Dynamic GNOME Configurations: Switching Environments with External Monitors

Introduction

In today’s fast-paced computing world, a seamless transition between laptop mode and desktop mode can dramatically enhance productivity. If you’re a GNOME user who often connects and disconnects an external monitor, you can configure your environment to automatically adjust to your needs. In this blog post, we’ll walk through the steps to set up GNOME with the right extensions and automations, allowing for dynamic adjustments based on your hardware.

Prerequisites

Before diving in, ensure you have the following:

• A system running GNOME
• Access to install GNOME extensions
• Basic understanding of scripts and terminal commands
• The supergfxctl utility for managing graphics modes on hybrid systems

Step 1: Install Necessary Extensions

To create a more desktop-friendly experience, consider the following extensions:

1. Dash to Panel: Combines the top bar and application launcher into one integrated panel.
2. Applications Menu: Adds a classic applications menu, similar to what's found in KDE.

You can install these through the GNOME extensions website or using the GNOME Tweaks tool.

Step 2: Install supergfxctl

The supergfxctl utility allows you to switch between integrated and discrete graphics modes. Install it via your package manager, if there is one, otherwise you need to build from source @ asus-linux

Step 3: The "Mode Switcher" Script

We need a script that checks if a monitor is connected and then toggles your extensions and GPU mode.

Create the file: vi ~/scripts/toggle_modes.sh

#!/bin/bash

# Configuration
USER_NAME="your_username" # Change this!
USER_ID=$(id -u $USER_NAME)
export DISPLAY=:0
export DBUS_SESSION_BUS_ADDRESS="unix:path=/run/user/$USER_ID/bus"

# Check if an external monitor is connected via sysfs (more reliable for udev)
MONITOR_STATUS=$(cat /sys/class/drm/card0/*HDMI*/status 2>/dev/null || cat /sys/class/drm/card0/*DP*/status 2>/dev/null)

if [ "$MONITOR_STATUS" = "connected" ]; then
    echo "Monitor detected: Switching to Desktop Mode"
    
    # Enable Desktop Extensions
    gnome-extensions enable [email protected]
    gnome-extensions enable [email protected]
    
    # Switch to Discrete Graphics and Logout
    supergfxctl -m Hybrid # Or 'Dedicated' if your hardware supports it
    gnome-session-quit --logout --no-prompt
else
    echo "No monitor: Switching to Laptop Mode"
    
    # Disable Desktop Extensions
    gnome-extensions disable [email protected]
    gnome-extensions disable [email protected]
    
    # Switch to Integrated Graphics and Logout
    supergfxctl -m Integrated
    gnome-session-quit --logout --no-prompt
fi

Don't forget to make it executable: chmod +x ~/scripts/toggle_modes.sh

Step 4: Triggering with udev

Now, we’ll tell the kernel to run this script whenever the "Direct Rendering Manager" (DRM) notices a change (i.e., a cable being plugged in).

1. Create a new udev rule: sudo vi /etc/udev/rules.d/99-monitor-hotplug.rules
2. Add this line:

ACTION=="change", SUBSYSTEM=="drm", RUN+="/home/your_username/scripts/toggle_modes.sh"

3. Reload your rules: sudo udevadm control --reload-rules

Step 5: Handling the Logout

Since supergfxctl requires a logout to swap the graphics drivers effectively, the script includes a gnome-session-quit command.

• Desktop Mode: Activates a bottom-panel layout with a traditional app menu.
• Laptop Mode: Reverts to the clean, gesture-heavy GNOME default.

Conclusion

By following these steps, you’ll have a dynamic GNOME environment that adapts automatically to your hardware setup. Now, when you connect an external monitor, your environment will seamlessly transition into a desktop mode, utilizing the right graphics settings and extensions tailored for your productivity needs.

Whether you’re coding on the go or setting up a workstation at home, this configuration will help you streamline your workflow. If you have any questions or further customization ideas, feel free to leave a comment below! Happy computing!