Drop event not generated after an accepted Drag Enter event

Violet Giraffe

I'm trying to create a tiny helper class that would facilitate processing drop events for any widget. Here's the definition, it should be pretty clear what the idea is:

FileDropHandler::FileDropHandler(QWidget* widget, const std::function<void (const FileNamesContainer&)>& handler) :
	QObject(widget),
	_handler(handler)
{
	assert(widget);
	assert(handler);

	widget->setAcceptDrops(true);
	widget->installEventFilter(this);
}

bool FileDropHandler::eventFilter(QObject* /*watched*/, QEvent* event)
{
	if (event->type() == QEvent::DragEnter)
	{
		auto * e = static_cast<QDragEnterEvent*>(event);
		if (e->mimeData()->hasUrls())
			e->acceptProposedAction();
	}
	else if (event->type() == QEvent::Drop)
	{
		auto * e = static_cast<QDropEvent*>(event);

		FileNamesContainer filePaths;
		for (const QUrl& url: e->mimeData()->urls())
			filePaths.emplace_back(url.toLocalFile());

		_handler(filePaths);
	}

	return false;
}

FileDropHandler is, of course, a subclass of QObject. And I'm instantiating it for a certain QTextEdit. Problem: DragEnter event is processed and acceptProposedAction is executed, but the Drop event does not follow. What did I miss?

Violet Giraffe

return true after e->acceptProposedAction() fixed it. And I get it. What I don't get is this: I have tried e->accept() before posting this question, and it did not help. Can someone please explain?

SGaist

Hi,

AFAIK, e-accept() just tells that the system want the event. Returning true from eventFilter means that the event has been handled and handling should stop there.

Hope it helps