1/*  Part of XPCE --- The SWI-Prolog GUI toolkit
    2
    3    Author:        Jan Wielemaker and Anjo Anjewierden
    4    E-mail:        jan@swi.psy.uva.nl
    5    WWW:           http://www.swi.psy.uva.nl/projects/xpce/
    6    Copyright (c)  1985-2002, University of Amsterdam
    7    All rights reserved.
    8
    9    Redistribution and use in source and binary forms, with or without
   10    modification, are permitted provided that the following conditions
   11    are met:
   12
   13    1. Redistributions of source code must retain the above copyright
   14       notice, this list of conditions and the following disclaimer.
   15
   16    2. Redistributions in binary form must reproduce the above copyright
   17       notice, this list of conditions and the following disclaimer in
   18       the documentation and/or other materials provided with the
   19       distribution.
   20
   21    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   22    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   23    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   24    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   25    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   26    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   27    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   28    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   29    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   31    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   32    POSSIBILITY OF SUCH DAMAGE.
   33*/
   34
   35:- module(pce_image,
   36          [ pce_image_directory/1
   37          ]).   38:- use_module(library(pce)).   39:- require([ absolute_file_name/3
   40           , atomic_list_concat/2
   41           , is_absolute_file_name/1
   42           ]).   43
   44/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
   45Prepend the given  directory  to  the   image  search-path.  Useful  for
   46applications defining a private image directory.
   47
   48Typically one would put all images required   by an application in *.xpm
   49files in a directory called bitmaps. The   load  file of the application
   50makes a call
   51
   52        :- pce_image_directory(bitmaps).
   53
   54after which the images from the  directory   may  be accessed using -for
   55example-:
   56
   57        send(Box, fill_pattern, image('my_image.bm')).
   58
   59See also the ImageViewer demo  tool  to   get  an  overview of available
   60images in a directory.
   61
   62Images and program resources
   63----------------------------
   64
   65pce_image_directory/1   prepends   the   given     directory    to   the
   66file_search_path/2 declarations using the alias   `image'. Especially if
   67the application should (eventually)  be  turned   into  a  runtime,  the
   68following skeleton for using images as program resources is adviced:
   69
   70resource(cute,  image, image('cute.xpm')).
   71
   72        ...
   73        new(I, image(resource(cute)),
   74        ...
   75- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
   76
   77pce_image_directory(Dir) :-
   78    (   atom(Dir)
   79    ->  (   \+ is_absolute_file_name(Dir),
   80            prolog_load_context(directory, Cwd)
   81        ->  atomic_list_concat([Cwd, /, Dir], DirPath)
   82        ;   DirPath = Dir
   83        ),
   84        asserta(user:file_search_path(image, DirPath))
   85    ;   asserta(user:file_search_path(image, Dir)),
   86        absolute_file_name(Dir, DirPath,
   87                           [ file_type(directory),
   88                             access(read)
   89                           ])
   90    ),
   91    (   compiling,
   92        get(@display, open, @off)   % don't force the display
   93                                    % when compiling
   94    ->  true
   95    ;   get(class(image), class_variable, path, PathVar),
   96        get(PathVar, value, Path),
   97        send(PathVar, value, string('%s:%s', DirPath, Path))
   98    )