[gnome-calendar] week-view: improve scroll timeout logic

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit dde6b5bf05c47ade70beeee00ce64372fb0fe0bc
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Tue May 16 17:48:25 2017 -0300

    week-view: improve scroll timeout logic
    
    Instead of keeping an active timeout source spamming the
    console, just connect to the right signal and wait for the
    week view to be visible again.

 src/views/gcal-week-view.c |   28 +++++++++++++++++++++++++++-
 1 files changed, 27 insertions(+), 1 deletions(-)
---
diff --git a/src/views/gcal-week-view.c b/src/views/gcal-week-view.c
index 61ebc7e..2f42530 100644
--- a/src/views/gcal-week-view.c
+++ b/src/views/gcal-week-view.c
@@ -69,6 +69,8 @@ struct _GcalWeekView
   gint            clicked_cell;
 };
 
+static void           schedule_position_scroll                  (GcalWeekView      *self);
+
 static void           gcal_view_interface_init                  (GcalViewInterface *iface);
 
 static void           gcal_data_model_subscriber_interface_init (ECalDataModelSubscriberInterface *iface);
@@ -101,6 +103,19 @@ on_event_activated (GcalWeekView *self,
   g_signal_emit (self, signals[EVENT_ACTIVATED], 0, widget);
 }
 
+static void
+stack_visible_child_changed_cb (GtkStack     *stack,
+                                GParamSpec   *pspec,
+                                GcalWeekView *self)
+{
+  if (gtk_stack_get_visible_child (stack) != (GtkWidget*) self)
+    return;
+
+  schedule_position_scroll (self);
+
+  g_signal_handlers_disconnect_by_func (stack, stack_visible_child_changed_cb, self);
+}
+
 /* Auxiliary methods */
 static gboolean
 update_grid_scroll_position (GcalWeekView *self)
@@ -117,7 +132,18 @@ update_grid_scroll_position (GcalWeekView *self)
   if (!gtk_widget_get_realized (self->scrolled_window) ||
       !gtk_widget_get_mapped (self->scrolled_window))
     {
-      GCAL_RETURN (G_SOURCE_CONTINUE);
+      GtkWidget *stack;
+
+      stack = gtk_widget_get_ancestor (GTK_WIDGET (self), GTK_TYPE_STACK);
+
+      g_signal_connect (stack,
+                        "notify::visible-child",
+                        G_CALLBACK (stack_visible_child_changed_cb),
+                        self);
+
+      self->scroll_grid_timeout_id = 0;
+
+      GCAL_RETURN (G_SOURCE_REMOVE);
     }
 
   now = g_date_time_new_now_local ();