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+% Copyright 2019 by Till Tantau
+% Copyright 2019 by Saso Zivanovic
+%
+% This file may be distributed and/or modified
+%
+% 1. under the LaTeX Project Public License and/or
+% 2. under the GNU Public License.
+%
+% See the file doc/generic/pgf/licenses/LICENSE for more details.
+%
+% Based on pgfmoduleoo.code.tex v1.8 by Till Tantau. This version adds inheritance.
+
+
+
+% Support of object-oriented programming in TeX, with inheritance.
+
+
+% The oo support works as follows:
+%
+% The main supported concepts are classes, objects, methods,
+% attributes and signal/slots. A class defines a set of methods, which are,
+% in the end, just normal TeX macros. Once a class has been created,
+% it can be instantiated by calling the \pgfoonew command, resulting
+% in a new object. Objects are local to their group. Given an object,
+% you can send it a message, resulting in the method code of the
+% object's method to be executed. While an object exists, it has a set
+% of attributes whose values can change over time. Attributes values
+% are not local to TeX groups, rather their life-cycle is the same as
+% the object's (which, however, is local to the group in which the
+% object was declared).
+%
+% The implementation is as follows: There is an ID counter that is
+% increased each time an object is created. This counter is local to
+% the group, which means that when a group ends the counter will
+% revert to the previous value, allowing objects to the reused in
+% subsequent groups.
+%
+% A method is just a normal \TeX macro, but to call it you write
+% \objecthandle.methodname(parameters). The \objecthandle is a macro
+% that is created when you say \pgfoonew. The special object
+% \pgfoothis is the current object.
+%
+% Attributes are stored globally in internal TeX macros whose name is
+% composed of the object number and the attribute name.
+
+
+
+
+% Declares a class
+%
+% #1 = class name
+% #2 = methods
+%
+% Description:
+%
+% This command declares a class for future use. Inside #2, the macro
+% \method can be used to declare a method. The \method macro takes a
+% method name, parameters (methods are normal TeX macros, after all)
+% and body.
+
+% base classes are put in parenthesis before the new class name, but
+% are optional.
+\def\pgfooclass{%
+ \pgfutil@ifnextchar ({%
+ \pgfooclass@
+ }{%
+ \pgfooclass@()
+ }%
+}%
+\long\def\pgfooclass@(#1)#2#3{%
+ \def\pgfoo@classname{#2}%
+ \expandafter\ifx\csname pgfooY\pgfoo@classname.@pgfooinit\endcsname\relax\else
+ \pgferror{class #2 is already defined}%
+ \fi
+ \pgfoo@ciii{#2}{#1}%
+ \expandafter\let\csname pgfooY#2@pgfoo@mro\endcsname\pgfoo@mro
+ \let\pgfoo@origmethod=\method%
+ \let\pgfoo@origattribute=\attribute%
+ \let\method=\pgfoo@declaremethod%
+ \let\attribute=\pgfoo@declareattribute%
+ \let\pgfoo@attributes=\pgfutil@empty%
+ \let\pgfoo@methods=\pgfutil@empty%
+ #3%
+ % inherit
+ \def\pgfoo@temp@baseclasses{#1}%
+ \pgfoo@inherit@methods
+ \pgfoo@inherit@attributes
+ % Always present (and never inherited) methods:
+ \expandafter\let\csname pgfooY\pgfoo@classname.get handle\endcsname\pgfoo@obj%
+ \expandafter\let\csname pgfooY\pgfoo@classname.get id\endcsname\pgfoo@id%
+ % for compatibility with previous versions of pgfoo, define method
+ % with the same name as the class as a synonym for init
+ \expandafter\let\expandafter\pgfoo@init\csname pgfooY\pgfoo@classname.init\endcsname
+ \expandafter\let\csname pgfooY\pgfoo@classname.\pgfoo@classname\endcsname\pgfoo@init
+ % Cleanup
+ \let\method=\pgfoo@origmethod%
+ \let\attribute=\pgfoo@origattribute%
+}%
+
+\def\pgfoo@emptyinit(){}%
+\def\pgfoo@escapeif#1#2\fi{\fi#1}% a little helper
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Compute MRO using C3 algorithm
+% The sequences are enclosed in brackets; elements of sequences and
+% the big list are terminated by a comma and a dot, respectively. (Why
+% comma *and* a dot: TeX's parset---brackets don't form groups! Soooo,
+% why not braces? Because I don't know how do delete excess "{},"s...)
+
+% #1 = current class, #2 = list of base classes
+\def\pgfoo@ciii#1#2{%
+ % \pgfoo@seq will hold a list of sequences.
