root/trunk/lisp/gnus/gnus-ems.el

;;; gnus-ems.el --- functions for making Gnus work under different Emacsen

;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
;;   2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.

;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Keywords: news

;; 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, 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; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:

;;; Code:

(eval-when-compile
  (require 'cl)
  (require 'ring))

;;; Function aliases later to be redefined for XEmacs usage.

(defvar gnus-mouse-2 [mouse-2])
(defvar gnus-down-mouse-3 [down-mouse-3])
(defvar gnus-down-mouse-2 [down-mouse-2])
(defvar gnus-widget-button-keymap nil)
(defvar gnus-mode-line-modified
  (if (or (featurep 'xemacs)
          (< emacs-major-version 20))
      '("--**-" . "-----")
    '("**" "--")))

(eval-and-compile
  (autoload 'gnus-xmas-define "gnus-xmas")
  (autoload 'gnus-xmas-redefine "gnus-xmas")
  (autoload 'appt-select-lowest-window "appt")
  (autoload 'gnus-get-buffer-create "gnus")
  (autoload 'nnheader-find-etc-directory "nnheader"))

(autoload 'smiley-region "smiley")
;; Fixme: shouldn't require message
(autoload 'message-text-with-property "message")

(defun gnus-kill-all-overlays ()
  "Delete all overlays in the current buffer."
  (let* ((overlayss (overlay-lists))
         (buffer-read-only nil)
         (overlays (delq nil (nconc (car overlayss) (cdr overlayss)))))
    (while overlays
      (delete-overlay (pop overlays)))))

;;; Mule functions.

(defun gnus-mule-max-width-function (el max-width)
  `(let* ((val (eval (, el)))
          (valstr (if (numberp val)
                      (int-to-string val) val)))
     (if (> (length valstr) ,max-width)
         (truncate-string-to-width valstr ,max-width)
       valstr)))

(eval-and-compile
  (defalias 'gnus-char-width
    (if (fboundp 'char-width)
        'char-width
      (lambda (ch) 1)))) ;; A simple hack.

(eval-and-compile
  (if (featurep 'xemacs)
      (gnus-xmas-define)
    (defvar gnus-mouse-face-prop 'mouse-face
      "Property used for highlighting mouse regions.")))

(eval-when-compile
  (defvar gnus-tmp-unread)
  (defvar gnus-tmp-replied)
  (defvar gnus-tmp-score-char)
  (defvar gnus-tmp-indentation)
  (defvar gnus-tmp-opening-bracket)
  (defvar gnus-tmp-lines)
  (defvar gnus-tmp-name)
  (defvar gnus-tmp-closing-bracket)
  (defvar gnus-tmp-subject-or-nil)
  (defvar gnus-check-before-posting)
  (defvar gnus-mouse-face)
  (defvar gnus-group-buffer))

(defun gnus-ems-redefine ()
  (cond
   ((featurep 'xemacs)
    (gnus-xmas-redefine))

   ((featurep 'mule)
    ;; Mule and new Emacs definitions

    ;; [Note] Now there are three kinds of mule implementations,
    ;; original MULE, XEmacs/mule and Emacs 20+ including
    ;; MULE features.  Unfortunately these APIs are different.  In
    ;; particular, Emacs (including original Mule) and XEmacs are
    ;; quite different.  However, this version of Gnus doesn't support
    ;; anything other than XEmacs 20+ and Emacs 20.3+.

    ;; Predicates to check are following:
    ;; (boundp 'MULE) is t only if Mule (original; anything older than
    ;;                     Mule 2.3) is running.
    ;; (featurep 'mule) is t when other mule variants are running.

    ;; It is possible to detect XEmacs/mule by (featurep 'mule) and
    ;; (featurep 'xemacs).  In this case, the implementation for
    ;; XEmacs/mule may be shareable between XEmacs and XEmacs/mule.

    (defvar gnus-summary-display-table nil
      "Display table used in summary mode buffers.")
    (defalias 'gnus-max-width-function 'gnus-mule-max-width-function)

    (when (boundp 'gnus-check-before-posting)
      (setq gnus-check-before-posting
            (delq 'long-lines
                  (delq 'control-chars gnus-check-before-posting))))

    (defun gnus-summary-line-format-spec ()
      (insert gnus-tmp-unread gnus-tmp-replied
              gnus-tmp-score-char gnus-tmp-indentation)
      (put-text-property
       (point)
       (progn
         (insert
          gnus-tmp-opening-bracket
          (format "%4d: %-20s"
                  gnus-tmp-lines
                  (if (> (length gnus-tmp-name) 20)
                      (truncate-string-to-width gnus-tmp-name 20)
                    gnus-tmp-name))
          gnus-tmp-closing-bracket)
         (point))
       gnus-mouse-face-prop gnus-mouse-face)
      (insert " " gnus-tmp-subject-or-nil "\n")))))

(defun gnus-region-active-p ()
  "Say whether the region is active."
  (and (boundp 'transient-mark-mode)
       transient-mark-mode
       (boundp 'mark-active)
       mark-active))

(defun gnus-mark-active-p ()
  "Non-nil means the mark and region are currently active in this buffer."
  mark-active) ; aliased to region-exists-p in XEmacs.

