improve eww

modules/home/wayland/apps/eww/bar/scripts/read-mode

@@ -1,23 +1,23 @@
 #!/usr/bin/env bash
-SHADER="$HOME/.config/eww/shaders/read-mode.glsl"
+# Toggle the warm/low-contrast screen shader.  fp16 rendering is switched off
+# with it: the shader is written for 8-bit output.
+shader="$HOME/.config/eww/shaders/read-mode.glsl"
 
-is_active() {
-  hyprctl getoption decoration:screen_shader | grep -qF "$SHADER"
-}
+active() { hyprctl getoption decoration:screen_shader 2>/dev/null | grep -qF "$shader"; }
 
-case "$1" in
-  status)
-    is_active && echo true || echo false
-    ;;
+case ${1:-} in
+  status) active && echo true || echo false ;;
   *)
-    if is_active; then
-      hyprctl eval 'hl.config({ decoration = { screen_shader = "" } })'
-      hyprctl eval 'hl.config({ render = { use_fp16 = 2 } })'
-      echo false
+    if active; then
+      hyprctl eval 'hl.config({ decoration = { screen_shader = "" } })' >/dev/null
+      hyprctl eval 'hl.config({ render = { use_fp16 = 2 } })' >/dev/null
+      state=false
     else
-      hyprctl eval 'hl.config({ render = { use_fp16 = 0 } })'
-      hyprctl eval "hl.config({ decoration = { screen_shader = \"$SHADER\" } })"
-      echo true
+      hyprctl eval 'hl.config({ render = { use_fp16 = 0 } })' >/dev/null
+      hyprctl eval "hl.config({ decoration = { screen_shader = \"$shader\" } })" >/dev/null
+      state=true
     fi
+    eww update read-mode="$state" 2>/dev/null
+    echo "$state"
     ;;
 esac