Re: yank-media: allow users to limit image types that can be inserted

[Visuwesh <visuweshm@gmail.com>]

[திங்கள் செப்டம்பர் 23, 2024] Eli Zaretskii wrote:

>> Date: Sun, 22 Sep 2024 13:53:06 -0300
>> From: pinmacs <pinmacs@cas.cat>
>> 
>> I submitted the following Feature Request in the orgmode list [1]. They 
>> said that the second part related to "limitting image types that can be 
>> inserted" should be done in the core emacs side.
>> 
>> In that same thread [1], Ihor proposed different ways to implement it 
>> [2], I also took how it explained the feature as part of this email-subject.
>> 
>> The thing is that with orgmode we can easily attach images to buffer 
>> thanks to `yank-media' feature, but there is a dialogue we cannot skip 
>> and that is: selecting image types. Find attached an image file 
>> "selecting-image-types.png", where you can see the 7 candidates for a 
>> screenshot I did to serve as an example.
>> 
>> 1. In case I want to be fast, I would like to skip that dialog entirely 
>> and just use the image/png variant.
>> 2. In another perspective, I would consider that the relevant decision 
>> for a screenshot would be between two of them: image/png and image/jpeg
>> 3. Another user could argue why the other 5 types are interesting in 
>> general or for their particular use case...
>> 
>> ... but let's stop that discussion here. Looks like filtering image 
>> types would be a useful customization for the users. If done as a 
>> variable, in certain cases, that could be local binded and specific to 
>> some fast function that immediately inserts an image, and in another 
>> case, the global var would select only those image types relevant for 
>> that particular user.
>> 
>> That is also positive if users want to add even more image types, with a 
>> good and reasonable default, users will not worry about too many options 
>> at some point.
>
> Isn't this already possible by using yank-media-handler to register
> only the handlers the Lisp program wants to handle?  If that doesn't
> fit the bill, please explain why.

When you copy an image in Firefox, it puts both image/png and image/jpeg
in the clipboard.  The Lisp program could register a handle for
image/png but if the non-Emacs program puts only, say, image/jpeg then
we wouldn't be able to handle the image anymore.  For the most part, the
Lisp program wouldn't care about the specific format of the image but
the fact that it is an image.  An user option that would tell the
preferred type in the presence of _multiple_ matches for the handler's
regexp would be nice to have.