(if (fboundp 'add-minor-mode)
    (defalias 'gnus-add-minor-mode 'add-minor-mode)
  (defun gnus-add-minor-mode (mode name map &rest rest)
    (set (make-local-variable mode) t)
    (unless (assq mode minor-mode-alist)
      (push `(,mode ,name) minor-mode-alist))
    (unless (assq mode minor-mode-map-alist)
      (push (cons mode map)
            minor-mode-map-alist))))

(defun gnus-x-splash ()
  "Show a splash screen using a pixmap in the current buffer."
  (interactive)
  (unless window-system
    (error "`gnus-x-splash' requires running on the window system"))
  (switch-to-buffer (gnus-get-buffer-create (if (or (gnus-alive-p)
                                                    (interactive-p))
                                                "*gnus-x-splash*"
                                              gnus-group-buffer)))
  (let ((inhibit-read-only t)
        (file (nnheader-find-etc-directory "images/gnus/x-splash" t))
        pixmap fcw fch width height fringes sbars left yoffset top ls)
    (erase-buffer)
    (sit-for 0) ;; Necessary for measuring the window size correctly.
    (when (and file
               (ignore-errors
                (let ((coding-system-for-read 'raw-text)
                      default-enable-multibyte-characters)
                  (with-temp-buffer
                    (insert-file-contents file)
                    (goto-char (point-min))
                    (setq pixmap (read (current-buffer)))))))
      (setq fcw (float (frame-char-width))
            fch (float (frame-char-height))
            width (/ (car pixmap) fcw)
            height (/ (cadr pixmap) fch)
            fringes (if (fboundp 'window-fringes)
                        (eval '(window-fringes))
                      '(10 11 nil))
            sbars (frame-parameter nil 'vertical-scroll-bars))
      (cond ((eq sbars 'right)
             (setq sbars
                   (cons 0 (/ (or (frame-parameter nil 'scroll-bar-width) 14)
                              fcw))))
            (sbars
             (setq sbars
                   (cons (/ (or (frame-parameter nil 'scroll-bar-width) 14)
                            fcw)
                         0)))
            (t
             (setq sbars '(0 . 0))))
      (setq left (- (* (round (/ (1- (/ (+ (window-width)
                                           (car sbars) (cdr sbars)
                                           (/ (+ (or (car fringes) 0)
                                                 (or (cadr fringes) 0))
                                              fcw))
                                        width))
                                 2))
                       width)
                    (car sbars)
                    (/ (or (car fringes) 0) fcw))
            yoffset (cadr (window-edges))
            top (max 0 (- (* (max (if (and tool-bar-mode
                                           (not (featurep 'gtk))
                                           (eq (frame-first-window)
                                               (selected-window)))
                                      1 0)
                                  (round (/ (1- (/ (+ (1- (window-height))
                                                      (* 2 yoffset))
                                                   height))
                                            2)))
                             height)
                          yoffset))
            ls (/ (or line-spacing 0) fch)
            height (max 0 (- height ls)))
      (cond ((>= (- top ls) 1)
             (insert
              (propertize
               " "
               'display `(space :width 0 :ascent 100))
              "\n"
              (propertize
               " "
               'display `(space :width 0 :height ,(- top ls 1) :ascent 100))
              "\n"))
            ((> (- top ls) 0)
             (insert
              (propertize
               " "
               'display `(space :width 0 :height ,(- top ls) :ascent 100))
              "\n")))
      (if (and (> width 0) (> left 0))
          (insert (propertize
                   " "
                   'display `(space :width ,left :height ,height :ascent 0)))
        (setq width (+ width left)))
      (when (> width 0)
        (insert (propertize
                 " "
                 'display `(space :width ,width :height ,height :ascent 0)
                 'face `(gnus-splash :stipple ,pixmap))))
      (goto-char (if (<= (- top ls) 0) (1- (point)) (point-min)))
      (redraw-frame (selected-frame))
      (sit-for 0))))

;;; Image functions.

(defun gnus-image-type-available-p (type)
  (and (fboundp 'image-type-available-p)
       (image-type-available-p type)
       (if (fboundp 'display-images-p)
           (display-images-p)
         t)))

(defun gnus-create-image (file &optional type data-p &rest props)
  (let ((face (plist-get props :face)))
    (when face
      (setq props (plist-put props :foreground (face-foreground face)))
      (setq props (plist-put props :background (face-background face))))
    (apply 'create-image file type data-p props)))

(defun gnus-put-image (glyph &optional string category)
  (let ((point (point)))
    (insert-image glyph (or string " "))
    (put-text-property point (point) 'gnus-image-category category)
    (unless string
      (put-text-property (1- (point)) (point)
                         'gnus-image-text-deletable t))
    glyph))

(defun gnus-remove-image (image &optional category)
  (dolist (position (message-text-with-property 'display))
    (when (and (equal (get-text-property position 'display) image)
               (equal (get-text-property position 'gnus-image-category)
                      category))
      (put-text-property position (1+ position) 'display nil)
      (when (get-text-property position 'gnus-image-text-deletable)
        (delete-region position (1+ position))))))

(provide 'gnus-ems)

;;; arch-tag: e7360b45-14b5-4171-aa39-69a44aed3cdb
;;; gnus-ems.el ends here