;;; printer.el --- support for hard-copy printing in XEmacs

;; Copyright (C) 2000, 2002 Ben Wing.
;; Copyright (C) 2000 Kirill Katsnelson.

;; Maintainer: XEmacs Development Team
;; Keywords: printer, printing, internal, dumped

;; 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, Inc., 59 Temple Place - Suite 330, Boston, MA
;; 02111-1307, USA.

;;; Synched up with: Not in FSF.

;;; Authorship:

;; Created 2000 by Ben Wing, to provide the high-level interface onto the
;; print support implemented by Kirill Katsnelson.

;;; Commentary:

;; This file is dumped with XEmacs.


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;                          generic printing code                        ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; #### should be named print-buffer, but that's currently in
;; lpr-buffer with some horrible definition: print-buffer == "print with
;; headings", lpr-buffer == "print without headings", and the headings are
;; generated by calling the external program "pr"!  This is major stone-age
;; here!
;;
;; I propose junking that package entirely and creating a unified,
;; modern API here that will work well with modern GUI's on top of it,
;; and with various different actual implementations (e.g. lpr or the
;; pretty-print package on Unix, built-in msprinter support on
;; Windows), where the workings of a particular implementation is
;; hidden from the user and there is a consistent set of options to
;; control how to print, which works across all implementations.
;;
;; The code here currently only really supports Windows.

(defgroup printing nil
  "Generic printing support."
  :group 'wp)

(defcustom printer-name nil
  "*Name of printer to print to.
If nil, use default.
Under Windows, use `mswindows-printer-list' to get names of installed
printers."
  :type 'string
  :group 'printing)

(defstruct Print-context pageno window start-time printer-name)

(defvar printer-current-device nil)

(defun Printer-get-device ()
  (or printer-current-device (setq printer-current-device
				   (make-device 'msprinter printer-name))))

(defun Printer-clear-device ()
  (setq printer-current-device nil))

(defcustom printer-page-header '((face bold date) nil (face bold buffer-name))
"*Controls printed page header.

This can be:
- nil.  Header is not printed.
- An fbound symbol or lambda expression.  The function is called with
   one parameter, a print-context object, every time the headers need
   to be set up.  It can use the function `print-context-property' to
   query the properties of this object.  The return value is treated as
   if it was literally specified: i.e. it will be reprocessed.
- A list of up to three elements, for left, center and right portions
   of the header.  Each of these can be
   - nil, not to print the portion
   - A string, which will be printed literally.
   - A predefined symbol, on of the following:
     printer-name     Name of printer being printed to
     short-file-name  File name only, no path
     long-file-name   File name with its path
     buffer-name      Buffer name
     date             Date current when printing started
     time             Time current when printing started
     page             Current printout page number, 1-based
     user-id          User logon id
     user-name        User full name
   - A list of three elements: (face FACE-NAME EXPR).  EXPR is any of the
     items given here.  The item will be displayed in the given face.
   - A cons of an extent and any of the items given here.  The item will
     be displayed using the extent's face, begin-glyph and end-glyph
     properties.
   - A list, each element of which is any of the items given here.
     Each element of the list is rendered in sequence.  For example,
     '(\"Page \" page) is rendered as \"Page 5\" on the fifth page.
   - An fbound symbol or lambda expression, called with one parameter,
     a print-context object, as above.  The return value is treated as
     if it was literally specified: i.e. it will be reprocessed."
  :type 'sexp
  :group 'printing)

(defcustom printer-page-footer '(nil (face bold ("Page " page)))
"*Controls printed page footer.

