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    jclass clazz( env->GetObjectClass(activity) );     jclass clazz(env->GetObjectClass(activity));
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    jmethodID method_id = env->GetMethodID( clazz, "showHome", "()V" );     jmethodID method_id = env->GetMethodID(clazz, "showHome", "()V");
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    env->CallVoidMethod( activity, method_id );
    
    env->CallVoidMethod(activity, method_id);

DRAFT

SDL_AndroidGetJNIEnv

Use this function to retrieve the Java native interface object (JNIEnv) of the current thread on Android builds.

Syntax

void* SDL_AndroidGetJNIEnv(void)

Return Value

Returns a pointer to Java native interface object (JNIEnv) to which the current thread is attached, or 0 on error.

Code Examples

// Calls the void MyActivity.showHome() method of the Java instance of MyActivity.
void showHome(void)
{
    // retrieve the JNI environment.
    JNIEnv* env = (JNIEnv*)SDL_AndroidGetJNIEnv();

    // retrieve the Java instance of the SDLActivity
    jobject activity = (jobject)SDL_AndroidGetActivity();

    // find the Java class of the activity. It should be SDLActivity or a subclass of it.
    jclass clazz(env->GetObjectClass(activity));

    // find the identifier of the method to call
    jmethodID method_id = env->GetMethodID(clazz, "showHome", "()V");

    // effectively call the Java method
    env->CallVoidMethod(activity, method_id);

    // clean up the local references.
    env->DeleteLocalRef(activity);
}

Remarks

The prototype of the function in SDL's code actually declare a void* return type, even if the implementation returns a pointer to a JNIEnv. The rationale being that it allows not to include jni.h in the headers of the SDL.

Version

This function is available in SDL 2.0.0


CategoryAPI, CategorySystem

None: SDL_AndroidGetJNIEnv (last edited 2016-11-20 22:03:47 by PhilippWiesemann)

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