Re: Simplification to mouse-avoidance-mode (patch) + redisplay bug?

[Jan Djärv]

> >                                       It is actually undefined how
> > many MotionNotify you will get when moiving the mouse, but you are
> > guaranteed to get one MotionNotify when the mouse movement stops.
>
> The problem is that the MotionNotify event that you get is not the
> final mouse position.

Then there is abug somewhere.  It could be in X but it could also be in Emacs 
event handling, i.e. we are not reading events even if they are in the X input 
queue.

> > A third thing to check is if the XWarpPointer requests are queued or
> > not.  You can add a call to XFlush after XWarpPointer and see if that
> > improves the situation.
>
> It actually makes the situation worse -- now the final mouse shape
> is wrong also when I type slowly, i.e. when I don't hit a key after
> the mouse cursor starts moving.

I hope you added x_flush, not XFlush.  I see now that XFlush is defined to be 
empty in xterm.c.  If an XSync after WarpPointer doesn't get you all events 
then there is a bug in X.

> > I tried, but could not reproduce the situation where the cursor shape
> > is wrong.  I'm sure it is timing related, i.e. events not sent or
> > received when expected to.
>
> So, it is probably a bug in the (old) version of Xfree that I'm using,
> and it looks like the bug is fixed in later versions.

Are you running with SYNC_INPUT or not?

> I tried to add an explicit call to note_mouse_highlight after the
> call to XWarpPointer, and it definitely has a positive effect,
> but even with that change, the pointer shape ends up wrong in
> some cases.
>
> I'm not sure how important it is to fix this, but there is 
> a patch which works for me -- of course a similar change
> is probably needed in x_set_mouse_pixel_position.

This patch has flaws, there may be several calls to XWarpPointer before we see 
any MotionNotify events.

        Jan D.

> *** xterm.c     10 May 2006 16:58:38 +0200      1.910
> --- xterm.c     11 May 2006 11:52:27 +0200      
> ***************
> *** 226,231 ****
> --- 226,233 ----
>   
>   static unsigned long ignore_next_mouse_click_timeout;
>   
> + static int ignore_next_motion_event;
> + 
>   /* Mouse movement.
>   
>      Formerly, we used PointerMotionHintMask (in standard_event_mask)
> ***************
> *** 6543,6548 ****
> --- 6545,6556 ----
>   
>       case MotionNotify:
>         {
> +       if (ignore_next_motion_event)
> +         {
> +           ignore_next_motion_event = 0;
> +           goto OTHER;
> +         }
> + 
>           previous_help_echo_string = help_echo_string;
>           help_echo_string = Qnil;
>   
> ***************
> *** 8453,8458 ****
> --- 8461,8471 ----
>   
>     XWarpPointer (FRAME_X_DISPLAY (f), None, FRAME_X_WINDOW (f),
>                 0, 0, 0, 0, pix_x, pix_y);
> + 
> +   last_mouse_motion_event.x = pix_x;
> +   last_mouse_motion_event.y = pix_y;
> +   note_mouse_movement (f, &last_mouse_motion_event);
> +   ignore_next_motion_event = 1;
>     UNBLOCK_INPUT;
>   }
>   
> ***************
> *** 10795,10800 ****
> --- 10808,10814 ----
>     last_tool_bar_item = -1;
>     any_help_event_p = 0;
>     ignore_next_mouse_click_timeout = 0;
> +   ignore_next_motion_event = 0;
>   #ifdef HAVE_X_SM
>     x_session_initialized = 0;
>   #endif
>
> --
> Kim F. Storm <address@hidden> http://www.cua.dk
>
>
>
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