Re: Allowing point to be outside the window?

[Po Lu]

Eli Zaretskii <eliz@gnu.org> writes:

>> Hmm, thanks.  One small question though: what should I do in order to
>> make a window's cursor invisible?

> Prevent display_and_set_cursor from being called, I presume?

What if the cursor is already displayed?  Is it OK to call
erase_phys_cursor from redisplay_window?

> There's also set_cursor_from_row, which calculates where to display
> the cursor, and something should be done about that to indicate that
> the cursor is not shown at all.

set_cursor_from_row can just immediately return if I indicate that the
cursor is invisible because point is before or after window start,
correct?

> display_and_set_cursor is also called from dispnew.c, so I'm not sure
> redisplay_window alone will be enough.

Hmm, thanks, I think I might put that logic in display_and_set_cursor
instead.

> And why only "before window start"? what about beyond window's end?

I don't know how to get that information inside redisplay_window.
AFAIU, it's not available until redisplay completes.

> I think you need to add something to the struct window's 'cursor' and
> 'phys_cursor' members.

Okay, I'll do that.

> You cannot express coordinates outside of the window as X/Y.

I meant "X/Y" question as in a question that goes somewhat like this:

 - User wants to do X.
 - User doesn't know how to do X, but thinks they can fumble their way
   to a solution if they can just manage to do Y.
 - User doesn't know how to do Y either.
 - User asks for help with Y.
 - Others try to help user with Y, but are confused because Y seems like
   a strange problem to want to solve.
 - After much interaction and wasted time, it finally becomes clear that
   the user really wants help with X, and that Y wasn't even a suitable
   solution for X.

I hope this isn't the case here, but I can't explain what the "X" here
is in terms more specific than "I want the ability to have point outside
the window".

Thanks in advance.