QTreeView shows all the subfolders, but not the parent folder.

[Punit]

I'm trying to get QTreeView (using an underlying QFileSystemModel) to show a directory tree. If I set the RootPath to the parent directory, then I see all the children, but not the parent.

I want to see parent folder and all it's subfolders.

Code:

QString dir = QFileDialog::getExistingDirectory(this, tr("Open Directory"), "/home", QFileDialog::ShowDirsOnly | QFileDialog::DontResolveSymlinks);
viewtree=new QTreeView; 
dir1=new QFileSystemModel(this); 
dir1->setRootPath(dir); 
dir1->setFilter(QDir::NoDotAndDotDot |QDir::AllDirs); 
viewtree->setModel(dir1); 
viewtree->setRootIndex(dir1->index(dir));

I want to show Parent folder along with it's subfolders in QTreeView.
Any Suggestions?
Thanks.

[giupigna]

I had the same problem and I resolved it using a QSortFilterProxyModel on the FileSystemModel, filtering just the folder that will be the root of the treeView.
Anyway I used the same proxy model to do something else.

[Punit]

@giupigna @Lifetime-Qt-Champion @Moderators @Qt-Champions-2015

I have a folder structure like this.

User 
   |-Mac
       |-Desktop
               |-test2
                      |-First
                      |-Second

I am trying to show a folder "test2" and all it's subfolders. I am a newbiew so don't know much about QSortFilterProxyModel. First of all if I select "test2" when prompt to select folder, my treeview only shows subfolders i.e. "First" and "Second". So I am using QDir::cdUp() function to set Desktop as my root folder. Now my treeview show all folders present inside "Desktop" including "test2". But, I want to show "test2" and all it's subfolders only.

I have created my own proxy model to do so, but it's not working. Please help!

CODE:

"MyProxy.h"

class MyProxy : public QSortFilterProxyModel
{
    Q_OBJECT
public:
    MyProxy();

protected:
    bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const;
};

"MyProxy.cpp"

#include "myproxy.h"

MyProxy::MyProxy()
{

}

bool MyProxy::filterAcceptsRow(int source_row, const QModelIndex &source_parent) const
{
    QModelIndex node= sourceModel()->index(source_row, 0, source_parent);
    QString foldername= sourceModel()->data(node, Qt::DisplayRole).toString();
    if(QString::compare(foldername ,"test2")==0)
          return true;
    else
         return false;
}

"mainwindow.cpp"

#include "myproxy.h"
................
  button=new QPushButton;
   button->setText("Click");


    connect(button,SIGNAL(clicked(bool)),this,SLOT(work()));

    dir=new QFileSystemModel;
    messagesTableWidget=new QTreeView;
    model=new MyProxy;    

void MainWindow::work()
{
    QString folderpath = QFileDialog::getExistingDirectory(this, tr("Open Directory"),
                                                  "/home",
                                                  QFileDialog::ShowDirsOnly
                                                  | QFileDialog::DontResolveSymlinks);

QDir* direct = new QDir(folderpath);
direct->setPath(folderpath);
direct->cdUp();

dir->setRootPath(direc->path());
dir->setFilter(QDir::NoDotAndDotDot |QDir::AllDirs);

model->setSourceModel(dir);
messagesTableWidget->setModel(model);

     messagesTableWidget->setRootIndex(model->mapFromSource(dir->index(direc->path())));
}

Thanks

[raven-worx]

@Punit
try something like this:

bool MyProxy::filterAcceptsRow(int source_row, const QModelIndex &source_parent) const
{
    QFileSystemModel* model = qobject_cast<QFileSystemModel*>( sourceModel );
    QModelIndex index = model->index(source_row, 0, source_parent);
    QModelIndex rootIndex = model->index( rootPath );   // create some getter/setter methods for the "rootPath" (QString)
    Q_ASSERT( rootIndex.isValid() );
    if( !rootIndex.isValid() )
         return false;
    return (index.isValid() && index == rootIndex) || this->isChildIndexOf(index, rootIndex);
} 

bool MyProxy::isChildIndexOf( const QModelIndex & child, const QModelIndex & parent )
{
     if( !child.isValid() )
         return false;

     QModelIndex idx = parent;
     do {
          if( child.parent() == idx )
                return true;
          idx = idx.parent();
          if( child.parent() == idx )  // in case parent is already invalid we need to check here again
                return true;
     }
     while( idx.isValid() );
     return false;
}

written straight from my head and thus untested.

[giupigna]

I did it in the following way:

bool PatternTreeFilterProxyModel::filterAcceptsRow(int source_row, const QModelIndex &source_parent) const
{    
    QFileSystemModel *model = qobject_cast<QFileSystemModel*>(sourceModel());
    QDir pathDir(m_path); // path of the root folder
    QModelIndex idx = source_parent.child(source_row, 0);
    QDir sourceFilePath(model->filePath(idx) + QDir::separator() + "test2");

    QString sourceAbsFilePath = sourceFilePath.absolutePath();
    QString pathDirAbsFilePath = pathDir.absolutePath();

    if (sourceAbsFilePath.startsWith(pathDirAbsFilePath))
        if (model->isDir(idx))
            return true;

    return false;
}

In my case I show only the folders in the treeView. Looking at the raven 's code it's better and more faster than mine, but I don't know if it works.

Anyway my advise it: debug, debug, debug a lot how I did.

[Punit]

Thanks a lot. :) @raven-worx @giupigna. Problem solved.

[fcarney]

I had issues making these solutions work for the QML TreeView. I ended up setting the root path of my QFileSystemModel to the directory I wanted to view. Then I set the rootIndex in the TreeView to the parent of the index for that directory. This is of course showed its siblings. Then I did the following to filter those siblings away. I also made this optional through a property as there are times when I want that behavior:

        bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const
        {
            FileSystemModel* tmodel = qobject_cast<FileSystemModel*>(parent());
            if(tmodel){
                QModelIndex index = tmodel->index(source_row, 0, source_parent);
                QModelIndex rootIndex = tmodel->index(tmodel->rootPath());
                if(!rootIndex.isValid() || !index.isValid())
                     return false;

                return ((index == rootIndex) || !(tmodel->filtersiblings() && isSiblingOf(index, rootIndex)));
            }

            return false;
        }

        bool isSiblingOf(const QModelIndex& index, const QModelIndex& parent) const
        {
            if(!index.isValid() || !parent.isValid())
                return false;

            QModelIndex sibling;
            int row=0;
            do{
                sibling = parent.sibling(row,0);
                if(sibling == index)
                    return true;
                ++row;
            }while(sibling.isValid());

            return false;
        }

I took more of a blacklist approach versus a whitelist approach.