diff --git a/themes/simonoff.zsh-theme b/themes/simonoff.zsh-theme
index fea2eff42..c906192a0 100644
--- a/themes/simonoff.zsh-theme
+++ b/themes/simonoff.zsh-theme
@@ -1,43 +1,22 @@
-# Prompt
-#
-# Below are the color init strings for the basic file types. A color init
-# string consists of one or more of the following numeric codes:
-# Attribute codes:
-# 00=none 01=bold 04=underscore 05=blink 07=reverse 08=concealed
-# Text color codes:
-# 30=black 31=red 32=green 33=yellow 34=blue 35=magenta 36=cyan 37=white
-# Background color codes:
-# 40=black 41=red 42=green 43=yellow 44=blue 45=magenta 46=cyan 47=white
-function precmd {
-
-  local TERMWIDTH
-  (( TERMWIDTH = ${COLUMNS} - 1 ))
-
-
-  ###
-  # Truncate the path if it's too long.
-
+function theme_precmd {
   PR_FILLBAR=""
   PR_PWDLEN=""
 
-  local promptsize=${#${(%):---(%n@%M:%l)---()}}
+  local promptsize=${#${(%):--(%n@%M:)--(%l)-}}
   local pwdsize=${#${(%):-%~}}
-  local gitbranch="$(git_prompt_info)"
-  local rvmprompt="$(ruby_prompt_info)"
-  local gitbranchsize=${#${gitbranch:-''}}
-  local rvmpromptsize=${#${rvmprompt:-''}}
+  local gitbranchsize="${#${(%)$(git_prompt_info)}:-}"
+  local rvmpromptsize="${#${(%)$(ruby_prompt_info):-}}"
 
-  if [[ "$promptsize + $pwdsize + $rvmpromptsize + $gitbranchsize" -gt $TERMWIDTH ]]; then
-    ((PR_PWDLEN=$TERMWIDTH - $promptsize))
+  # Truncate the path if it's too long.
+  if (( promptsize + pwdsize + rvmpromptsize + gitbranchsize > COLUMNS )); then
+    (( PR_PWDLEN = COLUMNS - promptsize ))
   else
-    PR_FILLBAR="\${(l.(($TERMWIDTH - ($promptsize + $pwdsize + $rvmpromptsize + $gitbranchsize)))..${PR_SPACE}.)}"
+    PR_FILLBAR="\${(l.$(( COLUMNS - (promptsize + pwdsize + rvmpromptsize + gitbranchsize) ))..${PR_SPACE}.)}"
   fi
 }
 
-
-setopt extended_glob
-
-preexec () {
+function theme_preexec {
+  setopt local_options extended_glob
   if [[ "$TERM" == "screen" ]]; then
     local CMD=${1[(wr)^(*=*|sudo|-*)]}
     echo -n "\ek$CMD\e\\"
@@ -53,47 +32,41 @@ preexec () {
 
 }
 
-setprompt () {
-###
+autoload -U add-zsh-hook
+add-zsh-hook precmd  theme_precmd
+add-zsh-hook preexec theme_preexec
+
+
+# Set the prompt
+
 # Need this so the prompt will work.
+setopt prompt_subst
 
-  setopt prompt_subst
-
-
-###
 # See if we can use colors.
+autoload zsh/terminfo
+for color in RED GREEN YELLOW BLUE MAGENTA CYAN WHITE GREY; do
+  print -v "PR_$color" "%{$terminfo[bold]$fg[${(L)color}]%}"
+  print -v "PR_LIGHT_$color" "%{$fg[${(L)color}]%}"
+done
+PR_NO_COLOUR="%{$terminfo[sgr0]%}"
 