+ % (i) the first sequence has just one element: the current class
+ \def\pgfoo@seq{[#1,].}%
+ % (ii) every subclass has a sequence (in the order as they were
+ % given): the class' sequence is its mro.
+ \pgfutil@for\pgfoo@baseclass:={#2}\do{%
+ \edef\pgfoo@baseclass@mro{\csname pgfooY\pgfoo@baseclass @pgfoo@mro\endcsname}%
+ \expandafter\ifx\expandafter\relax\pgfoo@baseclass@mro\relax\else
+ \edef\pgfoo@seq{\pgfoo@seq[\pgfoo@baseclass@mro,].}%
+ \fi
+ }%
+ % The final sequence is a sequence of base classes, in the order as
+ % they were given.
+ \ifx\relax#2\relax\else
+ \edef\pgfoo@seq{\pgfoo@seq[#2,].}%
+ \fi
+ \edef\pgfoo@temp{()(\pgfoo@seq)}%
+ \expandafter\pgfoo@ciii@merge\pgfoo@temp
+}%
+
+% #1 = MRO so far
+% #2 = remaining sequences
+% no empty sequences [] should arrive here: they should be removed
+% before calling this macro
+\def\pgfoo@ciii@merge(#1)(#2){%
+ \ifx\relax#2\relax
+ \pgfoo@ciii@done(#1)%
+ \else\pgfoo@escapeif{% split #2
+ \pgfoo@ciii@merge@A(#1)(#2)%
+ }\fi%
+}%
+% a splitter: to be only called from \pgfoo@ciii@merge
+\def\pgfoo@ciii@merge@A(#1)(#2.#3){%
+ \ifx\relax#3\relax % if #3 is empty, we can take the shortcut
+ \pgfoo@ciii@mergeA@done(#1)(#2)%
+ \else\pgfoo@escapeif{%
+ \pgfoo@ciii@merge@checkHead(#1)()(#2)()(#3)%
+ }\fi
+}%
+
+\def\pgfoo@ciii@mergeA@done(#1)([#2]){%
+ \pgfoo@ciii@done(#1#2)%
+}%
+
+% #1 = MRO so far
+% #2 = sequences with bad heads (dot after each sequence)
+% [#3,#4] = the sequence whose head we're testing right
+% now---obviously, it should not be empty! (#3 has no comma,
+% #4 has a comma after each class name)
+% #5 = #3 does not occur in the tail of these sequences (dot after
+% each sequence)
+% #6 = the remaining sequences (dot after each sequence)
+\def\pgfoo@ciii@merge@checkHead(#1)(#2)([#3,#4])(#5)(#6){%
+ \pgfutil@in@{[#3,}{#2}%
+ \ifpgfutil@in@\pgfoo@escapeif{% #3 is already blacklisted
+ \pgfoo@ciii@clean\pgfoo@ciii@merge@checkHead@P{(#1)(#2[#3,#4].)(#5#6)}%
+ }\else\pgfoo@escapeif{%
+ \ifx\relax#6\relax\pgfoo@escapeif{% no more sequences to test the head against!
+ % so, #3 is a good head, and we can recurse
+ \pgfoo@ciii@goodHeadFound(#1)(#3)(#2[#4].#5)%
+ }\else\pgfoo@escapeif{% split #6 and get to work
+ \pgfoo@ciii@merge@checkHead@A(#1)(#2)([#3,#4])(#5)(#6)%
+ }\fi
+ }\fi
+}%
+% splitter: to be only called from \pgfoo@ciii@merge@checkHead
+% we will check if #3 occurs in the tail of #6
+\def\pgfoo@ciii@merge@checkHead@A(#1)(#2)([#3,#4])(#5)(#6.#7){%
+ \pgfoo@ciii@merge@checkHead@B(#1)(#2)([#3,#4])(#5)(#6)(#7)%
+}%
+% splitter: to be only called from \pgfoo@ciii@merge@checkHead@A
+% &worker: we will check if #3 occurs in #7. If it does, #3 is a bad head.
+\def\pgfoo@ciii@merge@checkHead@B(#1)(#2)([#3,#4])(#5)([#6,#7])(#8){%
+% \def\pgfoo@ciii@tempA{#3}\def\pgfoo@ciii@tempB{#5}%
+% \ifx\pgfoo@ciii@tempA\pgfoo@ciii@tempB
+% \pgferror{An attempt to derive from the same class twice}%
+% \else\pgfoo@escapeif{%
+ \pgfutil@in@{,#3,}{,#7}%
+ \ifpgfutil@in@\pgfoo@escapeif{% bad head! get next head and restart
+ % but: need to clean up first!
