TreeView : How could I show directories first?

MSDQuick

Hi guys :

I wonder if there is a way to sort "TreeView" to show Directories first , then files?

Thanks.
MSD.

Joel Bodenmann

I assume that you are using QFileSystemModel?
As far as I know / can tell it's not possible to just flick a switch. However, you can still get this going by implementing a custom sort-filter model (subclassing QSortFilterProxyModel). You should be able to overwrite QSortFilterProxyModel::lessThan() to implement the behavior your are looking for. You would basically compare the isDir() attribute that you can retrieve from the underlying QFileSystemModel.

Something like this comes to mind (untested!):

bool MySortFilterModel::lessThan(const QModelIndex& left, const QModelIndex& right) const
{
	QFileSystemModel* model = qobject_cast<QFileSystemModel*>(sourceModel());
	if (!model) {
		qFatal("Shit hit the fan");
		return true;
	}
	
	if (!model->fileInfo(left).isDir() && model->fileInfo(right).isDir()) {
	    return false;
	}

	return true;
}

This is just a - most likely not even compiling - example showing the general idea behind this. You'd have to also take the sorting order into account by checking QSortFilterProxyModel::sortOrder().

I hope that helps somehow.