How to Disable or Uninstall On-Screen Keyboard (Caribou) in Ubuntu

Issue Overview

Users are experiencing frustration with the on-screen keyboard (OSK) known as Caribou in Ubuntu, particularly when using touchscreen devices. The main symptoms include:

• Persistent appearance of the on-screen keyboard despite attempts to disable it.
• Users report that the GNOME extension "block-caribou-36" sometimes gets disabled, causing the OSK to reappear unexpectedly.
• Some users have attempted to uninstall Caribou using commands like sudo apt uninstall caribou, raising concerns about potential system instability and removal of essential libraries (like gdm).

The issue occurs during regular usage of touchscreen devices, particularly when developing software for multiple units (over 200). The frequency of the problem is high, significantly impacting user experience by disrupting workflows.

Possible Causes

Several potential causes for the issue have been identified:

• Hardware Incompatibilities: Certain touchscreen devices may not work well with GNOME’s handling of the on-screen keyboard.

• Software Bugs or Conflicts: The interaction between the Caribou OSK and other GNOME components may lead to unexpected behavior.

• Configuration Errors: Misconfigurations in GNOME settings or extensions can lead to the OSK being enabled even after attempts to disable it.

• Driver Issues: Outdated or incompatible drivers for touchscreen devices may cause conflicts with the OSK functionality.

• User Errors or Misconfigurations: Incorrect use of commands or misunderstanding of package management tools can lead to unintended consequences.

Troubleshooting Steps, Solutions & Fixes

To address the issue effectively, follow these comprehensive troubleshooting steps:

1. Simulate Removal of Caribou:

   • Use the following command to check what would happen if you were to remove Caribou without actually doing it:

     sudo apt-get -s remove caribou
     

   • This command simulates removal and will show any dependencies that might also be affected.

2. Check Installed Packages:

   • Verify if Caribou is installed as a system package:

     dpkg -l | grep -i 'caribou'
     

   • If nothing is returned, check if it is installed via Snap:

     snap list | grep -i 'caribou'
     

3. Locate Caribou Executable:

   • If you suspect Caribou is installed but not recognized, locate its executable:

     which caribou
     

   • If found, gather more information about it:

     ls -l /usr/bin/caribou
     file /usr/bin/caribou
     

4. Recursive Search for Caribou Files:

   • If you cannot find it through standard commands, perform a recursive search:

     sudo -s
     cd /
     find . -iname '*caribou*'
     exit
     

5. Check GNOME Configuration:

   • Since Caribou is integrated into GNOME, check GNOME settings or use the Software Center to manage features related to the on-screen keyboard.

6. Install Alternative Solutions:

   • Consider using alternative extensions like "Block Caribou" from the Ubuntu Store if removal proves difficult.

7. Logging and Reporting:

   • Create a log file for any simulated removal attempts for further assistance from community forums:

     sudo -s
     apt-get -s remove caribou 2>&1 | tee log_rm_caribou.txt
     exit
     

8. Best Practices for Future Prevention:

   • Regularly update your system and extensions to avoid bugs.
   • Monitor community forums for updates on similar issues and solutions.

If users continue to face problems after following these steps, further investigation may be necessary, especially regarding specific configurations or hardware interactions.