Python GTK: confirm overwrite dialog blocks filechooser dialog

Question

I have a Gtk.Button that opens a Gtk.FileChooserDialog to save a file. I implemented a Gtk.Dialog for confirmation that pops up when the chosen file name already exists in the target folder to save the file in. If I click on 'cancel' in this dialog the confirmation dialog is destroyed but I cannot use the 'cancel' or 'save' buttons of the Gtk.FileChooserDialog any longer. Any help is appreciated. Thanks.

#!/usr/bin/python
# -*- coding: utf-8 -*-

import os
from gi.repository import Gtk

class MainWindow(Gtk.Window):
    def __init__(self):
        Gtk.Window.__init__(self, title="demo")
        self.set_position(Gtk.WindowPosition.CENTER)
        self.button = Gtk.Button()
        self.button.set_image(Gtk.Image(stock=Gtk.STOCK_SAVE))
        self.button.connect('clicked', self.on_button_clicked)
        self.add(self.button)

    def on_button_clicked(self, widget):
        dialog = Gtk.FileChooserDialog("Save file", self,
            Gtk.FileChooserAction.SAVE,
            (Gtk.STOCK_CANCEL, Gtk.ResponseType.CANCEL,
             Gtk.STOCK_SAVE, Gtk.ResponseType.OK))
        response = dialog.run()
        if response == Gtk.ResponseType.OK:  # OK button was pressed or existing file was double clicked
            cansave = False
            if os.path.exists(dialog.get_filename()) == True:  # does file already exists?
                dialog2 = DialogSaveFile(self, dialog.get_filename())  # ask to confirm overwrite
                response = dialog2.run()
                if response == Gtk.ResponseType.OK:
                    cansave = True
                else:
                    pass
                dialog2.destroy()
            else:
                cansave = True
            if cansave == True:  # save new file
                open(dialog.get_filename(), "w").close
                dialog.destroy()
            else:
                pass
        else:
            dialog.destroy()

class DialogSaveFile(Gtk.Dialog):
    def __init__(self, parent, db):
        Gtk.Dialog.__init__(self, "Confirm overwrite", parent, 0,
            (Gtk.STOCK_CANCEL, Gtk.ResponseType.CANCEL,
             Gtk.STOCK_OK, Gtk.ResponseType.OK))
        self.box = self.get_content_area()
        self.label = Gtk.Label("The file `" + db + "` exists.\nDo you want it to be overwritten?")
        self.box.add(self.label)
        self.show_all()

win = MainWindow()
win.connect("delete-event", Gtk.main_quit)
win.show_all()
Gtk.main()

Answer 1

Once you've left the response = dialog.run() run loop, you need to either recreate the file dialog, or call dialog.run() again to put the file dialog back into a run loop so you can find out what buttons have been pressed.

Restructuring it so the file dialog handler is in a separate function should do the trick (not tested, but you'll get the idea)

def on_button_clicked(self, widget):
    dialog = Gtk.FileChooserDialog("Save file", self,
        Gtk.FileChooserAction.SAVE,
        (Gtk.STOCK_CANCEL, Gtk.ResponseType.CANCEL,
         Gtk.STOCK_SAVE, Gtk.ResponseType.OK))
    self.handle_file_dialog(dialog)

def handle_file_dialog(self, dialog):
    response = dialog.run()
    if response == Gtk.ResponseType.OK:  # OK button was pressed or existing file was double clicked
        cansave = False
        if os.path.exists(dialog.get_filename()) == True:  # does file already exists?
            dialog2 = DialogSaveFile(self, dialog.get_filename())  # ask to confirm overwrite
            response = dialog2.run()
            if response == Gtk.ResponseType.OK:
                cansave = True
                dialog2.destroy()
            else:
                dialog2.destroy()
                # We need to re-run the file dialog to detect the buttons
                self.handle_file_dialog(dialog)
                return
        else:
            cansave = True
        if cansave == True:  # save new file
            open(dialog.get_filename(), "w").close
            dialog.destroy()
        else:
            pass
    else:
        dialog.destroy()