Add monitor input toggle

dotfiles/config/hypr/hyprland.conf

@@ -525,6 +525,7 @@ bind = $hyper, R, exec, rofi-systemd
 bind = $hyper, slash, exec, toggle_taffybar
 bind = $hyper, 9, exec, start_synergy.sh
 bind = $hyper, I, exec, rofi_select_input.hs
+bind = $hyper, backslash, exec, /home/imalison/dotfiles/dotfiles/lib/functions/monitor_input toggle
 bind = $hyper, O, exec, rofi_paswitch
 bind = $hyper, W, exec, rofi_wallpaper.sh
 bind = $hyper, Y, exec, rofi_agentic_skill

dotfiles/lib/functions/monitor_input

@@ -0,0 +1,93 @@
+#!/usr/bin/env zsh
+
+function monitor_input_usage {
+  cat <<'EOF'
+Usage:
+  monitor_input [toggle|dp|usb-c|hdmi1|hdmi2]
+
+Switches the current DDC/CI monitor input. On the MSI MPG341CX OLED:
+  dp     -> DisplayPort
+  usb-c  -> USB-C / Type-C
+  toggle -> DisplayPort <-> USB-C
+
+Environment:
+  MONITOR_INPUT_DDC_DISPLAY  ddcutil display number, default: 1
+EOF
+}
+
+function monitor_input_notify {
+  local message="$1"
+  if command -v notify-send >/dev/null 2>&1; then
+    notify-send "Monitor input" "$message"
+  fi
+}
+
+function monitor_input_current {
+  local display="$1"
+  ddcutil --display "$display" getvcp 60 --terse 2>/dev/null \
+    | grep -Eo 'x[0-9a-fA-F]+' \
+    | tail -1
+}
+
+function monitor_input {
+  local target="${1:-toggle}"
+  local display="${MONITOR_INPUT_DDC_DISPLAY:-1}"
+  local value label current
+
+  if [[ "$target" == "-h" || "$target" == "--help" ]]; then
+    monitor_input_usage
+    return 0
+  fi
+
+  if ! command -v ddcutil >/dev/null 2>&1; then
+    echo "monitor_input: ddcutil is not available on PATH" >&2
+    monitor_input_notify "ddcutil is not available"
+    return 1
+  fi
+
+  case "${target:l}" in
+    toggle)
+      current="$(monitor_input_current "$display")"
+      case "${current:l}" in
+        x0f)
+          target="dp"
+          ;;
+        x10)
+          target="usb-c"
+          ;;
+        *)
+          echo "monitor_input: current input is '${current:-unknown}', defaulting to DisplayPort" >&2
+          target="dp"
+          ;;
+      esac
+      ;;
+  esac
+
+  case "${target:l}" in
+    dp|displayport|display-port)
+      value="0x10"
+      label="DisplayPort"
+      ;;
+    usb-c|usbc|type-c|typec)
+      value="0x0f"
+      label="USB-C"
+      ;;
+    hdmi1|hdmi-1)
+      value="0x11"
+      label="HDMI 1"
+      ;;
+    hdmi2|hdmi-2)
+      value="0x12"
+      label="HDMI 2"
+      ;;
+    *)
+      monitor_input_usage >&2
+      return 2
+      ;;
+  esac
+
+  monitor_input_notify "Switching to $label"
+  ddcutil --display "$display" --noverify setvcp 60 "$value"
+}
+
+monitor_input "$@"

nixos/hyprland.nix

@@ -19,6 +19,12 @@ let
     # Needed for hyprlock authentication without PAM fallback warnings.
     security.pam.services.hyprlock = {};
 
+    # DDC/CI monitor control for keyboard-driven input switching.
+    hardware.i2c = {
+      enable = true;
+      group = "video";
+    };
+
     programs.hyprland = {
       enable = true;
       # Keep Hyprland and plugins on a matched flake input for ABI compatibility.
@@ -147,6 +153,7 @@ let
       swappy         # Screenshot annotation
       nwg-displays   # GUI monitor arrangement
       mpv            # Graphical screensaver payload
+      ddcutil        # Monitor input switching over DDC/CI
 
       # For scripts
       jq