Qt QFileDialog::setDirectory funny behavior in Ubuntu 12.04

Question

I have a class that inherits from QFileDialog. In the constructor, I call setDirectory and pass in the last directory visited (which the class keeps track of; see code below). On Windows, this works fine. And if I show the dialog multiple times, it is internally smart enough to resume at the last location (e.g. where the user saved a file before). This is the desired behavior.

On Ubuntu 12.04 (GCC 4.8 compiler), on the other hand, the system does not automatically resume where last left off if I call showFileDialog multiple times. So I tried adding the setDirectory call within that function as commented below, but that didn't change anything. Furthermore, if I take out setDirectory from the constructor so it is only called in showFileDialog, the file dialog opens to the folder from which the program was run. (i.e. setDirectory didn't work.) Subsequent calls to showFileDialog will open a file dialog starting in the directory requested.

So it seems like the call has a delayed effectiveness. Is this a Qt bug, or mine? Either way, how can I get the setDirectory call to be effective?

Example code:

QString FileDialog::defaultDir = QDir::homePath();

FileDialog::FileDialog(QWidget *parentWindow /*, ...*/)
    : QFileDialog(parentWindow)
{
    setDirectory(defaultDir);
    //...
}

QString FileDialog::showFileDialog()
{
    // Adding setDirectory(defaultDir) here doesn't help.

    if(!exec())
    {
        return QString::null;
    }

    defaultDir = directory().path();
    //...
}

Answer 1

Workaround found:

I happen to set the dialog title (setWindowTitle()) every time I open a FileDialog. If I connect to the QFileDialog::windowTitleChanged signal and call setDirectory within the slot, it is effective.

This is an unintuitive workaround though, so I am open to better answers.

Answer 2

It is not clear from the code above how you know that the path was changed. I'm not sure that directory() is responsible for that.

Consider using void QFileDialog::directoryEntered(const QString & directory) signal.