48853: improved handling of theme resets when changing prompt themes, especially for theme preview

ChangeLog

@@ -1,5 +1,9 @@
 2021-05-16  Bart Schaefer  <schaefer@zsh.org>
 
+	* Marlon Richert: 48853: Doc/Zsh/contrib.yo,
+	Functions/Prompts/promptinit: improved handling of theme resets
+	when changing prompt themes, especially for theme preview
+
 	* 48860: Etc/BUGS: remove mention of bugs that were fixed
 
 	* 48857: Src/builtin.c, Src/exec.c, Src/loop.c, Src/makepro.awk,

Doc/Zsh/contrib.yo

@@ -2041,10 +2041,12 @@ setopts (tt(promptbang), etc.) are turned on, all other prompt-related
 options are turned off.  The tt(prompt_opts) array preserves setopts even
 beyond the scope of tt(localoptions), should your function need that.
 )
-item(Modify precmd and preexec)(
+item(Modify hooks)(
-Use of tt(add-zsh-hook) is recommended.  The tt(precmd) and tt(preexec)
+Use of tt(add-zsh-hook) and tt(add-zle-hook-widget) is recommended (see
-hooks are automatically adjusted if the prompt theme changes or is
+ifzman(the bf(Manipulating Hook Functions) section above)\
-disabled.
+ifnzman(noderef(Manipulating Hook Functions))\
+). All hooks that follow the naming pattern tt(prompt_)var(theme)tt(_)var(hook)
+are automatically removed when the prompt theme changes or is disabled.
 )
 item(Declare cleanup)(
 If your function makes any other changes that should be undone when the

Functions/Prompts/promptinit

@@ -14,6 +14,8 @@ prompt_themes=()
 promptinit () {
   emulate -L zsh
   setopt extendedglob
+  autoload -Uz add-zsh-hook add-zle-hook-widget
+
   local ppath='' name theme
   local -a match mbegin mend
 
@@ -32,9 +34,6 @@ promptinit () {
     fi
   done
 
-  # To manipulate precmd and preexec hooks...
-  autoload -Uz add-zsh-hook
-
   # Variables common to all prompt styles
   prompt_newline=$'\n%{\r%}'
 }
@@ -47,38 +46,23 @@ prompt_preview_safely() {
     return
   fi
 
-  # This handles all the stuff from the default :prompt-theme restore
+  # Run this in a subshell, so we don't need to clean up afterwards.
-  local +h PS1=$PS1 PS2=$PS2 PS3=$PS3 PS4=$PS4 RPS1=$RPS1 RPS2=$RPS2
+  (
-  local +h PROMPT=$PROMPT RPROMPT=$RPROMPT RPROMPT2=$RPROMPT2 PSVAR=$PSVAR
+    # Execute current theme's cleanup sequence, if any.
-  local -a precmd_functions preexec_functions prompt_preview_restore
+    zstyle -t :prompt-theme cleanup
-  local -aLl +h zle_highlight
 
-  {
+    # If we can't find a _preview function, run the _setup function to see if
-    # Save and clear current restore-point if any
+    # it will create one.
-    zstyle -g prompt_preview_restore :prompt-theme restore
+    typeset +f prompt_${1}_preview >&/dev/null ||
-    {
-      zstyle -d :prompt-theme restore
-      # Execute current cleanup sequence, if any.
-      zstyle -t :prompt-theme cleanup
-
-      # The next line is a bit ugly.  It (perhaps unnecessarily)
-      # runs the prompt theme setup function to ensure that if
-      # the theme has a _preview function that it's been autoloaded.
       prompt_${1}_setup
 
-      if typeset +f prompt_${1}_preview >&/dev/null; then
+    # ...then try again.
-        prompt_${1}_preview "$@[2,-1]"
+    if typeset +f prompt_${1}_preview >&/dev/null; then
-      else
+      prompt_${1}_preview "$@[2,-1]"
-        prompt_preview_theme "$@"
+    else
-      fi
+      prompt_preview_theme "$@"
-    } always {
+    fi
-      # Run any theme-specific cleanup, then reset restore point
+  )
-      zstyle -t :prompt-theme cleanup
-    }
-  } always {
-    (( $#prompt_preview_restore )) &&
-      zstyle -e :prompt-theme restore "${prompt_preview_restore[@]}"
-  }
 }
 
 set_prompt() {
@@ -97,21 +81,6 @@ Options:
 Use prompt -h <theme> for help on specific themes.'
 
