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diff --git a/graphics/pgf/base/tex/generic/graphdrawing/lua/pgf/gd/interface/InterfaceToAlgorithms.lua b/graphics/pgf/base/tex/generic/graphdrawing/lua/pgf/gd/interface/InterfaceToAlgorithms.lua new file mode 100644 index 0000000000..1187fbc313 --- /dev/null +++ b/graphics/pgf/base/tex/generic/graphdrawing/lua/pgf/gd/interface/InterfaceToAlgorithms.lua @@ -0,0 +1,968 @@ +-- Copyright 2012 by Till Tantau +-- +-- This file may be distributed an/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 information + +-- @release $Header$ + + + +--- +-- This class provides the interface between the graph drawing system +-- and algorithms. Another class, |InterfaceToDisplay|, binds the +-- display layers (like \tikzname\ or a graph drawing editor) to the +-- graph drawing system ``from the other side''. +-- +-- The functions declared here can be used by algorithms to +-- communicate with the graph drawing system, which will usually +-- forward the ``requests'' of the algorithms to the display layers in +-- some way. For instance, when you declare a new parameter, this +-- parameter will become available on the display layer. + +local InterfaceToAlgorithms = {} + +-- Namespace +require("pgf.gd.interface").InterfaceToAlgorithms = InterfaceToAlgorithms + + +-- Imports +local InterfaceCore = require "pgf.gd.interface.InterfaceCore" +local InterfaceToDisplay = require "pgf.gd.interface.InterfaceToDisplay" +local InterfaceToC = require "pgf.gd.interface.InterfaceToC" + +local LookupTable = require "pgf.gd.lib.LookupTable" +local LayoutPipeline = require "pgf.gd.control.LayoutPipeline" + +local Edge = require "pgf.gd.model.Edge" + +local lib = require "pgf.gd.lib" + +local doc = require "pgf.gd.doc" + +-- Forwards + +local declare_handlers + + + + +--- +-- Adds a handler for the |declare| function. The |declare| +-- command is just a ``dispatcher'' to one of many possible +-- declaration functions. Which function is used, depends on which +-- fields are present in the table passed to |declare|. For each +-- registered handler, we call the |test| function. If it returns +-- neither |nil| nor |false|, the |handler| field of this handler is +-- called. If it returns |true|, the handler immediately +-- finishes. Otherwise, the next handler is tried. + +function InterfaceToAlgorithms.addHandler(test, handler) + table.insert(declare_handlers, 1, { test = test, handler = handler }) +end + + + +-- Local stuff + +local key_metatable = {} + +--- +-- This function is the ``work-horse'' for declaring things. It allows +-- you to specify on the algorithmic layer that a key ``is available'' +-- for use on the display layer. There is just one function for +-- handling all declarations in order to make the declarations +-- easy-to-use since you just need to import a single function: +-- % +--\begin{codeexample}[code only, tikz syntax=false] +--local declare = require "pgf.gd.interface.InterfaceToAlgorithms".declare +--\end{codeexample} +-- +-- You can now use |declare| it as follows: You pass it a table +-- containing information about the to-be-declared key. The table +-- \emph{must} have a field |key| whose value is unique and must be a +-- string. If the value of |key| is, say, |"foo"|, the +-- parameter can be set on the display layer such as, say, the +-- \tikzname\ layer, using |/graph drawing/foo|. Here is a typical +-- example of how a declaration is done: +-- % +--\begin{codeexample}[code only, tikz syntax=false] +-- --- +-- declare { +-- key = "electrical charge", +-- type = "number", +-- initial = "1.0", +-- +-- summary = "The ``electrical charge'' is a property...", +-- documentation = [[...]], +-- examples = [[...]] +-- } +--\end{codeexample} +-- +-- \medskip\noindent\textbf{Inlining Documentation.