unposted: a technique for overriding ZLE widgets within a selected keymap

ChangeLog

@@ -1,3 +1,9 @@
+2006-07-30  Barton E. Schaefer  <schaefer@zsh.org>
+
+	* unposted (see users/10559): Functions/Zle/keymap+widget: a
+	technique for overriding ZLE widgets only within a selected
+	keymap.
+
 2006-07-30  Peter Stephenson  <p.w.stephenson@ntlworld.com>
 
 	* 22565: Src/compcore.c: Fix bug with menu completion after failed
@@ -6,7 +12,7 @@
 	* 22562: Src/glob.c, Test/D07multibyte.ztst: make ${...#...} etc.
 	understand multibyte characters.	
 
-2006-07-29  Barton E. Schaefer  <schaefer@brasslantern.com>
+2006-07-29  Barton E. Schaefer  <schaefer@zsh.org>
 
 	* 22561: Functions/Zle/incremental-complete-word: fix display bug
 	introduced roughly five years ago when _main_complete was changed
@@ -159,7 +165,7 @@
 	* 22501: configure.ac: reduce default maximum function depth
 	to 1000.
 
-2006-06-17  Barton E. Schaefer  <schaefer@brasslantern.com>
+2006-06-17  Barton E. Schaefer  <schaefer@zsh.org>
 
 	* 22492: Functions/Zle/url-quote-magic: properly detect when a new
 	word (in the zsh syntax sense) has been started, and thus avoid

Functions/Zle/keymap+widget

@@ -0,0 +1,76 @@
+#autoload
+
+##
+# self-insert-by-keymap originally appeared in zsh-users/10559 (July 2006).
+# Changes have been made to the widget naming scheme, based on feedback on
+# the mailing list thread.
+##
+
+emulate -L zsh
+zmodload -i zsh/zleparameter || return 1
+
+# Rebind the most common widgets to override in multiple keymaps.  Ideally
+# complete-word would also be in this list, but so many other things
+# already rebind complete-word that doing so here is a waste of effort.
+
+local -a m
+local w='' k=''
+for w in self-insert accept-line forward-char backward-char \
+         up-{,line-or-}history down-{,line-or-}history \
+         magic-space backward-delete-char delete-char-or-list
+do
+
+  # If this is run early enough that all the widgets are still builtins,
+  # no explicit remapping is needed.  If they've already been rebound,
+  # it's not safe to assume we can do so again.
+
+  if [[ $widgets[$w] != (builtin|user:$w-by-keymap) ]]
+  then
+      m+="Cannot rebind $w: $widgets[$w]"
+      continue
+  fi
+
+  function $w-by-keymap {
+      if (( $+widgets[$KEYMAP+$WIDGET] == 1 ))
+      then zle $KEYMAP+$WIDGET "$@"
+      else zle .$WIDGET "$@"
+      fi
+  }
+
+  zle -N $w $w-by-keymap
+
+done
+
+[[ -n $m ]] && { zle && zle -M "${(F)m}" || print -l -u2 -R $m }
+
+return 0
+
+# With this in place, you should rarely need "zle -N self-insert frob"
+# again.  Instead you do this:
+#
+# 	bindkey -N frobber main
+# 	zle -N frobber+self-insert frob
+#
+# Then, whenever you wish to replace self-insert with frob, change
+# keymaps:
+#
+# 	zle recursive-edit -K frobber
+
+# Here's a simple example, which improves upon the caps-lock example in
+# the zsh manual entry for recursive-edit:
+#
+#   ucase+self-insert() {
+#     LBUFFER+=${(U)KEYS[-1]}
+#   }
+#   zle -N ucase+self-insert
+#   caps-lock() {
+#     bindkey -N ucase $KEYMAP
+#     bindkey -M ucase "$KEYS" .accept-line
+#     zle recursive-edit -K ucase || zle send-break
+#   }
+#   zle -N caps-lock
+#
+# To turn this on, pick a key sequence (I've chosen ctrl-x shift-L) and
+# bind the caps-lock widget to it:
+#
+#   bindkey -M main '^XL' caps-lock