[gnome-panel] panel-applet: add documentation for PanelApplet and PanelAppletClass

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 6c4ea0d8b1d32bc5e02ce26edd90d5453d4fb5e9
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sat Sep 12 02:32:52 2015 +0300

    panel-applet: add documentation for PanelApplet and PanelAppletClass

 libpanel-applet/panel-applet.h |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)
---
diff --git a/libpanel-applet/panel-applet.h b/libpanel-applet/panel-applet.h
index 9a59e56..ee6c085 100644
--- a/libpanel-applet/panel-applet.h
+++ b/libpanel-applet/panel-applet.h
@@ -127,6 +127,12 @@ typedef gboolean (*PanelAppletFactoryCallback) (PanelApplet *applet,
                                                const gchar *iid,
                                                gpointer     user_data);
 
+/**
+ * PanelApplet:
+ *
+ * #PanelApplet is an opaque data structure and can only be accessed using
+ * the following functions.
+ */
 struct _PanelApplet {
        GtkEventBox          event_box;
 
@@ -134,6 +140,18 @@ struct _PanelApplet {
        PanelAppletPrivate  *priv;
 };
 
+/**
+ * PanelAppletClass:
+ * @event_box_class: The parent class.
+ * @change_orient: Signal is emitted when the orientation of applet
+ *    has changed.
+ * @change_background: Signal is emmited when the background af applet
+ *    has changed.
+ * @move_focus_out_of_applet: Signal is emmited when the focus is moved
+ *    out of applet. This is an implementation detail.
+ *
+ * The class structure for the #PanelApplet class.
+ */
 struct _PanelAppletClass {
        GtkEventBoxClass     event_box_class;