file.h

#ifndef FILE_H
#define FILE_H

#include "base.hpp"
#include "Utility_global.h"

// file names rooted on the applications file system
class UTILITYSHARED_EXPORT File : public QFile
{
    static QString _root; // root of file name
public:
    File(QString dir, QString nm = "", QString ext = "")
    {
        QString s = QString("%1/%2").arg(_root).arg(dir);
        if(!nm.isEmpty()) {s += "/" ;  s += nm;}
        if(!ext.isEmpty()) s += ext;
        setFileName(s);
    };
    static QString root() { return _root;}
    static void setRoot(QString s) { _root = s;}
};

#endif // FILE_H

---