#!python
# -*- mode: python; Encoding: utf-8; coding: utf-8 -*-
# Last updated: <2022/04/02 09:37:01 +0900>
"""
tkinter Scrollbar + Canvas sample.

Tkinterの使い方: スクロールバー（Scrollbar）の使い方 | だえうホームページ
https://daeudaeu.com/scrollbar/

python - Tkinter button expand using grid - Stack Overflow
https://stackoverflow.com/questions/53073534/tkinter-button-expand-using-grid

python tkinter キャンバスのスクロールバーについて
https://teratail.com/questions/54103

* Windows10 x64 21H2 + Python 2.7.18 32bit + Tkinter + Pillow 6.2.2
* Windows10 x64 21H2 + Python 3.9.12 64bit + tkinter + Pillow 9.0.1
"""

try:
    # Python 2.7
    import Tkinter as tk
    # import ttk
except Exception:
    # Python 3.x
    import tkinter as tk
    # from tkinter import ttk

from PIL import Image
from PIL import ImageTk

imgfile = "tex_1024.png"

app = tk.Tk()

frame = tk.Frame(app, bg="green")
frame.pack(expand=1, fill=tk.BOTH)

frame.columnconfigure(0, weight=1)
frame.rowconfigure(0, weight=1)

# create Canvas
canvas = tk.Canvas(frame, bg="#888888")
canvas.grid(row=0, column=0, sticky=tk.N + tk.S + tk.W + tk.E)

# create Scrollbar
xbar = tk.Scrollbar(frame, orient=tk.HORIZONTAL, command=canvas.xview)
ybar = tk.Scrollbar(frame, orient=tk.VERTICAL, command=canvas.yview)
xbar.grid(row=1, column=0, sticky=tk.W + tk.E)
ybar.grid(row=0, column=1, sticky=tk.N + tk.S)
canvas.config(xscrollcommand=xbar.set)
canvas.config(yscrollcommand=ybar.set)

# load png image, set to canvas
im = Image.open(imgfile)
photo_image = ImageTk.PhotoImage(im)
canvas.create_image(16, 16, anchor=tk.NW, image=photo_image)

# set scroll region
iw = photo_image.width()
ih = photo_image.height()
region = (0, 0, iw + 32, ih + 32)
canvas.config(scrollregion=region)

# set drag scroll
canvas.bind("<ButtonPress-1>", lambda e: canvas.scan_mark(e.x, e.y))
canvas.bind("<B1-Motion>", lambda e: canvas.scan_dragto(e.x, e.y, gain=1))

app.mainloop()