+-----------------------------------+
|                                   |
|      Xfce4 Messenger Plugin       |
|                                   |
+-----------------------------------+

Xfce4 Messenger Plugin for Xfce4 Panel is a plugin that listens DBus 
messages and displays received messages in panel and/or popup
window, and maintains a log of received messages. The plugin is
written and maintained by Pasi Orovuo <pasi.ov@gmail.com>

The plugin listens bus name org.xfce.Panel.Plugin.Messenger, object
path /org/xfce/panel/plugin/messenger for signal "Message". To send
a message to the plugin you can use the dbus-send shell command. 

Example usage:
dbus-send --dest='org.xfce.Panel.Plugin.Messenger' \
          '/org/xfce/panel/plugin/messenger' \
          'org.xfce.Panel.Plugin.Messenger.Message' \
          string:'The plugin will show this'

NOTE: The data passed to DBus _must_be_ valid utf-8 data, or 
      DBus will not forward it to the plugin, and thus the plugin
      won't show it.

The amount of time a message is shown can also be defined:
dbus-send --dest='org.xfce.Panel.Plugin.Messenger' \
          '/org/xfce/panel/plugin/messenger' \
          'org.xfce.Panel.Plugin.Messenger.Message' \
          uint32:10 \
          string:'This is shown for 10 seconds'

NOTE: The time must be defined BEFORE the message for it to take
      effect.

When icon identifiers are defined the plugin will show the icon
associated with a particular identifier with each message prefixed
with the indentifier:

In settings define an identifier "testid" with icon "gtk-dialog-info"
for example.
dbus-send --dest='org.xfce.Panel.Plugin.Messenger' \
          '/org/xfce/panel/plugin/messenger' \
          'org.xfce.Panel.Plugin.Messenger.Message' \
          string:'testid:Behold a Gtk dialog info icon!'

See also the scripts subdirectory in the installation package for
scripts that you can use.