Question

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. If I set the RootPath to be the parent’s parent, then I see the parent directory with all its siblings. Is there a way to get it to show the parent without its siblings, and all the children?

Thanks

Answer 1

This works for me on Linux. I’m not claiming it’s the best implementation and I’m not sure if using backslash separators will work on Windows. I know Qt translates them to the native separator but I don’t know if it’s native separators that come out of the model’s data method.

#include <QApplication>
#include <QFileSystemModel>
#include <QSortFilterProxyModel>
#include <QTreeView>

class FilterModel : public QSortFilterProxyModel
{
public:
    FilterModel( const QString& targetDir ) : dir( targetDir )
    {
        if ( !dir.endsWith( "/" ) )
        {
            dir += "/";
        }
    }

protected:
    virtual bool filterAcceptsRow( int source_row
                                 , const QModelIndex & source_parent ) const
    {
        QString path;
        QModelIndex pathIndex = source_parent.child( source_row, 0 );
        while ( pathIndex.parent().isValid() )
        {
            path = sourceModel()->data( pathIndex ).toString() + "/" + path;
            pathIndex = pathIndex.parent();
        }
        // Get the leading "/" on Linux. Drive on Windows?
        path = sourceModel()->data( pathIndex ).toString() + path;

        // First test matches paths before we've reached the target directory.
        // Second test matches paths after we've passed the target directory.
        return dir.startsWith( path ) || path.startsWith( dir );
    }

private:
    QString dir;
};

int main( int argc, char** argv )
{
    QApplication app( argc, argv );

    const QString dir( "/home" );
    const QString targetDir( dir + "/sample"  );

    QFileSystemModel*const model = new QFileSystemModel;
    model->setRootPath( targetDir );

    FilterModel*const filter = new FilterModel( targetDir );
    filter->setSourceModel( model );

    QTreeView*const tree = new QTreeView();
    tree->setModel( filter );
    tree->setRootIndex( filter->mapFromSource( model->index( dir ) ) );
    tree->show();

    return app.exec();
}