Preventing file actions in QFileDialog, such as copying, viewing, deleting, etc

Question

We are looking at deploying a PyQt application on an Azure server, and the application works well enough, albeit a little slow to respond to user actions.

We have a problem, however, and that is that the QFileDialog allows pretty much any explore action: copy a file from the virtual machine to the user's local drive, open a file within 'Program Files (x86)' in Notepad, etc.

Approaches already considered:

1. As the python application has to have read and write permissions to run under 'Program Files (x86)', we can't use file permissions to control access.

2. We can turn the Python into an inscrutable .exe, but this could still be copied using the context menus in the file dialog.

3. We could use the file filters and then hide them, so you can only see (and mess with) the relevant files, but the user could still copy entire directories.

The only thing we can think of is to create our own file dialog from scratch, but that's very tedious. Are there any 'out of the box' solutions?

Answer 1

The QFileDialog class already has this functionality:

    dialog = QtGui.QFileDialog()
    dialog.setOption(QtGui.QFileDialog.ReadOnly, True)
    dialog.exec_()

This only seems to work with Qt's built-in file-dialog, though. If you use the static functions to open a native file-dialog, the ReadOnly option seems to be ignored (I've only tested this on Linux, though).

Answer 2

looking at exemple of qtreeview they show a file explorer so i think it's actually not a big task to implement a simple file system explorer. it's specialy easy thanks to QFileSystemModel http://doc.qt.io/qt-5/model-view-programming.html#using-models-and-views

Answer 3

Here's what I actually did, based on @ekhumoro's advice:

from PyQt4 import QtGui
import guidata
import re

class _DirectoryFilterProxyModel(QtGui.QSortFilterProxyModel):
    """ A basic filter to be applied to the file items to be displayed.
     Based on C++ example at:
      https://stackoverflow.com/questions/2101100/qfiledialog-filtering-folders. """

    def __init__(self, ignore_directories=[], *args, **kw):
        """ Constructor
        :param ignore_directories: A list of directories to exclude.  These
        can be regular expressions or straight names. """
        QtGui.QSortFilterProxyModel.__init__(self, *args, **kw)
        self.ignore_directories = ignore_directories

    def filterAcceptsRow(self, sourceRow, sourceParent):
        fileModel = self.sourceModel()
        index0 = fileModel.index(sourceRow, 0, sourceParent)

        if fileModel:
            if fileModel.isDir(index0):
                for directory in self.ignore_directories:
                    if re.match(directory, fileModel.fileName(index0)):
                        return False
                return True
            else:    # For files
                return True
        else:
            return False

And instantiated:

app = guidata.qapplication()
dialog = QtGui.QFileDialog()
proxyModel = _DirectoryFilterProxyModel(ignore_directories=["Program Files", "Program Files (x86)", "Windows"])
dialog.setProxyModel(proxyModel)
dialog.setOption(QtGui.QFileDialog.ReadOnly, True)
dialog.setOption(QtGui.QFileDialog.HideNameFilterDetails, True)
dialog.exec_()

My thanks to @serge_gubenko and @Gayan on the page qfiledialog - Filtering Folders? for providing the C++ implementation, from which I derived the above.