} +-- The three keys |summary|, |documentation| and |examples| are +-- intended for the display layer to give the users information about +-- what the key does. The |summary| should be a string that succinctly +-- describes the option. This text will typically be displayed for +-- instance as a ``tool tip'' or in an option overview. The +-- |documentation| optionally provides more information and should be +-- typeset using \TeX. The |examples| can either be a single string or +-- an array of strings. Each should be a \tikzname\ example +-- demonstrating how the key is used. +-- +-- Note that you can take advantage of the Lua syntax of enclosing +-- very long multi-line strings in |[[| and |]]|. As a bonus, if the +-- summary, documentation, or an example starts and ends with a quote, +-- these two quotes will be stripped. This allows you to enclose the +-- whole multi-line string (additionally) in quotes, leading to better +-- syntax highlighting in editors. +-- +-- \medskip\noindent\textbf{External Documentation.} +-- It is sometimes more desirable to put the documentation of a key +-- into an external file. First, this makes the code leaner and, thus, +-- faster to read (both for humans and for computers). Second, for C +-- code, it is quite inconvenient to have long strings inside a C +-- file. In such cases, you can use the |documentation_in| field: +-- % +--\begin{codeexample}[code only, tikz syntax=false] +-- --- +-- declare { +-- key = "electrical charge", +-- type = "number", +-- initial = "1.0", +-- documentation_in = "some_filename" +-- } +--\end{codeexample} +-- +-- The |some_filename| must be the name of a Lua file that will be +-- read ``on demand'', that is, whenever someone tries to access the +-- documentation, summary, or examples field of the key, this file +-- will be loaded using |require|. The file should then use +-- |pgf.gd.doc| to install the missing information in the keys. +-- +-- \medskip\noindent\textbf{The Use Field.} +-- When you declare a key, you can provide a |use| field. If present, +-- you must set it to an array of small tables which have two fields: +-- % +-- \begin{itemize} +-- \item |key| This is the name of another key or a function. +-- \item |value| This is either a value (like a string or a number) or +-- a function or |nil|. +-- \end{itemize} +-- +-- Here is an example: +-- % +--\begin{codeexample}[code only, tikz syntax=false] +-- --- +-- declare { +-- key = "binary tree layout", +-- use = { +-- { key = "minimum number of children", value = 2 }, +-- { key = "significant sep", value = 12 }, +-- { key = "tree layout" } +-- }, +-- summary = "The |binary tree layout| places node...", +-- documentation = ..., +-- examples = ..., +-- } +--\end{codeexample} +-- +-- The effect of a |use| field is the following: Whenever the key is +-- encountered on the option stack, the key is first handled +-- normally. Then, we iterate over all elements of the |use| +-- array. For each element, we perform the action as if the |key| of +-- the array had been set explicitly to the value given by the |value| +-- field. If the |value| is a function, we pass a different value to +-- the key, namely the result of applying the function to the value +-- originally passed to the original key. Here is a typical example: +-- % +--\begin{codeexample}[code only, tikz syntax=false] +-- --- +-- declare { +-- key = "level sep", +-- type = "length", +-- use = { +-- { key = "level pre sep", value = function (v) return v/2 end }, +-- { key = "level post sep", value = function (v) return v/2 end } +-- }, +-- summary = "..." +-- } +--\end{codeexample} +-- +-- Just like the value, the key itself can also be a function. In this +-- case, the to-be-used key is also computed by applying the function +-- to the value passed to the original key. +-- +-- As mentioned at the beginning, |declare| is a work-horse that will call +-- different internal functions depending on whether you declare a +-- parameter key or a new algorithm or a collection kind. Which kind +-- of declaration is being done is detected by the presence of certain +-- fields in the table passed to |t|. The different kind of +-- possible declarations are documented in the |declare_...| +-- functions. Note that these functions are internal and cannot be +-- called from outside; you must use the |declare| function. +-- +-- @param t A table contain the field |key| and other fields as +-- described. + +function InterfaceToAlgorithms.declare (t) + local keys = InterfaceCore.keys + + -- Sanity check: + assert (type(t.key) == "string" and t.key ~= "", "parameter key may not be the empty string") + if keys[t.key] or t.keys == "algorithm_phases" then + error("parameter '" .. t.key .. "' already declared") + end + + for _,h in ipairs (declare_handlers) do + if h.test(t) then + if h.handler(t) then + break + end + end + end + + -- Attach metatable: + setmetatable (t, key_metatable) + + -- Set! + keys[t.key] = t + keys[#keys + 1] = t +end + + +function key_metatable.