1/*  Part of XPCE --- The SWI-Prolog GUI toolkit
    2
    3    Author:        Jan Wielemaker and Anjo Anjewierden
    4    E-mail:        J.Wielemaker@cs.nu.nl
    5    WWW:           http://www.swi-prolog.nl/projects/xpce/
    6    Copyright (c)  1985-2011, University of Amsterdam
    7                              VU University Amsterdam
    8    All rights reserved.
    9
   10    Redistribution and use in source and binary forms, with or without
   11    modification, are permitted provided that the following conditions
   12    are met:
   13
   14    1. Redistributions of source code must retain the above copyright
   15       notice, this list of conditions and the following disclaimer.
   16
   17    2. Redistributions in binary form must reproduce the above copyright
   18       notice, this list of conditions and the following disclaimer in
   19       the documentation and/or other materials provided with the
   20       distribution.
   21
   22    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   23    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   24    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   25    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   26    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   27    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   28    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   29    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   30    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   31    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   32    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   33    POSSIBILITY OF SUCH DAMAGE.
   34*/
   35
   36:- module(pce_principal,
   37          [ new/2, free/1,
   38
   39            send/2, send/3, send/4, send/5, send/6, send/7,
   40            send/8,
   41
   42            get/3, get/4, get/5, get/6, get/7, get/8,
   43
   44            send_class/3,
   45            get_class/4,
   46
   47            object/1, object/2,
   48
   49            pce_class/6,
   50            pce_lazy_send_method/3,
   51            pce_lazy_get_method/3,
   52            pce_uses_template/2,
   53
   54            pce_method_implementation/2,
   55
   56            pce_open/3,                 % +Object, +Mode, -Stream
   57            in_pce_thread/1,            % :Goal
   58            set_pce_thread/0,
   59            pce_dispatch/0,
   60
   61            pce_postscript_stream/1,    % -Stream
   62
   63            op(200, fy,  @),
   64            op(250, yfx, ?),
   65            op(990, xfx, :=)
   66          ]).   67
   68
   69:- meta_predicate
   70    send_class(+, +, :),
   71    send(+, :),
   72    send(+, :, +),
   73    send(+, :, +, +),
   74    send(+, :, +, +, +),
   75    send(+, :, +, +, +, +),
   76    send(+, :, +, +, +, +, +),
   77
   78    get_class(+, +, :, -),
   79    get(+, :, -),
   80    get(+, :, +, -),
   81    get(+, :, +, +, -),
   82    get(+, :, +, +, +, -),
   83    get(+, :, +, +, +, +, -),
   84    get(+, :, +, +, +, +, +, -),
   85
   86    new(?, :).   87
   88:- op(100, fx, @).   89:- op(150, yfx, ?).   90:- op(990, xfx, :=).   91
   92                /********************************
   93                *             HOME              *
   94                ********************************/
   95
   96%!  pce_home(-Home) is det.
   97%
   98%   True when Home is the home directory of XPCE.
   99
  100pce_home(PceHome) :-
  101    absolute_file_name(pce('.'), PceHome,
  102                       [ file_type(directory),
  103                         file_errors(fail)
  104                       ]),
  105    exists_directory(PceHome),
  106    !.
  107pce_home(PceHome) :-
  108    getenv('XPCEHOME', PceHome),
  109    exists_directory(PceHome),
  110    !.
  111pce_home(PceHome) :-
  112    (   current_prolog_flag(xpce_version, Version),
  113        atom_concat('/xpce-', Version, Suffix)
  114    ;   Suffix = '/xpce'
  115    ),
  116    absolute_file_name(swi(Suffix), PceHome,
  117                       [ file_type(directory),
  118                         file_errors(fail)
  119                       ]),
  120    exists_directory(PceHome),
  121    !.
  122pce_home(PceHome) :-
  123    current_prolog_flag(saved_program, true),
  124    !,
  125    (   current_prolog_flag(home, PceHome)
  126    ->  true
  127    ;   current_prolog_flag(executable, Exe)
  128    ->  file_directory_name(Exe, PceHome)
  129    ;   PceHome = '.'
  130    ).
  131pce_home(_) :-
  132    throw(error(pce_error(no_home), _)).
