Creating a QMainWindow from Java using JNI
- by ebasconp
Hi everybody:
I'm trying to create a Qt main windows from Java using JNI directly and I got a threading error.
My code looks like this:
Test class:
public class Test
{
public static void main(String... args)
{
System.out.println(System.getProperty("java.library.path"));
TestWindow f = new TestWindow();
f.show();
}
}
TestWindow class:
public class TestWindow
{
static { System.loadLibrary("mylib"); }
public native void show();
}
C++ impl:
void JNICALL Java_testpackage_TestWindow_show
(JNIEnv *, jobject)
{
int c = 0; char** a = NULL;
QApplication* app = new QApplication(c, a);
QMainWindow* mw = new QMainWindow();
mw->setWindowTitle("Hello");
mw->setGeometry(150, 150, 400, 300);
mw->show();
QApplication::exec();
}
and I get my window painted but frozen (it does not receive any event) and the following error message when instantiating the QMainWindow object:
QCoreApplication::sendPostedEvents: Cannot send posted events for objects in another thread
I know all the UI operations must done in the UI thread but in my example I created the QApplication in the only thread I have running, so, everything should work properly.
I did some tests executing the code of my "show" method from a QMetaObject::invokeMethod stuff using Qt::QueuedConnection but nothing works properly.
I know I could use Jambi... but I know that it could be done natively too and that is what I want to do :)
Any ideas on this? Thanks in advance!
Ernesto
