[orca-list] Status update for Orcas new Plugin System Level 1

[chrys <chrys linux-a11y org>]

Howdy Joanie, Howdy List,

I just did some more work the last days. Just a small update what i did.

1. I created a new class "orca" in orca.py. this should represent the applications main class in mid term future. We should move all "global" functionality into this to have an entry point for references for our plugins (like already suggested by Andy Borka). I already added some API for signal handling and dynamic storage of objects. last is currently used to have some "compatibility" and keeps all of orcas internal stuff. this should be moved step by step to "real" objects. The handling of dynamic objects is there to register stuff by plugins what could be used by others (as libpeas supports dependencies in plugins, this could be very useful).
2. A simple API helper class what supports me a little with a useful functions library.
   
3. Time Plugin: Works! but it currently uses an hard coded shortcut. the binding API of orca is not very friendly to consume. i still have to figure how to get shortcuts for given functionality with loop through list every time. I will come up with some nice compatibility solution here. The User settings of Time is already respected as expected. the shortcut is the default one Orca + t. I removed the build-in functionality completely
   
4. Date Plugin: same situation as for time (hard coded shortcut, user settings respected). the double tap  shortcut (pressing t two times fast Orca + t) works here as well.
5. Mouse Review: Works! japp, it reads the object below the mouse pointer for me :)! i completely removed the build-in functionality. It for some quirks in the default.py and web/script_utilities.py are solved by the dynamic API usage. but the plugin is optional. if its not loaded, the stuff still works as expect. i reused almost all the code with some kind of compatibility replace global import of modules by have global variables set by the plugin activation. it respect the settings on startup. toggle shortcut is registered :) but hard coded to orca + e.
   

whats missing (well, as expected, as we wanna take that in an next step):

• the settings are mostly respected but the keybinding definition stuff.
  
• any UI handling

@Joanie, let me clean up some stuff then we could take a look at it and take the next step.

cheers chrys