Setup Run Configuration dialog with filename *fname*

def setup(self, fname):
        """Setup Run Configuration dialog with filename *fname*"""
        combo_label = QLabel(_("Select a run configuration:"))
        self.combo = QComboBox()
        self.combo.setMaxVisibleItems(20)
        self.combo.setSizeAdjustPolicy(QComboBox.AdjustToMinimumContentsLength)
        self.combo.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Fixed)
        
        self.stack = QStackedWidget()

        configurations = _get_run_configurations()
        for index, (filename, options) in enumerate(configurations):
            if fname == filename:
                break
        else:
            # There is no run configuration for script *fname*:
            # creating a temporary configuration that will be kept only if
            # dialog changes are accepted by the user
            configurations.insert(0, (fname, RunConfiguration(fname).get()))
            index = 0
        for filename, options in configurations:
            widget = RunConfigOptions(self)
            widget.set(options)
            self.combo.addItem(filename)
            self.stack.addWidget(widget)
        self.combo.currentIndexChanged.connect(self.stack.setCurrentIndex)
        self.combo.setCurrentIndex(index)

        self.add_widgets(combo_label, self.combo, 10, self.stack)
        self.add_button_box(QDialogButtonBox.Ok|QDialogButtonBox.Cancel)

        self.setWindowTitle(_("Run configuration per file"))