Lispvirt Announcements

Hi everybody!

I'd like to announce the first release (1.0.0) of Lispvirt: Common Lisp bindings for Libvirt.

You can download the source code from GitHub at:
https://github.com/jcfaracco/lispvirt

There you can find any instrunctions to install, test and use Lispvirt. There are some examples and tests to teach how to use the API. As this release is the first one, there is nothing to announce as a new feature.

This version is based on Libvirt (>= 1.2). So, if you are using an old version of libvirt, I cannot guarantee that Lispvirt will work.

Please, clone the code and enjoy!

If you want to contribute, please, send me a message, email, commits or anything you want.
We still need many tests to check if the API is correctly implemented, examples and some missing structures.

Any contribution is welcome and I would be glad if people help me. =D

How to Develop a Cairo Clock using Common Lisp and GTK+

A Short Introduction

In my last project based on Lisp and GTK+ Toolkit, I need to use some graphics to build a drawing module. Then, the best solution found was the use of cairo libraries to render this kind of graphics. The Cairo API provides anti-aliasing and a simple handling.  However, I didn't find some books or tutorials that show how I could do it. With some searchs at Google, I found a tutorial made by the author of the Cairo bindings for Common Lisp, but the article didn't show an Cairo integration with Gtk+.

Then, in our laboratory, we understood the source code of the Cairo bindings for Lisp and built a solution to implement a application Lisp based, using Gtk+ and Cairo.

If you interested yourself or only want to learn the Common Lisp Language, I suggest the on-line book: "Practical Common Lisp". A suggestions for people who want to start programming Lisp is download, or a Eclipse plug-in called Cusp, or use Emacs running Slime. You can install the essentials packages using the command line,

$ sudo apt-get install emacs23 sbcl slime cl-alexandria cl-asdf cl-babel cl-cffi cl-closer-mop cl-clg cl-trivial-features cl-swank

The source packages of cl-cairo2 can be found at Cliki cl-cairo2 project. The installation is so easy, you need to extract the source and paste it in ~/.sbcl/site/. After create the symbolic links of all .asd,

$ ln -s ~/.sbcl/site/YOUR_CAIRO_FOLDER/*.asd ~/.sbcl/systems

Now, you're ready to start developing common lisp, gtk+ and cairo applications.


Developing Lisp Apps using Cairo and Gtk+

First you need to import the libraries using Asdf,

(asdf:load-system :cl-gtk2-gtk)
(asdf:load-system :cl-cairo2)
(asdf:load-system :cl-cairo2-x11)

The assignment of cairo context can be made with,

...
(let ((cr (make-instance 'cl-cairo2:context
                     :pointer cr-p
                     :width draw-w
                     :height draw-h
                     :pixel-based-p t)))
             (setq cl-cairo2:*context* cr)
             (cl-cairo2:rectangle 0 0 500 500 cr)
             (cl-cairo2:clip cr)
             (draw-clock cr)))))
...

The function that draws the cairo clock is,

;; Function to create the clock from a Cairo context
(defun draw-clock (context)
   (setq radius 180)
   (cl-cairo2:set-source-rgb 1 1 1 context)
   (cl-cairo2:arc (/ draw-h 2) (/ draw-w 2) (/ radius 2) 0 (* 2 pi) context)
   (cl-cairo2:fill-path context)
   (cl-cairo2:set-source-rgb 0 0 0 context)
   (cl-cairo2:arc (/ draw-h 2) (/ draw-w 2) (/ radius 2) 0 (* 2 pi) context)
   (cl-cairo2:stroke context)

   ;; 0 to 11 hours
   (loop for i from 1 to 12 do
          ...
   )
)

Then, we finished an example of using Cairo and Gtk on Lisp.
You can download the source code here: cairoclock.lisp