How to add CheckBox on QTreeView + QFileSystemModel - c++

Question

I want to select some different folders in the treeview. There are two solution in QT like this:
QTreeView + QFileSystemModel, But how add the treebox in it? I dotn't know at all. In the same time, QFileSystemModel is asychronised, so after you choose a folder, then expand the directory, you will find the sub-folder were not choosen. How can I solve the this problem?
QTreeView + QDirModel, there is a good model and it work well:
http://www.programmershare.com/2041913/
But QDirModel is synchronised. So we have to wait a long time when choose a big folder. We can accept a long time, but how I can know the selection is finished?
Thanks anyway.

Answer 1

Your example should be tweaked a bit to use QFileSystemModel.
The trick is to declare the checkedIndexes set as mutable and update it inside the CFileSystemModel::data method.
QVariant CFileSystemModel::data(const QModelIndex &index, int role) const
{
if(role == Qt::CheckStateRole)
{
if (checkedIndexes.contains(index))
{
return checkedIndexes.contains(index) ? Qt::Checked : Qt::Unchecked;
}
else
{
int checked = Qt::Unchecked;
QModelIndex parent = index.parent();
while (parent.isValid())
{
if (checkedIndexes.contains(parent))
{
checked = Qt::Checked;
break;
}
parent = parent.parent();
}
if (checked == Qt::Checked)
{
checkedIndexes.insert(parent);
}
return checked;
}
}
else
{
return QFileSystemModel::data(index, role);
}
}
When you open a directory node in a view, QFileSystemModel starts to load new contents. After they are loaded, the view retieves new data using CFileSystemModel::data function, which checks if new nodes anchestors were checked and returns proper Qt::CheckStateRole value (and also updates the checkedIndexes set).