+ \pgfoo@ciii@clean\pgfoo@ciii@merge@checkHead@P{(#1)(#2[#3,#4].)(#5[#6,#7].#8)}%
+ }\else\pgfoo@escapeif{% so far, so good
+ \ifx\relax#8\relax\pgfoo@escapeif{% if #8 is empty, we won:
+ % #3 is a good head! we will move it to MRO
+ % but clean-up first!
+ \pgfoo@ciii@goodHeadFound(#1)(#3)(#2[#4].#5[#6,#7].)%
+ }\else\pgfoo@escapeif{% proceed to the first seq in #8
+ \pgfoo@ciii@clean\pgfoo@ciii@merge@checkHead{(#1)(#2)([#3,#4])(#5[#6,#7].)(#8)}%
+ }\fi
+ }\fi
+% }\fi
+}%
+
+% #1 = MRO
+% #2 = good head
+% #3 = the remaining sequences (in need of removing the good head from
+% them, and then also some general cleanup)
+\def\pgfoo@ciii@goodHeadFound(#1)(#2)(#3){%
+ \pgfutil@in@{,#2,}{#3}%
+ \ifpgfutil@in@\pgfoo@escapeif{%
+ \def\pgfoo@ciii@removeGoodHead(##1)(##2)(##3,#2,##4){%
+ \pgfoo@ciii@goodHeadFound(##1)(##2)(##3,##4)}%
+ \pgfoo@ciii@removeGoodHead(#1)(#2)(#3)%
+ }\else\pgfoo@escapeif{%
+ \pgfutil@in@{[#2,}{#3}%
+ \ifpgfutil@in@\pgfoo@escapeif{%
+ \def\pgfoo@ciii@removeGoodHead(##1)(##2)(##3[#2,##4){%
+ \pgfoo@ciii@goodHeadFound(##1)(##2)(##3[##4)}%
+ \pgfoo@ciii@removeGoodHead(#1)(#2)(#3)%
+ }\else\pgfoo@escapeif{%
+ \pgfoo@ciii@clean\pgfoo@ciii@merge{(#1#2,)(#3)}%
+ }\fi
+ }\fi
+}%
+
+% mediates between the bad head exit of \pgfoo@ciii@merge@checkHead@B
+% and \pgfoo@ciii@merge@checkHead; we need the mediator because #3
+% below might have been affected by cleaning.
+\def\pgfoo@ciii@merge@checkHead@P(#1)(#2)(#3){%
+ \if\relax#3\relax % no more good head candidates!
+ \pgferror{Bad MRO: There is no good (monotonic etc.)
+ Method Resolution Order for your class hierarchy}%
+ \else\pgfoo@escapeif{%
+ \pgfoo@ciii@merge@checkHead@Q(#1)(#2)(#3)%
+ }\fi
+}%
+% splitter for \pgfoo@ciii@merge@checkHead@P
+% #3 = the sequence containing the newest good head candidate
+\def\pgfoo@ciii@merge@checkHead@Q(#1)(#2)(#3.#4){%
+ \pgfoo@ciii@merge@checkHead(#1)(#2)(#3)()(#4)%
+}%
+
+% cyclically removes all occurrences of "[]," and "[]." (i.e., empty
+% sequences) in #2. When done, calls #1 with whatever remains.
+\def\pgfoo@ciii@clean#1#2{% clean commas
+ \pgfutil@in@{[].}{#2}% clean dots
+ \ifpgfutil@in@\pgfoo@escapeif{%
+ \pgfoo@ciii@clean@dot#1#2\pgfoo@ciii@clean@END
+ }\else\pgfoo@escapeif{%
+ #1#2%
+ }\fi
+}%
+\def\pgfoo@ciii@clean@dot#1#2[].#3\pgfoo@ciii@clean@END{%
+ \pgfoo@ciii@clean#1{#2#3}%
+}%
+
+\def\pgfoo@ciii@done(#1,){%
+ \def\pgfoo@mro{#1}%
+}%
+
+% end of C3
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+% Declare a method
+%
+% Description:
+%
+% Defines a method. To use/invoke this method for an object \object,
+% you write \object.methodname(parameters). This will cause the method
+% body to be invoked with the argument "(parameters)".
+%
+% To define the method \method should be directly followed by the
+% method name and, then, by (, followed by a parameter pattern,
+% followed by ), followed by the message body. Spaces are allowed only
+% after "\method" and after the closing ).