__index (key_table, what) + if what == "documentation" or what == "summary" or what == "examples" then + local doc = rawget(key_table,"documentation_in") + if doc then + require (doc) + return rawget(key_table, what) + end + end +end + + + +--- +-- This function is called by |declare| for ``normal parameter keys'', +-- which are all keys for which no special field like |algorithm| or +-- |layer| is declared. You write +-- % +--\begin{codeexample}[code only, tikz syntax=false] +-- --- +-- declare { +-- key = "electrical charge", +-- type = "number", +-- initial = "1.0", +-- +-- summary = "The ``electrical charge'' is a property...", +-- documentation = [[...]], +-- examples = [[...]] +-- } +--\end{codeexample} +-- +-- When an author writes |my node[electrical charge=5-3]| in the +-- description of her graph, the object |vertex| corresponding to the +-- node |my node| will have a field |options| attached to it with +-- % +--\begin{codeexample}[code only, tikz syntax=false] +--vertex.options["electrical charge"] == 2 +--\end{codeexample} +-- +-- The |type| field does not refer to Lua types. Rather, these types are +-- sensible types for graph drawing and they are mapped by the higher +-- layers to Lua types. In detail, the following types are available: +-- % +-- \begin{itemize} +-- \item |number| A dimensionless number. Will be mapped to a normal +-- Lua |number|. So, when the author writes |foo=5*2|, the |foo| key +-- of the |options| field of the corresponding object will be set to +-- |10.0|. +-- \item |length| A ``dimension'' in the sense of \TeX\ (a number with +-- a dimension like |cm| attached to it). It is the job of the display +-- layer to map this to a number in ``\TeX\ points'', that is, to a +-- multiple of $1/72.27$th of an inch. +-- \item |time| A ``time'' in the sense of |\pgfparsetime|. Examples +-- are |6s| or |0.1min| or |6000ms|, all of which will map to |6|. +-- \item |string| Some text. Will be mapped to a Lua |string|. +-- \item |canvas coordinate| A position on the canvas. Will be mapped +-- to a |model.Coordinate|. +-- \item |boolean| A Boolean value. +-- \item |raw| Some to-be-executed Lua text. +-- \item |direction| Normally, an angle; however, +-- the special values of |down|, |up|, |left|, |right| as well as the +-- directions |north|, |north west|, and so on are also legal on the +-- display layer. All of them will be mapped to a number. Furthermore, +-- a vertical bar (\verb!|!) will be mapped to |-90| and a minus sign +-- (|-|) will be mapped to |0|. +-- \item |hidden| A key of this type ``cannot be set'', that is, +-- users cannot set this key at all. However algorithms can still read +-- this key and, through the use of |alias|, can use the key as a +-- handle to another key. +-- \item |user value| The key stores a Lua user value (userdata). Such +-- keys can only be set from C since user values cannot be created in +-- Lua (let alone in \tikzname). +-- \end{itemize} +-- +-- If the |type| field is missing, it is automatically set to +-- |"string"|. +-- +-- A parameter can have an |initial| value. This value will be used +-- whenever the parameter has not been set explicitly for an object. +-- +-- A parameter can have a |default| value. This value will be used as +-- the parameter value whenever the parameter is explicitly set, but +-- no value is provided. For a key of type |"boolean"|, if no +-- |default| is provided, |"true"| will be used automatically. +-- +-- A parameter can have an |alias| field. This field must be set to +-- the name of another key or to a function. Whenever you access the +-- current key and this key is not set, the |alias| key is tried +-- instead. If it is set, its value will be returned (if the |alias| +-- key has itself an alias set, this is tried recursively). If the +-- alias is not set either and neither does it have an initial value, +-- the |initial| value is used. Note that in case the alias has its +-- |initial| field set, the |initial| value of the current key will +-- never be used. +-- +-- The main purpose of the current key