;; Keymap functions.
;; Copyright (C) 1993, 1994 Free Software Foundation, Inc.
;; Copyright (C) 1995 Tinker Systems and INS Engineering Corp.

;; This file is part of XEmacs.

;; XEmacs is free software; you can redistribute it and/or modify it
;; under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; XEmacs is distributed in the hope that it will be useful, but
;; WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;; General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with XEmacs; see the file COPYING.  If not, write to the 
;; Free Software Foundation, 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Synched up with: FSF 19.28.
;;; Note: FSF does not have a file keymap.el.  This stuff is
;;; in keymap.c.

;Prevent the \{...} documentation construct
;from mentioning keys that run this command.
(put 'undefined 'suppress-keymap t)

(defun undefined ()
  (interactive)
  (ding))

(defun suppress-keymap (map &optional nodigits)
  "Make MAP override all normally self-inserting keys to be undefined.
Normally, as an exception, digits and minus-sign are set to make prefix args,
but optional second arg NODIGITS non-nil treats them like other chars."
  (substitute-key-definition 'self-insert-command 'undefined map global-map)
  (or nodigits
      (let ((string (make-string 1 ?0)))
	(define-key map "-" 'negative-argument)
	;; Make plain numbers do numeric args.
	(while (<= (aref string 0) ?9)
	  (define-key map string 'digit-argument)
	  (incf (aref string 0))))))

(defun substitute-key-definition (olddef newdef keymap &optional oldmap prefix)
  "Replace OLDDEF with NEWDEF for any keys in KEYMAP now defined as OLDDEF.
In other words, OLDDEF is replaced with NEWDEF wherever it appears.
Prefix keymaps are checked recursively.  If optional fourth argument OLDMAP
is specified, we redefine in KEYMAP as NEWDEF those chars which are defined
as OLDDEF in OLDMAP, unless that keybinding is already present in keymap.
If optional fifth argument PREFIX is defined, then only those occurrences of
OLDDEF found in keymaps accessible through the keymap bound to PREFIX in
KEYMAP are redefined.  See also `accessible-keymaps'."
  (let ((maps (accessible-keymaps (or oldmap keymap) prefix))
	(shadowing (not (null oldmap)))
	prefix map)
    (while maps
      (setq prefix (car (car maps))
	    map (cdr (car maps))
	    maps (cdr maps))
      ;; Substitute in this keymap
      (map-keymap #'(lambda (key binding)
		      (if (eq binding olddef)
			  ;; The new bindings always go in KEYMAP even if we
			  ;; found them in OLDMAP or one of it's children.
			  ;; If KEYMAP will be shadowing OLDMAP, then do not
			  ;; redefine the key if there is another binding
			  ;; in KEYMAP that will shadow OLDDEF.
			  (or (and shadowing
				   (lookup-key keymap key))
			      ;; define-key will give an error if a prefix
			      ;; of the key is already defined.  Otherwise
			      ;; it will define the key in the map. 
			      ;; #### - Perhaps this should be protected?
			      (define-key
				keymap
				(vconcat prefix (list key))
				newdef))))
		  map)
      )))


;; From Bill Dubuque <wgd@martigny.ai.mit.edu>

;; This used to wrap forms into an interactive lambda.  It is unclear
;; to me why this is needed in this function.  Anyway,
;; `key-or-menu-binding' doesn't do it, so this function no longer
;; does it, either.
(defun insert-key-binding (key)         ; modeled after describe-key
  "Insert the command bound to KEY."
  (interactive "kInsert command bound to key: ")
  (let ((defn (key-or-menu-binding key)))
    (if (or (null defn) (integerp defn))
	(error "%s is undefined" (key-description key))
      (if (or (stringp defn) (vectorp defn))
          (setq defn (key-binding defn))) ;; a keyboard macro
      (insert (format "%s" defn)))))

;; From Bill Dubuque <wgd@martigny.ai.mit.edu>
(defun read-command-or-command-sexp (prompt)
  "Read a command symbol or command sexp.
A command sexp is wrapped in an interactive lambda if needed.
Prompts with PROMPT."
  ;; Todo: it would be better if we could reject symbols that are not
  ;; commandp (as does 'read-command') but that is not easy to do
  ;; because we must supply arg4 = require-match = nil for sexp case.
  (let ((result (car (read-from-string
                      (completing-read prompt obarray 'commandp)))))
    (if (and (consp result)
             (not (eq (car result) 'lambda)))
        `(lambda ()
	   (interactive)
	   ,result)
      result)))