+%
+% Example:
+%
+% \pgfooclass{MyPlot}{
+%
+% \attribute x=0;
+% \attribute y=0;
+%
+% \method MyPlot() {
+% }
+%
+% \method getX(#1) {
+% \pgfooget{x}{#1}
+% }
+%
+% \method setPoint(#1,#2) {
+% \pgfooset{x}{#1}
+% \pgfooset{y}{#2}
+% }
+% }
+
+% define the method macro and append the method to the method collection
+\long\def\pgfoo@declaremethod#1(#2)#3{%
+ \def\pgfoo@method{#1}%
+ \ifx\pgfoo@classname\pgfoo@method
+ \def\pgfoo@method{init}%
+ \fi
+ \expandafter\long\expandafter\def\csname pgfooY\pgfoo@classname.\pgfoo@method\endcsname(#2){#3}%
+ \edef\pgfoo@methods{\pgfoo@methods,\pgfoo@method}%
+}%
+
+\def\pgfoo@inherit@methods{%
+ % for non-derived classes:
+ \expandafter\ifx\expandafter\relax\pgfoo@temp@baseclasses\relax
+ % if init is not defined, define an empty one
+ \expandafter\ifx\csname pgfooY\pgfoo@classname.init\endcsname\relax
+ \expandafter\let\csname pgfooY\pgfoo@classname.init\endcsname\pgfoo@emptyinit%
+ \edef\pgfoo@methods{,init\pgfoo@methods}%
+ \fi
+ \fi
+ \if\relax\pgfoo@methods\relax\else
+ % gobble the initial comma
+ \edef\pgfoo@methods{\expandafter\pgfutil@gobble\pgfoo@methods}%
+ \fi
+ % remember the list of collected methods
+ \expandafter\let\csname pgfooY\pgfoo@classname @pgfoo@methods\endcsname\pgfoo@methods
+ % get MRO
+ \expandafter\let\expandafter\pgfoo@mro\csname pgfooY\pgfoo@classname @pgfoo@mro\endcsname
+ % loop throough base classes in MRO
+ \pgfutil@for\pgfoo@baseclass:=\pgfoo@mro\do{%
+ \ifx\pgfoo@baseclass\pgfoo@classname % skip self
+ \else\pgfoo@escapeif{%
+ % get methods defined in this base class
+ \expandafter\let\expandafter\pgfoo@methods\csname pgfooY\pgfoo@baseclass @pgfoo@methods\endcsname
+ \pgfutil@for\pgfoo@method:=\pgfoo@methods\do{% for each method
+ % check if it is already defined in our class
+ \expandafter\ifx\csname pgfooY\pgfoo@classname.\pgfoo@method\endcsname\relax
+ % if not, link the method name from our class to base class
+ \edef\pgfoo@temp{\noexpand\let
+ \expandafter\noexpand\csname pgfooY\pgfoo@classname.\pgfoo@method\endcsname
+ \expandafter\noexpand\csname pgfooY\pgfoo@baseclass.\pgfoo@method\endcsname}%
+ \pgfoo@temp
+ \fi
+ }%
+ }\fi
+ }%
+}%
+
+\def\pgfoosuper(#1,#2).#3({%
+ #2.get id(\pgfoo@temp@id)%
+ \edef\pgfoo@classname{\csname pgfooX\pgfoo@temp@id @class\endcsname}%
+ \def\pgfoo@super@A##1,#1,##2.##3({%
+ \pgfoo@super@B##2.##3(%
+ }%
+ \expandafter\let\expandafter\pgfoo@mro\csname pgfooY\pgfoo@classname @pgfoo@mro\endcsname
+ \expandafter\pgfoo@super@A\expandafter,\pgfoo@mro,.#3(%
+}%
+\def\pgfoo@super@B#1,#2.#3({%
+ \expandafter\ifx\csname pgfooY#1.#3\endcsname\relax
+ \pgfoo@escapeif{\pgfoo@super@B#2.#3(}%
+ \else
+ \pgfoo@escapeif{\expandafter\pgfoo@caller\pgfoo@temp@id.#1.#3(}%
+ \fi
+}%
+
+
+
+% Declare an attribute
+%
+% #1 = attribute name
+% #2 = optional default value
+%
+% Description:
+%
+% Declares the attribute #1 for the current class. If the attribute
+% name is followed by =, the text following the equal sign is the
+% default value.
