/*  Part of XPCE --- The SWI-Prolog GUI toolkit

    Author:        Jan Wielemaker and Anjo Anjewierden
    E-mail:        jan@swi.psy.uva.nl
    WWW:           http://www.swi.psy.uva.nl/projects/xpce/
    Copyright (c)  2002-2011, University of Amsterdam
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in
       the documentation and/or other materials provided with the
       distribution.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.
*/

:- module(pce_print_text, []).
:- use_module(library(pce)).

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
This module extends class text_buffer with   the ->print method, dealing
with printing plain text.  This  issue   is  completely  different  when
comparing Windows and Unix.

Windows
=======

We create an editor and print the image thereof on a win_printer, page
by page.

Unix
====

There are many options here, unfortunately   none  is very standard. You
can pipe the output directly through the   lpr  command, use an external
beautifier that creates nice-looking  PostScript,   such  as  nenscript,
mpage or aps or create the  PostScript   yourself.  At the moment, class
text_image does not provide for generating   PostScript,  so this is not
yet an option. To keep things simple we   pipe through lpr and leave the
details to the lpr installation.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

:- pce_extend_class(text_buffer).

print(TB, From:from=[int], To:to=[int],
      JobName:job=[name],
      Editor:editor=[editor],
      Font:font=[font]) :->
    "Print (region of) the text-buffer"::
    get(TB, size, Size),
    default(From, 0, F),
    default(To, Size, T),
    (   get(@pce, convert, win_printer, class, _)
    ->  send(TB, win_print, F, T, JobName, Editor, Font)
    ;   send(TB, unix_print, F, T, JobName, Editor, Font)
    ).

                 /*******************************
                 *       WINDOWS PRINTING       *
                 *******************************/

win_print(TB, From:int, To:int,
          JobName:[name], Editor:[editor], Font:[font]) :->
    new(Prt, win_printer(JobName)),
    (   Editor \== @default,
        get(Editor, frame, Frame)
    ->  true
    ;   Frame = @default
    ),
    send(Prt, setup, Frame),
    (   send(Prt, open)
    ->  true
    ;   send(TB, report, error, 'Failed to open printer'),
        fail
    ),
    new(E, editor(TB, 80)),
    send(E?image, elevation, @nil),
    send(E?image, pen, 0),
    send(TB, setup_print_editor, E, Editor),
    (   Font \== @default
    ->  send(E, font, Font)
    ;   true
    ),
    get(E?area, width, Width),
    get(Prt, size, size(W,H)),
    get(Prt, dpi, size(DPIX,DPIY)),
    InchW is W/DPIX,
    InchH is H/DPIY,
    PageW is round(Width*(InchW/(InchW-2))), % 1 inch margin
    PageH is round(PageW*(H/W)),
    send(Prt, resolution, PageH),
    Height is round(PageH*((InchH-2)/InchH)),
    LDPI is round(PageH/InchH),
    send(E, do_set, 0, 0, Width, Height),

    new(BG, device),                % background
    (   JobName \== @default
    ->  send(BG, display, new(T, text(JobName))),
        send(BG, display, new(P, text)),
        send(P, name, pageno),
        get(T, height, TH),
        BT is LDPI-TH/2,
        Right is LDPI+Width,
        send(T, position, point(LDPI, BT-TH)),
        send(P, position, point(Right, BT-TH)),
        send(BG, display, line(LDPI, BT, Right, BT)),
        send(BG, attribute, page_right, Right)
    ;   true
    ),

    send(E, scroll_to, From, 1),
    print_pages(Prt, E, To, margin(LDPI,LDPI), BG, 1, Pages),
    send(TB, report, status, 'Sent %d pages to the printer', Pages),
    send(Prt, close),
    send(E, destroy).

setup_print_editor(_TB, E:editor, From:[editor]) :->
    "Get defaults from editor"::
    (   From \== @default
    ->  get(From, styles, Styles),
        send(Styles, for_all,
             message(E, style, @arg1?name, @arg1?value)),
        get(From, font, Font),
        send(E, font, Font)
    ;   true
    ).

%!  print_pages(+Printer, +Editor, +EndIndex, +Margin,
%!              +Background, +Page, -LastPage) is det.
%
%   Actual page printing loop.
%
%   @param Margin   Term margin(+X,+Y) representing the page margins

print_pages(Printer, Editor, End, Margin, BG, Page, Pages) :-
    get(Editor, image, Image),
    Margin = margin(MX, MY),
    (   get(BG, member, pageno, PageNoText)
    ->  send(PageNoText, string, string('%s %d', page?label_name, Page)),
        get(BG, page_right, Right),
        send(PageNoText, x, Right-PageNoText?width)
    ;   true
    ),
    send(Printer, draw_in, BG),
    get(Image, end, EndImg),
    (   EndImg > End
    ->  get(Image, start, Start),
        get(Image, character_position, End, point(_,BaseY)),
        send(Editor, do_set, height := BaseY),
        send(Editor, scroll_to, Start, 1) % make sure it doesn't move
    ;   true
    ),
    send(Printer, draw_in, Image, point(MX, MY)),
    (   (   EndImg >= End
        ;   get(Image, eof_in_window, @on)
        )
    ->  Pages = Page
    ;   send(Printer, next_page),
        send(Editor, scroll_to, EndImg, 1),
        NextPage is Page+1,
        print_pages(Printer, Editor, End, Margin, BG, NextPage, Pages)
    ).


                 /*******************************
                 *         UNIX PRINTING        *
                 *******************************/

unix_print(TB, From:int, To:int,
           _JobName:[name], Editor:[editor], _Font:[font]) :->
    "Print on Unix printer"::
    (   getenv('PRINTER', LP)
    ->  true
    ;   LP = lp
    ),
    atom_concat('lpr -P', LP, DefCommand),
    new(D, dialog(print_command?label_name)),
    send(D, append, new(TI, text_item(command, DefCommand))),
    send(D, append, button(print, message(D, return, TI?selection))),
    send(D, append, button(cancel, message(D, destroy))),
    send(D, default_button, print),
    (   Editor \== @default,
        get(Editor, frame, Frame)
    ->  send(D, transient_for, Frame),
        send(D, modal, transient),
        get(Frame?area, center, Center)
    ;   Center = @default
    ),
    get(D, confirm_centered, Center, Command),
    send(D, destroy),
    get(TB, contents, From, To-From, String),
    get(String, value, Atom),
    catch(do_print(Command, Atom), E,
          (   message_to_string(E, Msg),
              send(TB, report, error, Msg))),
    send(TB, report, status, 'Document sent to printer').

do_print(Command, Text) :-
    open(pipe(Command), write, Out),
    write(Out, Text),
    close(Out).

:- pce_end_class.

/*
test :-
        new(TB, text_buffer),
        send(TB, insert_file, 0, 'print_text.pl'),
        send(TB, try_print, job := 'Test me').

test(To) :-
        new(TB, text_buffer),
        send(TB, insert_file, 0, 'print_text.pl'),
        send(TB, try_print, to := To, job := 'Test me').
*/
