(message "%s%s" prompt (char-to-string char))
char))
+(defun read-multiple-choice (prompt choices)
+ "Ask user a multiple choice question.
+PROMPT should be a string that will be displayed as the prompt.
+
+CHOICES is an alist where the first element in each entry is a
+character to be entered, the second element is a short name for
+the entry to be displayed while prompting (if there's room, it
+might be shortened), and the third, optional entry is a longer
+explanation that will be displayed in a help buffer if the user
+requests more help.
+
+The return value is the matching entry from the CHOICES list.
+
+Usage example:
+
+\(read-multiple-choice \"Continue connecting?\"
+ '((?a \"always\")
+ (?s \"session only\")
+ (?n \"no\")))"
+ (let* ((altered-names nil)
+ (full-prompt
+ (format
+ "%s (%s): "
+ prompt
+ (mapconcat
+ (lambda (elem)
+ (let* ((name (cadr elem))
+ (pos (seq-position name (car elem)))
+ (altered-name
+ (cond
+ ;; Not in the name string.
+ ((not pos)
+ (format "[%c] %s" (car elem) name))
+ ;; The prompt character is in the name, so highlight
+ ;; it on graphical terminals...
+ ((display-supports-face-attributes-p
+ '(:underline t) (window-frame))
+ (setq name (copy-sequence name))
+ (put-text-property pos (1+ pos)
+ 'face 'read-multiple-choice-face
+ name)
+ name)
+ ;; And put it in [bracket] on non-graphical terminals.
+ (t
+ (concat
+ (substring name 0 pos)
+ "["
+ (upcase (substring name pos (1+ pos)))
+ "]"
+ (substring name (1+ pos)))))))
+ (push (cons (car elem) altered-name)
+ altered-names)
+ altered-name))
+ (append choices '((?? "?")))
+ ", ")))
+ tchar buf wrong-char)
+ (save-window-excursion
+ (save-excursion
+ (while (not tchar)
+ (message "%s%s"
+ (if wrong-char
+ "Invalid choice. "
+ "")
+ full-prompt)
+ (setq tchar
+ (if (and (display-popup-menus-p)
+ last-input-event ; not during startup
+ (listp last-nonmenu-event)
+ use-dialog-box)
+ (x-popup-dialog
+ t
+ (cons prompt
+ (mapcar
+ (lambda (elem)
+ (cons (capitalize (cadr elem))
+ (car elem)))
+ choices)))
+ (condition-case nil
+ (let ((cursor-in-echo-area t))
+ (read-char))
+ (error nil))))
+ ;; The user has entered an invalid choice, so display the
+ ;; help messages.
+ (when (not (assq tchar choices))
+ (setq wrong-char (not (memq tchar '(?? ?\C-h)))
+ tchar nil)
+ (when wrong-char
+ (ding))
+ (with-help-window (setq buf (get-buffer-create
+ "*Multiple Choice Help*"))
+ (with-current-buffer buf
+ (erase-buffer)
+ (pop-to-buffer buf)
+ (insert prompt "\n\n")
+ (let* ((columns (/ (window-width) 25))
+ (fill-column 21)
+ (times 0)
+ (start (point)))
+ (dolist (elem choices)
+ (goto-char start)
+ (unless (zerop times)
+ (if (zerop (mod times columns))
+ ;; Go to the next "line".
+ (goto-char (setq start (point-max)))
+ ;; Add padding.
+ (while (not (eobp))
+ (end-of-line)
+ (insert (make-string (max (- (* (mod times columns)
+ (+ fill-column 4))
+ (current-column))
+ 0)
+ ?\s))
+ (forward-line 1))))
+ (setq times (1+ times))
+ (let ((text
+ (with-temp-buffer
+ (insert (format
+ "%c: %s\n"
+ (car elem)
+ (cdr (assq (car elem) altered-names))))
+ (fill-region (point-min) (point-max))
+ (when (nth 2 elem)
+ (let ((start (point)))
+ (insert (nth 2 elem))
+ (unless (bolp)
+ (insert "\n"))
+ (fill-region start (point-max))))
+ (buffer-string))))
+ (goto-char start)
+ (dolist (line (split-string text "\n"))
+ (end-of-line)
+ (if (bolp)
+ (insert line "\n")
+ (insert line))
+ (forward-line 1)))))))))))
+ (when (buffer-live-p buf)
+ (kill-buffer buf))
+ (assq tchar choices)))
+
(defun sit-for (seconds &optional nodisp obsolete)
"Redisplay, then wait for SECONDS seconds. Stop when input is available.
SECONDS may be a floating-point value.