/*  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)  1997-2011, 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_arrow_item, []).
:- use_module(library(pce)).
:- require([ forall/2
           , send_list/3
           ]).

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Class arrow_item defines an item for editing   an arrow object. The item
does not edit the specified arrow itself,  but just uses its attributes.
Also, the <-selection returns a `fresh' arrow.

This module can be seen as an  advanced example of using class label_box
for creating compound dialog items.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

:- pce_autoload(colour_item, library(pce_colour_item)).

:- pce_begin_class(arrow_item, label_box,
                   "Extry for viewing/editing an arrow-head").

initialise(AI, Name:[name], Default:[function|arrow], Message:[code]*) :->
    send(AI, send_super, initialise, Name, Message),
    send(AI, display, new(line)),
    send(AI, append, new(Arrow, arrow)),
    send(Arrow, points, 100, 0, 0, 0),
    send(AI, append, new(WI, int_item(wing,   0, @nil, 0, 50))),
    send(AI, append, new(LI, int_item(length, 0, @nil, 0, 50)), right),
    send(AI, append, new(PI, int_item(pen,    0, @nil, 0,  1)), right),
    send(AI, append, new(Style, menu(style, choice, @nil))),
    send(AI, append, new(Fill, menu(fill, choice, @nil)), right),
    styles(Style),
    fill_patterns(Fill),
    send(AI, append,
         new(SelCol, button(select_colour,
                            message(AI, select_colour))),
         right),
    send_list([PI, SelCol], alignment, left),
    send_list([Style, Fill], show_label, @off),
    send_list([Style, Fill], auto_label_align, @off),
    send_list([WI, LI, PI, Style, Fill, SelCol], reference, point(0,0)),
    fix_labels(AI),
    (   Default \== @default
    ->  send(AI, default, Default)
    ;   new(Proto, arrow),
        copy_attributes(AI, Proto)
    ).

fill(@nil).
fill(white).
fill(black).

fill_patterns(Menu) :-
    fill(Pattern),
    new(I, image(@nil, 30, 16)),
    new(A, arrow(20, 10, closed, Pattern)),
    new(L, line(0, 7, 25, 7)),
    send(A, pen, 1),
    send(L, second_arrow, A),
    send(I, draw_in, L),
    send(Menu, append, menu_item(Pattern, @default, I)),
    fail.
fill_patterns(_).

style(open).
style(closed).

styles(Menu) :-
    style(Style),
    new(I, image(@nil, 30, 16)),
    new(A, arrow(20, 10, Style, @nil)),
    send(A, pen, 1),
    new(L, line(0, 7, 25, 7)),
    send(L, second_arrow, A),
    send(I, draw_in, L),
    send(Menu, append, menu_item(Style, @default, I)),
    fail.
styles(_).

%       ->layout_dialog
%
%       Does the normal layout, but afterwards adjusts the arrow and its
%       line, as this doesn't fit in the automatic layout specification.
%       Note that the arrow is not part of the line (see `joint->second_arrow')
%       because changes to the line will not be visualised then.

layout_dialog(AI) :->
    send(AI, send_super, layout_dialog),
    get(AI, member, arrow, Arrow),
    get(AI, member, line, Line),
    get(AI, reference, point(_, RY)),
    send(Arrow, points, 100, RY, 0, RY),
    send(Line, points, 0, RY, 100, RY).

                 /*******************************
                 *             LABELS           *
                 *******************************/

%       The code below assigns the image labels.  This is easier to addapt
%       and more flexible then direct sending of messages.  Also, fix_label
%       takes care of the case where the image cannot be located.

label(wing,             '16x16/arrow_wing.png').
label(length,           '16x16/arrow_length.png').
label(select_colour,    '16x16/cpalette2.png').
label(pen,              '16x16/pen.png').

resource(Name, image, image(File)) :-
    label(Name, File).

fix_labels(AI) :-
    send(AI?graphicals, for_all, message(@prolog, fix_label, @arg1)).

fix_label(Gr) :-
    get(Gr, name, Name),
    label(Name, _),
    new(I, image(resource(Name))),
    send(Gr, label, I).
fix_label(_).

:- pce_group(selection).

selection(AI, Selection:arrow) :->
    "Set the selection"::
    copy_attributes(AI, Selection),
    send(AI, modified, @off).
selection(AI, Selection:arrow) :<-
    "Get the selection"::
    new(Selection, arrow),
    get_attributes(AI, Selection),
    send(AI, modified, @off).

clear(_AI) :-> true.

get_attributes(AI, Into) :-
    get(AI, member, arrow, Arrow),
    edited_attribute(Attribute),
    get(Arrow, Attribute, Value),
    send(Into, Attribute, Value),
    fail.
get_attributes(_, _).

copy_attributes(AI, Proto) :-
    edited_attribute(Attribute),
    get(Proto, Attribute, Value),
    set_value(AI, Attribute, Value),
    fail.
copy_attributes(_, _).

edited_attribute(wing).
edited_attribute(length).
edited_attribute(pen).
edited_attribute(style).
edited_attribute(fill).
edited_attribute(colour).

set_value(AI, Attribute, Value) :-
    get(AI, member, arrow, Arrow),
    send(Arrow, Attribute, Value),
    (   get(AI, member, Attribute, Item)
    ->  send(Item, selection, Value)
    ;   true
    ).


:- pce_group(edit).

rule(fill = @black_image,       pen = 0).
rule(fill = @black_image,       style = closed).
rule(fill = @nil,               pen = 1).
rule(fill = @white_image,       pen = 1).
rule(style        = open,               fill = @nil).

apply_rules(AI, Sel, Val) :-
    set_value(AI, Sel, Val),
    forall(rule(Sel=Val, Sel2=Val2),
           apply_rules(AI, Sel2, Val2)).


modified_item(AI, Item:graphical, _Modified:bool) :->
    get(Item, name, Sel),
    get(Item, selection, Val),
    apply_rules(AI, Sel, Val),
    send(AI, modified, @on),
    send(AI?device, modified_item, AI, @on).

select_colour(AI) :->
    "Query a colour"::
    get(AI, member, arrow, Arrow),
    get(Arrow, colour, Old),
    new(D, dialog('Select colour')),
    send(D, transient_for, AI?frame),
    send(D, append, new(CI, colour_item(colour, Old))),
    send(D, append, button(ok, message(D, return, CI?selection))),
    send(D, append, button(cancel, message(D, return, @nil))),
    get(D, confirm_centered, AI?frame?area?center, Rval),
    (   Rval == @nil
    ->  true
    ;   send(Arrow, colour, Rval),
        send(AI, modified, @on),
        send(AI?device, modified_item, AI, @on)
    ),
    send(D, destroy).

:- pce_end_class.

test :-
    new(D, dialog),
    send(D, append, new(_AI, arrow_item)),
    send(D, open).