is to allow algorithms to +-- introduce their own terminology for keys while still having access +-- to the standard keys. For instance, the |OptimalHierarchyLayout| +-- class uses the name |layerDistance| for what would be called +-- |level distance| in the rest of the graph drawing system. In this +-- case, we can declare the |layerDistance| key as follows: +-- % +--\begin{codeexample}[code only, tikz syntax=false] +-- declare { +-- key = "layerDistance", +-- type = "length", +-- alias = "level distance" +-- } +--\end{codeexample} +-- +-- Inside the algorithm, we can write |...options.layerDistance| and +-- will get the current value of the |level distance| unless the +-- |layerDistance| has been set explicitly. Indeed, we might set the +-- |type| to |hidden| to ensure that \emph{only} the |level distance| +-- can and must set to set the layerDistance. +-- +-- Note that there is a difference between |alias| and the |use| +-- field: Suppose we write +-- % +--\begin{codeexample}[code only, tikz syntax=false] +-- declare { +-- key = "layerDistance", +-- type = "length", +-- use = { +-- { key = "level distance", value = lib.id } +-- } +-- } +--\end{codeexample} +-- +-- Here, when you say |layerDistance=1cm|, the |level distance| itself +-- will be modified. When the |level distance| is set, however, the +-- |layerDistance| will not be modified. +-- +-- If the alias is a function, it will be called with the option table +-- as its parameter. You can thus say things like +-- % +--\begin{codeexample}[code only, tikz syntax=false] +-- declare { +-- key = "layerDistance", +-- type = "length", +-- alias = function (option) +-- return option["layer pre dist"] + option["layer post dist"] +-- end +-- } +--\end{codeexample} +-- +-- As a special courtesy to C code, you can also set the key +-- |alias_function_string|, which allows you to put the function into +-- a string that is read using |loadstring|. +-- +-- (You cannot call this function directly, it is included for +-- documentation purposes only.) +-- +-- @param t The table originally passed to |declare|. + +local function declare_parameter (t) + + t.type = t.type or "string" + + if t.type == "boolean" and t.default == nil then + t.default = true + end + + -- Normal key + assert (type(t.type) == "string", "key type must be a string") + + -- Declare via the hub: + if t.type ~= "hidden" then + InterfaceCore.binding:declareCallback(t) + + -- Handle initials: + if t.initial then + InterfaceCore.option_initial[t.key] = InterfaceCore.convert(t.initial, t.type) + end + end + + if t.alias_function_string and not t.alias then + local count = 0 + t.alias = load ( + function () + count = count + 1 + if count == 1 then + return "return " + elseif count == 2 then + return t.alias_function_string + else + return nil + end + end)() + end + + if t.alias then + assert (type(t.alias) == "string" or type(t.alias == "function"), "alias must be a string or a function") + InterfaceCore.option_aliases[t.key] = t.alias + end + + return true +end + + + + +--- +-- This function is called by |declare| for ``algorithm +-- keys''. These keys are normally used without a value as in just +-- |\graph[tree layout]|, but you can optionally pass a value to +-- them. In this case, this value must be the name of a \emph{phase} +-- and the algorithm of this phase will be set (and not the +-- default phase of the key), see the description of phases below for +-- details. +-- +-- Algorithm keys are detected by the presence of the field |algorithm| +-- in the table |t| passed to |declare|. Here is an example of how it +-- is used: +-- % +--\begin{codeexample}[code only, tikz syntax=false] +-- local ReingoldTilford1981 = {} +-- +-- --- +-- declare { +-- key = "tree layout", +-- algorithm = ReingoldTilford1981, +-- +-- preconditions = { +-- connected = true, +-- tree = true +-- }, +-- +-- postconditions = { +-- upward_oriented = true +-- }, +-- +-- summary = "The Reingold--Tilford method is...", +-- documentation = ..., +-- examples = ..., +-- } +-- +-- function ReingoldTilford1981:run() +-- ... +-- end +--\end{codeexample} +-- +-- The |algorithm| field expects either a table or a string as +-- value. If you provide a string, then |require| will be applied to +-- this string to obtain the table; however, this