views: add time direction property

The time direction property tells which orientation one
needs to scroll to change the time of the view. In these
directions (up/down v left/right) the new prev/next
buttons will be pointing.

The two buttons will be added in a subsequent commit,
and will gain view-dependent tooltips.

Signed-off-by: Markus Göllnitz <camelcasenick@bewares.it>
Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/542>

src/gui/views/gcal-view.c

@@ -66,6 +66,19 @@ gcal_view_default_init (GcalViewInterface *iface)
                                                             GCAL_TYPE_CONTEXT,
                                                             G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS));
 
+  /**
+   * GcalView::time-direction:
+   *
+   * Orientation determining in which direction time is going for the view
+   */
+  g_object_interface_install_property (iface,
+                                       g_param_spec_enum ("time-direction",
+                                                          NULL,
+                                                          NULL,
+                                                          GTK_TYPE_ORIENTATION,
+                                                          GTK_ORIENTATION_VERTICAL,
+                                                          G_PARAM_READABLE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS));
+
   /**
    * GcalView::create-event:
    *
@@ -148,6 +161,26 @@ gcal_view_get_context (GcalView *self)
   return context;
 }
 
+/**
+ * gcal_view_get_time_direction:
+ * @self: a #GcalView
+ *
+ * Retrieves the orientation of the direction in which the view visualises time.
+ *
+ * Returns: (transfer none): a #GtkOrientation
+ */
+GtkOrientation
+gcal_view_get_time_direction (GcalView *self)
+{
+  GtkOrientation time_direction;
+
+  g_return_val_if_fail (GCAL_IS_VIEW (self), GTK_ORIENTATION_VERTICAL);
+
+  g_object_get (self, "time-direction", &time_direction, NULL);
+
+  return time_direction;
+}
+
 /**
  * gcal_view_get_date:
  * @view: a #GcalView