+
+\def\pgfoo@declareattribute#1;{%
+ \pgfutil@in@{ =}{#1}%
+ \ifpgfutil@in@%
+ \pgfoo@declareunpackspace#1;%
+ \else%
+ \pgfutil@in@={#1}%
+ \ifpgfutil@in@%
+ \pgfoo@declareunpack#1;%
+ \else%
+ \pgfoo@declareattribute@\let{#1}\pgfutil@empty
+ \fi%
+ \fi%
+}%
+\def\pgfoo@declareunpack#1=#2;{\pgfoo@declareattribute@\def{#1}{{#2}}}%
+\def\pgfoo@declareunpackspace#1 =#2;{\pgfoo@declareattribute@\def{#1}{{#2}}}%
+
+% put the initial value in the class's namespace
+% put the attr name in a list
+\def\pgfoo@declareattribute@#1#2#3{%
+ \expandafter#1\csname pgfooY\pgfoo@classname @#2\endcsname#3%
+ \expandafter\def\expandafter\pgfoo@attributes\expandafter{\pgfoo@attributes,#2}%
+}%
+
+% for each base class:
+% for each attribute declared in that class:
+% add the attr on a list if it's not there yet
+% convert the list of (attr,class which it comes from) into an
+% efficient sequence of triples \op{attrname}\pointer-to-initial-value
+% (\op is then set differently in init and garbage collection)
+\def\pgfoo@inherit@attributes{%
+ % store the list of attributes declared in this class for use in
+ % derived classes
+ \if\relax\pgfoo@attributes\relax\else
+ \edef\pgfoo@attributes{\expandafter\pgfutil@gobble\pgfoo@attributes}% gobble comma
+ \fi
+ \expandafter\let\csname pgfooY\pgfoo@classname.@pgfoo@attributes\endcsname\pgfoo@attributes%
+ % get MRO
+ \expandafter\let\expandafter\pgfoo@mro\csname pgfooY\pgfoo@classname @pgfoo@mro\endcsname
+ \def\pgfoo@allattributes{}% here we will store the attrs declared in base classes
+ \pgfutil@for\pgfoo@baseclass:=\pgfoo@mro\do{% for each base class in MRO order
+ % the attributes declared in this base class
+ \expandafter\let\expandafter\pgfoo@attributes\csname pgfooY\pgfoo@baseclass.@pgfoo@attributes\endcsname
+ \pgfutil@for\pgfoo@attribute:=\pgfoo@attributes\do{% for each attribute
+ % check if we have already found it in some previous base class
+ \edef\pgfoo@temp{{,\pgfoo@attribute=}{\pgfoo@allattributes,}}%
+ \expandafter\pgfutil@in@\pgfoo@temp
+ \ifpgfutil@in@\else % don't overwrite
+ % append to the list
+ \edef\pgfoo@allattributes{\pgfoo@allattributes,\pgfoo@attribute=\pgfoo@baseclass}%
+ \fi
+ }%
+ }%
+ \if\relax\pgfoo@allattributes\relax\else
+ \edef\pgfoo@allattributes{\expandafter\pgfutil@gobble\pgfoo@allattributes}% gobble comma
+ \fi
+ % this macro will hold a list of attributes from all base classes
+ % we run this macro at init and gc
+ \def\pgfoo@process@attributes{}%
+ \pgfutil@for\pgfoo@attributeclass:=\pgfoo@allattributes\do{% for each (attribute, class) pair
+ % append to the attribute processor
+ \expandafter\pgfoo@inherit@attributes@appendattribute\pgfoo@attributeclass.%
+ }%
+ \expandafter\let\csname pgfooY\pgfoo@classname .@pgfoo@process@attributes\endcsname\pgfoo@process@attributes
+}%
+
+
+% #1=attr, #2=class which the attr comes from
+\def\pgfoo@inherit@attributes@appendattribute#1=#2.{%
+ \def\pgfoo@tempA{\pgfoo@attribute@op{#1}}%
+ \expandafter\expandafter\expandafter\def\expandafter\expandafter\expandafter\pgfoo@tempB\expandafter\expandafter\expandafter{\expandafter\pgfoo@tempA\csname pgfooY#2@#1\endcsname}%
+ \expandafter\expandafter\expandafter\def\expandafter\expandafter\expandafter\pgfoo@process@attributes\expandafter\expandafter\expandafter{\expandafter\pgfoo@process@attributes\pgfoo@tempB}%
+ % above is just this:
+ % \def\pgfoo@process@attributes{\pgfoo@process@attributes\pgfoo@attribute@op{#1}%
+ % \csname pgfooY#2@#1\endcsname}
+ % with \pgfoo@process@attributes and \csname expanded exactly once:
+}%
+
+% \pgfoo@attribute@op for garbage collection
+\def\pgfoo@gc@attribute#1#2{\pgfoolet{#1}\relax}%
+
+
+\newcount\pgfoo@objectcount
+\newcount\pgfoothis@count
+
+% The attribute value method
+%
+% #1 = attr
+%
+% This method inserts the current value of the given attribute for the
+% current object.
