Re: Obtain X / HPOS with move_it_to at eol when buffer-display-table line-feed

[Keith David Bershatsky <esq@lawlist.com>]

Thank you, Eli, for the suggestion to stop IT before it gets to the new line (which is displayed using the display-table entry).

The argument of it.last_visible_x is important for the very last line of the visible window, or else IT will not continue looking for POS until it reaches the window-end.

I am assuming by your comments that we are looking for EOL_POSITION minus 1 point, and from there I should examine the character at that location to obtain its width and then add that width to it.current_x in order to get the X of the pilcrow beginning ....

This is a work in progress and I'll keep plugging away as time permits.

Keith

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

DATE:  [08-30-2017 12:03:52] <30 Aug 2017 22:03:52 +0300>
FROM:  Eli Zaretskii <eliz@gnu.org>
> 
> * * *
> 
> > With respect to eol pilcrows, move_it_to gives X and HPOS coordinates for an invisible \n to the right of the pilcrow.  We essentially have ¶\n, and IT cannot see the pilcrow.  The X and HPOS returned by move_it_to gives us ¶|\n instead of |¶\n.  Stated another way, X and HPOS are reported as being on the end of the pilcrow, instead of the beginning of the pilcrow.
> 
> But this is because you told move_it_to to move to the end of the
> screen line, by specifying it.last_visible_x - 1 as the X coordinate.
> What happens if you tell it to stop at the buffer position of the
> newline instead?
> 
> > Perhaps there is some way to help move_it_to see the pilcrow, or at least pretend that it exists?
> 
> move_it_to always stops when it delivers characters from the buffer,
> so if there are display or overlay strings, or glyphs come from a
> display table, it will go on until those are exhausted, and it is back
> at the next character from buffer text.  So you should try stopping it
> before it gets to the newline, which is displayed using the
> display-table entry.