Re: [Emacs.app dev]: ghost cursor problem is still there

[Adrian Robert]

On Aug 20, 2008, at 1:22 AM, David Reitter wrote:

> Adrian et al,
>
> On 22 Jul 2008, at 09:41, David Reitter wrote:
> > The main changes are that we check cursor_type instead of  
> > cursorType and draw the text glyph rather than the cursor when  
> > erasing anything (`hl' variable).  There's a range of steps that we  
> > do to ensure that the cursor area is actually visible; I'm not sure  
> > if they are really needed, but the corresponding X code does it, too.
> > There is a good bit of guess-work involved, but I'm sure that  
> > testing will take care of any problems.
>
> OK, in my latest build, things work a lot better and the original  
> blink-cursor-mode appears to work fine now.  (I don't quite  
> understand which change made the event mechanisms work better.)

This is great news.


> To repeat, these changes address the following issues:
>
> - frame background rather than the right glyph in the white-out  
> phases during blinking
> - `cursor-type' variable as in core Emacs, rather than NS specific  
> solution
> - with it, support for things like (box . 2)
> - box/hollow cursors too narrow

OK, these were from before.


> - standard blink-cursor-mode with all its bells and whistles  
> (whether one needs them or not)

This is new, and good.


> I would also take the blink rate stuff out of the preferences (a  
> patch to the nib) - it doesn't work with the generic blinking code  
> and I believe it's there for historic reasons (because the NS port  
> implemented blinking separately) rather than because it would be  
> very important to have for users (one could think of much more  
> important settings that could be there).

This is a matter of opinion and at least I personally find blink and  
other cursor attributes I like to change easily and frequently.  It  
should be an extremely simple matter to update the prefs controller  
code to set the core emacs blink rate, and I will do so once you've  
checked your changes in.  The prefs window may be removed completely  
before 23.1 as it faces hostility from many quarters so I'd rather  
keep it fully functional until then.


> The occasional ghost cursors seem to remain.

I've been occasionally looking at this when I've had the chance.  It  
has not been easy to track down.  I get it (Leopard) in latest source  
and for a while back to around the merge, but not in rc2a.  I think  
the best chance will be to try to find the first date/version when the  
problem appeared and then diff the source code (xdisp.c, dispnew.c,  
and xterm.c will probably tell the story).  If anyone has information  
on this, please post it.


> Any objections?

I'm fine with this being committed.


thanks,
Adrian