;;; lucid.el --- emulate some Lucid Emacs functions

;; Copyright (C) 1993, 1995, 2001-2020 Free Software Foundation, Inc.

;; Maintainer: emacs-devel@gnu.org
;; Keywords: emulations
;; Obsolete-since: 23.2

;; This file is part of GNU Emacs.

;; GNU Emacs 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 of the License, or
;; (at your option) any later version.

;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;;; Code:

;; XEmacs autoloads CL so we might as well make use of it.
(require 'cl)

(defalias 'current-time-seconds 'current-time)

(defun real-path-name (name &optional default)
  (file-truename (expand-file-name name default)))

;; It's not clear what to return if the mouse is not in FRAME.
(defun read-mouse-position (frame)
  (let ((pos (mouse-position)))
    (if (eq (car pos) frame)
	(cdr pos))))

(defun switch-to-other-buffer (arg)
  "Switch to the previous buffer.
With a numeric arg N, switch to the Nth most recent buffer.
With an arg of 0, buries the current buffer at the
bottom of the buffer stack."
  (interactive "p")
  (if (eq arg 0)
      (bury-buffer (current-buffer)))
  (switch-to-buffer
   (if (<= arg 1) (other-buffer (current-buffer))
     (nth arg
	  (apply 'nconc
		 (mapcar
		  (lambda (buf)
		    (if (= ?\  (string-to-char (buffer-name buf)))
			nil
		      (list buf)))
		  (buffer-list)))))))

(defun device-class (&optional device)
  "Return the class (color behavior) of DEVICE.
This will be one of `color', `grayscale', or `mono'.
This function exists for compatibility with XEmacs."
  (cond
   ((display-color-p device) 'color)
   ((display-grayscale-p device) 'grayscale)
   (t 'mono)))

(defalias 'find-face 'facep)
(defalias 'get-face 'facep)
;; internal-try-face-font was removed from faces.el in rev 1.139, 1999/07/21.
;;;(defalias 'try-face-font 'internal-try-face-font)

(defalias 'exec-to-string 'shell-command-to-string)


;; Buffer context

(defun buffer-syntactic-context (&optional buffer)
  "Syntactic context at point in BUFFER.
Either of `string', `comment' or nil.
This is an XEmacs compatibility function."
  (with-current-buffer (or buffer (current-buffer))
    (let ((state (syntax-ppss (point))))
      (cond
       ((nth 3 state) 'string)
       ((nth 4 state) 'comment)))))


(defun buffer-syntactic-context-depth (&optional buffer)
  "Syntactic parenthesis depth at point in BUFFER.
This is an XEmacs compatibility function."
  (with-current-buffer (or buffer (current-buffer))
    (nth 0 (syntax-ppss (point)))))


;; Extents
(defun make-extent (beg end &optional buffer)
  (make-overlay beg end buffer))

(defun extent-properties (extent) (overlay-properties extent))
(unless (fboundp 'extent-property) (defalias 'extent-property 'overlay-get))

(defun extent-at (pos &optional object property before)
  (with-current-buffer (or object (current-buffer))
    (let ((overlays (overlays-at pos 'sorted)))
      (when property
	(let (filtered)
	  (while overlays
	    (if (overlay-get (car overlays) property)
		(setq filtered (cons (car overlays) filtered)))
	    (setq overlays (cdr overlays)))
	  (setq overlays filtered)))
      (if before
	  (nth 1 (memq before overlays))
	(car overlays)))))