+
+\def\pgfoovalueof#1{%
+ \csname pgfooX\the\pgfoothis@count @#1\endcsname%
+}%
+
+
+% The attribute get method
+%
+% #1 = attr
+% #2 = macro
+%
+% This method makes the macro equal to the current value of the
+% attribute for the current object.
+
+\def\pgfooget#1#2{%
+ \expandafter\let\expandafter#2\csname pgfooX\the\pgfoothis@count @#1\endcsname%
+}%
+
+
+% The attribute set method
+%
+% #1 = attr
+% #2 = value
+%
+% This method sets the given attribute for the current object to the
+% given value.
+
+\long\def\pgfooset#1#2{%
+ \expandafter\gdef\csname pgfooX\the\pgfoothis@count @#1\endcsname{#2}%
+}%
+
+
+% The attribute set method (expanded version)
+%
+% #1 = attr
+% #2 = value
+%
+% This method sets the given attribute for the current object to the
+% expanded version of the given value.
+
+\long\def\pgfooeset#1#2{%
+ \expandafter\xdef\csname pgfooX\the\pgfoothis@count @#1\endcsname{#2}%
+}%
+
+
+% The attribute let method
+%
+% #1 = attr
+% #2 = value
+%
+% This method sets the given attribute for the current object to the
+% given value using \let.
+
+\def\pgfoolet#1#2{%
+ \expandafter\global\expandafter\let\csname pgfooX\the\pgfoothis@count @#1\endcsname#2%
+}%
+
+
+% Add something to an attribute at the end
+%
+% #1 = attr
+% #2 = code
+%
+% This method adds the give code to the attr at the end.
+
+\def\pgfooappend#1#2{%
+ \expandafter\expandafter\expandafter\def%
+ \expandafter\expandafter\expandafter\pgf@oo@temp\expandafter\expandafter\expandafter{\csname pgfooX\the\pgfoothis@count @#1\endcsname#2}%
+ \expandafter\global\expandafter\let\csname pgfooX\the\pgfoothis@count @#1\endcsname\pgf@oo@temp%
+}%
+
+
+% Add something to an attribute at the beginning
+%
+% #1 = attr
+% #2 = code
+%
+% This method adds the give code to the attr at the beginning.
+
+\def\pgfooprefix#1#2{%
+ \pgfooget{#1}\pgf@oo@temp%
+ \def\pgf@oo@@temp{#2}%
+ \expandafter\expandafter\expandafter\def%
+ \expandafter\expandafter\expandafter\pgf@oo@temp%
+ \expandafter\expandafter\expandafter{\expandafter\pgf@oo@@temp\pgf@oo@temp}%
+ \pgfoolet{#1}\pgf@oo@temp%
+}%
+
+
+
+% Help macro for scanning arguments
+\newtoks\pgfoo@toks
+
+\def\pgfoo@collect@args{%
+ \pgfutil@ifnextchar\bgroup\pgfoo@collect@args@group\pgfoo@collect@args@nogroup%
+}%
+\def\pgfoo@collect@args@nogroup#1){%
+ \pgfoo@toks{#1}%
+ \pgfoo@continue%
+}%
+\def\pgfoo@collect@args@group#1{%
+ \pgfutil@ifnextchar){\pgfoo@toks{{#1}}\expandafter\pgfoo@continue\pgfutil@gobble}{\pgfoo@collect@args@nogroup{#1}}%
+}%
+
+
+% Instantiate an object
+%
+% Possible syntax:
+%
+% 1) \pgfoonew new <class name>(<constructor parameters)
+% 2) \pgfoonew \<objectname>=new <class name>(<constructor parameters)
+% 3) \pgfoonew{attribute}=new <class name>(<constructor parameters)
+%
+% Description:
+%
+% Creates an object. After the object has been created, the method
+% called <class name> (the constructor) is invoked. If the
+% \<objectname>= part is present, the macro is assigned to the newly
+% created object.
