screensaver.py

import kivy
kivy.require('1.4.1')

import random, os, sys, os.path
from kivy.app import App
from kivy.uix.image import Image
from kivy.core.window import Window
from kivy.clock import Clock
from kivy.config import Config
from plyer import notification

class PhotoScreensaver(App):

    def __init__(self):
        App.__init__(self)
        self.photos = []
        self.find_all_photos()

    def build(self):
        keyb = Window.request_keyboard(self.stop, self)
        keyb.bind(on_key_down = self.key_pressed)
        self.image = Image()
        self.change_image()
        Clock.schedule_interval(self.change_image, 10)
        return self.image

    def key_pressed(self, keyboard, keycode, text, modifiers):
        self.stop()

    def change_image(self, whatever = None):
        self.image.source = random.choice(self.photos)

    def find_all_photos(self):
        try:
            photoPath = os.path.expanduser('~/Pictures')
            self.photos = []
            for root, dirs, files in os.walk(photoPath):
                for file in files:
                   if file.endswith('.jpg') or file.endswith('.JPG'):
                      self.photos.append(os.path.join(root,file))

            if not self.photos:
               notification.notify("Can't load photos", "The photo list is empty" % photoPath)
               sys.exit(1)
        except IOError:
            notification.notify("Can't load photos", "Couldn't load the photos from %s" % photoPath)
        
if __name__ == '__main__':
    Config.set('graphics', 'fullscreen', '1')
    Config.set('graphics', 'size', '0x0')
    PhotoScreensaver().run()