How can I use custom unity sidebar icons?

Question

I am having trouble to reconstruct how I changed my geany icon in the sidebar from the default oil lamp to a custom one.

My custom geany icon is the green tie fighter.

I know I simply had to change one line in a larger textfile to point to the new icon image. Somewhat like the index.theme files in /usr/share/icons, with - as far as i recall - a line that said geany=xyz.png, but I cant find the correct one.

Which file do I have to edit to achieve this?

EDIT:

Maybe worthwhile to say, that I want to change the icon of pycharm (python IDE) in my sidebar.

this thread How can I change the icon of an application in the Unity launcher? is basically what I want to do, but pycharm does not show up in my /usr/share/applications/

Answer 1

I managed to solve changeing my pycharm icon by finding the image used for the icon in ~/.local/share/icons/jetbrains-pycharm-ce.png and simply renamed this and placed my new icon with the same name there.

Not exactly how I changed the geany icon, but it works for me.