Drag and drop of files from Qt application to MS Edge - c++

Question

I have a Qt application for Windows which contains a list of files in a widget. I want to be able to drag the files from this widget to another application. I am using Qt-base drag and drop mechanism and it works well in most cases. One case which does not work is to drag and drop it into MS Edge browser, for example when I open MS Edge and start writing an email with mail.google.com and I want to add the files as attachment by drag and drop from my Qt application. It is strange that this does work in Chrome, Firefox and also in ancient Internet Explorer. But not in Edge. Here is my minimalistic example. Try to drag files from the widget to a web page which accepts drag and drop of a file. On my computer this works for all browsers except Edge.
#include <QApplication>
#include <QDrag>
#include <QLabel>
#include <QMimeData>
#include <QMouseEvent>
class Window : public QLabel
{
public:
void mousePressEvent(QMouseEvent *event)
{
if (event->button() == Qt::LeftButton)
{
QList<QUrl> urls;
urls.append(QUrl::fromLocalFile("C:/test/test1"));
urls.append(QUrl::fromLocalFile("C:/test/test2"));
QMimeData* mimeData = new QMimeData();
mimeData->setUrls(urls);
QDrag* drag = new QDrag(this);
drag->setMimeData(mimeData);
drag->exec(Qt::CopyAction);
}
}
};
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
Window w;
w.setText("Drag from here...");
w.show();
return a.exec();
}
Note that I am passing data as text/uri-list MIME type. I was observing how other applications behave as drag source, and they seem to work fine - e.g. when dragging from File Explorer, Total Commander etc to MS Edge. When I look at the MIME types that they send, I can see also application/x-qt-windows-mime;value="Shell IDList Array" type, which I am missing in my example. So this is what I assume is the problem, Edge probably expects this MS-centric data type. I would also like to wrap data in this format but I do not know how to do it.
I assume I will have to use Win32 API. So I browsed around and got some snippets which should be able to create some useful data structures...
QVector<LPITEMIDLIST> idLists;
for (const QString &nativePath: qAsConst(nativePaths))
{
PCWSTR pszFile = PCWSTR(nativePath.utf16());
LPITEMIDLIST idl = ILCreateFromPathW(pszFile);
if (idl == nullptr)
{
for (LPITEMIDLIST pid : qAsConst(idLists))
ILFree(pid);
return nullptr;
}
idLists.append(idl);
}
IShellItemArray *iArray = nullptr;
HRESULT result = SHCreateShellItemArrayFromIDLists(UINT(idLists.size()), (LPCITEMIDLIST*)idLists.data(), &iArray);
for (LPITEMIDLIST pid : qAsConst(idLists))
ILFree(pid);
This seems to me as the way that could lead to the desired outcome but there are still some steps missing. I do not know how to wrap this data (are they of any use at all?) into QMimeData::setData(). Any ideas?