compton-trans: add error handling. better option parsing.

bin/compton-trans

@@ -1,19 +1,25 @@
 #!/bin/bash
 
+#
+# compton-trans
 # transset in a bash script
 # Copyright (c) 2011-2012, Christopher Jeffrey
+#
 
 # Usage:
-# by window id
-#   settrans -w "$WINDOWID" -o 75
-# by name
-#   settrans -n "urxvt" -o 75
-# by current window
-#   settrans -c -o 75
-# by selection
-#   settrans -s -o 75
-# increment current window 5%
-#   settrans -c -o +5
+# By window id
+#   $ compton-trans -w "$WINDOWID" 75
+# By name
+#   $ compton-trans -n "urxvt" 75
+# By current window
+#   $ compton-trans -c 75
+# By selection
+#   $ compton-trans 75
+#   $ compton-trans -s 75
+# Increment current window 5%
+#   $ compton-trans -c +5
+# Remove opacity property of current window
+#   $ compton-trans -c none
 
 if test -z "$(which xprop)" -o -z "$(which xwininfo)"; then
   echo "Please install x11-utils/xorg-xprop/xorg-xwininfo." >& 2
@@ -25,42 +31,82 @@ opacity=
 cur=
 root=
 parent=
-active=
 i=
 
-while getopts "scn:w:o:" option; do
-  case "$option" in
-    s) window="" ;;
-    c)
+#
+# Options
+#
+
+arg=
+val=
+active=
+select=
+
+while test $# -gt 0; do
+  arg="$1"
+  shift
+  case "$arg" in
+    -s | -select | --select) ;;
+    -c | -current | --current)
       active=$(xprop -root -notype "_NET_ACTIVE_WINDOW" \
         | sed 's/^.*\(0x\S*\).*$/\1/')
       window="-id $active"
     ;;
-    n) window="-name $OPTARG" ;;
-    w) window="-id $OPTARG" ;;
-    o) opacity="$OPTARG" ;;
+    -n | -name | --name)
+      val="$1"
+      shift
+      window="-name $val"
+    ;;
+    -w | -window | --window)
+      val="$1"
+      shift
+      window="-id $val"
+    ;;
+    -o | -opacity | --opacity)
+      val="$1"
+      shift
+      opacity="$val"
+    ;;
+    *)
+      opacity="$arg"
+    ;;
   esac
 done
 
+if test -z "$window"; then
+  select=$(xwininfo | grep 'Window id:' | sed 's/^.*\(0x\S*\).*$/\1/')
+  window="-id $select"
+fi
+
+#
+# Find Window
+#
+
 root=$(xwininfo -all -root \
   | grep "Root window id" \
   | sed 's/^.*\(0x\S*\).*$/\1/')
 
 parent=$window
 i=0
+
 while true; do
   parent=$(xwininfo -all $parent \
     | grep Parent \
     | sed 's/^.*\(0x\S*\).*$/\1/')
 
+  if test -z "$parent"; then
+    echo "Window not found." >& 2
+    exit 1
+  fi
+
   if test "$parent" = "$root"; then
     break
   fi
 
   parent="-id $parent"
   window=$parent
 
-  i=$((i+1))
+  i=$((i + 1))
   if test $i -ge 1000; then
     echo "An error occurred while traversing up the window tree." >& 2
     echo "Please report this to https://github.com/chjj/compton/issues." >& 2
@@ -69,24 +115,46 @@ while true; do
   fi
 done
 
-inc=$(echo "$opacity" | sed 's/^\(+\|-\).*$\|^.*$/\1/')
-if test -n "$inc"; then
+if test -z "$window"; then
+  echo "Window not found." >& 2
+  exit 1
+fi
+
+#
+# Check (or Delete) Opacity
+#
+
+if test "$opacity" = "none"; then
+  xprop $window -remove _NET_WM_WINDOW_OPACITY
+  exit $?
+fi
+
+opacity=$(echo "$opacity" | sed 's/[^-+0-9]//g')
+if test -z "$opacity"; then
+  echo "Bad opacity value." >& 2
+  exit 1
+fi
+
+#
+# Determine Relative Opacity
+#
+
+if test -n "$(echo "$opacity" | sed 's/^\(+\|-\).*$\|^.*$/\1/')"; then
   cur=$(xprop $window -notype "_NET_WM_WINDOW_OPACITY" \
     | sed 's/^.*\b\([0-9]\+\).*$\|^.*$/\1/')
   test -z "$cur" && cur=$((0xffffffff))
-  cur=$((cur*100/0xffffffff))
-  opacity=$(echo "$opacity" | sed 's/\(\+\|\-\)//')
-  if test "$inc" = "+"; then
-    opacity=$((cur+opacity))
-  else
-    opacity=$((cur-opacity))
-  fi
+  cur=$((cur * 100 / 0xffffffff))
+  opacity=$((cur + opacity))
 fi
 
+#
+# Determine and Set Opacity
+#
+
 if test -n "$opacity" -a -n "$window"; then
   test $opacity -lt 0 && opacity=0
   test $opacity -gt 100 && opacity=100
-  opacity=$((opacity*0xffffffff/100))
+  opacity=$((opacity * 0xffffffff / 100))
   xprop $window -f _NET_WM_WINDOW_OPACITY 32c \
     -set _NET_WM_WINDOW_OPACITY "$opacity"
 fi

man/compton-trans.1

@@ -6,7 +6,7 @@ compton\-trans \- an opacity setter tool
 
 .SH SYNOPSIS
 .nf
-.B compton-trans [-wncs] [window] -o [opacity]
+.B compton-trans [-wncs] [window] opacity
 .fi
 
 .SH DESCRIPTION
@@ -17,20 +17,20 @@ It is similar to other utilities like transset(1) or transset-df(1).
 
 .SH OPTIONS
 .TP
-.BI \-w\ window\-id
+.BI \-w,\ \-window,\ \-\-window\ \fIwindow\-id\fP
 Specify the window id to target.
 .TP
-.BI \-n\ window\-name
+.BI \-n,\ \-name,\ \-\-name\ \fIwindow\-name\fP
 Specify and try to match a window name.
 .TP
-.BI \-c
+.BI \-c,\ \-current,\ \-\-current
 Specify the current window as a target.
 .TP
-.BI \-s
+.BI \-s,\ \-select,\ \-\-select
 Select target window with mouse cursor.
 This is the default if no window has been specified.
 .TP
-.BI \-o\ opacity
+.BI \-o,\ \-opacity,\ \-\-opacity\ \fIopacity\fP
 Specify the new opacity value for the window. This value
 can be anywhere from 1-100. If it is prefixed with a plus
 or minus (+/-), this will increment or decrement from the
@@ -39,19 +39,22 @@ target window's current opacity instead.
 .SH EXAMPLES
 .TP
 Set window id to opacity of 75%.
-compton-trans -w "$WINDOWID" -o 75
+compton-trans -w "$WINDOWID" 75
 .TP
 Set window name, "urxvt", to opacity of 75%.
-compton-trans -n "urxvt" -o 75
+compton-trans -n "urxvt" 75
 .TP
 Set current window to opacity of 75%.
-compton-trans -c -o 75
+compton-trans -c 75
 .TP
 Select target window and set opacity to 75%.
-compton-trans -s -o 75
+compton-trans 75
 .TP
 Increment current window 5% opacity.
-compton-trans -c -o +5
+compton-trans -c +5
+.TP
+Remove opacity property of current window.
+compton-trans -c none
 
 .SH BUGS
 Please report any you find to https://github.com/chjj/compton.