Add delay before BundleRegistry.add_bundle

As discussed in SL#4841, when installing activities via system
packages there is no guarantee that diretory contents are available
yet even if the GFileMonitor has detected the directory creation.

Therefore some delay before trying actually calling BundleRegistry
add_bundle method. Plus, use a best-effort approach to cover different
ranges of delay.

Signed-off-by: Martin Abente Lahaye <tch@sugarlabs.org>

src/jarabe/model/bundleregistry.py

@@ -71,6 +71,8 @@ class BundleRegistry(GObject.GObject):
                            ([GObject.TYPE_PYOBJECT])),
     }
 
+    _MAX_DELAY = 10000
+
     def __init__(self):
         logging.debug('STARTUP: Loading the bundle registry')
         GObject.GObject.__init__(self)
@@ -137,10 +139,25 @@ def __desktop_view_icons_changed_cb(self, model):
     def __file_monitor_changed_cb(self, monitor, one_file, other_file,
                                   event_type):
         if event_type == Gio.FileMonitorEvent.CREATED:
-            self.add_bundle(one_file.get_path(), set_favorite=True)
+            bundle_path = one_file.get_path()
+            # XXX ignore debian packages temporary directories
+            if bundle_path.endswith('.dpkg-new'):
+                return
+            # XXX SL4841 we can't guarantee the contents are all set yet
+            delay = 100
+            GLib.timeout_add(delay, self.__timeout_add_cb, bundle_path, delay)
         elif event_type == Gio.FileMonitorEvent.DELETED:
             self.remove_bundle(one_file.get_path())
 
+    def __timeout_add_cb(self, bundle_path, delay):
+        bundle = self.add_bundle(bundle_path, set_favorite=True)
+        if not bundle and delay < self._MAX_DELAY:
+            delay *= 10
+            GLib.timeout_add(delay, self.__timeout_add_cb, bundle_path, delay)
+        else:
+            logging.debug('stopping for %s after %d ms', bundle_path, delay)
+        return False
+
     def _load_mime_defaults(self):
         defaults = {}