   getopts "chlps:" opt
-  case "$opt" in
-    (h|p)
-      setopt localtraps
-      if [[ -z "$prompt_theme[1]" ]]; then
-        # Not using a prompt theme; save settings
-        local +h PS1=$PS1 PS2=$PS2 PS3=$PS3 PS4=$PS4 RPS1=$RPS1 RPS2=$RPS2
-        local +h PROMPT=$PROMPT RPROMPT=$RPROMPT RPROMPT2=$RPROMPT2 PSVAR=$PSVAR
-        local -a precmd_functions preexec_functions
-        local theme_reset=''
-      else
-        local theme_reset='prompt_${prompt_theme[1]}_setup "${(@)prompt_theme[2,-1]}"'
-      fi
-      trap 'zstyle -t :prompt-theme cleanup;'"${theme_reset:+ $theme_reset}" 0
-      ;;
-  esac
   case "$opt" in
     c) if [[ -n $prompt_theme ]]; then
          print -n "Current prompt theme"
@@ -123,21 +92,26 @@ Use prompt -h <theme> for help on specific themes.'
        return
        ;;
     h) if [[ -n "$2" && -n $prompt_themes[(r)$2] ]]; then
-         if functions prompt_$2_setup >/dev/null; then
+         # Run this in a subshell, so we don't need to clean up afterwards.
+         (
+           # Execute current theme's cleanup sequence, if any.
            zstyle -t :prompt-theme cleanup
-           # The next line is a bit ugly.  It (perhaps unnecessarily)
+
-           # runs the prompt theme setup function to ensure that if
+           # If we can't find a _help function, run the _setup function to see
-           # the theme has a _help function that it's been autoloaded.
+           # if it will create one.
-           prompt_$2_setup
+           typeset +f prompt_$2_help >/dev/null ||
-         fi
+               prompt_$2_setup
-         if functions prompt_$2_help >/dev/null; then
+
-           print "Help for $2 theme:\n"
+           # ...then try again.
-           prompt_$2_help
+           if typeset +f prompt_$2_help >/dev/null; then
-         else
+             print "Help for $2 theme:\n"
-           print "No help available for $2 theme."
+             prompt_$2_help
-         fi
+           else
-         print "\nType \`prompt -p $2' to preview the theme, \`prompt $2'"
+             print "No help available for $2 theme."
-         print "to try it out, and \`prompt -s $2' to use it in future sessions."
+           fi
+           print "\nType \`prompt -p $2' to preview the theme, \`prompt $2'"
+           print "to try it out, and \`prompt -s $2' to use it in future sessions."
+         )
        else
          print "$usage"
        fi
@@ -178,8 +152,13 @@ Use prompt -h <theme> for help on specific themes.'
 
        # Reset some commonly altered bits to the default
        local hook
-       for hook in chpwd precmd preexec periodic zshaddhistory zshexit; do
+       for hook in chpwd precmd preexec periodic zshaddhistory zshexit \
-         add-zsh-hook -D "${hook}" "prompt_*_${hook}"
+           zsh_directory_name; do
+         add-zsh-hook -D "$hook" "prompt_*_$hook"
+       done
+       for hook in isearch-exit isearch-update line-pre-redraw line-init \
+           line-finish history-line-set keymap-select; do
+         add-zle-hook-widget -D "$hook" "prompt_*_$hook"
        done
        typeset -ga zle_highlight=( ${zle_highlight:#default:*} )
        (( ${#zle_highlight} )) || unset zle_highlight
@@ -192,11 +171,8 @@ Use prompt -h <theme> for help on specific themes.'
 
