[Geany-Users] new plugin for automatic alignment

[Matthew Brush]

On 2015-11-18 2:32 PM, Max Voss wrote:
> I also know the following:
>
> Listening to all editor notify notifications is bad, but I the python
> documentation doesn't really cover further filtering. I'm sure it's
> in the C++ docs, but I don't know how many and what parts made it
> from C++ to python. If you know how to do this filtering in python
> please do tell.
>

As you guessed, it's similar-ish to the C code, which is based on how 
Scintilla and GObject works (actually two different "styles" of async 
notifications; Win32 API messaging adapted to GObject signals-based API).

In your "main()" method (customarily called something similar to the 
signal name, like "on_editor_notify"), you need to change the signature 
to something like:


class AlignPlugin(geany.Plugin):
     ...
     def main(self, editor, notification):
         " Responds to signals from the Editor "
         # see 'help(geany.scintilla)' for codes
         if notification.nmhdr.code == geany.scintilla.ONE_OF_THE_CODES:
           # do stuff only when that message/signal is sent
           ...


For this plugin you probably want something like 
"geany.scintilla.MODIFIED" code. You can further filter it for only when 
text was added or removed, by checking the "modification_type" property 
on the "notification" argument as show above. It's a bitfield/flags for 
the kinds of changes that happened (see "help(geany.scintilla)" for 
listing as well). It might be useful to check whether the 
"MOD_INSERT_TEXT" or "MOD_DELETE_TEXT" bits are set. Depending on your 
algorithm, you might also check that the character typed was a newline 
(ex. using the "lines_added" property of the notification) or that the 
char was '=', or whatever suits the algorithm. The part in Geany that 
handles this signal, albeit in C, is here[0], it might give some ideas 
at least.

Sorry the docs suck. This part is fairly well documented generically by 
the Scintilla documentation[1], but adapting it to GeanyPy isn't exactly 
straightforward without digging around looking at the exposed objects 
(or reading its C source, ugh), and adapting from the C docs. It would 
be great to add more example plugins into GeanyPy showing (with loads of 
comments) how this kind of non-Python stuff works.

Feel free to ask any specific questions in devel list or on IRC or whatever.

Cheers,
Matthew Brush

[0]: https://github.com/geany/geany/blob/1.26.0/src/editor.c#L1014
[1]: http://www.scintilla.org/ScintillaDoc.html#Notifications