Tkinter; how to use scrollbar in a popup/top-level window that opens when a button is pressed in main root window

Question

I'm trying to create an app with a scrollbar in a top level window that opens when a button,bttn, is pressed in the main root window and from the code below I'd need help with the following:

• the scrollbar should be in a new, top-level, window from the main root window by pressing the button bttn defined in widget()
• the new popup window should contain the scrollbar vscrollbar defined in VerticalScrollFrame

• the scrollbar vscrollbar shouldn't appear in the main root window, only in the new popup window

  from Tkinter import * 
  class VerticalScrolledFrame(Frame):
  
  
      def __init__(self, parent, *args, **kw):
          Frame.__init__(self, parent, *args, **kw)            
  
          # create a canvas object and a vertical scrollbar for scrolling it
          vscrollbar = Scrollbar(self, orient=VERTICAL)
          vscrollbar.pack(fill=Y, side=RIGHT, expand=FALSE)
          canvas = Canvas(self, bd=0, highlightthickness=0,
                          yscrollcommand=vscrollbar.set)
          canvas.pack(side=LEFT, fill=BOTH, expand=TRUE)
          vscrollbar.config(command=canvas.yview)
  
          # reset the view
          canvas.xview_moveto(0)
          canvas.yview_moveto(0)
  
          # create a frame inside the canvas which will be scrolled with it
          self.interior = interior = Frame(canvas)
          interior_id = canvas.create_window(0, 0, window=interior,
                                             anchor=NW)
  
          # track changes to the canvas and frame width and sync them,
          # also updating the scrollbar
          def _configure_interior(event):
              # update the scrollbars to match the size of the inner frame
              size = (interior.winfo_reqwidth(), interior.winfo_reqheight())
              canvas.config(scrollregion="0 0 %s %s" % size)
              if interior.winfo_reqwidth() != canvas.winfo_width():
                  # update the canvas's width to fit the inner frame
                  canvas.config(width=interior.winfo_reqwidth())
          interior.bind('<Configure>', _configure_interior)
  
          def _configure_canvas(event):
              if interior.winfo_reqwidth() != canvas.winfo_width():
                  # update the inner frame's width to fill the canvas
                  canvas.itemconfigure(interior_id, width=canvas.winfo_width())
          canvas.bind('<Configure>', _configure_canvas)
  
  
  if __name__ == "__main__":
  
      class SampleApp(Frame):
          def __init__(self,root, *args, **kwargs):
              Frame.__init__(self, root,*args, **kwargs)
  
  
              self.frame = VerticalScrolledFrame(root)
              self.frame.pack()
  
              self.widget()
  
  
          def widget(self):
              self.label = Label(text="Shrink the window to activate the scrollbar.")
              self.label.pack()
  
              bttn = Button(self.frame.interior, text = "Flytta fram/bak i listvy", command = self.open_new_window_with_text_and_scrollbar)
              bttn.pack()
  
          # Should be opened in a new, top-level, window from the main root window by pressing the #button bttn defined in widget()
          # the new popup window should contain the scrollbar vscrollbar defined in SampleApp
          # the scrollbar vscrollbar shouldn't appear in the main root window, only in the new #popup window
  
          def open_new_window_with_text_and_scrollbar(self):
  
              self.top = tk.Toplevel(self)
              frame = VerticalScrolledFrame(root)
              frame.pack()
              Button = tk.Button(self.top, text="Close window", command=self.top.destroy)
              Label = tk.Label(self.top, wraplength = 500,text="testing")
              Label.pack(side="left", fill="both", expand=True)
              Button.pack()
  
  
  
      root = tk.Tk()
      root.title("Maltparser1.0_demo")
  
      root.geometry("900x700")
      app = SampleApp(root)
      root.mainloop()
  

Answer 1

You're passing root as the parent to VerticalScrolledFrame, you need to pass self.top instead:

class SampleApp(Frame):

     # ...Other code...

     def open_new_window_with_text_and_scrollbar(self):
        self.top = tk.Toplevel(self)
        frame = VerticalScrolledFrame(self.top)
        frame.pack()
        # Other widgets

That's why it's adding itself to the main root window instead of the Toplevel.