#!/usr/bin/python3
import tkinter as tk
class Bug:
    
    def __init__(self,parent):
        self.parent = parent
        self.gui()
        
    def move_up(self,event=None,value=-1):
        self.cvs.yview_scroll(value,'units')
        
    def move_down(self,event=None,value=1):
        self.cvs.yview_scroll(value,'units')
    
    def bindings(self):
        self.parent.bind('<Down>',self.move_down)
        self.parent.bind('<Up>',self.move_up)
    
    def gui(self):
        self.frames()
        self.widgets()
        self.bindings()
        
    def frames(self):
        self.frm1 = tk.Frame(self.parent)
        self.frm1.pack(expand=1)
    
    def widgets(self):
        self.cvs = tk.Canvas(self.frm1)
        self.cvs.pack()
        self.lbl = tk.Label(self.frm1)
        self.lbl.pack(expand=1)
        self.cvs.create_window(0,0,window=self.lbl)
        
    def add_row(self,text):
        frm = tk.Frame(self.lbl)
        frm.pack()
        cbox = tk.Checkbutton(frm)
        cbox.pack(side='left')
        lbl = tk.Label(frm)
        lbl.config(text=text)
        lbl.pack(side='left')
    
    def fill(self):
        for i in range(100):
            self.add_row('Row %d' % i)
            
    def region (self,x=0,y=0
               ,x_border=0,y_border=0
               ):
        # Both integer and float values are allowed at input
        if x and y:
            self.cvs.configure (scrollregion = (-x/2 - x_border
                                               ,-y/2 - y_border
                                               , x/2 + x_border
                                               , y/2 + y_border
                                               )
                               )
        else:
            print('Empty input is not allowed!')
    
    def scroll(self,event=None,x=0,y=0):
        self.cvs.xview_moveto(x)
        self.cvs.yview_moveto(y)
if __name__ == '__main__':
    root = tk.Tk()
    root.geometry('400x300')
    bug = Bug(root)
    bug.fill()
    bug.region (x        = 400
               ,y        = 2050
               ,x_border = 5
               ,y_border = 20
               )
    bug.scroll()
    root.wait_window()
    root.mainloop()