QFileDialog: block access to folders or drives on Windows

[the_]

Hi guys,

Is there a proper way to block access to folders and/or drives ?
There is a signal, that is emitted when changing a directory, but this seems to work only if you doubleclick a folder, so i can check if the returned directory path is valid or not. But how to disable access via the address bar or the "Open" button?

Thanks for help

[kshegunov]

@the_
Hello,
Aren't the flags working for you, namely QFileDialog::FileMode and QFileDialog::Option?

Kind regards.

[the_]

@kshegunov

I am not sure if that will work for me, FileMode only sets the selection mode, as I need to select single files it is set to QFileDialog::ExistingFile. As i correctly understand the QFileDialog::Option there is no way to deny access to some path

Maybe I should add some more description to my problem:

The app i wrote is a reporting tool for special forms. Users are able to add attachments to each report but should not be able to access every drive, for example, if you have C: (the OS drive itself), D: (a flash drive, usb stick, whatever) and X: (a network drive), any access to C: should be denied (by doubleclicking this drive in "Computer", by entering C:<any path><anyfile> in the address bar and by selecting the drive and click the Open button in the dialog)

[kshegunov]

@the_
I see, what about setting a proxy model to the dialog and filtering up the restricted locations there? I think it should work in your case.

[the_]

@kshegunov

Sounds to be a proper way. Thanks for the hint. I will give it a try and post an update.

[the_]

@kshegunov
Well I had some "funny" things here about ProxyModels....

I found an example on stackoverflow, which i tried to implement:

class FileFilterProxyModel : public QSortFilterProxyModel
{
protected:
    virtual bool filterAcceptsRow(int source_row, const QModelIndex& source_parent) const;
};

bool FileFilterProxyModel::filterAcceptsRow(int sourceRow, const QModelIndex &sourceParent) const
{
    QModelIndex index0 = sourceModel()->index(sourceRow, 0, sourceParent);
    QFileSystemModel* fileModel = qobject_cast<QFileSystemModel*>(sourceModel());

    if (fileModel!=NULL && fileModel->isDir(index0))
    {
        if(fileModel->filePath(index0).startsWith("/home/")) {
            qDebug() << fileModel->filePath(index0);
            //        qDebug() << fileModel->fileName(index0);
            return true;
        }
        else
            return false;
    }
    else
        return false;
    // uncomment to execute default implementation
    //return QSortFilterProxyModel::filterAcceptsRow(sourceRow, sourceParent);
}

//...
filed = new QFileDialog(this);
FileFilterProxyModel *ffpm = new FileFilterProxyModel;
filed->setProxyModel(ffpm);
qDebug() << filed->proxyModel();

QFileDialog *filed; is defined in the header file;

When I run this on my linux box it returns

QSortFilterProxyModel(0x7c3a10) QSortFilterProxyModel(0x7c3a10)

but when I run the same code (ok not exactly the same, I changed the "/home/" to "C:" :) ) it returns

QSortFilterProxyModel(0x7c3a10) QObject(0x0)

The only difference is that Win8.1 has Qt5.4.2 and my Arch has Qt5.5.1...

Is there something wrong?

[kshegunov]

@the_
Hello,
If there were, I can't spot it directly. There's one thing I don't understand though, where are those addresses printed and what they're supposed to mean.

When I run this on my linux box it returns
QSortFilterProxyModel(0x7c3a10) QSortFilterProxyModel(0x7c3a10)
but when I run the same code (ok not exactly the same, I changed the "/home/" to "C:" :) ) it returns
QSortFilterProxyModel(0x7c3a10) QObject(0x0)

This I don't get. What do you mean by "it returns" and what's the relation to: "QSortFilterProxyModel(0x7c3a10)"?

Kind regards.

[the_]

@kshegunov

That's what qDebug prints. Sorry for being not precise enough.

[kshegunov]

@the_
Not about precision, I just don't understand the meaning of it.
Is this:

qDebug() << filed->proxyModel();

printing those?

Additionally, where does this piece of code:

filed = new QFileDialog(this);
FileFilterProxyModel *ffpm = new FileFilterProxyModel;
filed->setProxyModel(ffpm);
qDebug() << filed->proxyModel();

reside?

[the_]

@kshegunov

The thing is, that I did not get the expected result on windows, so i checked if the proxymodel is applied correctly, which seems to be not.

The code is inside the constructor of the class that builds the ui where i want to use the QFileDialog.

mainwindow.cpp

//includes

class FileFilterProxyModel : public QSortFilterProxyModel {
 //class goes here 
};

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow) {

//...

filed = new QFileDialog(this);
FileFilterProxyModel *ffpm = new FileFilterProxyModel;
filed->setProxyModel(ffpm);
qDebug() << filed->proxyModel();

//...
}

Thats for short the structure.
The part I do not understand is why on linux proxyModel() returns the one I set and on windows it returns a NULL Object.

[kshegunov]

@the_
Hello,

The thing is, that I did not get the expected result on windows, so i checked if the proxymodel is applied correctly, which seems to be not.

It should, but you may have stumbled upon a bug, however before jumping the gun let's suppose there's a subtle problem with the code (still) and try to fix that. About your qDebug() statement, the thing that baffled me is that you output a single address with this:

qDebug() << filed->proxyModel();

but you get two objects output:

QSortFilterProxyModel(0x7c3a10) QSortFilterProxyModel(0x7c3a10)

Am I misunderstanding?

Your constructor looks okay, as far as I can tell, but you should (at least I believe you should) also disable the nativeness of the dialog, provided you haven't done already, like this:

filed->setOptions(QFileDialog::DontUseNativeDialog);

Let me know how that turns out.

Kind regards.

[Devopia53]

@the_

As said @kshegunov,

ProxyModel is unsupported feature on native dialog mode.

[the_]

@Devopia53

This did it with Windows. Thanks