+
+\def\pgfoonew{%
+ \pgfutil@ifnextchar n{%
+ \pgfoo@new\pgfoo@dummy=%
+ }{%
+ \pgfutil@ifnextchar\bgroup{%
+ \pgfoo@new@attribute%
+ }{%
+ \pgfoo@new%
+ }%
+ }%
+}%
+\def\pgfoo@new#1={%
+ \def\pgfutil@reserved@a{#1}%
+ \let\pgfutil@next\pgfoo@@new
+ \futurelet\pgfutil@let@token\pgfutil@ignorespaces}%
+\def\pgfoo@@new new #1({%
+ \expandafter\ifx\csname pgfooY#1.get id\endcsname\relax%
+ \pgferror{Unknown class '#1'}%
+ \else%
+ \expandafter\pgfoo@new@create\pgfutil@reserved@a{#1}%
+ {%
+ \pgfoothis@count\pgfoo@objectcount%
+ \let\pgfoo@attribute@op\pgfoolet
+ \csname pgfooY#1.@pgfoo@process@attributes\endcsname%
+ }%
+ \let\pgfoo@continue=\pgf@oo@new@cont%
+ \expandafter\pgfoo@collect@args%
+ \fi%
+}%
+
+\def\pgf@oo@new@cont{%
+ \expandafter\pgfoolastobj\expandafter.\expandafter i\expandafter n\expandafter i\expandafter t\expandafter(\the\pgfoo@toks)%
+ \aftergroup\pgfoogc% cleanup after group
+}%
+
+\def\pgfoo@new@attribute#1={%
+ \def\pgfutil@reserved@a{#1}%
+ \let\pgfutil@next\pgfoo@@new@attribute
+ \futurelet\pgfutil@let@token\pgfutil@ignorespaces}%
+\def\pgfoo@@new@attribute new #1({%
+ \expandafter\ifx\csname pgfooY#1.get id\endcsname\relax%
+ \pgferror{Unknown class '#1'}%
+ \else%
+ \pgfoo@new@create\pgfoo@temp{#1}%
+ {%
+ \pgfoothis@count\pgfoo@objectcount%
+ \let\pgfoo@attribute@op\pgfoolet%
+ \csname pgfooY#1.@pgfoo@process@attributes\endcsname%
+ }%
+ \expandafter\pgfoolet\expandafter{\pgfutil@reserved@a}\pgfoo@temp%
+ \let\pgfoo@continue=\pgf@oo@new@cont%
+ \expandafter\pgfoo@collect@args%
+ \fi%
+}%
+
+\def\pgfoo@new@create#1#2{%
+ \advance\pgfoo@objectcount by 1\relax%
+ \edef\pgfoolastobj{\noexpand\pgfoo@caller{\the\pgfoo@objectcount}}%
+ \expandafter\gdef\csname pgfooX\the\pgfoo@objectcount @class\endcsname{#2}%
+ \let#1\pgfoolastobj%
+}%
+
+\def\pgfoo@caller#1.#2({%
+ \expandafter\let\expandafter\pgfoo@caller@temp\csname pgfooY\csname pgfooX#1@class\endcsname.#2\endcsname%
+ \ifx\pgfoo@caller@temp\relax%
+ % assume that #2 is of form "superclass.method"
+ \expandafter\let\expandafter\pgfoo@caller@temp\csname pgfooY#2\endcsname%
+ \ifx\pgfoo@caller@temp\relax%
+ \pgferror{Object #1 has no method '#2'}%
+ \fi%
+ \fi%
+ \def\pgf@marshal{%
+ \pgfoothis@count=#1\relax%
+ }%
+ \let\pgfoo@continue\pgfoo@caller@cont%
+ \pgfoo@collect@args%
+}%
+\def\pgfoo@caller@cont{%
+ \edef\pgf@marshal{%
+ \pgf@marshal%
+ \noexpand\pgfoo@caller@temp(\the\pgfoo@toks)%
+ }%
+ \expandafter\pgf@marshal\expandafter\pgfoothis@count\the\pgfoothis@count\relax%
+}%
+\let\pgfoo@orig@caller=\pgfoo@caller
+
+% The special "this" object
+
+\def\pgfoothis.#1({%
+ \expandafter\let\expandafter\pgfoo@caller@temp\csname pgfooY\csname pgfooX\the\pgfoothis@count @class\endcsname.#1\endcsname%
+ \ifx\pgfoo@caller@temp\relax%
+ % assume that #1 is of form "superclass.method"
+ \expandafter\let\expandafter\pgfoo@caller@temp\csname pgfooY#1\endcsname%
+ \fi%
+ \let\pgfoo@continue\pgfoothis@cont%
+ \pgfoo@collect@args%
+}%
+\def\pgfoothis@cont{%
+ \expandafter\pgfoo@caller@temp\expandafter(\the\pgfoo@toks)%
+}%
+
+
+
+% Get the object id
+%
+% #1 = macro to store the id
+%
+% Description:
+%
+% This special method allows you to access the object id. You can then
+% use \pgfoocall to call a method using this id. This is mainly useful
+% when you wish to store the id for a longer time.
