[orca-list] orca and scripts, part 1

[José Vilmar Estácio de Souza <vilmar informal com br>]

Hi all.
As promised in the previous email, I will try to write something about 
how to build scripts in Orca.
I do not have much knowledge on the subject but I will try to pass what 
I learned.

Criticism, suggestions, corrections, questions or beers are welcome!

This is the part 1.
First some recommendations:

1. Learn how to build and install orca from the git repository. There 
are messages in the list with instructions.
2. Try to become familiar with the use of git. Things that you should know.
a. How to configure git so that git knows your name and your e-mail.
b. How to clone a repository (git clone).
c. How to update a local repository (git pull).
d. How to create/remove a branch. (git branch).
e. How to switch between branches (git checkout).
f. How to create a patch (git format-patch) or (git diff).
g. How to apply a patch (git apply).
Probably there are more.

3. If you plan to change orca, grab a copy directly from the git 
repository. The git clone command is your friend. Create a new branch to 
experiment your changes.

4. You need to know python since orca is written in that language.


Orca  works  with  applications and toolkits that support the Assistive 
Technology service Provider Interface (AT-SPI). Orca reacts to events 
created by at-spi. If I understood correctly, the applications uses 
at-spi to generate events according to the operation performed by the 
application. If for exemple an application receives the focus, an event 
is created to inform orca that an application received the focus. If the 
caret is moved, another event is generated to inform orca that the caret 
was moved.

Orca receives the event, load a script associated to the application 
that generated the event and execute a function associated to that 
event. Seems that there is in the script one function for each kind of 
event.

If orca does not find a script associated to the application that 
generated the event, a script called default.py is loaded.


One script is  a python class that extends another script and in general 
it is present in the following folder:
src/orca/scripts/apps/.
Inside that folder there are a folder for each application.
For exemple:
src/orca/scripts/apps/gedit
src/orca/scripts/apps/Banshee

The script default.py, the script that is loaded when there is no script 
to the current application, stays in the following folder:
src/orca/scripts/.


I'll stop here but will write more soon.
I hope these information are of any use. Feel free to suggestions / 
corrections.
A Happy New Year to all.
Thanks.



 s


--
[]s  José Vilmar Estácio de Souza