[pitivi] transitions: Reuse the logic in _update_ui

[Alexandru Băluț <alexbalut src gnome org>]

commit 0d363a6aac85b463cd5ee5382ed2cd21038c5afb
Author: Alexandru Băluț <alexandru balut gmail com>
Date:   Mon Aug 31 21:30:24 2020 +0200

    transitions: Reuse the logic in _update_ui

 pitivi/transitions.py | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)
---
diff --git a/pitivi/transitions.py b/pitivi/transitions.py
index 09907b569..1df39afaa 100644
--- a/pitivi/transitions.py
+++ b/pitivi/transitions.py
@@ -187,17 +187,14 @@ class TransitionsListWidget(Gtk.Box, Loggable):
     def _transition_selected_cb(self, unused_widget):
         transition_asset = self.get_selected_item()
         if not transition_asset:
-            # The user clicked between icons
+            # Nothing to apply. The user clicked between icons.
             return False
 
-        self.debug(
-            "New transition type selected: %s", transition_asset.get_id())
-        if transition_asset.get_id() == "crossfade":
-            self.props_widgets.set_sensitive(False)
-        else:
-            self.props_widgets.set_sensitive(True)
+        self.debug("New transition type selected: %s", transition_asset.get_id())
 
         self.element.get_parent().set_asset(transition_asset)
+        self._update_ui()
+
         self.app.write_action("element-set-asset",
                               asset_id=transition_asset.get_id(),
                               element_name=self.element.get_name())