Support different keyboard layouts in search on keypress function

https://bugzilla.gnome.org/show_bug.cgi?id=723942

gnomemusic/window.py

@@ -237,8 +237,9 @@ class Window(Gtk.ApplicationWindow):
             self.toolbar.searchbar.show_bar(False)
             if self.toolbar._selectionMode:
                 self.toolbar.set_selection_mode(False)
-        elif (event.state & modifiers) == 0 and \
-                event.keyval in range(33, 126) and \
+        elif (event.state & modifiers) == Gdk.ModifierType.SHIFT_MASK or (event.state & modifiers) == 0 and \
+                GLib.unichar_isprint(chr((Gdk.keyval_to_unicode(event.keyval)))) and \
+                not event.keyval == Gdk.KEY_space and \
                 not self.toolbar.searchbar.get_reveal_child():
             self.toolbar.searchbar.show_bar(True)