-  autoload zsh/terminfo
-  for color in RED GREEN YELLOW BLUE MAGENTA CYAN WHITE; do
-  eval PR_$color='%{$terminfo[bold]$fg[${(L)color}]%}'
-  eval PR_LIGHT_$color='%{$fg[${(L)color}]%}'
-  (( count = $count + 1 ))
-  done
-  PR_NO_COLOUR="%{$terminfo[sgr0]%}"
+# Use extended characters to look nicer
+PR_HBAR="-"
+PR_ULCORNER="-"
+PR_LLCORNER="-"
+PR_LRCORNER="-"
+PR_URCORNER="-"
 
+# Modify Git prompt
+ZSH_THEME_GIT_PROMPT_PREFIX=" ["
+ZSH_THEME_GIT_PROMPT_SUFFIX="]"
 
-###
-# See if we can use extended characters to look nicer.
-  PR_HBAR=${altchar[q]:--}
-  PR_ULCORNER=${altchar[l]:--}
-  PR_LLCORNER=${altchar[m]:--}
-  PR_LRCORNER=${altchar[j]:--}
-  PR_URCORNER=${altchar[k]:--}
+# Modify RVM prompt
+ZSH_THEME_RUBY_PROMPT_PREFIX=" ["
+ZSH_THEME_RUBY_PROMPT_SUFFIX="]"
 
-  ###
-  # Modify Git prompt
-  ZSH_THEME_GIT_PROMPT_PREFIX=" ["
-  ZSH_THEME_GIT_PROMPT_SUFFIX="]"
-  ###
-  # Modify RVM prompt
-  ZSH_THEME_RUBY_PROMPT_PREFIX=" ["
-  ZSH_THEME_RUBY_PROMPT_SUFFIX="]"
-
-
-###
 # Decide if we need to set titlebar text.
-
-  case $TERM in
+case $TERM in
   xterm*|*rxvt*)
     PR_TITLEBAR=$'%{\e]0;%(!.-=*[ROOT]*=- | .)%n@%M:%~ $(git_prompt_info) $(rvm_prompt_info) | ${COLUMNS}x${LINES} | %y\a%}'
     ;;
@@ -101,26 +74,22 @@ setprompt () {
     PR_TITLEBAR=$'%{\e_screen \005 (\005t) | %(!.-=[ROOT]=- | .)%n@%m:%~ | ${COLUMNS}x${LINES} | %y\e\\%}'
     ;;
   *)
-    PR_TITLEBAR=''
+    PR_TITLEBAR=""
     ;;
-  esac
+esac
 
-
-###
 # Decide whether to set a screen title
-  if [[ "$TERM" == "screen" ]]; then
-    PR_STITLE=$'%{\ekzsh\e\\%}'
-  else
-    PR_STITLE=''
-  fi
+if [[ "$TERM" == "screen" ]]; then
+  PR_STITLE=$'%{\ekzsh\e\\%}'
+else
+  PR_STITLE=""
+fi
 
-###
 # Finally, the prompt.
-#
-  PROMPT='$PR_SET_CHARSET$PR_STITLE${(e)PR_TITLEBAR}\
+PROMPT='$PR_SET_CHARSET$PR_STITLE${(e)PR_TITLEBAR}\
 $PR_RED$PR_HBAR<\
 $PR_BLUE%(!.$PR_RED%SROOT%s.%n)$PR_GREEN@$PR_BLUE%M:$PR_GREEN%$PR_PWDLEN<...<%~$PR_CYAN$(git_prompt_info)$(rvm_prompt_info)\
-$PR_RED>$PR_HBAR$PR_SPACE${(e)PR_FILLBAR}\
+$PR_RED>$PR_HBAR${(e)PR_FILLBAR}\
 $PR_RED$PR_HBAR<\
 $PR_GREEN%l$PR_RED>$PR_HBAR\
 
@@ -128,7 +97,3 @@ $PR_RED$PR_HBAR<\
 %(?..$PR_LIGHT_RED%?$PR_BLUE:)\
 $PR_LIGHT_BLUE%(!.$PR_RED.$PR_WHITE)%#$PR_RED>$PR_HBAR\
 $PR_NO_COLOUR '
-
-}
-
-setprompt