(defun local-key-binding (keys)
  "Return the binding for command KEYS in current local keymap only.
KEYS is a string, a vector of events, or a vector of key-description lists
as described in the documentation for the `define-key' function.
The binding is probably a symbol with a function definition; see
the documentation for `lookup-key' for more information."
  (let ((map (current-local-map)))
    (if map
        (lookup-key map keys)
        nil)))

(defun global-key-binding (keys)
  "Return the binding for command KEYS in current global keymap only.
KEYS is a string or vector of events, a sequence of keystrokes.
The binding is probably a symbol with a function definition; see
the documentation for `lookup-key' for more information."
  (lookup-key (current-global-map) keys))

;; from Bill Dubuque <wgd@martigny.ai.mit.edu>
(defun global-set-key (key command)
  "Give KEY a global binding as COMMAND.
COMMAND is a symbol naming an interactively-callable function.
KEY is a string, a vector of events, or a vector of key-description lists
as described in the documentation for the `define-key' function.
Note that if KEY has a local binding in the current buffer
that local binding will continue to shadow any global binding."
  ;;(interactive "KSet key globally: \nCSet key %s to command: ")
  (interactive (list (setq key (read-key-sequence "Set key globally: "))
                     ;; Command sexps are allowed here so that this arg
                     ;; may be supplied interactively via insert-key-binding.
                     (read-command-or-command-sexp
                       (format "Set key %s to command: "
                               (key-description key)))))
  (define-key (current-global-map) key command)
  nil)

;; from Bill Dubuque <wgd@martigny.ai.mit.edu>
(defun local-set-key (key command)
  "Give KEY a local binding as COMMAND.
COMMAND is a symbol naming an interactively-callable function.
KEY is a string, a vector of events, or a vector of key-description lists
as described in the documentation for the `define-key' function.
The binding goes in the current buffer's local map,
which is shared with other buffers in the same major mode."
  ;;(interactive "KSet key locally: \nCSet key %s locally to command: ")
  (interactive (list (setq key (read-key-sequence "Set key locally: "))
                     ;; Command sexps are allowed here so that this arg
                     ;; may be supplied interactively via insert-key-binding.
                     (read-command-or-command-sexp
                       (format "Set key %s locally to command: "
                               (key-description key)))))
  (if (null (current-local-map))
      (use-local-map (make-sparse-keymap)))
  (define-key (current-local-map) key command)
  nil)

(defun global-unset-key (key)
  "Remove global binding of KEY.
KEY is a string, a vector of events, or a vector of key-description lists
as described in the documentation for the `define-key' function."
  (interactive "kUnset key globally: ")
  (global-set-key key nil))

(defun local-unset-key (key)
  "Remove local binding of KEY.
KEY is a string, a vector of events, or a vector of key-description lists
as described in the documentation for the `define-key' function."
  (interactive "kUnset key locally: ")
  (if (current-local-map)
      (define-key (current-local-map) key nil)))


;; brain-death.
(defun minor-mode-key-binding (key &optional accept-default)
  "Find the visible minor mode bindings of KEY.
Return an alist of pairs (MODENAME . BINDING), where MODENAME is
the symbol which names the minor mode binding KEY, and BINDING is
KEY's definition in that mode.  In particular, if KEY has no
minor-mode bindings, return nil.  If the first binding is a
non-prefix, all subsequent bindings will be omitted, since they would
be ignored.  Similarly, the list doesn't include non-prefix bindings
that come after prefix bindings.

