[Geany-Devel] Plugin development questions

Matthew Brush mbrush at xxxxx
Tue Oct 8 01:22:07 UTC 2013

On 13-10-07 01:06 PM, Thomas Martitz wrote:
> Am 07.10.2013 21:53, schrieb Thomas Martitz:
>> Am 07.10.2013 12:27, schrieb v01d:
>>> Hi,
>>> I'm writing a simple plugin for geany (which I will call LiveDiff)
>>> which allows for having
>>> indicators inside the editor for changed/added/modified lines, which
>>> is updated as you type. The base for comparing
>>> the buffer can be either the version of the file on disk or (which I
>>> will soon attempt to add) the latest version from the git repository,
>>> if the file is versioned so.
>>> This resembles what netbeans does (one something I really liked). So
>>> far it works OK but there are some quirks.
>>> I'm doing this out of spare time so dont expect a pretty serious
>>> commitement to it. I will however make it available on github.
>>> I wanted to ask regarding the ScitillaObject handling. Currently my
>>> plugin needs to define RGBA markers (which are used to indicate the
>>> diff results per-line).
>>> What it is not really clear to me is that there appears to be one
>>> ScintillaObject associated with each GeanyDocument. However, some
>>> messages sent to the ScintillaObject (like changing the margin or
>>> defining markers) appear to be global across all instances (unless I'm
>>> mistaken). Is this so? What would be the proper handling? Is it ok to
>>> repeat the definition of the markers for each editor?
>>> Moreover, I'm not sure how to handle correctly the size of the RGBA
>>> markers since it depends on the font size of the editor. I tried to
>>> set the marker scale using the text_height to image height ratio, but
>>> the marker still appears to be a bit taller than the line and this
>>> creates some visual artifacts.
>> Hello,
>> [1] might be of interest for you. It does something very similar.
>> Regarding your other question, are you talking about the
>> "editor-notify" signal? Yes, that's not really per-document, I came
>> across this recently. The solution is to connect to "sci-notify" of
>> ScintillaObject directly, this will give a proper per-document signal
>> (the document-specific ScintillaObject pointer). However you need to
>> get the GeanyDocument pointer elsewhere. See how I did it here[2].
>> Some might consider this as a defect in Geany.
>> [1]: http://lists.geany.org/pipermail/devel/2010-June/002584.html
>> [2]:
>> https://github.com/kugel-/geany-plugins/commit/7f19c3035abf6f8a7fa66c7b4c1efe0851cb2f83
> I need to correct myself. "editor-notify" is correctly per-document and
> you can get the GeanyDocument pointer via the GeanyEditor pointer passed
> to it. What I meant to say is that you cannot use "editor-notify" if you
> need to attach user_data on a per-document basis. The user_data pointer
> passed to plugin_signal_connect("editor-notify", ...) will be
> overwritten on each successive all. My suggested workaround works for
> this case. With sci-notify you can attach user_data on a per-document
> basis.

As long as the Scintilla view doesn't switch document models, like some 
view recycling optimizations or split/multi view magic or something. I 
don't think anything actually does this at present, but it could in 
theory, without "breaking" the API, or it could even be done by another 

Last time I needed to do this, I made a hash table that used 
g_direct_hash on the GeanyDocument pointer as the key, and the value was 
my custom/user data structure. Then I had a function that effectively 
did this:

     void *document_get_context(GeanyDocument *doc) {
       return g_hash_table_lookup(global_hash, doc);

Then to keep it sync, I used code like this:


Where the dm_*() calls are keeping the hash table consistent with the 
current set of documents. It's kind of a lot of boiler-plate to attach 
data to a document, but it seems to work quite well :)

Matthew Brush

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