  133
  134
  135                /********************************
  136                *           LOAD C-PART         *
  137                ********************************/
  138
  139init_pce :-
  140    catch(load_foreign_library(foreign(pl2xpce)),
  141          error(Error, _Context),           % suppress stack trace
  142          (   print_message(error, error(Error, _)),
  143              fail
  144          )),
  145    pce_home(Home),
  146    pce_init(Home),
  147    !,
  148    create_prolog_flag(xpce, true, []),
  149    thread_self(Me),
  150    assert(pce:pce_thread(Me)).
  151init_pce :-
  152    print_message(error, error(pce_error(init_failed), _)),
  153    halt(1).
  154
  155:- initialization(init_pce, now).  156
  157:- noprofile((send_implementation/3,
  158              get_implementation/4,
  159              send_class/3,
  160              get_class/4,
  161              new/2,
  162              send/2,
  163              get/3)).  164
  165
  166                /********************************
  167                *          PROLOG LAYER         *
  168                ********************************/
  169
  170
  171%!  free(+Ref) is det.
  172%
  173%   Delete object if it exists.
  174
  175free(Ref) :-
  176    object(Ref),
  177    !,
  178    send(Ref, free).
  179free(_).
  180
  181
  182%!  send(+Object, +Selector, +Arg...) is semidet.
  183%
  184%   Succeeds if sending a message to Object with Selector and the
  185%   given Arguments succeeds. Normally, goal_expansion/2 expands all
  186%   these goals into send(Receiver, Method(Args...)).
  187
  188send(Receiver, M:Selector, A1) :-
  189    functor(Message, Selector, 1),
  190    arg(1, Message, A1),
  191    send(Receiver, M:Message).
  192
  193send(Receiver, M:Selector, A1, A2) :-
  194    functor(Message, Selector, 2),
  195    arg(1, Message, A1),
  196    arg(2, Message, A2),
  197    send(Receiver, M:Message).
  198
  199send(Receiver, M:Selector, A1, A2, A3) :-
  200    functor(Message, Selector, 3),
  201    arg(1, Message, A1),
  202    arg(2, Message, A2),
  203    arg(3, Message, A3),
  204    send(Receiver, M:Message).
  205
  206send(Receiver, M:Selector, A1, A2, A3, A4) :-
  207    functor(Message, Selector, 4),
  208    arg(1, Message, A1),
  209    arg(2, Message, A2),
  210    arg(3, Message, A3),
  211    arg(4, Message, A4),
  212    send(Receiver, M:Message).
  213
  214send(Receiver, M:Selector, A1, A2, A3, A4, A5) :-
  215    functor(Message, Selector, 5),
  216    arg(1, Message, A1),
  217    arg(2, Message, A2),
  218    arg(3, Message, A3),
  219    arg(4, Message, A4),
  220    arg(5, Message, A5),
  221    send(Receiver, M:Message).
  222
  223send(Receiver, M:Selector, A1, A2, A3, A4, A5, A6) :-
  224    functor(Message, Selector, 6),
  225    arg(1, Message, A1),
  226    arg(2, Message, A2),
  227    arg(3, Message, A3),
  228    arg(4, Message, A4),
  229    arg(5, Message, A5),
  230    arg(6, Message, A6),
  231    send(Receiver, M:Message).
  232
  233
  234%!  get(+Object, :Selector, +Arg..., ?Rval) is semidet.
  235%
  236%   See the comments with send/[3-12].
  237
  238get(Receiver, M:Selector, A1, Answer) :-
  239    functor(Message, Selector, 1),
  240    arg(1, Message, A1),
  241    get(Receiver, M:Message, Answer).
  242
  243get(Receiver, M:Selector, A1, A2, Answer) :-
  244    functor(Message, Selector, 2),
  245    arg(1, Message, A1),
  246    arg(2, Message, A2),
  247    get(Receiver, M:Message, Answer).
  248
  249get(Receiver, M:Selector, A1, A2, A3, Answer) :-
  250    functor(Message, Selector, 3),
  251    arg(1, Message, A1),
  252    arg(2, Message, A2),
  253    arg(3, Message, A3),
  254    get(Receiver, M:Message, Answer).