If optional argument ACCEPT-DEFAULT is non-nil, recognize default
bindings; see the description of `lookup-key' for more details about this."
  (let ((tail minor-mode-map-alist)
        a s v)
    (while tail
      (setq a (car tail)
            tail (cdr tail))
      (and (consp a)
           (symbolp (setq s (car a)))
           (boundp s)
           (symbol-value s)
           ;; indirect-function deals with autoloadable keymaps
           (setq v (indirect-function (cdr a)))
           (setq v (lookup-key v key accept-default))
           ;; Terminate loop, with v set to non-nil value
           (setq tail nil)))
    v))


(defun current-minor-mode-maps ()
  "Return a list of keymaps for the minor modes of the current buffer."
  (let ((l '())
        (tail minor-mode-map-alist)
        a s v)
    (while tail
      (setq a (car tail)
            tail (cdr tail))
      (and (consp a)
           (symbolp (setq s (car a)))
           (boundp s)
           (symbol-value s)
           ;; indirect-function deals with autoloadable keymaps
           (setq v (indirect-function (cdr a)))
           (setq l (cons v l))))
    (nreverse l)))


;;#### What a crock
(defun define-prefix-command (name &optional mapvar)
  "Define COMMAND as a prefix command.
A new sparse keymap is stored as COMMAND's function definition.
If second optional argument MAPVAR is not specified,
 COMMAND's value (as well as its function definition) is set to the keymap.
If a second optional argument MAPVAR is given and is not `t',
  the map is stored as its value.
Regardless of MAPVAR, COMMAND's function-value is always set to the keymap."
  (let ((map (make-sparse-keymap name)))
    (fset name map)
    (cond ((not mapvar)
           (set name map))
          ((eq mapvar 't)
           )
          (t
           (set mapvar map)))
    name))


;;; Converting vectors of events to a read-equivalent form.
;;; This is used both by call-interactively (for the command history)
;;; and by macros.el (for saving keyboard macros to a file).

;; ### why does (events-to-keys [backspace]) return "\C-h"?
;; BTW, this function is a mess, and macros.el does *not* use it, in
;; spite of the above comment.  `format-kbd-macro' is used to save
;; keyboard macros to a file.
(defun events-to-keys (events &optional no-mice)
 "Given a vector of event objects, returns a vector of key descriptors,
or a string (if they all fit in the ASCII range).
Optional arg NO-MICE means that button events are not allowed."
 (if (and events (symbolp events)) (setq events (vector events)))
 (cond ((stringp events)
        events)
       ((not (vectorp events))
        (signal 'wrong-type-argument (list 'vectorp events)))
       ((let* ((length (length events))
               (string (make-string length 0))
               c ce
               (i 0))
          (while (< i length)
            (setq ce (aref events i))
            (or (eventp ce) (setq ce (character-to-event ce)))
            ;; Normalize `c' to `?c' and `(control k)' to `?\C-k'
            ;; By passing t for the `allow-meta' arg we could get kbd macros
            ;; with meta in them to translate to the string form instead of
            ;; the list/symbol form; but I expect that would cause confusion,
            ;; so let's use the list/symbol form whenever there's 
            ;; any ambiguity.
            (setq c (event-to-character ce))
            (if (and c
                     character-set-property
                     (key-press-event-p ce))
                (cond ((symbolp (event-key ce))
                       (if (get (event-key ce) character-set-property)
                           ;; Don't use a string for `backspace' and `tab' to
                           ;;  avoid that unpleasant little ambiguity.
                           (setq c nil)))
                      ((and (= (event-modifier-bits ce) 1) ;control
                            (integerp (event-key ce)))
                       (let* ((te (character-to-event c)))
                         (if (and (symbolp (event-key te))
                                  (get (event-key te) character-set-property))
                             ;; Don't "normalize" (control i) to tab
                             ;;  to avoid the ambiguity in the other direction
                             (setq c nil))
                         (deallocate-event te)))))
            (if c
                (aset string i c)
                (setq i length string nil))
            (setq i (1+ i)))
          string))
       (t
        (let* ((length (length events))
               (new (copy-sequence events))
               event mods key
               (i 0))
          (while (< i length)
            (setq event (aref events i))
            (cond ((key-press-event-p event)
                   (setq mods (event-modifiers event)
                         key (event-key event))
                   (if (numberp key)
                       (setq key (intern (make-string 1 key))))
                   (aset new i (if mods
                                   (nconc mods (cons key nil))
                                   key)))
                  ((misc-user-event-p event)
                   (aset new i (list 'menu-selection
                                     (event-function event)
                                     (event-object event))))
                  ((or (button-press-event-p event)
                       (button-release-event-p event))
                   (if no-mice
                       (error 
                         "Mouse events can't be saved in keyboard macros."))
                   (setq mods (event-modifiers event)
                         key (intern (concat "button"
                                             (event-button event)
                                             (if (button-release-event-p event)
                                                 "up" ""))))
                   (aset new i (if mods
                                   (nconc mods (cons key nil))
                                   key)))
                  ((or (and event (symbolp event))
                       (and (consp event) (symbolp (car event))))
                   (aset new i event))
                  (t
                   (signal 'wrong-type-argument (list 'eventp event))))
            (setq i (1+ i)))
          new))))


