Fun with Bluetooth Controllers - Pro Android Games - page 286

3. The third argument is the string message for OnMessage or the

encoded event information for OnEvent . In this way the same function
can be reused for both WiiC callbacks, OnMessage and OnEvent .

Listing 8-12. WiiC Callback Methods to Wiimote.java

static void jni_send_str(int rc, const char * methodName, const char * text) {
JNIEnv *env;

if ( !g_VM) {
LOGE("%s\n", text);
return;
}

(*g_VM)->AttachCurrentThread (g_VM, &env, NULL);

if ( jCbClass == 0 ) {
LOGE("No callback class. Abort!");
return;
}

// Call Java method
jmethodID mSendStr = (*env)->GetStaticMethodID(env, jCbClass
, methodName
, "(ILjava/lang/String;)V");

if (mSendStr) {
jstring jstr = (*env)->NewStringUTF(env, text);

(*env)->CallStaticVoidMethod(env, jCbClass
, mSendStr , rc, jstr );

(*env)->DeleteLocalRef(env,jstr);
}
}

/**
* Send message callback. Invokes jni_send_str
*/
void jni_send_message(char *format, ...)
{
va_list argptr;
static char string[1024];

va_start (argptr, format);
vsprintf (string, format,argptr);
va_end (argptr);

jni_send_str(0, "OnMessage", string);
}