[gnome-music/wip/mschraal/tracker-detection] emptyview: Add Tracker outdated state and use it

[Marinus Schraal <mschraal src gnome org>]

commit c33bea22b960c24dbc6e0e056fcc37c53bae328a
Author: Marinus Schraal <mschraal gnome org>
Date:   Tue Jul 23 23:59:35 2019 +0200

    emptyview: Add Tracker outdated state and use it

 gnomemusic/views/emptyview.py | 16 +++++++++++++++-
 gnomemusic/window.py          | 24 ++++++++++++++++--------
 2 files changed, 31 insertions(+), 9 deletions(-)
---
diff --git a/gnomemusic/views/emptyview.py b/gnomemusic/views/emptyview.py
index a9ae13da..1e4c989c 100644
--- a/gnomemusic/views/emptyview.py
+++ b/gnomemusic/views/emptyview.py
@@ -48,6 +48,7 @@ class EmptyView(Gtk.Stack):
         EMPTY = 1
         SEARCH = 2
         NO_TRACKER = 3
+        TRACKER_OUTDATED = 4
 
     __gtype_name__ = "EmptyView"
 
@@ -84,7 +85,7 @@ class EmptyView(Gtk.Stack):
 
         self._state = EmptyView.State.INITIAL
 
-    @GObject.Property(type=int, default=0, minimum=0, maximum=3)
+    @GObject.Property(type=int, default=0, minimum=0, maximum=4)
     def state(self):
         """Get the state of the empty view
 
@@ -108,6 +109,8 @@ class EmptyView(Gtk.Stack):
             self._set_search_state()
         elif self._state == EmptyView.State.NO_TRACKER:
             self._set_no_tracker_state()
+        elif self._state == EmptyView.State.TRACKER_OUTDATED:
+            self._set_tracker_outdated_state()
         self.show_all()
 
     @log
@@ -144,6 +147,17 @@ class EmptyView(Gtk.Stack):
 
         self._icon.props.icon_name = "dialog-error-symbolic"
 
+    @log
+    def _set_tracker_outdated_state(self):
+        self._main_label.props.margin_bottom = 12
+        self._main_label.props.label = _(
+            "Your system Tracker version seems outdated")
+        self._icon.props.margin_bottom = 18
+        self._information_label.props.label = _(
+            "Music needs Tracker version 2.2.0 or higher")
+
+        self._icon.props.icon_name = "dialog-error-symbolic"
+
     @log
     def select_all(self):
         """Cannot select songs from EmptyView."""
diff --git a/gnomemusic/window.py b/gnomemusic/window.py
index e518f9e7..69f0c0b6 100644
--- a/gnomemusic/window.py
+++ b/gnomemusic/window.py
@@ -173,6 +173,9 @@ class Window(Gtk.ApplicationWindow):
         self._app.props.coremodel.connect(
             "notify::songs-available", self._on_songs_available)
 
+        self._app.props.coremodel._grilo.connect(
+            "notify::tracker-available", self._on_tracker_available)
+
         if self._app.props.coremodel.props.songs_available:
             self._switch_to_player_view()
         else:
@@ -182,18 +185,17 @@ class Window(Gtk.ApplicationWindow):
     def _switch_to_empty_view(self):
         did_initial_state = self._settings.get_boolean('did-initial-state')
 
-        # FIXME: Tracker just checks for TrackerWrapper right now.
-        # It should also check for the viability of certain queries to
-        # make sure we have a recent version available.
         state = self._app.props.coremodel._grilo.props.tracker_available
-        if (state == TrackerState.UNAVAILABLE
-                or state == TrackerState.OUTDATED):
-            self.views[View.EMPTY].props.state = EmptyView.State.NO_TRACKER
+        empty_view = self.views[View.EMPTY]
+        if state == TrackerState.UNAVAILABLE:
+            empty_view.props.state = EmptyView.State.NO_TRACKER
+        elif state == TrackerState.OUTDATED:
+            empty_view.props.state = EmptyView.State.TRACKER_OUTDATED
         elif did_initial_state:
-            self.views[View.EMPTY].props.state = EmptyView.State.EMPTY
+            empty_view.props.state = EmptyView.State.EMPTY
         else:
             # FIXME: On switch back this view does not show properly.
-            self.views[View.EMPTY].props.state = EmptyView.State.INITIAL
+            empty_view.props.state = EmptyView.State.INITIAL
 
         self._headerbar.props.state = HeaderBar.State.EMPTY
 
@@ -203,6 +205,12 @@ class Window(Gtk.ApplicationWindow):
         else:
             self._switch_to_empty_view()
 
+    def _on_tracker_available(self, klass, value):
+        new_state = self._app.props.coremodel._grilo.props.tracker_available
+
+        if new_state != TrackerState.AVAILABLE:
+            self._switch_to_empty_view()
+
     @log
     def _switch_to_player_view(self):
         self._settings.set_boolean('did-initial-state', True)