fetchMore() not working on the top-level index in a QFileSystemModel

[Guett_31]

I have implemented the proxi model in the view itself, because only that view needs that trick with an artificial index to display the rootindex.
I create the proxi model when I call setModel(). SetModel() is called with the source model.

void FileSysSelectView::setModel(QAbstractItemModel * model)
{
 
    m_sourceModel = static_cast<FileSysSelectModel *> (model);
    m_proxiModel = new QSortFilterProxyModel();
    m_proxiModel->setSourceModel(m_sourceModel);
 
    QTreeView::setModel(m_proxiModel);
 
    // Limit the view to the File name Column (1st Column)
    for (int i(1); i < m_proxiModel->columnCount(QModelIndex::QModelIndex()); i++) this->setColumnHidden(i,true);
}

void FileSysSelectView::setModel(QAbstractItemModel * model)
{

    m_sourceModel = static_cast<FileSysSelectModel *> (model);
    m_proxiModel = new QSortFilterProxyModel();
    m_proxiModel->setSourceModel(m_sourceModel);

    QTreeView::setModel(m_proxiModel);

    // Limit the view to the File name Column (1st Column)
    for (int i(1); i < m_proxiModel->columnCount(QModelIndex::QModelIndex()); i++) this->setColumnHidden(i,true);
}

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At that point everything works well, my proxi model sits bettween my view and the source model, and it acts transparently.
I try to insert the artificial index when I call setRootIndex().

For exemple, if I want to show what is under C:/, I have to do the folowing:

before:
- root
--C:\
---Program Files
---Windows
---Users
--D:\
--X:\

after:
- root
-- artififical index
---C:\
----Program Files
----Windows
---Users
--D:\
--X:\

void FileSysSelectView::setRootIndex(const QModelIndex & index)
{
 
   // insert a new index under the specified root index. 
    QModelIndex idxParent = m_proxiModel->mapFromSource(index.parent());
    m_proxiModel->insertRow(0, idxParent);
 
    // move the the root index under the new index
    QModelIndex idxNew = m_proxiModel->index(0,0, idxParent);
    QModelIndex idx = m_proxiModel->mapFromSource(index);
    int idxPosition = idx.row();
    m_proxiModel->moveRow(idxParent, idxPosition, idxNew, 0);
    QTreeView::setRootIndex(idx);
}

void FileSysSelectView::setRootIndex(const QModelIndex & index)
{

   // insert a new index under the specified root index. 
    QModelIndex idxParent = m_proxiModel->mapFromSource(index.parent());
    m_proxiModel->insertRow(0, idxParent);
    
    // move the the root index under the new index
    QModelIndex idxNew = m_proxiModel->index(0,0, idxParent);
    QModelIndex idx = m_proxiModel->mapFromSource(index);
    int idxPosition = idx.row();
    m_proxiModel->moveRow(idxParent, idxPosition, idxNew, 0);
    QTreeView::setRootIndex(idx);
}

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Actually int idxPosition = idx.row() at line 11 doesn't work for the reasons I mentioned earlier in the thread. The underlying QFileSystemModel needs to be populated before idx.row() is called. That means I have to call fetchMore() and check for directroyLoaded() signal in that situation too...

[Guett_31]

Also, I have found another old thread from a different forum that said:

"Regarding folder sorting on Windows: I think I got it. The damn model only sorts items below its "root path()" as the statrting point which is "/" on Linux /UNIX / Mac Os X, but on windows it's the system driver's root directory. Effectively, only "c:/" and it's sub-folders were sorted...
Now I'm using "QFileSystemModel::myComputer" as the model's root and as a result everything is sorted as expected."

http://forums.bannister.org/ubbthrea...68709&page=289

That might be related to my issue. I don't know how that person managed to use "QFileSystemModel::myComputer" as the model's root, though... it does not retrun a QModelIndex.

[wysota]

A sort-filter proxy model can't do what you require. You have to implement your own proxy model derived either from QAbstractProxyModel or from QIdentityProxyModel.

[Guett_31]

QIdentityProxyModel is what I tried in the first place. It didn't work either. I'm not familiar whith proxi models. why do I need my own proxi? Could you give my some guidance or some useful links...
I search the internet without any success for that...

[wysota]

QIdentityProxyModel is what I tried in the first place. It didn't work either.

It won't "work" because it is a transparent proxy. You need to subclass it and implement the functionality you need.

I'm not familiar whith proxi models. why do I need my own proxi?

Because you want to add an artificial item to an existing model without changing the original model itself.