how do I use a custom icon in an install4j generated launcher?

Question

I have a install4j generated launcher. It displays the custom icon in the desktop, but when it runs in ubuntu, the application icon (the one you see when you press ALT+Tab ) is the install4j one (a computer with a green arrow). In windows and mac looks fine. What I'm missing?

Answer 1

This worked for me on Ubuntu 13.04, using Gnome Shell 3:

Identify the startup class of your application by running the following from the terminal:

xprop | grep WM_CLASS | awk '{print $4}'

Click in your application window and see what is returned to the terminal. For launchers created by Install4j, the class is likely to be com-install4j-runtime-Launcher.

Update your application's .desktop file with a StartupWMClass property, set to the value returned by the xprop command, for example:

StartupWMClass=com-install4j-runtime-Launcher

Finally, rename your application's .desktop file to the name of the startup class, with one important difference: change the uppercase letter in the class name to lowercase. For example:

com-install4j-runtime-launcher.desktop

Close the application and relaunch.