+
+\def\pgfoo@id(#1){%
+ \edef#1{\the\pgfoothis@count}%
+}%
+
+% Yields the object with the given id
+%
+% #1 = id
+%
+% Description:
+%
+% Given an object id, \pgfooobj{<id>} will yield the object having
+% this id.
+
+\def\pgfooobj#1{%
+ \pgfoo@caller{#1}%
+}%
+
+
+% Get the object
+%
+% #1 = macro to store the object
+%
+% Description:
+%
+% This special method allows you to get a new handle to a given
+% object. If \obj is an object, you could normally just say
+% \let#1=\obj. However, if \obj happens to be \pgfoothis, then you may
+% wish to get a handle to the object itself, not to the special macro
+% \pgfoothis. In this case you can say \obj.get handle(#1).
+
+\def\pgfoo@obj(#1){%
+ \edef#1{\noexpand\pgfoo@caller{\the\pgfoothis@count}}%
+}%
+
+
+
+% The garbage collector
+%
+% Description:
+%
+% This method frees space occupied by unused objects. Garbage are
+% objects that have been destroyed because of the end of the scope in
+% which they were created. In this case, however, the memory used by
+% this object is not immediately reused because the attributes of the
+% object are actually stored in global variables. When the garbage
+% collector is called, it will set all these global variables to
+% \relax, thereby ensuring that no memory is needed for them.
+
+\def\pgfoogc{%
+ {%
+ % We do this in a group...
+ \pgfoothis@count\pgfoo@objectcount% this is temporary...
+ \let\pgfoo@next=\pgfoo@dogc%
+ \pgfoo@next%
+ }%
+}%
+\def\pgfoo@dogc{%
+ \advance\pgfoothis@count by 1\relax%
+ \expandafter\ifx\csname pgfooX\the\pgfoothis@count @class\endcsname\relax%
+ \let\pgfoo@next=\relax%
+ \else%
+ % Cleanup this object:
+ % The following is the fast version of \pgfooobj{\the\pgfoo@objectcount}.@pgfoogc:
+ \let\pgfoo@attribute@op\pgfoo@gc@attribute
+ \csname pgfooY\csname pgfooX\the\pgfoothis@count @class\endcsname.@pgfoo@process@attributes\endcsname%
+ \expandafter\global\expandafter\let\csname pgfooX\the\pgfoothis@count @class\endcsname\relax%
+ \fi%
+ \pgfoo@next%
+}%
+
+
+
+%
+%
+% Object class
+% defines method "copy"
+%
+%
+
+\pgfooclass{object}{%
+ \method copy(#1) {%
+ % create a new object
+ \edef\pgfoo@temp@classname{\csname pgfooX\the\pgfoothis@count @class\endcsname}%
+ \expandafter\pgfoo@new@create\expandafter#1\expandafter{\pgfoo@temp@classname}%
+ \def\pgfoo@copy@attributes##1##2{%
+ \pgfooget{##1}\pgfoo@attrvalue
+ \expandafter\let\csname pgfooX\the\pgfoo@objectcount @##1\endcsname\pgfoo@attrvalue
+ }%
+ \let\pgfoo@attribute@op\pgfoo@copy@attributes
+ \csname pgfooY\pgfoo@temp@classname .@pgfoo@process@attributes\endcsname
+ \aftergroup\pgfoogc% cleanup after group
+ }%
+}%
+
+
+%
+%
+% Signal class
+%
+%
+
+\pgfooclass{signal}
+{%
+ %
+ % This class implements signals.
+ %
+ % After you have created a signal object, you can call
+ % connect to connect a slot. Then, whenever the emit method is
+ % called, all connected methods get called.
+
+ % Attribute
+ \attribute emitter;%
+ % Collects the objects that should be called.
+
+ % Constructor
+ \method signal() {}%
+
+ % Connect a slot (method) #2 of object #1
+ \method connect(#1,#2) {%
+ {%
+ #1.get id(\pgf@tempid)%
+ % Save in emitter
+ \pgfooget{emitter}\pgf@temp%
+ \let\pgfoo@signal@call=\relax% avoid expansion
+ \edef\pgf@temp{\pgf@temp\pgfoo@signal@call{\pgf@tempid}{#2}}%
+ \pgfoolet{emitter}\pgf@temp%
+ }%
+ }%
+
+ \def\pgfoo@signal@call#1#2{%
+ \def\pgf@temp{\pgfooobj{#1}.#2}%
+ \expandafter\pgf@temp\expandafter(\pgfoo@signal@args)%
+ }%
+
+ % Emit a signal
+ \method emit(#1) {%
+ \def\pgfoo@signal@args{#1}%
+ \pgfoovalueof{emitter}
+ }%
+}%
+
+
+
+
+\endinput