i3blocks: add brightness

i3blocks.conf

@@ -39,6 +39,11 @@ instance=audacious
 interval=5
 signal=10
 
+# Brightness indicator
+# [brightness]
+# label=
+# interval=5
+
 # Volume indicator
 #
 # The first parameter sets the step (and units to display)

scripts/i3blocks/brightness

@@ -0,0 +1,65 @@
+#!/bin/bash
+#
+# Copyright (c) 2021 Jesús E. <heckyel@hyperbola.info>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# One of the following: xrandr, xbacklight, kernel
+METHOD="xbacklight"
+
+case "${BLOCK_BUTTON}" in
+    1) xbacklight -inc 5 ;; # Left click
+    3) xbacklight -dec 5 ;; # Right click
+esac
+
+URGENT_VALUE=10
+
+case "${METHOD}" in
+    xrandr) device="${BLOCK_INSTANCE:-primary}"
+            xrandrOutput=$(xrandr --verbose)
+            case "${device}" in
+                primary) device=$(echo "${xrandrOutput}" | grep 'primary' | head -n 1 | awk -F ' ' '{print $1}') ;;
+            esac
+            curBrightness=$(echo "${xrandrOutput}" | grep "${device}" -A 5 | grep -i "Brightness" | awk -F ':' '{print $2}')
+            ;;
+    kernel) device="${BLOCK_INSTANCE:-intel_backlight}"
+            maxBrightness=$(cat "/sys/class/backlight/${device}/max_brightness")
+            curBrightness=$(cat "/sys/class/backlight/${device}/brightness")
+            ;;
+    xbacklight) curBrightness=$(xbacklight -get) ;;
+esac
+
+if [[ "${curBrightness}" -le 0 ]]; then
+    exit
+fi
+
+case "${METHOD}" in
+    xrandr) percent=$(echo "scale=0;${curBrightness} * 100" | bc -l) ;;
+    kernel) percent=$(echo "scale=0;${curBrightness} * 100 / ${maxBrightness}" | bc -l) ;;
+    xbacklight) percent=$(echo "scale=0;${curBrightness}" | bc -l) ;;
+esac
+
+percent=${percent%.*}
+
+if [[ "${percent}" -le 0 ]]; then
+  exit
+fi
+
+echo "${percent}%"
+echo "${percent}%"
+echo ""
+
+if [[ "${percent}" -le "${URGENT_VALUE}" ]]; then
+  exit 33
+fi