Add option to don't update if no event coming

main.py

@@ -34,7 +34,7 @@ locale.setlocale(locale.LC_ALL, 'fr_FR.UTF-8')
 
 from PIL import Image, ImageDraw, ImageFont
 
-def main():
+def main(only_on_coming_evt=False):
     image = Image.new('1', (480, 800), 255)
     #image = Image.new('L', (480, 800), 'white')
     draw = ImageDraw.Draw(image)
@@ -73,6 +73,9 @@ def main():
         nstops = RATPNextStopModule().draw_module(config, ["RB/cite+universitaire", "M7/porte+d'italie"], int(480/1.6), 275)
         image.paste(nstops, (480-int(480/1.6), 255))
         occuped_space = nstops.height
+    elif only_on_coming_evt:
+        # stop here in this case
+        return
 
     if occuped_space < 250:
         # weekly weather
@@ -141,4 +144,13 @@ def main():
         image.save("screen.png")
 
 if __name__ == '__main__':
-    main()
+    import argparse
+
+    parser = argparse.ArgumentParser(description='E-ink status generator.')
+
+    parser.add_argument('--only-on-coming-evt', '-O', action='store_const', const=True,
+                    help='Refresh screen only if there is upcoming event')
+
+    args = parser.parse_args()
+
+    main(args.only_on_coming_evt)