randombg

#! /usr/bin/env python

# Pick a new random background
# usage: randombg [directory]
# Default directory is ~/Images/Backgrounds/$dpy_width

import sys, os, subprocess
import random

def set_random_bg(bgdir, arg) :
    images = os.listdir(bgdir)
    while len(images) > 0 :
        img = random.choice(images)
        if img.find('.') :
            print "Setting background to", os.path.join(bgdir, img)
            subprocess.call(['hsetroot', arg, os.path.join(bgdir, img)])
            sys.exit(0)
    print "No images in", bgdir
    sys.exit(1)

# If the dir is specified explicitly, go ahead and do it.
if len(sys.argv) > 1 :
    set_random_bg(sys.argv[1], '-fill')

# Find the current resolution:
fp = os.popen("xdpyinfo")
while True :
    line = fp.readline().strip()
    if line[0:11] == 'dimensions:' :
        parts = line[12:].split()[0].split('x')
        width = int(parts[0])
        height = int(parts[1])
        break
fp.close()
if not width or not height :
    print "Couldn't find screen dimensions!"
    sys.exit(1)

basedir = os.path.expanduser("~/Images/Backgrounds")
bgdir = os.path.join(basedir, '%dx%d' % (width, height))

# If the exact right directory exists, use it.
if os.path.exists(bgdir) :
    print bgdir, "exists: using it"
    set_random_bg(bgdir, '-fill')

# We don't have images at exactly the right resolution.
# Try to find the closest match:
print "Looking for the closest match"
mindiff = 99999
bgdir = None
for d in os.listdir(basedir) :
    try :
        parts = d.split('x')
        if len(parts) == 2 :
            w = int(parts[0])
            h = int(parts[1])
            diff = abs(w - width) + abs(h - height)
            if diff < mindiff :
                mindiff = diff
                bgdir = os.path.join(basedir, d)
    except :
        continue

print "Will use", bgdir
set_random_bg(bgdir, '-fill')