nasa_apod_desktop.py

#!/usr/bin/env python
'''
Copyright (c) 2012 David Drake
Modified for OSX by Theo Belaire
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.


nasa_apod_desktop.py
https://github.com/TyrGodOfWar/nasa-apod-desktop

Written/Modified by David Drake
http://randomdrake.com 
http://twitter.com/randomdrake 

Modified for OSX by Theo Belaire 
I don't have a website yet 

Based on apodbackground: http://sourceforge.net/projects/apodbackground/
Which, is based on: http://0chris.com/nasa-image-day-script-python.html
-Removed adding text
-Resizing without scaling and adding black background
-Cleaned up code and comments
-Added debug lines
-Check to see if file already exists before attempting download
-Saving as PNG instead of JPG for improved quality
-Removed scaling, as OSX handles that for you when you set it as a desktop background



DESCRIPTION
1) Grabs the latest image of the day from NASA (http://apod.nasa.gov/apod/). 
2) Sets the image as your desktop.


INSTALLATION
Ensure you have Python installed, which is required for OSX.

Set your resolution variables and your download path (make sure it's writeable):
'''
DOWNLOAD_PATH = '/Users/theobelaire/backgrounds/'
''' 

RUN AT STARTUP
To have this run whenever you startup your computer, perform the following steps:
1) Click on the settings button (cog in top right)
2) Select "Startup Applications..."
3) Click the "Add" button
4) Enter the following:
Name: NASA APOD Desktop
Command: python /path/to/nasa_apod_desktop.py
Comment: Downloads the latest NASA APOD and sets it as the background.
5) Click on the "Add" button
'''
import commands
import urllib
import urllib2
import re
import os
#from PIL import Image
from sys import stdout

from appscript import app, mactypes


# Configurable settings:
NASA_APOD_SITE = 'http://apod.nasa.gov/apod/'
SHOW_DEBUG = True

def download_site(url):
    ''' Download HTML of the site'''
    if SHOW_DEBUG:
        print "Downloading contents of the site to find the image name"
    opener = urllib2.build_opener()
    req = urllib2.Request(url)
    response = opener.open(req)
    reply = response.read()
    return reply

def get_image(text):
    ''' Finds the image URL and saves it '''
    if SHOW_DEBUG:
        print "Grabbing the image URL"
    reg = re.search('<a href="(image.*?)"', text, re.DOTALL)
    if 'http' in reg.group(1):
        # Actual url
        file_url = reg.group(1)
    else:
        # Relative path, handle it
        file_url = NASA_APOD_SITE + reg.group(1)

    filename = os.path.basename(file_url)
    save_to = DOWNLOAD_PATH + os.path.splitext(filename)[0] + '.png'
    if not os.path.isfile(save_to):
        if SHOW_DEBUG:
            print "Opening remote URL"
        remote_file = urllib.urlopen(file_url)

        if SHOW_DEBUG:
            file_size = float(remote_file.headers.get("content-length"))
            print "Retrieving image"
            urllib.urlretrieve(file_url, save_to, print_download_status)

            # Adding additional padding to ensure entire line 
            if SHOW_DEBUG:
                print "\rDone downloading", human_readable_size(file_size), "       "
        else: 
            urllib.urlretrieve(file_url, save_to)
    elif SHOW_DEBUG:
        print "File exists, moving on"

    return save_to

#def resize_image(filename):
    #''' Resizes the image to the provided dimensions '''
    #if SHOW_DEBUG:
        #print "Opening local image"
#
    #image = Image.open(filename)
    #if SHOW_DEBUG:
        #print "Resizing the image to", RESOLUTION_X, 'x', RESOLUTION_Y
    #image = image.resize((RESOLUTION_X, RESOLUTION_Y), Image.ANTIALIAS)
#
    #if SHOW_DEBUG:
        #print "Saving the image to", filename
    #fhandle = open(filename, 'w')
    #image.save(fhandle, 'PNG')

def set_gnome_wallpaper(file_path):
    ''' Sets the new image as the wallpaper '''
    if SHOW_DEBUG:
        print "Setting the wallpaper"
    command = "gsettings set org.gnome.desktop.background picture-uri file://" + file_path
    status, output = commands.getstatusoutput(command)
    return status

def set_OSX_wallpaper(file_path):
    ''' Sets the new image as the wallpaper '''
    if SHOW_DEBUG:
        print "Setting the wallpaper"
    app('Finder').desktop_picture.set(mactypes.File(file_path))


def print_download_status(block_count, block_size, total_size):
    written_size = human_readable_size(block_count * block_size)
    total_size = human_readable_size(total_size)

    # Adding space padding at the end to ensure we overwrite the whole line
    stdout.write("\r%s bytes of %s         " % (written_size, total_size))
    stdout.flush()

def human_readable_size(number_bytes):
    for x in ['bytes', 'KB', 'MB']:
        if number_bytes < 1024.0:
            return "%3.2f%s" % (number_bytes, x)
        number_bytes /= 1024.0

if __name__ == '__main__':
    ''' Our program '''
    if SHOW_DEBUG: 
        print "Starting"
    # Create the download path if it doesn't exist
    if not os.path.exists(os.path.expanduser(DOWNLOAD_PATH)):
        os.makedirs(os.path.expanduser(DOWNLOAD_PATH))

    # Grab the HTML contents of the file 
    site_contents = download_site(NASA_APOD_SITE)

    # Download the image
    filename = get_image(site_contents)

    # Resize the image
    #resize_image(filename)

    # Set the wallpaper
    #status = set_gnome_wallpaper(filename)
    set_OSX_wallpaper(filename)
    if SHOW_DEBUG:
        print "Finished!"