Two icons on Unity Launcher on non-standard application launch [duplicate]

Solution 1:

You have to add a StartupWMClass string into your .desktop file. This is a string that defines in which class the application is grouped in the Unity Launcher at startup.

The solution is to add StartupWMClass to your desktop file. First you need to find the proper class for your application.

It is explained here (Thanks to @chaos).

Open your Light Table window and type in terminal:

xprop WM_CLASS

Then click on the LIght Table window.

For gnome terminal WM_CLASS should be something like

WM_CLASS(STRING) = "gnome-terminal", "Gnome-terminal"

So all windows with WM_CLASS "gnome-terminal" and "Gnome-terminal" are grouped together. For light table you will see different class. Pick one and remember it.

After you find your program class add this to your .desktop file:

StartupWMClass=CLASS

Replace CLASS with the class from previous command.