Format is the same as `printer-page-header'."
  :type 'sexp
  :group 'printing)

(defun generate-header-element (element context)
    (cond ((null element) nil)
	  ((stringp element) (insert element))
	  ((memq element '(printer-name
			   short-file-name long-file-name buffer-name
			   date time page user-id user-name))
	   (insert (print-context-property context element)))
	  ((and (consp element) (eq 'face (car element)))
	   (let ((p (point)))
	     (generate-header-element (third element) context)
	     (let ((x (make-extent p (point))))
	       (set-extent-face x (second element)))))
	  ((and (consp element) (extentp (car element)))
	   (let ((p (point)))
	     (generate-header-element (cdr element) context)
	     (let ((x (make-extent p (point))))
	       (set-extent-face x (extent-face (car element)))
	       (set-extent-begin-glyph x (extent-begin-glyph (car element)))
	       (set-extent-end-glyph x (extent-end-glyph (car element))))))
	  ((listp element)
	   (mapcar #'(lambda (el) (generate-header-element el context))
		   element))
	  ((functionp element)
	   (generate-header-element (funcall element context) context))
	  (t (error 'invalid-argument "Unknown header element" element))))

(defun generate-header-line (spec context)
  (let* ((left (first spec))
	 (middle (second spec))
	 (right (third spec))
	 (left-start (point))
	 (middle-start (progn (generate-header-element left context)
			      (point)))
	 (right-start (progn (generate-header-element middle context)
			     (point)))
	 (right-end (progn (generate-header-element right context)
			   (point)))
	 (left-width (- middle-start left-start))
	 (middle-width (- right-start middle-start))
	 (right-width (- right-end right-start))
	 (winwidth (- (window-width (Print-context-window context)) 1))
	 (spaces1 (max (- (/ (- winwidth middle-width) 2) left-width) 0))
	 (spaces2 (max (- (- winwidth right-width)
			  (+ left-width spaces1 middle-width))
		       0)))
    (goto-char right-start)
    (insert-char ?\  spaces2)
    (goto-char middle-start)
    (insert-char ?\  spaces1)))

(defun print-context-property (print-context prop)
  "Return property PROP of PRINT-CONTEXT.

Valid properties are

print-buffer     Buffer being printed
print-window     Window on printer device containing print buffer
print-frame      Frame on printer device corresponding to current page
print-device     Device referring to printer
print-start-time Time current when printing started (`current-time' format)
print-page       Current printout page number, 1-based
printer-name     Name of printer being printed to
short-file-name  File name only, no path
long-file-name   File name with its path
buffer-name      Buffer name
date             Date current when printing started (as a string)
time             Time current when printing started (as a string)
page             Current printout page number, 1-based (as a string)
user-id          User logon id (as a string)
user-name        User full name"
  (let* ((window (Print-context-window print-context))
	 (pageno (Print-context-pageno print-context))
	 (start-time (Print-context-start-time print-context))
	 (printer-name (Print-context-printer-name print-context))
	 (buffer (window-buffer window)))
    (case prop
      (print-buffer buffer)
      (print-window window)
      (print-frame (window-frame window))
      (print-device (frame-device (window-frame window)))
      (print-start-time start-time)
      (print-page pageno)
      (printer-name printer-name)
      (short-file-name (let ((name (buffer-file-name buffer)))
			 (if name (file-name-nondirectory name) "")))
      (long-file-name (let ((name (buffer-file-name buffer)))
			(or name "")))
      (buffer-name (buffer-name buffer))
      (date (format-time-string "%x" start-time))
      (time (format-time-string "%X" start-time))
      (page (format "%d" pageno))
      (user-id (format "%d" (user-uid)))
      (user-name (format "%d" (user-login-name)))
      (t (error 'invalid-argument "Unrecognized print-context property"
		prop)))))

(defun generic-page-setup ()
  "Display the Page Setup dialog box.
Changes made are recorded internally."
  (interactive)
  (let* ((d (Printer-get-device))
	 (props
	  (condition-case err
	      (make-dialog-box 'page-setup :device d
			       :properties (declare-boundp
					    default-msprinter-frame-plist))
	    (error
	     (Printer-clear-device)
	     (signal (car err) (cdr err))))))
    (while props
      (with-boundp 'default-msprinter-frame-plist
	(setq default-msprinter-frame-plist
	      (plist-put default-msprinter-frame-plist (car props)
			 (cadr props))))
      (setq props (cddr props)))))

(defun generic-print-buffer (&optional buffer display-print-dialog)
  "Print buffer BUFFER using a printing method appropriate to the O.S. being run.
Under Unix, `lpr' is normally used to spool out a no-frills version of the
buffer, or the `ps-print' package is used to pretty-print the buffer to a
PostScript printer.  Under MS Windows, the built-in printing support is used.