will happen only +-- when the key is actually used for the first time. This means that +-- you can declare (numerous) algorithms in a library without these +-- algorithms actually being loaded until they are needed. +-- +-- Independently of how the table is obtained, it will be ``upgraded'' +-- to a class by setting its |__index| field and installing a static +-- |new| function (which takes a table of initial values as +-- argument). Both these settings will only be done if they have not +-- yet been performed. +-- +-- Next, you can specify the fields |preconditions| and +-- |postconditions|. The preconditions are a table that tell the graph +-- drawing engine what kind of graphs your algorithm expects. If the +-- input graph is not of this kind, it will be automatically +-- transformed to meet this condition. Similarly, the postconditions +-- tell the engine about properties of your graph after the algorithm +-- has run. Again, additional transformations may be performed. +-- +-- You can also specify the field |phase|. This tells the graph +-- drawing engine which ``phase'' of the graph drawing process your +-- option applies to. Each time you select an algorithm later on +-- through use of the algorithm's key, the algorithm for this phase +-- will be set; algorithms of other phases will not be changed. +-- For instance, when an algorithm is part of the spanning tree +-- computation, its phase will be |"spanning tree computation"| and +-- using its key does not change the main algorithm, but only the +-- algorithm used during the computation of a spanning tree for the +-- current graph (in case this is needed by the main algorithm). In +-- case the |phase| field is missing, the phase |main| is used. Thus, +-- when no phase field is given, the key will change the main +-- algorithm used to draw the graph. +-- +-- Later on, the algorithm set for the current phase can be accessed +-- through the special |algorithm_phases| field of |options| +-- tables. The |algorithm_phases| table will contain two fields for each +-- phase for which some algorithm has been set: One field is the name +-- of the phase and its value will be the most recently set algorithm +-- (class) set for this phase. The other field is the name of the +-- phase followed by |" stack"|. It will contain an array of all +-- algorithm classes that have been set for this key with the most +-- recently at the end. +-- +-- The following example shows the declaration of an algorithm that is +-- the default for the phase |"spanning tree computation"|: +-- % +--\begin{codeexample}[code only, tikz syntax=false] +-- --- +-- declare { +-- key = "breadth first spanning tree", +-- algorithm = { +-- run = +-- function (self) +-- return SpanningTreeComputation.computeSpanningTree(self.ugraph, false, self.events) +-- end +-- }, +-- phase = "spanning tree computation", +-- phase_default = true, +-- summary = ... +-- } +--\end{codeexample} +-- +-- The algorithm is called as follows during a run of the main +-- algorithms: +-- % +--\begin{codeexample}[code only, tikz syntax=false] +-- local graph = ... -- the graph object +-- local spanning_algorithm_class = graph.options.algorithm_phases["spanning tree computation"] +-- local spanning_algorithm = +-- spanning_algorithm_class.new{ +-- ugraph = ugraph, +-- events = scope.events +-- } +-- local spanning_tree = spanning_algorithm:run() +--\end{codeexample} +-- +-- If you set the |phase_default| field of |t| to |true|, the algorithm will +-- be installed as the default algorithm for the phase. This can be +-- done only once per phase. Furthermore, for such a default algorithm +-- the |algorithm| key must be table, it may not be a string (in other +-- words, all default algorithms are loaded immediately). Accessing +-- the |algorithm_phases| table for a phase for which no algorithm has +-- been set will result in the default algorithm and the phase stack +-- will also contain this algorithm; otherwise the phase stack will be empty. +-- +-- (You cannot call this function directly, it is included for +-- documentation purposes only.) +-- +-- @param t The table originally passed to |declare|. + +local function declare_algorithm (t) + -- Algorithm declaration! + assert(type(t.algorithm) == "table" or type(t.algorithm) == "string") + + t.phase = t.phase or "main" + + local function make_class () + local class + + if type(t.algorithm) == "table" then + class = lib.class(t.algorithm) + else + class = lib.class(require(t.algorithm)) + end + + -- Now, save pre- and postconditions + class.preconditions = t.preconditions or {} + class.postconditions = t.postconditions or {} + + -- Save phase + class.phase = t.phase + + -- Compatibility + class.old_graph_model = t.old_graph_model + + return class + end + + -- Store this: + local store_me + if type(t.algorithm) == "table" then + store_me = make_class() + else + store_me = make_class + end + + -- Save in the algorithm_classes table: + InterfaceCore.algorithm_classes[t.key] = store_me + + assert(t.type == nil, "type may not be set for an algorithm key") + t.type = "string" + + -- Install! + InterfaceCore.binding:declareCallback(t) + + if t.phase_default then + assert (not InterfaceCore.option_initial.algorithm_phases[t.phase], + "default algorithm for phase already set") + assert (type(store_me) == "table", + "default algorithms must be loaded immediately") + InterfaceCore.option_initial.algorithm_phases[t.phase] = store_me + InterfaceCore.option_initial.algorithm_phases[t.phase .. " stack"] = { store_me } + else + InterfaceCore.option_initial.algorithm_phases[t.phase .. " stack"] = { + dummy = true -- Remove once Lua Link Bug is fixed + } + end + + return true +end + + + + +--- +-- This function is called by |declare| for ``collection kinds''. They +-- are detected by the presence of the field |layer| +-- in the table |t| passed to |declare|. See the class |Collection| +-- for details on what a collection and a collection kind is. +-- +-- The |key| field of the table |t| passed to this function is both +-- the name of the to-be-declared collection kind as well as the key +-- that is used on the display layer to indicate that a node or edge +-- belongs to a collection. +-- +-- \medskip +-- \noindent\textbf{The Display Layer.} +-- Let us first have a look at what happens on the display layer: +-- A key |t.key| is setup on the display layer that, when used inside +-- a graph drawing scope, starts a new collection of the specified +-- kind. ``Starts'' means that all nodes and edges mentioned in the +-- rest of the current option scope will belong to a new collection +-- of kind |t.key|. +-- % +--\begin{codeexample}[code only, tikz syntax=false] +--declare { key = "hyper", layer = 1 } +--\end{codeexample} +-- % +-- you can say on the \tikzname\ layer +-- % +--\begin{codeexample}[code only] +-- \graph { +-- a, b, c, d; +-- { [hyper] a, b, c } +-- { [hyper] b, c, d } +-- }; +--\end{codeexample} +-- +-- In this case, the nodes |a|, |b|, |c| will belong to a collection of +-- kind |hyper|. The nodes |b|, |c|, and |d| will (also) belong to +-- another collection of the same kind |hyper|. You can nest +-- collections; in this case, nodes will belong to several +-- collections. +-- +-- The effect of declaring a collection kind on the algorithm layer +-- it, first of all, that |scope.collections| will have a field named +-- by the collection kind. This field will store an array that +-- contains all collections that were declared as part of the +-- graph. For instance, |collections.hyper| will contain all +-- hyperedges, each of which is a table with the following fields: The +-- |vertices| and |edges| fields each contain arrays of all objects +-- being part of the collection. The |sub| field is an array of +-- ``subcollections'', that is, all collections that were started +-- inside another collection. (For the collection kinds |hyper| and +-- |same layer| this makes no sense, but subgraphs could, for instance, +-- be nested.) +-- +-- \medskip +-- \noindent\textbf{Rendering of Collections.