#Jay Summet - CS 2316 - Spring 2014
#
#Demo that creates a "scrollable frame".
# Left as an exercise to the student:
# Add a scrollbar (orient=HORIZONTAL) at the bottom
# to scroll left and right....
from tkinter import *

root = Tk()
root.title("Scroll Frame")

scrollbarY = Scrollbar(root, orient=VERTICAL)
scrollbarY.pack(side=RIGHT, fill=Y)

canvas = Canvas(root,width=200, height=300)
#Be sure to allow the canvas to expand
# if the user makes the window larger!
canvas.pack(side=LEFT, expand=True, fill=BOTH)

#The inner frame MUST be created as a child of the
#canvas, even though we add it as a window later.
#otherwise, it may draw over other elements of the main window!
f = Frame(canvas)

#add some widgets to the frame
Label(f,text="A Widget").grid(row=0, column=0)
width = 10
height = 20

#Dynamicly allocated buttons!
#Use a lambda function that takes x*y as an argument to do
#something different for each button... (q=x*y gets around
# the natural closure behavior of a lambda function...)
for x in range(1,width):
    for y in range(1,height):
       tmp =  Button(f, text=str(x*y),
                     command = lambda q=x*y: print(q) )
       tmp.grid(row=y, column=x)

#Add the frame as a "window" onto the canvas.
#Anchor the top left corner of the frame at 0,0
canvas.create_window((0,0), anchor=NW, window=f)

#Link the canvas to the Y-scrollbar
canvas.config(yscrollcommand=scrollbarY.set)
#Link the Y-scrollbar to the canvas
scrollbarY.config(command=canvas.yview)

#Update the frame so that it's bounding box is correct!
f.update()
#Tell the canvas how big the frame is that needs to scroll!
canvas.config(scrollregion= f.bbox("all")  )

#The mainloop waits for and handles user input!
mainloop()