Chen Yulin's Blog

Posted 2024-10-17Updated 2025-03-24Note2 minutes read (About 321 words)

Objective

I use a hyprland plugin called hyprscroller to emulate the scroll functionality of PaperWM.
However, I can’t get whether I am in row mode or column mode, so I want to show the mode status on my waybar.

Implementation

I wrote two shell script under ~/.config/waybar/

scroller_mode_listener.sh, responsible for listening the IPC message of hyprscroller and store that information in a tmp file. This script can be executed in hyprland config file using exec-once

#!/bin/bash

MODE_FILE="/tmp/hyprland_scroller_mode"

function handle {
  if [[ ${1:0:8} == "scroller" ]]; then
    if [[ ${1:10:9} == "mode, row" ]]; then
        echo "Row" > "$MODE_FILE"
    elif [[ ${1:10:12} == "mode, column" ]]; then
        echo "Column" > "$MODE_FILE"
    #else
        #echo "" > "$MODE_FILE"
    fi
    hyprctl dispatch submap reset && pkill -SIGRTMIN+8 waybar # update the widget on waybar
  fi
}

# Initialize the mode file
echo "" > "$MODE_FILE"

socat - "UNIX-CONNECT:$XDG_RUNTIME_DIR/hypr/$HYPRLAND_INSTANCE_SIGNATURE/.socket2.sock" | while read -r line; do handle "$line"; done

scroller_mode_reader.sh, responsible for reading the tmp file and return the json value to waybar to change the shown icon.

#!/bin/bash

MODE_FILE="/tmp/hyprland_scroller_mode"

current_mode=$(cat "$MODE_FILE")

if [[ "$current_mode" == "Row" ]]; then
    icon="Row"
    percent=0
    class="mode-row"
elif [[ "$current_mode" == "Column" ]]; then
    icon="Column"
    percent=100
    class="mode-column"
else
    icon="Row"
    percent=0
    class=""
fi

echo "{\"text\":\"$icon\", \"tooltip\":\"Scroller Mode: $current_mode\", \"class\":\"$class\",\"percentage\": $percent}"

Then add the custom module to waybar in config file (we use signal to update the module):

"custom/scroller-mode": {
    "exec": "~/.config/waybar/scroller_mode_reader.sh",
    "return-type": "json",
    "interval": "once",
    "signal": 8,
    "on-click": "hyprctl dispatch submap reset && pkill -SIGRTMIN+8 waybar",
    "format": "{icon}",
    "format-icons": ["", ""],
}