} +-- For some kinds of collections, it makes sense to \emph{render} them, +-- but only after the graph drawing algorithm has run. For this +-- purpose, the binding layer will use a callback for each collection +-- kind and each collection, see the |Binding| class for details. +-- Suppose, for instance, you would +-- like hyperedges to be rendered. In this case, a graph drawing +-- algorithm should iterate over all collections of type |hyper| and +-- compute some hints on how to render the hyperedge and store this +-- information in the |generated_options| table of the hyperedge. Then, +-- the binding layer will ask the display layer to run some some code +-- that is able to read key--value pairs passed to +-- it (which are the key--value pairs of the |generated_options| table) +-- and use this information to nicely draw the hyperedge. +-- +-- The number |t.layer| determines in which order the different +-- collection kinds are rendered. +-- +-- The last parameter, the layer number, is used to specify the order +-- in which the different collection kinds are rendered. The higher the +-- number, the later the collection will be rendered. Thus, if there is +-- a collection kind with layer number 10 and another with layer number +-- 20, all collections of the first kind will be rendered first, +-- followed by all collections of the second kind. +-- +-- Collections whose layer kinds are non-negative get rendered +-- \emph{after} the nodes and edges have already been rendered. In +-- contrast, collections with a negative layer number get shown +-- ``below'' the nodes and edges. +-- +-- (You cannot call this function directly, it is included for +-- documentation purposes only.) +-- +-- @param t The table originally passed to |declare|. + +local function declare_collection_kind (t) + assert (type(t.layer) == "number", "layer must be a number") + + local layer = t.layer + local kind = t.key + local kinds = InterfaceCore.collection_kinds + local new_entry = { kind = kind, layer = layer } + + -- Insert into table part: + kinds[kind] = new_entry + + -- Insert into array part: + local found + for i=1,#kinds do + if kinds[i].layer > layer or (kinds[i].layer == layer and kinds[i].kind > kind) then + table.insert(kinds, i, new_entry) + return + end + end + + kinds[#kinds+1] = new_entry + + -- Bind + InterfaceCore.binding:declareCallback(t) + + return true +end + + + +-- Build in handlers: + +declare_handlers = { + { test = function (t) return t.algorithm_written_in_c end, handler = InterfaceToC.declare_algorithm_written_in_c }, + { test = function (t) return t.algorithm end, handler = declare_algorithm }, + { test = function (t) return t.layer end, handler = declare_collection_kind }, + { test = function (t) return true end, handler = declare_parameter } +} + + + + + + + + +--- +-- Finds a node by its name. This method should be used by algorithms +-- for which a node name is specified in some option and, thus, needs +-- to be converted to a vertex object during a run of the algorithm. +-- +-- @param name A node name +-- +-- @return The vertex of the given name in the syntactic digraph or +-- |nil|. + +function InterfaceToAlgorithms.findVertexByName(name) + return InterfaceCore.topScope().node_names[name] +end + + + + + +-- Helper function +local function add_to_collections(collection,where,what) + if collection then + LookupTable.addOne(collection[where],what) + add_to_collections(collection.parent,where,what) + end +end + +local unique_count = 1 + +--- +-- Generate a new vertex in the syntactic digraph. Calling this method +-- allows algorithms to create vertices that are not present in the +-- original input graph. Using the graph drawing coroutine, this +-- function will pass back control to the display layer in order to +-- render the vertex and, thereby, create precise size information +-- about it. +-- +-- Note that creating new vertices in the syntactic digraph while the +-- algorithm is already running is a bit at odds with the notion of +-- treating graph drawing as a series of graph transformations: For +-- instance, when a new vertex is created, the graph will (at least +-- temporarily) no longer be connected; even though an algorithm may +-- have requested that it should only be fed connected +-- graphs. Likewise, more complicated requirements like insisting on +-- the graph being a tree also cannot be met. +-- +-- For these reasons, the following happens, when a new vertex is +-- created using the function: +-- % +-- \begin{enumerate} +-- \item The vertex is added to the syntactic digraph. +-- \item It is added to all layouts on the current layout stack. When +-- a graph drawing algorithm is run, it is not necessarily run on the +-- original syntactic digraph. Rather, a sequence / stack of nested +-- layouts may currently +-- be processed