QFileDialog setNameFilter can be fooled

Amomum

Let's say I want a QFileDialog that can open only specific extensions. I do this:

m_dialog.setFileMode(QFileDialog::ExistingFile);
m_dialog.setOption(QFileDialog::ReadOnly, true);

m_dialog.setNameFilter(tr("Models (*.jpg)"));

m_dialog.setOption(QFileDialog::ReadOnly, true);
m_dialog.setViewMode(QFileDialog::List);
m_dialog.setAcceptMode(QFileDialog::AcceptOpen);

Unfortunately, I still can write a filename by hand in the textbox and it will be opened even if its extension is not listed in the setNameFilter arguments.

I thought that maybe that's the 'feature' of the windows native window, so I set

m_dialog.setOption( QFileDialog::DontUseNativeDialog);

and 'Open' button in the dialog became disabled. Unfortunately, writing filename by hand and pressing 'Enter' still opens incorrect file.

So I have to filter by extension twice.

I just want to know, if that behaviour is normal or if it's a bug in Qt.

SGaist

Hi,

What version of Qt are you using on which platform ?

Amomum

@SGaist I'm using QT 5.7.1 on Windows.

SGaist

Can you validate that with a more recent version of Qt ?

Note that I suspect that it's a Windows specific behaviour. By default Qt uses the native file dialog which may have some quirks.

JonB

@Amomum
You want the filter to actually prevent a user from being able to specify a filename with a certain extension. But I don't think "filters" have ever claimed to do that. From the docs:

In the above example, the filter is set to "Images (*.png *.xpm *.jpg)", this means that only files with the extension png, xpm, or jpg will be shown in the QFileDialog.

I think they only determine what filenames are shown for selection. If the user types something, I don't they have anything to do with validating the response.

So, yes, for safety you have to validate the final result yourself if it matters.