WA_TranslucentBackground does not work with direct2d engine

WA_TranslucentBackground does not work with direct2d engine

In our application, a top level QWidget, which is constructed with Qt::WA_TranslucentBackground, does not become visible after calling show(), when platform is "direct2d".

The same application works perfectly with platform "windows".

The custom widget constructor is like this:

CMyWidget::CMyWidget()
: QWidget( 0, Qt::WindowStaysOnTopHint | Qt::Tool | Qt::FramelessWindowHint )
{
setAttribute( Qt::WA_TranslucentBackground, true );
}