;;; dropdown-list.el --- Drop-down menu interface
;;
;; Filename: dropdown-list.el
;; Description: Drop-down menu interface
;; Author: Jaeyoun Chung [jay.chung@gmail.com]
;; Maintainer:
;; Copyright (C) 2008 Jaeyoun Chung
;; Created: Sun Mar 16 11:20:45 2008 (Pacific Daylight Time)
;; Version:
;; Last-Updated: Sun Mar 16 12:19:49 2008 (Pacific Daylight Time)
;; By: dradams
;; Update #: 43
;; URL: http://www.emacswiki.org/cgi-bin/wiki/dropdown-list.el
;; Keywords: convenience menu
;; Compatibility: GNU Emacs 21.x, GNU Emacs 22.x
;;
;; Features that might be required by this library:
;;
;; `cl'.
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;;; Commentary:
;;
;; According to Jaeyoun Chung, "overlay code stolen from company-mode.el."
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;;; Change log:
;;
;; 2008/03/16 dadams
;; Clean-up - e.g. use char-to-string for control chars removed by email posting.
;; Moved example usage code (define-key*, command-selector) inside the library.
;; Require cl.el at byte-compile time.
;; Added GPL statement.
;; 2008/01/06 Jaeyoun Chung
;; Posted to gnu-emacs-sources@gnu.org at 9:10 p.m.
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; This program 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 3, or
;; (at your option) any later version.
;;
;; This program 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 this program; see the file COPYING. If not, write to
;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth
;; Floor, Boston, MA 02110-1301, USA.
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;;; Code:
(eval-when-compile (require 'cl)) ;; decf, fourth, incf, loop, mapcar*
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defface dropdown-list-face
'((t :inherit default :background "lightyellow" :foreground "black"))
"*Bla." :group 'dropdown-list)
(defface dropdown-list-selection-face
'((t :inherit dropdown-list-face :background "purple"))
"*Bla." :group 'dropdown-list)
(defvar dropdown-list-overlays nil)
(defun dropdown-list-hide ()
(while dropdown-list-overlays
(delete-overlay (pop dropdown-list-overlays))))
(defun dropdown-list-put-overlay (beg end &optional prop value prop2 value2)
(let ((ov (make-overlay beg end)))
(overlay-put ov 'window t)
(when prop
(overlay-put ov prop value)
(when prop2 (overlay-put ov prop2 value2)))
ov))
(defun dropdown-list-line (start replacement &optional no-insert)
;; start might be in the middle of a tab, which means we need to hide the
;; tab and add spaces
(let ((end (+ start (length replacement)))
beg-point end-point
before-string after-string)
(goto-char (point-at-eol))
(if (< (current-column) start)
(progn (setq before-string (make-string (- start (current-column)) ? ))
(setq beg-point (point)))
(goto-char (point-at-bol)) ;; Emacs bug, move-to-column is wrong otherwise
(move-to-column start)
(setq beg-point (point))
(when (> (current-column) start)
(goto-char (1- (point)))
(setq beg-point (point))
(setq before-string (make-string (- start (current-column)) ? ))))
(move-to-column end)
(setq end-point (point))
(let ((end-offset (- (current-column) end)))
(when (> end-offset 0) (setq after-string (make-string end-offset ?b))))
(when no-insert
;; prevent inheriting of faces
(setq before-string (when before-string (propertize before-string 'face 'default)))
(setq after-string (when after-string (propertize after-string 'face 'default))))
(let ((string (concat before-string replacement after-string)))
(if no-insert
string
(push (dropdown-list-put-overlay beg-point end-point 'invisible t
'after-string string)
dropdown-list-overlays)))))
(defun dropdown-list-start-column (display-width)
(let ((column (mod (current-column) (window-width)))
(width (window-width)))
(cond ((<= (+ column display-width) width) column)
((> column display-width) (- column display-width))
((>= width display-width) (- width display-width))
(t nil))))
(defun dropdown-list-move-to-start-line (candidate-count)