If DISPLAY-PRINT-DIALOG is t, the print dialog will first be
displayed, allowing the user to select various printing settings
\(e.g. which printer to print to, the range of pages, number of copies,
modes such landscape/portrait/2-up/4-up [2 or 4 (small!) logical pages
per physical page], etc.).  At this point the user can cancel the printing
operation using the dialog box, and `generic-print-buffer' will not print
anything.  When called interactively, use a prefix arg to suppress the
display of the print dialog box.

If BUFFER is nil or omitted, the current buffer is used."
  (interactive (list nil (not current-prefix-arg)))
  (let* ((print-region (and (interactive-p) (region-active-p)))
	 (start (if print-region (region-beginning) (point-min buffer)))
	 (end (if print-region (region-end) (point-max buffer))))
    (if (or (not (valid-specifier-tag-p 'msprinter))
	    (not display-print-dialog))
	(generic-print-region start end buffer)
      (let* ((d (Printer-get-device))
	     (props (condition-case err
			(make-dialog-box 'print :device d
					 :allow-selection print-region
					 :selected-page-button
					 (if print-region 'selection 'all))
		      (error
		       (Printer-clear-device)
		       (signal (car err) (cdr err))))))
	(and props
	     (let ((really-print-region
		    (eq (plist-get props 'selected-page-button) 'selection)))
	       (generic-print-region (if really-print-region start
				       (point-min buffer))
				     (if really-print-region end
				       (point-max buffer))
				     buffer d props)))))))

(defun generic-print-region (start end &optional buffer print-device props)
  "Print region using a printing method appropriate to the O.S. being run.
The region between START and END of BUFFER (defaults to the current
buffer) is printed.

Under Unix, `lpr' is normally used to spool out a no-frills version of the
buffer, or the `ps-print' package is used to pretty-print the buffer to a
PostScript printer.  Under MS Windows, the built-in printing support is used.

Optional PRINT-DEVICE is a device, already created, to use to do the
printing.  This is typically used when this function was invoked from
`generic-print-buffer' and it displayed a dialog box.  That function created
the device, and then the dialog box stuffed it with the user's selections
of how the buffer should be printed.

PROPS, if given, is typically the plist returned from the call to
`make-dialog-box' that displayed the Print box.  It contains properties
relevant to us when we print.  

Recognized properties are the same as those in `make-dialog-box':

  name       Printer device name.  If omitted, the current system-selected
             printer will be used.
  from-page  First page to print, 1-based. If omitted, printing starts from
             the beginning.
  to-page    Last page to print, inclusive, If omitted, printing ends at
             the end.
  copies     Number of copies to print.  If omitted, one copy is printed."
  (cond ((valid-specifier-tag-p 'msprinter)
	 ;; loop, printing one copy of document per loop.  kill and
	 ;; re-create the frame each time so that we eject the piece
	 ;; of paper at the end even if we're printing more than one
	 ;; page per sheet of paper.
	 (let ((copies (plist-get props 'copies 1))
	       ;; This is not relevant to printing and can mess up
	       ;; msprinter frame sizing
	       default-frame-plist)
	   (while (> copies 0)
	     (let (d f header-buffer footer-buffer)
	       (setq buffer (decode-buffer buffer))
	       (unwind-protect
		   (with-current-buffer buffer
		     (save-restriction
		       (narrow-to-region start end)
		       (setq d (or print-device (Printer-get-device)))
		       (setq f (make-frame
				(list* 'name
				       (concat
					(substitute ?_ ?. (buffer-name buffer))
					" - XEmacs")
				       '(menubar-visible-p
					 nil
					 has-modeline-p nil
					 default-toolbar-visible-p nil
					 default-gutter-visible-p nil
					 minibuffer none
					 modeline-shadow-thickness 0
					 vertical-scrollbar-visible-p nil
					 horizontal-scrollbar-visible-p nil))
				d))
		       (let* ((w (frame-root-window f))
			      (vertdpi
			       (cdr (device-system-metric d 'device-dpi)))
			      (pixel-vertical-clip-threshold (/ vertdpi 2))
			      (from-page (plist-get props 'from-page 1))
			      (to-page (plist-get props 'to-page))
			      (context (make-Print-context
					:start-time (current-time)
					;; #### bogus! we need accessors for
					;; print-settings objects.
					:printer-name
					(or (plist-get props 'name)
					    printer-name
					    (declare-fboundp
					     (mswindows-get-default-printer)
					     ))))
			      header-window
			      footer-window)