(defun next-key-event ()
  "Return the next available keyboard event."
  (let (event)
    (while (not (key-press-event-p (setq event (next-command-event))))
      (dispatch-event event))
    event))

(defun key-sequence-list-description (keys)
  "Convert a key sequence KEYS to the full [(modifiers... key)...] form.
Argument KEYS can be in any form accepted by `define-key' function."
  (let ((vec
	  (cond ((vectorp keys)
		 keys)
		((stringp keys)
		 (vconcat keys))
		(t
		 (vector keys))))
	 (event-to-list
	  #'(lambda (ev)
	    (append (event-modifiers ev) (list (event-key ev))))))
    (mapvector
     #'(lambda (key)
       (cond ((key-press-event-p key)
	      (funcall event-to-list key))
	     ((characterp key)
	      (funcall event-to-list (character-to-event key)))
	     ((listp key)
	      key)
	     (t
	      (list key))))
     vec)))


;;; Support keyboard commands to turn on various modifiers.

;;; These functions -- which are not commands -- each add one modifier
;;; to the following event.

(defun event-apply-alt-modifier (ignore-prompt)
  (event-apply-modifier 'alt))
(defun event-apply-super-modifier (ignore-prompt)
  (event-apply-modifier 'super))
(defun event-apply-hyper-modifier (ignore-prompt)
  (event-apply-modifier 'hyper))
(defun event-apply-shift-modifier (ignore-prompt)
  (event-apply-modifier 'shift))
(defun event-apply-control-modifier (ignore-prompt)
  (event-apply-modifier 'control))
(defun event-apply-meta-modifier (ignore-prompt)
  (event-apply-modifier 'meta))

;;; #### `key-translate-map' is ignored for now.
(defun event-apply-modifier (symbol)
  "Return the next key event, with a modifier flag applied.
SYMBOL is the name of this modifier, as a symbol.
`function-key-map' is scanned for prefix bindings."
  (let (events binding)
    ;; read keystrokes scanning `function-key-map'
    (while (keymapp
	    (setq binding
		  (lookup-key
		   function-key-map
		   (vconcat
		    (setq events
			  (append events (list (next-key-event)))))))))
    (if binding				; found a binding
	(progn
	  ;; allow for several modifiers
	  (if (and (symbolp binding) (fboundp binding))
	      (setq binding (funcall binding nil)))
	  (setq events (append binding nil))
	  ;; put remaining keystrokes back into input queue
	  (setq unread-command-events
		(mapcar 'character-to-event (cdr events))))
      (setq unread-command-events (cdr events)))
    ;; add a modifier SYMBOL to the first keystroke or event
    (vector
     (append (list symbol)
	     (delq symbol
		   (aref (key-sequence-list-description (car events)) 0))))))

;; This looks dirty.  The following code should maybe go to another
;; file, and `create-console-hook' should maybe default to nil.
(add-hook
 'create-console-hook
 #'(lambda (console)
   (letf (((selected-console) console))
     (define-key function-key-map [?\C-x ?@ ?h] 'event-apply-hyper-modifier)
     (define-key function-key-map [?\C-x ?@ ?s] 'event-apply-super-modifier)
     (define-key function-key-map [?\C-x ?@ ?m] 'event-apply-meta-modifier)
     (define-key function-key-map [?\C-x ?@ ?S] 'event-apply-shift-modifier)
     (define-key function-key-map [?\C-x ?@ ?c] 'event-apply-control-modifier)
     (define-key function-key-map [?\C-x ?@ ?a] 'event-apply-alt-modifier))))
