Simple Gnome extension may be worth to try. (I'm not sure about naming, in Ubuntu 14.04: Gnome classic uses same Gnome shell extensions, Where old classic renamed to Gnome Fallback)

Gnome Classic & Mate

1. Download panel-applet-generator



2. Generate a new applet:

   
   
   

   python panel-applet-generator.py -n mylabel -d "my custom label"
   
   




3. Modify mylabelApplet.py

   
   
   

   try:
   
       from gi.repository import Gtk
   
   except: # Can't use ImportError, as gi.repository isn't quite that nice...
   
       import gtk as Gtk
   
   
   
   def applet_factory(applet, iid, data = None):
   
       button = Gtk.Button("It works!")
   
       label = Gtk.Label("It works!")
   
       applet.add(label)
   
       applet.show_all()
   
       return True
   
   

   
   
   

   I added label = Gtk.Label("It works!") and modified applet.add(label) (It was applet.add(button))




4. Compress mylabel folder as tar.gz then rename it to mylabel_1.0.orig.tar.gz




5. Build Debian package

   
   
   

   cd mylabel/
   
   debuild -us -uc
   
   




6. Install package

   
   
   

   sudo dpkg -i ../*.deb
   
   




7. Alt+Right Click or Super+Alt+Right Click on panel, then add to panel




8. Look for mylabel applet, then add

References:

• Making panel applets for Gnome 2 and 3


• IntroDebianPackaging

Note:

• If for any reason unable to install, It is possible to do it manually:

  
  
  

  sudo cp org.gnome.applets.mylabel.panel-applet /usr/share/gnome-panel/4.0/applets/
  
  sudo cp org.gnome.panel.applet.mylabel.service /usr/share/dbus-1/services/
  
  sudo cp *.py /usr/lib/gnome-applets/
  
  

  
  
  

  32bit system:

  
  
  

  sudo cp mylabel.server /usr/lib/bonobo/servers/ 
  
  

  
  
  

  64bit system:

  
  
  

  sudo cp mylabel.server /usr/lib/x86_64-linux-gnu/bonobo/servers/
  
  

Gnome Shell

I have tested it with Gnome 3.10:

1. Install Gnome tweak tool

   
   
   

   sudo apt-get install gnome-tweak-tool
   
   




2. Create new extension:

   
   
   

   gnome-shell-extension-tool --create-extension
   
   




3. Enter requested info: name My Label, description Extension shows my custom text, uuid mylabel@yourname or leave as default mylabel@hostname

   
   
   

   Extension created in /home/username/.local/share/gnome-shell/extensions/mylabel@hostname




4. extension.js is auto opened. Replace Icon with your custom label. As below:

   
   
   

   function init() {
   
       button = new St.Bin({ style_class: 'panel-button',
   
                             reactive: true,
   
                             can_focus: true,
   
                             x_fill: true,
   
                             y_fill: false,
   
                             track_hover: true });
   
       let icon = new St.Icon({ icon_name: 'system-run-symbolic',
   
                                style_class: 'system-status-icon' });
   
   
   
       let label = new St.Label({ text: "Hello, world!" });
   
       button.set_child(label);
   
       button.connect('button-press-event', _showHello);
   
   }
   
   

   
   
   

   I added let label = new St.Label({ text: "Hello, world!" }); and modified 'button.set_child(label); (It was button.set_child(icon);)




5. Save, Restart Gnome-Shell using Alt+F2, enter r then Enter




6. Launch Gnome Tweak Tool → Extensions → Enable My Label extension.




7. Restart Gnome-Shell again.

   
   
   

   

References:

• Step by step tutorial to create extensions


• St Reference Manual


• Documentation for writing Gnome shell extensions


• Making GNOME Shell Extensions