Add notification on preload next track

addon.xml

 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
 <addon id="script.spotify.screensaver"
     name="Spotify Screensaver"
-    version="0.0.13"
+    version="0.0.14"
     provider-name="Benoît Harrault">
     <requires>
         <import addon="xbmc.python" version="2.25.0"/>

gui.py

@@ -148,7 +148,19 @@ class GUI(xbmcgui.WindowXMLDialog):
 
     def _preload_images(self, track_id):
         self.log('preload images for track: ' + track_id)
-        self._get_track_data(track_id)
+
+        track_data = self._get_track_data(track_id)
+        track_name = track_data.get('track_name')
+        track_image_url = track_data.get('track_image_url')
+
+        if (track_name is None) or (track_image_url is None):
+            self.log('failed to get track data', xbmc.LOGERROR)
+        else:
+            notification = (
+                'Notification("Next:", ' + track_name
+                + ', 29000, ' + track_image_url + ')'
+            )
+            xbmc.executebuiltin(notification)
 
     def _reload_images(self, track_id):
         self.log('load images for track: ' + track_id)