zcurses scrolling

zcurses scrolling

[Ray Andrews]

All:

I'm experimenting with mouse input and getting strange results with the 
scrolling wheel. If I grab input like this:

     zcurses input status key keypad

... then the scroll wheel returns either 'UP' or 'DOWN' in '$keypad'. So 
it simulates the arrow keys, which is logical and it works fine. 
However, when I attempt to handle mouse events explicitly:

     zcurses input status key keypad mouse

... things change.  Now, if I scroll up:

     $keypad is 'MOUSE' and
     $mouse is  '0 40 18 0 PRESSED4'

... but if I scroll down:

     $keypad is 'MOUSE' and
     $mouse is  [unset]

So if I want to capture mouse clicks (which is working fine) then I'm 
not able to capture scrolling down, tho I can capture scrolling up.

Re: zcurses scrolling

[Ray Andrews]

On 11/17/2015 09:34 AM, Ray Andrews wrote:
> All:
>
> I'm experimenting with mouse input and getting strange results with 
> the scrolling wheel. If I grab input like this:
>
No advice on my troubles with zcurses gentlemen?  I've come up with this 
hack:


n_get_key () # Capture keystroke or mouse action:
{
     # Clear input buffer, doing this here reduces typeahead :-)
     MSG=  # New keystroke will erase old MSG.
     NKEY= # NB, must do this, or ^C goes strange when searching.
     MOUSE=()
     zcurses timeout status 0        # Need this, or first keystrokes 
disappear.
     zcurses input status key keypad # w.o. this, typeahead is much worse.
     zcurses timeout status -1       # This is essential.
     typeset -g _flag
     local key= keypad= mouse=
     zcurses input status key keypad mouse

     # Get the "keypad" key or regular key:
     NKEY="$key"
     [ -z "$NKEY" ] && NKEY="$keypad"
     [ -z "$NKEY" ] &&
         { n_status_msg "Improper input detected"; zcurses refresh status }

     MOUSE[X]="${mouse[2]}"
     MOUSE[Y]="${mouse[3]}"
     MOUSE[!]="${mouse[5]}"

     if [ "$NKEY" = 'MOUSE' ]; then
         if [ "$MOUSE[!]" = 'PRESSED4' ]; then NKEY='UP'; MOUSE[!]=
         elif [ -z "$MOUSE[!]" ] && [ "$_flag" != '1' ]; then
             NKEY='DOWN'; MOUSE[!]=
         # Otherwise a slow click becomes a 'DOWN'!!
         elif [ -n "$MOUSE[!]" ]; then
             if [ "$MOUSE[!]" = 'PRESSED1' ]; then _flag=1; else _flag=0; fi
         fi
     fi
}

I've restored the scroll wheel's output to UP and DOWN so that no 
special handling is needed, and I can capture mouse clicks, but there's 
a gotcha: If your click timing is not perfect, then you get a click and 
a DOWN thrown in as a bonus.  The above more or less works, but should 
it be necessary?  Should not up-scrolling and down-scrolling be handled 
the same way?  In the SRC there's code for 'PRESSED5' which I guessed 
might be down-scrolling, but it won't compile if defined and it's 
commented as being only available in 64 bits.  But could it really be 
the case that we can't handle down-scrolling in 32 bits?  Hard to believe.

"zcurses mouse 500" gave me a segmentation fault.