(defun set-extent-property (extent prop value)
  ;; Make sure that separate adjacent extents
  ;; with the same mouse-face value
  ;; do not run together as one extent.
  (and (eq prop 'mouse-face)
       (symbolp value)
       (setq value (list value)))
  (if (eq prop 'duplicable)
      (cond ((and value (not (overlay-get extent prop)))
	     ;; If becoming duplicable, copy all overlayprops to text props.
	     (add-text-properties (overlay-start extent)
				  (overlay-end extent)
				  (overlay-properties extent)
				  (overlay-buffer extent)))
	    ;; If becoming no longer duplicable, remove these text props.
	    ((and (not value) (overlay-get extent prop))
	     (remove-text-properties (overlay-start extent)
				     (overlay-end extent)
				     (overlay-properties extent)
				     (overlay-buffer extent))))
    ;; If extent is already duplicable, put this property
    ;; on the text as well as on the overlay.
    (if (overlay-get extent 'duplicable)
	(put-text-property  (overlay-start extent)
			    (overlay-end extent)
			    prop value (overlay-buffer extent))))
  (overlay-put extent prop value))

(defun set-extent-face (extent face)
  (set-extent-property extent 'face face))

(defun set-extent-end-glyph (extent glyph)
  (set-extent-property extent 'after-string glyph))

(defun delete-extent (extent)
  (set-extent-property extent 'duplicable nil)
  (delete-overlay extent))

;; Support the Lucid names with `screen' instead of `frame'.

(defalias 'current-screen-configuration 'current-frame-configuration)
(defalias 'delete-screen 'delete-frame)
(defalias 'find-file-new-screen 'find-file-other-frame)
(defalias 'find-file-read-only-new-screen 'find-file-read-only-other-frame)
(defalias 'find-tag-new-screen 'find-tag-other-frame)
;;(defalias 'focus-screen 'focus-frame)
(defalias 'iconify-screen 'iconify-frame)
(defalias 'mail-new-screen 'mail-other-frame)
(defalias 'make-screen-invisible 'make-frame-invisible)
(defalias 'make-screen-visible 'make-frame-visible)
;; (defalias 'minibuffer-screen-list 'minibuffer-frame-list)
(defalias 'modify-screen-parameters 'modify-frame-parameters)
(defalias 'next-screen 'next-frame)
;; (defalias 'next-multiscreen-window 'next-multiframe-window)
;; (defalias 'previous-multiscreen-window 'previous-multiframe-window)
;; (defalias 'redirect-screen-focus 'redirect-frame-focus)
(defalias 'redraw-screen 'redraw-frame)
;; (defalias 'screen-char-height 'frame-char-height)
;; (defalias 'screen-char-width 'frame-char-width)
;; (defalias 'screen-configuration-to-register 'frame-configuration-to-register)
;; (defalias 'screen-focus 'frame-focus)
(defalias 'screen-list 'frame-list)
;; (defalias 'screen-live-p 'frame-live-p)
(defalias 'screen-parameters 'frame-parameters)
(defalias 'screen-pixel-height 'frame-pixel-height)
(defalias 'screen-pixel-width 'frame-pixel-width)
(defalias 'screen-root-window 'frame-root-window)
(defalias 'screen-selected-window 'frame-selected-window)
(defalias 'lower-screen 'lower-frame)
(defalias 'raise-screen 'raise-frame)
(defalias 'screen-visible-p 'frame-visible-p)
(defalias 'screenp 'framep)
(defalias 'select-screen 'select-frame)
(defalias 'selected-screen 'selected-frame)
;; (defalias 'set-screen-configuration 'set-frame-configuration)
;; (defalias 'set-screen-height 'set-frame-height)
(defalias 'set-screen-position 'set-frame-position)
(defalias 'set-screen-size 'set-frame-size)
;; (defalias 'set-screen-width 'set-frame-width)
(defalias 'switch-to-buffer-new-screen 'switch-to-buffer-other-frame)
;; (defalias 'unfocus-screen 'unfocus-frame)
(defalias 'visible-screen-list 'visible-frame-list)
(defalias 'window-screen 'window-frame)
(defalias 'x-create-screen 'x-create-frame)
(defalias 'x-new-screen 'make-frame)

(provide 'lucid)

;; Local Variables:
;; byte-compile-warnings: (not cl-functions)
;; End:

;;; lucid.el ends here
