[gnome-music] window: Show loading notification after a small delay

[Marinus Schraal <mschraal src gnome org>]

commit 35f03930b4cdb91c095d86c4f9a583dd3231fc73
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Wed Dec 21 20:22:17 2016 -0200

    window: Show loading notification after a small delay
    
    When loading e.g. an artists, the notification can show and
    hide very quickly, causing a very bad impression since we didn't
    really spend any time loading it.
    
    Fix that by setting a small timeout of 500ms before showing
    the notification.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=776157

 gnomemusic/window.py |   15 ++++++++++++++-
 1 files changed, 14 insertions(+), 1 deletions(-)
---
diff --git a/gnomemusic/window.py b/gnomemusic/window.py
index 8e90ab4..b70788b 100644
--- a/gnomemusic/window.py
+++ b/gnomemusic/window.py
@@ -602,8 +602,16 @@ class Window(Gtk.ApplicationWindow):
         running. If there is no notification is visible, the loading
         notification is started.
         """
-        if self._loading_counter == 0:
+        def show_notification_cb(self):
             self._loading_notification.set_reveal_child(True)
+            self._show_notification_timeout_id = 0
+            return GLib.SOURCE_REMOVE
+
+        if self._loading_counter == 0:
+            # Only show the notification after a small delay, thus
+            # add a timeout. 500ms feels good enough.
+            self._show_notification_timeout_id = GLib.timeout_add(
+                    500, show_notification_cb, self)
 
         self._loading_counter = self._loading_counter + 1
 
@@ -615,4 +623,9 @@ class Window(Gtk.ApplicationWindow):
         self._loading_counter = self._loading_counter - 1
 
         if self._loading_counter == 0:
+            # Remove the previously set timeout, if any
+            if self._show_notification_timeout_id > 0:
+                GLib.source_remove(self._show_notification_timeout_id)
+                self._show_notification_timeout_id = 0
+
             self._loading_notification.set_reveal_child(False)