(decf candidate-count)
(let ((above-line-count (save-excursion (- (vertical-motion (- candidate-count)))))
(below-line-count (save-excursion (vertical-motion candidate-count))))
(cond ((= below-line-count candidate-count)
t)
((= above-line-count candidate-count)
(vertical-motion (- candidate-count))
t)
((>= (+ below-line-count above-line-count) candidate-count)
(vertical-motion (- (- candidate-count below-line-count)))
t)
(t nil))))
(defun dropdown-list-at-point (candidates &optional selidx)
(dropdown-list-hide)
(let* ((lengths (mapcar #'length candidates))
(max-length (apply #'max lengths))
(start (dropdown-list-start-column (+ max-length 3)))
(i -1)
(candidates (mapcar* (lambda (candidate length)
(let ((diff (- max-length length)))
(propertize
(concat (if (> diff 0)
(concat candidate (make-string diff ? ))
(substring candidate 0 max-length))
(format "%3d" (+ 2 i)))
'face (if (eql (incf i) selidx)
'dropdown-list-selection-face
'dropdown-list-face))))
candidates
lengths)))
(save-excursion
(and start
(dropdown-list-move-to-start-line (length candidates))
(loop initially (vertical-motion 0)
for candidate in candidates
do (dropdown-list-line (+ (current-column) start) candidate)
while (/= (vertical-motion 1) 0)
finally return t)))))
(defun dropdown-list (candidates)
(let ((selection)
(temp-buffer))
(save-window-excursion
(unwind-protect
(let ((candidate-count (length candidates))
done key (selidx 0))
(while (not done)
(unless (dropdown-list-at-point candidates selidx)
(switch-to-buffer (setq temp-buffer (get-buffer-create "*selection*"))
'norecord)
(delete-other-windows)
(delete-region (point-min) (point-max))
(insert (make-string (length candidates) ?\n))
(goto-char (point-min))
(dropdown-list-at-point candidates selidx))
(setq key (read-key-sequence ""))
(cond ((and (stringp key)
(>= (aref key 0) ?1)
(<= (aref key 0) (+ ?0 (min 9 candidate-count))))
(setq selection (- (aref key 0) ?1)
done t))
((member key `(,(char-to-string ?\C-p) [up] "p"))
(setq selidx (mod (+ candidate-count (1- (or selidx 0)))
candidate-count)))
((member key `(,(char-to-string ?\C-n) [down] "n"))
(setq selidx (mod (1+ (or selidx -1)) candidate-count)))
((member key `(,(char-to-string ?\f))))
((member key `(,(char-to-string ?\r) [return]))
(setq selection selidx
done t))
(t (setq done t)))))
(dropdown-list-hide)
(and temp-buffer (kill-buffer temp-buffer)))
;; (when selection
;; (message "your selection => %d: %s" selection (nth selection candidates))
;; (sit-for 1))
selection)))
(defun define-key* (keymap key command)
"Add COMMAND to the multiple-command binding of KEY in KEYMAP.
Use multiple times to bind different COMMANDs to the same KEY."
(define-key keymap key (combine-command command (lookup-key keymap key))))
(defun combine-command (command defs)
"$$$$$ FIXME - no doc string"
(cond ((null defs) command)
((and (listp defs)
(eq 'lambda (car defs))
(= (length defs) 4)
(listp (fourth defs))
(eq 'command-selector (car (fourth defs))))
(unless (member `',command (cdr (fourth defs)))
(setcdr (fourth defs) (nconc (cdr (fourth defs)) `(',command))))
defs)
(t
`(lambda () (interactive) (command-selector ',defs ',command)))))
(defvar command-selector-last-command nil "$$$$$ FIXME - no doc string")
(defun command-selector (&rest candidates)
"$$$$$ FIXME - no doc string"
(if (and (eq last-command this-command) command-selector-last-command)
(call-interactively command-selector-last-command)
(let* ((candidate-strings
(mapcar (lambda (candidate)
(format "%s" (if (symbolp candidate)
candidate
(let ((s (format "%s" candidate)))
(if (>= (length s) 7)
(concat (substring s 0 7) "...")
s)))))
candidates))
(selection (dropdown-list candidate-strings)))
(when selection
(let ((cmd (nth selection candidates)))
(call-interactively cmd)
(setq command-selector-last-command cmd))))))
;;;;;;;;;;;;;;;;;;;;
(provide 'dropdown-list)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; dropdown-list.el ends here
