"""
same, but make thumb images in memory without saving to or loading from files:
seems just as fast for small directories, but saving to files makes startup much 
quicker for large image collections; saving may be needed in some apps (web pages)
"""

import os, sys
from PIL import Image
from tkinter import Tk
import viewer_thumbs

def makeThumbs(imgdir, size=(100, 100), subdir='thumbs'):
    """
    create thumbs in memory but don't cache to files
    """
    thumbs = []
    for imgfile in os.listdir(imgdir):
        imgpath = os.path.join(imgdir, imgfile)
        try:
            imgobj = Image.open(imgpath)          # make new thumb
            imgobj.thumbnail(size)
            thumbs.append((imgfile, imgobj))
        except:
            print("Skipping: ", imgpath)
    return thumbs

if __name__ == '__main__':
    imgdir = (len(sys.argv) > 1 and sys.argv[1]) or 'images'
    viewer_thumbs.makeThumbs = makeThumbs
    main, save = viewer_thumbs.viewer(imgdir, kind=Tk)
    main.mainloop()