[gnome-music] window: Move songs available check to Grilo

[Marinus Schraal <mschraal src gnome org>]

commit 77be4ead5cec6b4aa66c8ec4a168bed06888e953
Author: Marinus Schraal <mschraal src gnome org>
Date:   Fri Dec 2 17:10:04 2016 +0100

    window: Move songs available check to Grilo
    
    Move the async songs check that appears twice in Window to Grilo,
    this reduces code duplication and keeps functionality properly
    separated.

 gnomemusic/grilo.py  |   40 ++++++++++++++++++++++
 gnomemusic/window.py |   92 +++++++++++++++----------------------------------
 2 files changed, 68 insertions(+), 64 deletions(-)
---
diff --git a/gnomemusic/grilo.py b/gnomemusic/grilo.py
index 2037022..929d3c3 100644
--- a/gnomemusic/grilo.py
+++ b/gnomemusic/grilo.py
@@ -403,4 +403,44 @@ class Grilo(GObject.GObject):
         self.tracker.store_metadata_sync(media, [Grl.METADATA_KEY_LAST_PLAYED],
                                          Grl.WriteFlags.NORMAL)
 
+    @log
+    def songs_available(self, callback):
+        """Checks if there are any songs available
+
+        Calls a callback function with True or False depending on the
+        availability of songs.
+        :param callback: Function to call on result
+        """
+        def cursor_next_cb(conn, res, data):
+            try:
+                has_next = conn.next_finish(res)
+            except GLib.Error as err:
+                logger.warn("Error: %s, %s", err.__class__, err)
+                callback(False)
+                return
+
+            if has_next:
+                count = conn.get_integer(0)
+
+                if count > 0:
+                    callback(True)
+                    return
+
+            callback(False)
+
+        def songs_query_cb(conn, res, data):
+            try:
+                cursor = conn.query_finish(res)
+            except GLib.Error as err:
+                logger.warn("Error: %s, %s", err.__class__, err)
+                callback(False)
+                return
+
+            cursor.next_async(None, cursor_next_cb, None)
+
+        # TODO: currently just checks tracker, should work with any
+        # queryable supported Grilo source.
+        self.sparqltracker.query_async(Query.all_songs_count(), None,
+                                       songs_query_cb, None)
+
 grilo = Grilo()
diff --git a/gnomemusic/window.py b/gnomemusic/window.py
index 9b63982..f155f4f 100644
--- a/gnomemusic/window.py
+++ b/gnomemusic/window.py
@@ -108,47 +108,29 @@ class Window(Gtk.ApplicationWindow):
 
     @log
     def _on_changes_pending(self, data=None):
+        def songs_available_cb(available):
+            if available:
+                if self.views[0] == self.views[-1]:
+                    view = self.views.pop()
+                    view.destroy()
+                    self._switch_to_player_view()
+                    self.toolbar._search_button.set_sensitive(True)
+                    self.toolbar._select_button.set_sensitive(True)
+                    self.toolbar.show_stack()
+            elif (self.toolbar._selectionMode is False
+                    and len(self.views) != 1):
+                self._stack.disconnect(self._on_notify_model_id)
+                self.disconnect(self._key_press_event_id)
+                view_count = len(self.views)
+                for i in range(0, view_count):
+                    view = self.views.pop()
+                    view.destroy()
+                self.toolbar.hide_stack()
+                self._switch_to_empty_view()
+
+        grilo.songs_available(songs_available_cb)
 
-        def cursor_next_cb(conn, res, data):
-            try:
-                has_next = conn.next_finish(res)
-            except GLib.Error as err:
-                logger.warn("Error: %s, %s", err.__class__, err)
-                return
-
-            if has_next:
-                count = conn.get_integer(0)
-                if (count > 0):
-                    if (self.views[0] == self.views[-1]):
-                        view = self.views.pop()
-                        view.destroy()
-                        self._switch_to_player_view()
-                        self.toolbar._search_button.set_sensitive(True)
-                        self.toolbar._select_button.set_sensitive(True)
-                        self.toolbar.show_stack()
-                elif (self.toolbar._selectionMode is False
-                        and len(self.views) != 1):
-                    self._stack.disconnect(self._on_notify_model_id)
-                    self.disconnect(self._key_press_event_id)
-                    view_count = len(self.views)
-                    for i in range(0, view_count):
-                        view = self.views.pop()
-                        view.destroy()
-                    self.toolbar.hide_stack()
-                    self._switch_to_empty_view()
-
-        def songs_query_cb(conn, res, data):
-            try:
-                cursor = conn.query_finish(res)
-            except GLib.Error as err:
-                logger.warn("Error: %s, %s", err.__class__, err)
-                return
-
-            cursor.next_async(None, cursor_next_cb, None)
-
-        tracker.query_async(Query.all_songs_count(), None, songs_query_cb,
-                            None)
-
+    @log
     def _on_configure_event(self, widget, event):
         if self.window_size_update_timeout is None:
             self.window_size_update_timeout = GLib.timeout_add(500, self.store_window_size_and_position, 
widget)
@@ -233,33 +215,15 @@ class Window(Gtk.ApplicationWindow):
         self._box.pack_start(self.selection_toolbar.actionbar, False, False, 0)
         self.add(self._box)
 
-        def cursor_next_cb(conn, res, data):
-            try:
-                has_next = conn.next_finish(res)
-            except GLib.Error as err:
-                logger.warn("Error: %s, %s", err.__class__, err)
-                return
-
-            if has_next:
-                count = conn.get_integer(0)
-                if count > 0:
-                    self._switch_to_player_view()
-                else:
-                    self._switch_to_empty_view()
-
-        def songs_query_cb(conn, res, data):
-            try:
-                cursor = conn.query_finish(res)
-            except GLib.Error as err:
-                logger.warn("Error: %s, %s", err.__class__, err)
-                return
-
-            cursor.next_async(None, cursor_next_cb, None)
+        def songs_available_cb(available):
+            if available:
+                self._switch_to_player_view()
+            else:
+                self._switch_to_empty_view()
 
         Query()
         if Query.music_folder:
-            tracker.query_async(Query.all_songs_count(), None, songs_query_cb,
-                                None)
+            grilo.songs_available(songs_available_cb)
         else:
             self._switch_to_empty_view()