Re: [orca-list] Pluginsystem for Orca using libpeas

[Joanmarie Diggs <jdiggs igalia com>]

Two words: Woo hoo!

Yes, I think this is worth continuing and I'm super happy you've found
time for this! Totally agree also that Orca's code needs a major
refactor (several actually). There's just not enough time in the day.

I'm not sure what all falls under the heading of "Core". Could you list
some more examples?

Would system also include speech, braille, maybe flat review, mouse
review, etc.?

And I assume that as part of this work we can slowly but surely move
keybindings and settings management to these plugins rather than have
Orca itself manage them centrally. Is that your understanding as well?
If so, maybe we can *finally* move things over to gsettings as part of
this work.

A couple of hopefully easy to port things would be Orca's day-time
commands, and the notifications list. I need to totally rewrite Orca's
flat review find support. But once I get that working, hopefully it
should also be easy to port.

Lastly, for the GUI, we'll obviously need to add GUI in Orca to manage
the plugins. But then can we move all the other GUI (e.g. the current
page tabs in Orca's preferences) to the plugins themselves?

Anyhoo, you just made my day. Thanks!
--joanie

On Fri, 2021-06-04 at 23:41 +0200, chrys wrote:
> Hello Joanie, Hello list,
>
> i know there are plans to create a plugin system for orca. i created 
> SOPS to work around a bit but it does not replace something "real".
> Joanie suggested libpeas. I just got some spare time to dive into
> this. 
> I read some documentation about libpeas and it sounds very reasonable
> to 
> me. it provides all the stuff what a plugin system need already.
> libpeas plugin engine has the ability to load plugins wirtten python
> 2, 
> python 3, C, and Lua. what sounds very impressive. special C looks
> like 
> an benefit if we need to squeeze out every bit of performance.
> So i checked out how libpeas is working and started with an basic
> plugin 
> system for orca what i just want to introduce here.
>
> # Why i did this:
> - Orcas code needs IMO to be be cleaned. its a mixture of Object 
> Orientation and Procedual programming. Migrating things step by step 
> over to an plugin driven architecture would allow us to clean up
> thins 
> step by step and modernize it to an bright future :).
> - Users can easy share addons and additional functionality, well
> thats 
> the point of an plugin system :).
> - Users can overload orcas "core" plugins if different behave is 
> prefered or requred.
> - coding is fun
>
> # What i did:
> - I create a new Class PluginSystemManager what does all the plugin 
> handling and loading / unloading stuff
> - there are currently 3 types of plugins handled:
>      1. Core: the idea is to port in midterm orcas core functionality
> to 
> this plugin layer. it will provide the basic functionality what is
> not 
> allowed to be unloaded. its living in orcas install path
>      2. System: here we can deploy system wide plugins. those can be 
> activated and deactivated. its living in orcas install path
>      3. User: can be installed per user to be able to customize orca 
> individual or without root access. is living in the orca settings of
> the 
> user
> - an API class to share orcas API with the plugins. it contains the
> API 
> to fire signals and the signals itself. There are currently just 2
> signals:
>      1. start-orca: is fired after orca is completly initialized
>      2. stop-orca: is fired while stopping orca
> - an APIHelper class with some common stuff needed by the plugins
> more 
> often. Lets say a collection of useful functions.
> - integrate into build system
> - create 2 core plugins  and 3 system plugins just for prototyping
> and 
> try out different things. i reused some code from SOPS. The idea is
> to 
> shortcuts or connect to signals while an do_activate and remove them 
> while do_deactivate.
>      - The core Plugins:
>          1. HelloOrca: startup notification of orca, consuming the 
> "start-orca" signal (so you will hear "screenreader on" now twice,
> once 
> still hard coded, once by the plugin
>          2. ByeOrca: stop notification of orca, consuming the 
> "stop-orca" signal (so you will hear "screenreader off" now twice,
> once 
> still hard coded, once by the plugin
>      - The system Plugins
>          1. helloworld: just prints some debug output and says hello
> on 
> startup
>          2. SelfVoice: starts / stops an listening thread when plugin
> is 
> enabled. it waits for incoming text using unix sockets. the text is
> just 
> spoken.
>          3. Clipboard: registers an keyboard shortcut Orca + w. it 
> announces the content of the current clipboard
>
> # what is currently missing:
> - A GUI for Plugin management - a plugin manager (Enable Disable 
> Configure). Currently just all available plugins are loaded. i
> currently 
> work on this.
> - The setting management is not done yet. (not important as there is
> no 
> plugin  manager to change the settings currently lol)
> - integrate more events (this could happen by migrate the current 
> functionality step by step)
>
> what do you guys think?
> @Joanie, what do you think?
> is this worth to be continued?
>
> you can find my work currently on github:
> https://github.com/chrys87/orca-plugin
>
> sorry that i just started without ask or something. I don't want to
> make 
> anybody angry. i just tried and played a little. it was something
> like 
> an "selfrunner" + it was really fun to me to do so.
> IMO its an chance to modernize the codebase step by step.
>
> cheers chrys
>
>
>
>
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