On Thu, 2007-07-19 at 17:18 -0500, Glimmer Labs wrote:
We have developed a feature which allows Scheme Scripting from a console inside of Inkscape.
Wow, lots of code. This e-mail is going to get long, sorry in advance.
I really thought that Python would be the first language implemented for internal scripting with all the Python folks around. But, I'd vote for Scheme personally :)
BTW, what is "Glimmer Labs"?
The tar file included at the directory below contains a README with directions to aid in the process of installing the patch contained in the tar file. The README also has instructions on running the console.
First off, some housekeeping things. The tarball that you posted has a lot of extra things like .a files and the Linux penguin as an SVG file. While fun, it would probably be easier for people to download the file if those were removed. If you've used Subversion (which it appears you have as there are subversion files included also) you can just do an "svn diff" which will give you a diff to the upstream repository. Then the whole thing, new files and all (if added through 'svn add') will be in one large patch file.
What problem were you trying to solve by adding the 'update' flag to the document object? I'm concerned that this is working around some synchronization issue that has broader implications in the codebase. Perhaps we have a different way of solving that problem.
I notice that you've included some source code called "tinyscheme". Is there are reason to use that over guile's bindings? I'm curious because it would be nice if we didn't have maintain code for a scheme interpreter in our codebase. Linking to one that is already maintained is a bonus.
I'm a little bit concerned over the interface between C++ and Scheme. I think it might be a little too high level as there is a lot of code duplicated between the Inkscape code base and the function implemented for the interface. I still think the functions are useful, but perhaps a better place to put them is in Scheme. For example (please excuse my rusty Scheme):
Add an interface function:
(define inkscape-call-verb (lambda (desktop verbname) () ))
And then a function like 'desktop_exit' can be implemented like:
(define desktop_exit (lambda (desktop) (inkscape-call-verb desktop 'FileQuit')))
But then it becomes really easy to implement:
(define desktop_close (lambda (desktop) (inkscape-call-verb desktop 'FileClose')))
or
(define selection_path_union (lambda (desktop) (inkscape-call-verb desktop 'SelectionUnion')))
Without editing any C code. It also allows script writers to quickly use any new functionality that is added to the main codebase without the scheme interface being updated.
This can also effect the XML side. Imagine this:
(define rectangle (lambda (desktop layer x y w h) ( let ((layerNode (getElementById (inkscape-desktop-document desktop) layer)) (node (createElementNS (inkscape-desktop-document desktop) "svg" "rect"))) (appendChild layerNode node) (setAttributeNS node "svg" "x" x) (setAttributeNS node "svg" "y" y) (setAttributeNS node "svg" "width" w) (setAttributeNS node "svg" "height" h) node) ))
This would give a script writer the flexibility to add their own function with another line:
(setAttributeNS node "tedSpace" "whoDoWeLove" "ted")
A very requested feature :)
Lastly, (if you've made it this far) while I think a scheme console is cool I'm not sure how useful it is to most users. (Though, AutoCAD people seem to really like it). I think it would be really cool if you'd implement a subclass of Inkscape::Extension::Implementation that would use scheme. I'm thinking someone could define an extension something like this: (the INX file)
<inkscape-extension> <name>Draw Rectangle</name> <effect/> <scheme> (define effect lambda (desktop) ( rectangle desktop (selected-layer desktop) 100 100 100 100 ) </scheme> </inkscape-extension>
I think this would work well for normal users to have ways to select and run the scheme scripts developed from the effects menu directly.
--Ted