and the vertex is added to all of them. +-- \item The vertex is added to both the |digraph| and the |ugraph| of +-- the current algorithm. +-- \end{enumerate} +-- +-- @param algorithm An algorithm for whose syntactic digraph the node +-- should be added +-- @param init A table of initial values for the node that is passed +-- to |Binding:createVertex|, see that function for details. +-- +-- @return The newly created node +-- +function InterfaceToAlgorithms.createVertex(algorithm, init) + + -- Setup + local scope = InterfaceCore.topScope() + local binding = InterfaceCore.binding + + -- Setup node + if not init.name then + init.name = "internal@gd@node@" .. unique_count + unique_count = unique_count + 1 + end + + -- Does vertex already exist? + assert (not scope.node_names[name], "node already created") + + if not init.shape or init.shape == "none" then + init.shape = "rectangle" + end + + -- Call binding + binding:createVertex(init) + + local v = assert(scope.node_names[init.name], "internal node creation failed") + + -- Add vertex to the algorithm's digraph and ugraph + algorithm.syntactic_component:add {v} + algorithm.digraph:add {v} + algorithm.ugraph:add {v} + + -- Compute bounding boxes: + LayoutPipeline.prepareBoundingBoxes(algorithm.rotation_info, algorithm.adjusted_bb, algorithm.digraph, {v}) + + -- Add the node to the layout stack: + add_to_collections(algorithm.layout, "vertices", v) + + algorithm.layout_graph:add { v } + + return v +end + + + +--- +-- Generate a new edge in the syntactic digraph. This method is quite +-- similar to |createVertex| and has the same effects with respect to +-- the edge: The edge is added to the syntactic digraph and also to +-- all layouts on the layout stack. Furthermore, appropriate edges are +-- added to the |digraph| and the |ugraph| of the algorithm currently +-- running. +-- +-- @param algorithm An algorithm for whose syntactic digraph the node should be added +-- @param tail A syntactic tail vertex +-- @param head A syntactic head vertex +-- @param init A table of initial values for the edge. +-- +-- The following fields are useful for |init|: +-- % +-- \begin{itemize} +-- \item |init.direction| If present, a direction for the edge. Defaults to "--". +-- \item |init.options| If present, some options for the edge. +-- \item |init.generated_options| A table that is passed back to the +-- display layer as a list of key-value pairs in the syntax of +-- |declare_parameter|. +-- \end{itemize} + +function InterfaceToAlgorithms.createEdge(algorithm, tail, head, init) + + init = init or {} + + -- Setup + local scope = InterfaceCore.topScope() + local binding = InterfaceCore.binding + local syntactic_digraph = algorithm.layout_graph + local syntactic_component = algorithm.syntactic_component + + assert (syntactic_digraph:contains(tail) and + syntactic_digraph:contains(head), + "attempting to create edge between nodes that are not in the syntactic digraph") + + local arc = syntactic_digraph:connect(tail, head) + + local edge = Edge.new { + head = head, + tail = tail, + direction = init.direction or "--", + options = init.options or algorithm.layout.options, + path = init.path, + generated_options = init.generated_options + } + + -- Add to arc + arc.syntactic_edges[#arc.syntactic_edges+1] = edge + + local s_arc = syntactic_component:connect(tail, head) + s_arc.syntactic_edges = arc.syntactic_edges + + -- Create Event + local e = InterfaceToDisplay.createEvent ("edge", { arc, #arc.syntactic_edges }) + edge.event = e + + -- Make part of collections + for _,c in ipairs(edge.options.collections) do + LookupTable.addOne(c.edges, edge) + end + + -- Call binding + binding.storage[edge] = {} + binding:everyEdgeCreation(edge) + + -- Add edge to digraph and ugraph + local direction = edge.direction + if direction == "->" then + algorithm.digraph:connect(tail, head) + elseif direction == "<-" then + algorithm.digraph:connect(head, tail) + elseif direction == "--" or direction == "<->" then + algorithm.digraph:connect(tail, head) + algorithm.digraph:connect(head, tail) + end + algorithm.ugraph:connect(tail, head) + algorithm.ugraph:connect(head, tail) + + -- Add edge to layouts + add_to_collections(algorithm.layout, "edges", edge) + +end + + + + + +-- Done + +return InterfaceToAlgorithms |