week-header, week-grid: update drawing when time changes

When minutes change, the week grid should update the today strip
if it's visible and, if the day change, week header should update
the blue week name.

src/views/gcal-week-grid.c

@@ -58,6 +58,7 @@ struct _GcalWeekGrid
   GcalRangeTree      *events;
 
   gboolean            children_changed;
+  gint                redraw_timeout_id;
 
   GcalManager        *manager;
 };
@@ -172,6 +173,12 @@ gcal_week_grid_finalize (GObject *object)
   g_clear_pointer (&self->active_date, g_free);
   g_clear_pointer (&self->current_date, g_free);
 
+  if (self->redraw_timeout_id > 0)
+    {
+      g_source_remove (self->redraw_timeout_id);
+      self->redraw_timeout_id = 0;
+    }
+
   G_OBJECT_CLASS (gcal_week_grid_parent_class)->finalize (object);
 }
 
@@ -364,6 +371,7 @@ gcal_week_grid_draw (GtkWidget *widget,
 {
   GtkStyleContext *context;
   GtkStateFlags state;
+  GcalWeekGrid *self;
   GtkBorder padding;
   GdkRGBA color;
 
@@ -372,6 +380,7 @@ gcal_week_grid_draw (GtkWidget *widget,
   PangoLayout *layout;
   PangoFontDescription *font_desc;
 
+  self = GCAL_WEEK_GRID (widget);
   context = gtk_widget_get_style_context (widget);
   state = gtk_widget_get_state_flags (widget);
 
@@ -450,6 +459,14 @@ gcal_week_grid_draw (GtkWidget *widget,
 
   GTK_WIDGET_CLASS (gcal_week_grid_parent_class)->draw (widget, cr);
 
+  /* Fire the redraw timeout if needed */
+  if (self->redraw_timeout_id == 0)
+    {
+      self->redraw_timeout_id = g_timeout_add_seconds (5,
+                                                       (GSourceFunc) gtk_widget_queue_draw,
+                                                       self);
+    }
+
   return FALSE;
 }