adding x and y Scrollbar to a canvas

Question

Creating a program that will place an image onto a canvas. I want to add an X-axis, and Y-axis scrollbar onto the canvas, but I am not sure how to.

I would normally use a Frame, but the program I'm working on is using tkinter.Toplevel instead of using a Frame.

#----- Imports ---------------------
import os
import os.path
import sys

import tkinter
tk = tkinter
from tkinter import font

#----- Set flag for JPEG support ---
noJPEG = False
try:
    from PIL import Image
    Pimg = Image
    from PIL import ImageDraw
    Pdraw = ImageDraw.Draw
    from PIL import ImageTk
    Pimgtk = ImageTk
except ImportError:
    noJPEG = True
#

#------------------------------------
# Create an invisible global parent window to hold all children.
# Facilitates easy closing of all windows by a mouse click.
_root = tk.Tk()
_root.withdraw()
#


#------------------------------------
# A writeable window for holding an image.
#
class ImageView(tk.Canvas):

    def __init__(self, image, title=''):
        master = tk.Toplevel(_root)
        master.protocol("WM_DELETE_WINDOW", self.close)
        tk.Canvas.__init__(self, master,
                           width = 600, height = 500,
                           scrollregion=(0,0, image.getWidth(),
                                         image.getHeight()))

        # Define class fields
        ## Image properties
        self.master.title(title)
        self.pack()
        master.resizable(0,0)
        self.foreground = "black"
        self.image = image
        self.height = image.getHeight()
        self.width = image.getWidth()
        # for later
        #self.customFont = font.Font(family="Helvetica", size=12)

        ## Actionable items
        self.mouseX = None
        self.mouseY = None
        self.mouseFxn = None
        self.bind("<Button-1>", self.onClick)  #bind action to button1 click
        self.tags = None

        _root.update()  #redraw global window

Answer 1

There's nothing special about using a Toplevel rather than a Frame. You attach a scrollbar the way you do it for any scrollable widget in any container.

I've never seen a widget create it's own parent. That's quite unusual, though it really doesn't change anything. Just add the scrollbars inside the toplevel.

You might want to switch to grid instead of pack since that makes it a bit easier to get the scrollbars to line up properly. You just need to remove the call to self.pack(), and add something like this to your code:

vsb = tk.Scrollbar(master, orient="vertical", command=self.yview)
hsb = tk.Scrollbar(master, orient="horizontal", command=self.xview)
self.configure(yscrollcommand=vsb.set, xscrollcommand=hsb.set)

self.grid(row=0, column=0, sticky="nsew")
vsb.grid(row=0, column=1, sticky="ns")
hsb.grid(row=1, column=0, sticky="ew")
master.grid_rowconfigure(0, weight=1)
master.grid_columnconfigure(0, weight=1)