how can I set qdialog parent with another process(x11 based)'s main window

[java9d]

I am doing qt app required to have a dialog show in browsers,etc,chrome,firefox,.., I use QWindow::setTransientParent,here is my code:

QApplication a(argc, argv);
// wait for browser becoming active
std::this_thread::sleep_for(std::chrono::seconds(5));
// get browser's native window handle with x11 lib,
// to get active window ,see :
// https://gist.githubusercontent.com/kui/2622504/raw/c11f4c94e11107311f3c8c20732ce1472dba25ed/gistfile1.c
Window w = get_active_top_window();
auto qw = QWindow::fromWinId(w);
QDialog dlg; // here is my dialog
dlg.winId(); // ensure to create native window
dlg.windowHandle()->setTransientParent(qw);
dlg.exec();

everything is good ,except that my qdialog is fixed in the browser ,when i drag the dialog's titlebar, the browser move also, how can I get it work? TIA.

[JonB]

@java9d
I have just had to move to Ubuntu 18.04, so I got moved from Unity desktop to GNOME desktop, which is what you have. As far as I know that behaviour whereby dragging a sub-dialog around drags its parent along with it, is a native GNOME behaviour, nothing to do with Qt. If anything at all can be done to alter it I would expect it to be via GNOME settings tweaks. Just a heads-up, unless you/someone else knows any better....

[java9d]

@JonB
thanks for your reply.
I don't know whether I understand QWindow::setTransientParent exactly. When I set QDialog parent with main window in identical process, the problem is still here:

//your code here
int main()
{
	QApplication a(argc, argv);
	// wait for browser becoming active
	std::this_thread::sleep_for(std::chrono::seconds(5));
	MainWindow w;
	w.show();
	a.exec();
}
// click listener
void button1_click()
{
	// get browser's native window handle with x11 lib,
	// to get active window ,see :
	// https://gist.githubusercontent.com/kui/2622504/raw/c11f4c94e11107311f3c8c20732ce1472dba25ed/gistfile1.c
	Window w = get_active_top_window();
	auto qw = QWindow::fromWinId(w);
	QDialog dlg; // here is my dialog
	dlg.winId(); // ensure to create native window
	dlg.windowHandle()->setTransientParent(qw);
}

It's quite simple in windows platform, I just want an equivalence of X11 :

	HWND hwndDialog = ...; // my dialog 
	HWND fore = GetForegroundWindow(); // get active window API , possibly in another process.
	SetWindowLongPtr(hwndDialog, GWLP_HWNDPARENT, (LONG_PTR)fore);

[JonB]

@java9d
I know nothing about "transient parent".

When I set QDialog parent with main window in identical process, the problem is still here:

Yes, as I said, it seems to be the behaviour of GNOME (at least by default) that dragging a dialog drags its parent/main window with it.