Ubuntu – I unlocked the ‘Files’ button/icon from the unity launcher and now it disappearead and I cannot restore it or get it back

1. Command line:

You can do that by the command:

gsettings set com.canonical.Unity.Devices blacklist "[]"

Explanation

By removing the icon from the launcher, you blacklisted the device from the launcher. With the command above, you "empty" the blacklist.

If you want to to have a more selective way to set which device to keep in the launcher, first run:

gsettings get com.canonical.Unity.Devices blacklist

The output will be like:

['<device_1>', '<device_2>']

To restore device_1 in the launcher:

gsettings set com.canonical.Unity.Devices blacklist "['<device_2>']"

2. GUI

Alternatively, you can restore your icons with dconf-editor. You might have to install it first:

sudo apt-get install dconf-editor

(Or simply install it via Software-Center)

Then open the editor, browse to: com > canonical > unity > devices:

Then you can either set the blacklist to "default" settings (which is none), or remove devices from the blacklist selectively.

Use the command described by @JonasCz. "Tools" > "Create desktop entry / launcher"

Then go to unity, search for DataGrip and drag it to the bar.

I don't know why pinning it doesn't work but the above worked for me. I imagine it has to do with pining the shortcut vs the running java app. The shortcut is probably a wrapper to start the main app.