  255
  256get(Receiver, M:Selector, A1, A2, A3, A4, Answer) :-
  257    functor(Message, Selector, 4),
  258    arg(1, Message, A1),
  259    arg(2, Message, A2),
  260    arg(3, Message, A3),
  261    arg(4, Message, A4),
  262    get(Receiver, M:Message, Answer).
  263
  264get(Receiver, M:Selector, A1, A2, A3, A4, A5, Answer) :-
  265    functor(Message, Selector, 5),
  266    arg(1, Message, A1),
  267    arg(2, Message, A2),
  268    arg(3, Message, A3),
  269    arg(4, Message, A4),
  270    arg(5, Message, A5),
  271    get(Receiver, M:Message, Answer).
  272
  273
  274                 /*******************************
  275                 *           NEW SEND           *
  276                 *******************************/
  277
  278:- multifile
  279    send_implementation/3,
  280    get_implementation/4.  281
  282%!  send_implementation(+Id, +Message, +Object)
  283%
  284%   Method-bodies are compiled into clauses for this predicate. Id
  285%   is a unique identifier for the implementation, Message is a
  286%   compound whose functor is the method name and whose arguments
  287%   are the arguments to the method-call. Object is the receiving
  288%   object.
  289
  290send_implementation(true, _Args, _Obj).
  291send_implementation(fail, _Args, _Obj) :- fail.
  292send_implementation(once(Id), Args, Obj) :-
  293    send_implementation(Id, Args, Obj),
  294    !.
  295send_implementation(spy(Id), Args, Obj) :-
  296    (   current_prolog_flag(debug, true)
  297    ->  trace,
  298        send_implementation(Id, Args, Obj)
  299    ;   send_implementation(Id, Args, Obj)
  300    ).
  301send_implementation(trace(Id), Args, Obj) :-
  302    pce_info(pce_trace(enter, send_implementation(Id, Args, Obj))),
  303    (   send_implementation(Id, Args, Obj)
  304    ->  pce_info(pce_trace(exit, send_implementation(Id, Args, Obj)))
  305    ;   pce_info(pce_trace(fail, send_implementation(Id, Args, Obj)))
  306    ).
  307
  308
  309%!  get_implementation(+Id, +Message, +Object, -Return)
  310%
  311%   As send_implementation/3, but for get-methods.
  312
  313get_implementation(true, _Args, _Obj, _Rval).
  314get_implementation(fail, _Args, _Obj, _Rval) :- fail.
  315get_implementation(once(Id), Args, Obj, Rval) :-
  316    get_implementation(Id, Args, Obj, Rval),
  317    !.
  318get_implementation(spy(Id), Args, Obj, Rval) :-
  319    (   current_prolog_flag(debug, true)
  320    ->  trace,
  321        get_implementation(Id, Args, Obj, Rval)
  322    ;   get_implementation(Id, Args, Obj, Rval)
  323    ).
  324get_implementation(trace(Id), Args, Obj, Rval) :-
  325    pce_info(pce_trace(enter, get_implementation(Id, Args, Obj, Rval))),
  326    (   get_implementation(Id, Args, Obj, Rval)
  327    ->  pce_info(pce_trace(exit, get_implementation(Id, Args, Obj, Rval)))
  328    ;   pce_info(pce_trace(fail, get_implementation(Id, Args, Obj, Rval))),
  329        fail
  330    ).
  331
  332%       SWI-Prolog: make this a normal user (debug-able) predicate.
  333
  334pce_ifhostproperty(prolog(swi), [
  335(:- unlock_predicate(send_implementation/3)),
  336(:- unlock_predicate(get_implementation/4)),
  337(:- '$set_predicate_attribute'(send_implementation(_,_,_),  hide_childs, false)),
  338(:- '$set_predicate_attribute'(get_implementation(_,_,_,_), hide_childs, false))
  339                   ]).
  340
  341
  342                 /*******************************
  343                 *          DECLARATIONS        *
  344                 *******************************/
  345
  346:- multifile
  347    pce_class/6,
  348    pce_lazy_send_method/3,
  349    pce_lazy_get_method/3,
  350    pce_uses_template/2.  351
  352
  353                 /*******************************
  354                 *            @PROLOG           *
  355                 *******************************/
  356
  357:- initialization
  358   (object(@prolog) -> true ; send(@host, name_reference, prolog)).