Android openglwindow no dialog, messagbox problem

[sinnlos]

Hi,

in the example gui/openglwindow i added some MessageBoxes and a Dialog, but only QMessageBox::information(..) is shown correctly :

@//! [2]
int main(int argc, char **argv)
{
//QGuiApplication app(argc, argv);
QApplication app(argc, argv);

QSurfaceFormat format;
format.setSamples(16);
format.setDepthBufferSize(24);


TriangleWindow window;
window.setFormat(format);
window.resize(640, 480);
window.show();
window.setAnimating(true);

//works android, linux+osx desktop, ios
QMessageBox::information(0,"Title","Text");

// works linux+osx desktop, ios  / android button missing
QMessageBox box;
box.setText("?????");
box.addButton("Click",QMessageBox::AcceptRole);
box.exec();

//works linux+osx desktop, ios /android not showing
MyDialog md;
md.setWindowTitle("Dialog from ui file");
md.exec();

return app.exec();

}
//! [2]@

I get this errors (android only. desktop, ios works):

W/Qt (21829): kernel/qwidget_qpa.cpp:998 (virtual QPaintEngine* QWidget::paintEngine() const): QWidget::paintEngine: Should no longer be called
W/Qt (21829): painting/qpainter.cpp:1734 (bool QPainter::begin(QPaintDevice*)): QPainter::begin: Paint device returned engine == 0, type: 1
W/Qt (21829): painting/qpainter.cpp:8164 (const QTransform& QPainter::deviceTransform() const): QPainter::deviceTransform: Painter not active
W/Qt (21829): painting/qpainter.cpp:8237 (const QTransform& QPainter::worldTransform() const): QPainter::worldTransform: Painter not active
W/Qt (21829): painting/qpainter.cpp:3932 (const QPen& QPainter::pen() const): QPainter::pen: Painter not active
W/Qt (21829): painting/qpainter.cpp:3875 (void QPainter::setPen(const QPen&)): QPainter::setPen: Painter not
W/Qt (21829): painting/qpainter.cpp:3875 (void QPainter::setPen(const QPen&)): QPainter::setPen: Painter not active

Why ? How do i solve this ?