key = env->GetStringUTFChars(key_obj, 0);
@@ -271,8 +359,8 @@ static void ScummVM_setConfManInt(JNIEnv *env, jclass cls,
 	env->ReleaseStringUTFChars(key_obj, key);
 }
 
-static void ScummVM_setConfManString(JNIEnv *env, jclass cls, jstring key_obj,
-										jstring value_obj) {
+void JNI::setConfManString(JNIEnv *env, jclass cls, jstring key_obj,
+							jstring value_obj) {
 	ENTER("%p, %p", key_obj, value_obj);
 
 	const char *key = env->GetStringUTFChars(key_obj, 0);
@@ -293,97 +381,16 @@ static void ScummVM_setConfManString(JNIEnv *env, jclass cls, jstring key_obj,
 	env->ReleaseStringUTFChars(key_obj, key);
 }
 
-static void ScummVM_enableZoning(JNIEnv *env, jobject self, jboolean enable) {
-	assert(g_sys);
+void JNI::enableZoning(JNIEnv *env, jobject self, jboolean enable) {
+	assert(_system);
 
-	g_sys->enableZoning(enable);
+	_system->enableZoning(enable);
 }
 
-static void ScummVM_setSurfaceSize(JNIEnv *env, jobject self,
-									jint width, jint height) {
-	assert(g_sys);
-
-	g_sys->setSurfaceSize(width, height);
-}
-
-const static JNINativeMethod gMethods[] = {
-	{ "create", "(Landroid/content/res/AssetManager;)V",
-		(void *)ScummVM_create },
-	{ "nativeDestroy", "()V",
-		(void *)ScummVM_nativeDestroy },
-	{ "scummVMMain", "([Ljava/lang/String;)I",
-	 	(void *)ScummVM_scummVMMain },
-	{ "pushEvent", "(Lorg/inodes/gus/scummvm/Event;)V",
-		(void *)ScummVM_pushEvent },
-	{ "audioMixCallback", "([B)V",
-		(void *)ScummVM_audioMixCallback },
-	{ "setConfMan", "(Ljava/lang/String;I)V",
-		(void *)ScummVM_setConfManInt },
-	{ "setConfMan", "(Ljava/lang/String;Ljava/lang/String;)V",
-		(void *)ScummVM_setConfManString },
-	{ "enableZoning", "(Z)V",
-		(void *)ScummVM_enableZoning },
-	{ "setSurfaceSize", "(II)V",
-		(void *)ScummVM_setSurfaceSize },
-};
-
-JNIEXPORT jint JNICALL
-JNI_OnLoad(JavaVM *jvm, void *reserved) {
-	cached_jvm = jvm;
-
-	JNIEnv *env;
-
-	if (jvm->GetEnv((void **)&env, JNI_VERSION_1_2))
-		return JNI_ERR;
-
-	jclass cls = env->FindClass("org/inodes/gus/scummvm/ScummVM");
-	if (cls == 0)
-		return JNI_ERR;
-
-	if (env->RegisterNatives(cls, gMethods, ARRAYSIZE(gMethods)) < 0)
-		return JNI_ERR;
-
-	FID_ScummVM_nativeScummVM = env->GetFieldID(cls, "nativeScummVM", "J");
-	if (FID_ScummVM_nativeScummVM == 0)
-		return JNI_ERR;
+void JNI::setSurfaceSize(JNIEnv *env, jobject self, jint width, jint height) {
+	assert(_system);
 
-	jclass event = env->FindClass("org/inodes/gus/scummvm/Event");
-	if (event == 0)
-		return JNI_ERR;
-
-	FID_Event_type = env->GetFieldID(event, "type", "I");
-	if (FID_Event_type == 0)
-		return JNI_ERR;
-
-	FID_Event_synthetic = env->GetFieldID(event, "synthetic", "Z");
-	if (FID_Event_synthetic == 0)
-		return JNI_ERR;
-
-	FID_Event_kbd_keycode = env->GetFieldID(event, "kbd_keycode", "I");
-	if (FID_Event_kbd_keycode == 0)
-		return JNI_ERR;
-
-	FID_Event_kbd_ascii = env->GetFieldID(event, "kbd_ascii", "I");
-	if (FID_Event_kbd_ascii == 0)
-		return JNI_ERR;
-
-	FID_Event_kbd_flags = env->GetFieldID(event, "kbd_flags", "I");
-	if (FID_Event_kbd_flags == 0)
-		return JNI_ERR;
-
-	FID_Event_mouse_x = env->GetFieldID(event, "mouse_x", "I");
-	if (FID_Event_mouse_x == 0)
-		return JNI_ERR;
-
-	FID_Event_mouse_y = env->GetFieldID(event, "mouse_y", "I");
-	if (FID_Event_mouse_y == 0)
-		return JNI_ERR;
-
-	FID_Event_mouse_relative = env->GetFieldID(event, "mouse_relative", "Z");
-	if (FID_Event_mouse_relative == 0)
-		return JNI_ERR;
-
-	return JNI_VERSION_1_2;
+	_system->setSurfaceSize(width, height);
 }
 
 #endif
diff --git a/backends/platform/android/jni.h b/backends/platform/android/jni.h
new file mode 100644
index 0000000000..39276b9388
--- /dev/null
+++ b/backends/platform/android/jni.h
@@ -0,0 +1,87 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU 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 General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+#ifndef _ANDROID_JNI_H_
+#define _ANDROID_JNI_H_
+
+#if defined(__ANDROID__)
+
+#include <jni.h>
+
+extern jobject back_ptr;
+
+class OSystem_Android;
+
+class JNI {
+public:
+	static jint onLoad(JavaVM *vm);
+
+	static JNIEnv *getEnv();
+
+	static void attachThread();
+	static void detachThread();
+
+private:
+	JNI();
+	virtual ~JNI();
+
+private:
+	static JavaVM *_vm;
+	// back pointer to (java) peer instance
+	static jobject _jobj;
+	static OSystem_Android *_system;
+
+	static jfieldID _FID_Event_type;
+	static jfieldID _FID_Event_synthetic;
+	static jfieldID _FID_Event_kbd_keycode;
+	static jfieldID _FID_Event_kbd_ascii;
+	static jfieldID _FID_Event_kbd_flags;
+	static jfieldID _FID_Event_mouse_x;
+	static jfieldID _FID_Event_mouse_y;
+	static jfieldID _FID_Event_mouse_relative;
+	static jfieldID _FID_ScummVM_nativeScummVM;
+
+	static const JNINativeMethod _natives[];
+
+	static void throwByName(JNIEnv *env, const char *name, const char *msg);
+
+	// natives for the dark side
+	static void create(JNIEnv *env, jobject self, jobject am);
+	static void destroy(JNIEnv *env, jobject self);
+	static jint main(JNIEnv *env, jobject self, jobjectArray args);
+	static void pushEvent(JNIEnv *env, jobject self, jobject java_event);
+	static void audioMixCallback(JNIEnv *env, jobject self, jbyteArray jbuf);
+	static void setConfManInt(JNIEnv *env, jclass cls, jstring key_obj,
+								jint value);
+	static void setConfManString(JNIEnv *env, jclass cls, jstring key_obj,
+							   		jstring value_obj);
+	static void enableZoning(JNIEnv *env, jobject self, jboolean enable);
+	static void setSurfaceSize(JNIEnv *env, jobject self, jint width,
+								jint height);
+};
+
+#endif
+#endif
+