 prompt_cleanup () {
   local -a cleanup_hooks theme_active
-  if ! zstyle -g cleanup_hooks :prompt-theme cleanup
+  if ! zstyle -g cleanup_hooks :prompt-theme cleanup; then
-  then
+    if ! zstyle -g theme_active :prompt-theme restore; then
-    (( $+prompt_preview_restore == 0 )) &&
-    if ! zstyle -g theme_active :prompt-theme restore
-    then
       print -u2 "prompt_cleanup: no prompt theme active"
       return 1
     fi
@@ -225,22 +201,21 @@ prompt () {
     [[ -o promptpercent ]] && prompt_opts+=(percent)
     [[ -o promptsp ]] && prompt_opts+=(sp)
     [[ -o promptsubst ]] && prompt_opts+=(subst)
-    zstyle -e :prompt-theme restore \
+    zstyle -e :prompt-theme restore "
-        'zstyle -d :prompt-theme restore;' \
+        zstyle -d :prompt-theme restore
-	'prompt_default_setup;' \
+        prompt_default_setup
-        ${PS1+PS1="${(q)PS1}"} \
+        ${PS1+PS1=${(q+)PS1}}
-        ${PS2+PS2="${(q)PS2}"} \
+        ${PS2+PS2=${(q+)PS2}}
-        ${PS3+PS3="${(q)PS3}"} \
+        ${PS3+PS3=${(q+)PS3}}
-        ${PS4+PS4="${(q)PS4}"} \
+        ${PS4+PS4=${(q+)PS4}}
-        ${RPS1+RPS1="${(q)RPS1}"} \
+        ${RPS1+RPS1=${(q+)RPS1}}
-        ${RPS2+RPS2="${(q)RPS2}"} \
+        ${RPS2+RPS2=${(q+)RPS2}}
-        ${RPROMPT+RPROMPT="${(q)RPROMPT}"} \
+        ${RPROMPT+RPROMPT=${(q+)RPROMPT}}
-        ${RPROMPT2+RPROMPT2="${(q)RPROMPT2}"} \
+        ${RPROMPT2+RPROMPT2=${(q+)RPROMPT2}}
-        ${PSVAR+PSVAR="${(q)PSVAR}"} \
+        ${PSVAR+PSVAR=${(q+)PSVAR}}
-        "precmd_functions=(${(q)precmd_functions[@]})" \
+        prompt_opts=( $prompt_opts[*] )
-        "preexec_functions=(${(q)preexec_functions[@]})" \
+        reply=( yes )
-        "prompt_opts=( ${prompt_opts[*]} )" \
+    "
-        'reply=(yes)'
   }
   set_prompt "$@"
 
@@ -253,12 +228,6 @@ prompt () {
 prompt_preview_theme () {
   emulate -L zsh
 
-  # Check for proper state handling
-  (( $+prompt_preview_restore )) || {
-    prompt_preview_safely "$@"
-    return
-  }
-
   # Minimal preview for prompts that don't supply one
   local -a prompt_opts
   print -n "$1 theme"
@@ -268,12 +237,20 @@ prompt_preview_theme () {
   prompt_${1}_setup "$@[2,-1]"
   (( ${#prompt_opts} )) &&
       setopt noprompt{bang,cr,percent,sp,subst} "prompt${^prompt_opts[@]}"
+
+  [[ -n ${chpwd_functions[(r)prompt_${1}_chpwd]} ]] &&
+      prompt_${1}_chpwd
   [[ -n ${precmd_functions[(r)prompt_${1}_precmd]} ]] &&
-    prompt_${1}_precmd
+      prompt_${1}_precmd
-  [[ -o promptcr ]] && print -n $'\r'; :
+
-  print -P "${PS1}command arg1 arg2 ... argn"
+  # We'd like to call zle-line-init/finish hooks, too, but that's not possible
+  # while the ZLE is not active.
+
+  [[ -o promptcr ]] && print -n $'\r'
+  :; print -P -- "${PS1}command arg1 arg2 ... argn"
+
   [[ -n ${preexec_functions[(r)prompt_${1}_preexec]} ]] &&
-    prompt_${1}_preexec
+      prompt_${1}_preexec
 }
 
 [[ -o kshautoload ]] || promptinit "$@"