Re: Getting point-and-click working

[Aaron Hill]

On 2019-02-10 1:14 am, Andrew Bernard wrote:
> Didn't this come up in 2015 on the list here:
>
> https://lists.gnu.org/archive/html/lilypond-user/2015-06/msg00168.html

That's an interesting thread.  It turns up an alternate script [1] for 
handling the textedit: URI scheme, however curiously the script 
incorrectly interprets [2] the parameters of a link.  The proper format 
is "file:line:char:column" not "file:line:start:end".

[1]: https://github.com/markk/textedit-ly
[2]: 
https://github.com/markk/textedit-ly/blob/master/textedit.py#L29-L32

This scheme stems from ly:input-file-line-char-column (backed by 
Source_file::get_counts internally) which returns the zero-based 
character index and the one-based column number.  Of note, columns are 
computed assuming eight-wide tabulation.

It seems the script author was not aware of this scheme and assumed 
there was an off-by-one error, as they mention their solution "places 
the cursor at the character number in the url, rather than one character 
to the left".

Providing you do not use tab characters in your input files, you would 
see that 'column' will always be one more than 'char'.  It could be 
misinterpreted that this is a character range, rather than two different 
values.  As such, if you try to use 'char' as a column number rather 
than a character index, you will see a problem with editors that assume 
a one-based value.

The script in particular applies their fix when using vim, which is an 
editor that expects a one-based column number.  But adding one to 'char' 
(which is called 'start' in the script) is invalid if there are tab 
characters on the line, as you will still end up at a column left of 
where you would expect the cursor to be.

The solution is to ignore the 'char' value completely and only use 
'column' to launch vim with a command similar to the following:

    vim --remote '+:norm%(line)sG%(column)s|' %(file)s

(This is using the same Python-style substitution arguments expected in 
the LYEDITOR variable.)

-- Aaron Hill