[libnotify] spec: Explicitly document components of on image data

[Matthias Clasen <matthiasc src gnome org>]

commit 52cb20bb53fdb8ed8b0f2ffdaa5d67b11d77356a
Author: Colin Walters <walters verbum org>
Date:   Wed Apr 13 10:47:41 2011 -0400

    spec: Explicitly document components of on image data
    
    Since we're just passing it ultimately to gdk_pixbuf_new_from_data in
    the server, we really should be documenting the restrictions here, such
    as bits_per_sample always being 8.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=647672

 docs/notification-spec.xml |   15 ++++++++++++---
 1 files changed, 12 insertions(+), 3 deletions(-)
---
diff --git a/docs/notification-spec.xml b/docs/notification-spec.xml
index a9dad38..2923fa1 100644
--- a/docs/notification-spec.xml
+++ b/docs/notification-spec.xml
@@ -380,9 +380,18 @@
   <sect2 id="icons-and-images-formats" xreflabel="Icons and Images Formats">
    <title>Formats</title>
    <para>
-    The "image-data" and "icon_data" hints should be a raw image data structure
-    of signature (iiibiiay) which describes the width, height, rowstride, has
-    alpha, bits per sample, channels and image data respectively.
+    The "image-data" and "icon_data" hints should be a DBus structure
+    of signature (iiibiiay).  The components of this structure are as follows:
+    <orderedlist>
+     <listitem><para>width (i): Width of image in pixels</para></listitem>
+     <listitem><para>height (i): Height of image in pixels</para></listitem>
+     <listitem><para>rowstride (i): Distance in bytes between row starts</para></listitem>
+     <listitem><para>has_alpha (b): Whether the image has an alpha channel</para></listitem>
+     <listitem><para>bits_per_sample (i): Must always be 8</para></listitem>
+     <listitem><para>channels (i): If has_alpha is TRUE, must be 4, otherwise 3</para></listitem>
+     <listitem><para>data (ay): The image data, in RGB byte order</para></listitem>
+    </orderedlist>
+    This image format is derived from <ulink url="http://developer.gnome.org/gdk-pixbuf/stable/";>gdk-pixbuf</ulink>.
   </para>
    <para>
     The "app_icon" parameter and "image-path" hint should be either an URI