RE: Precise locating rendered items

[James Lowe]

Jacek,
________________________________________
From: address@hidden address@hidden on behalf of Jacek Gajek address@hidden
Sent: 26 June 2011 23:06
To: lilypond-user
Subject: Precise locating rendered items

Hello!

I am developing an app in which user should be capable to place notes
on a staff. I don't want to implement a whole rendering engine, I
decided to use lilypond. Now.

My idea is to allow user to place notes by clicking on a prerendered
image by lily. All I need is to determine where did the user clicked.
Is it possible to get such characteristics from lily? Of course I
could scan an image and find staff lines etc., but that would be
implementation-dependant and ugly, so I would prefer to gather
objects' locations directly from lily. Is it possible?

-----

I am sure you will get other answers from people that know the code more. 
However by default, in case you were not aware the PDF files that are generated 
have links on the musical notes (as an example) that allow a user to click on 
the PDF and take it back directly to the .ly source.

See:

http://lilypond.org/doc/v2.14/Documentation/notation/available-music-functions#index-pointAndClickOn

However I don't have much experience with the code of this, there are also a 
couple of old threads

http://thread.gmane.org/gmane.comp.gnu.lilypond.devel/33382/focus=33390

is one.

I have done a quick look about the old devel and user lists but have not come 
up with anything else, but I know that a couple of people had asked for this or 
discussed this in the last 2 years with regard to generating clickable SVG as 
well as HTML output.

Maybe one of the others (Carl (who I see has had some dealings with the 
original 'pointAndClickOn' function) and Mike (who is part of the thread 
above)) can give you some guidelines?

James