[FF] - 2009-02-18 - This widget is a [canvas] specialized for dataflow [http://en.wikipedia.org/wiki/Dataflow] software. It features high level operations, as adding, moving, editing, removing, connecting and track objects. Other relevant features include: [OO]-design (by using the new [TclOO], completion, gui objects, (minimal) internal dataflow capability.

The class loading mechanism is defined in DataflowCanvas::enumClasses. By default it looks for subclasses of DataflowClass, so it is possible to add classes which specify how many inlet/outlets object instances will have, and manage their initialization parameters.

[http://dev.gentoo.org/~mescalinum/tclwiki-img/DataflowCanvas01.png]

----
Example: we are going to create a `+` class, which performs the `f(x, y) = x + y` function, so it has two inlets (inbound connections), and one outlet (outgoing conn.).

======
oo::class create + {
    superclass DataflowClass
    method setup {args} {
        my variable state
        set state {0 0}
        return {inlets 2 outlets 1}
    }
    method inlet {n args} {
        my variable state
        lset state $n $args
        if {$n == 0} {
            my outlet 0 [expr [join $state +]]
        }
    }
}
======

The resulting patch:

[http://dev.gentoo.org/~mescalinum/tclwiki-img/DataflowCanvas02.png]

`entry` and `scale` classes (found in source distribution) have been used to interact with the object

----
[Drawing Diagrams] may be related to this package

----
[AMG]: Interesting.  I am working on a project that has a dataflow model.  Perhaps I can find some inspiration in your work, and maybe I can even use it as a graphical front-end.  Will you post a link to the sources soon?

----
!!!!!!
%| enter categories here |%
!!!!!!