			 (when printer-page-header
			   (let ((window-min-height 2))
			     (setq header-window w)
			     (setq w (split-window w 2)))
			   (setq header-buffer
				 (generate-new-buffer " *header*"))
			   (set-window-buffer header-window header-buffer))

			 (when printer-page-footer
			   (let ((window-min-height 2))
			     (setq footer-window
				   (split-window w (- (window-height w) 2))))
			   (setq footer-buffer
				 (generate-new-buffer " *footer*"))
			   (set-window-buffer footer-window footer-buffer))

			 (setf (Print-context-window context) w)

			 (let ((last-end 0) ; bufpos at end of previous page
			       reached-end ; t if we've reached the end of the
					; text we're printing
			       (pageno 1))
			   (set-window-buffer w buffer)
			   (set-window-start w start)

			   ;; loop, printing one page per loop
			   (while (and (not reached-end)
				       ;; stop at end of region of text or
				       ;; outside of ranges of pages given
				       (or (not to-page) (<= pageno to-page)))

			     (setf (Print-context-pageno context) pageno)

			     ;; only actually print the page if it's in the
			     ;; range.
			     (when (>= pageno from-page)
			       (when printer-page-header
				 (with-current-buffer header-buffer
				   (erase-buffer)
				   (generate-header-line printer-page-header
							 context)
				   (goto-char (point-min))
				   (set-window-start header-window
						     (point-min))))

			       (when printer-page-footer
				 (with-current-buffer footer-buffer
				   (erase-buffer)
				   (insert "\n")
				   (generate-header-line printer-page-footer
							 context)
				   (goto-char (point-min))
				   (set-window-start footer-window
						     (point-min))))

			       (redisplay-frame f t)
			       (print-job-eject-page f)
			       )
			     ;; but use the GUARANTEE argument to `window-end'
			     ;; so that we get the right value even if we
			     ;; didn't do a redisplay.
			     (let ((this-end (window-end w t))
				   (pixvis
				    (window-last-line-visible-height w)))
			       ;; in case we get stuck somewhere, bow out
			       ;; rather than printing an infinite number of
			       ;; pages.  #### this will fail with an image
			       ;; bigger than an entire page.  but we really
			       ;; need this check here.  we should be more
			       ;; clever in our check, to deal with this case.
			       (if (or (= this-end last-end)
				       ;; #### fuckme!  window-end returns a
				       ;; value outside of the valid range of
				       ;; buffer positions!!!
				       (>= this-end end))
				   (setq reached-end t)
				 (setq last-end this-end)
				 (set-window-start w this-end)
				 (if pixvis
				     (with-selected-window w
				       ;; #### scroll-down should take a
				       ;; window arg.
				       (let ((window-pixel-scroll-increment
					      pixvis))
					 (scroll-down 1))))))
			     (setq pageno (1+ pageno)))))))
		 (and f (delete-frame f))
		 (and header-buffer (kill-buffer header-buffer))
		 (and footer-buffer (kill-buffer footer-buffer))))
	     (setq copies (1- copies)))))
	((and (not (eq system-type 'windows-nt))
	      (fboundp 'lpr-region))
	 (declare-fboundp (lpr-region start end)))
	(t (error "No print support available"))))