Re: move_panel not working with pads

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On Tue, Jun 16, 2026 at 08:11:08PM +0300, Giorgos Xou wrote:
> Why, though? PADs are WINDOWs, just special ones.

man newpad:

       A curses pad is like a window, except that it is not restricted  by =
 the
       screen size, and is not necessarily associated with a particular par=
t of
       the  screen.   Pads can be used when a large window is needed, only =
part
       of which is to be visible on the screen.  Pads are not automatically=
 re=E2=80=90
       freshed by scrolling or input-echoing operations.
=20
man new_panel:

       Panels  are  ncurses(3NCURSES) windows with the added property of de=
pth.
       Panel functions allow the use of stacked windows  and  ensure  that =
 the
       proper  portions  of each window and the curses stdscr window are hi=
dden
       or displayed when panels are added, moved, modified,  or  removed.  =
 The
       set of currently visible panels is the stack of panels.  The stdscr =
win=E2=80=90
       dow is beneath all panels, and is not considered part of the stack.

The panel library really wants to know how big (on the screen) and where
a window will be put when ncurses wants to repaint it.  Those details are
set -- on each prefresh or pnoutrefresh call - by the calling application.

subpad creates a window in a pad.  If there were a lot of panel & pad users,
it might be useful to provide a function that creates a pad in a window.
Having that, the way to put a pad in a panel would be this hypothetical
function -- leaving panel handling windows.

> On Tue, Jun 16, 2026 at 7:12=E2=80=AFPM Juergen Pfeifer <juergen@familiep=
feifer.de>
> wrote:
>=20
> > IMHO the panel library should be modified to return an error if one tri=
es
> > to wrap a PAD with a PANEL. PANELs are/were intended for WINDOWs.
> >
> > J=C3=BCrgen
> >
> > Am 16.06.2026 um 04:43 schrieb Giorgos Xou <[email protected]>:
> >
> > =EF=BB=BF
> >
> >
> > ---------- Forwarded message ---------
> > From: Giorgos Xou <[email protected]>
> > Date: Tue, Jun 16, 2026 at 4:35=E2=80=AFAM
> > Subject: Re: move_panel not working with pads
> > To: Thomas Dickey <[email protected]>
> >
> >
> > On Mon, Jun 15, 2026 at 07:11:11PM -0400, Thomas Dickey wrote:
> > > On Mon, Jun 15, 2026 at 06:12:27PM -0400, Bill Gray wrote:
> > > > On 6/15/26 16:56, Thomas Dickey wrote:
> > > > > On Mon, Jun 15, 2026 at 02:57:45PM -0400, Bill Gray wrote:
> > > > > >     Hmmm... please post the test code you're using for this?  H=
ave
> > you tried
> > > > > > it with PDCursesMod?  (Its panel library is a near-total rewrit=
e,
> > but its
> > > > > > move_panel() does use mvwin() internally.)
> >
> > No, I haven't tested it against PDCursesMod nor PDCurses, it was just a
> > speculation
> > considering it uses mvwin internally too.
> >
> >
> > > > >
> > > > > yes... a test-program is needed to see how it compares with the
> > > > > various implementations :-)
> >
> > Here's a simple test-program i guess :-D
> >
> > ```
> >     #include <curses.h>
> >     #include <panel.h>
> >
> >
> >     int main( void)
> >     {
> >         int ch =3D -1;
> >         int y =3D 0, x =3D 0;
> >         WINDOW *pad1;
> >         PANEL  *panel1;
> >
> >         initscr    ();
> >         noecho     ();
> >         start_color();
> >
> >         init_pair(1, COLOR_BLUE, COLOR_RED);
> >         keypad(stdscr, TRUE);
> >
> >         refresh();
> >
> >         pad1 =3D newpad(10,10);
> >
> >         wbkgd   (pad1, COLOR_PAIR(1));
> >         waddstr (pad1,"Test.");
> >         prefresh(pad1, 0, 0, 1, 2, 4 , 9);
> >
> >         panel1 =3D new_panel(pad1);
> >
> >         while(ch !=3D 'q' && ch !=3D 'Q')
> >         {
> >             ch =3D getch();
> >
> >             if      (ch =3D=3D KEY_UP   ) ++y;
> >             else if (ch =3D=3D KEY_DOWN ) --y;
> >             else if (ch =3D=3D KEY_RIGHT) ++x;
> >             else if (ch =3D=3D KEY_LEFT ) --x;
> >
> >             move_panel(panel1, y, x);
> >             update_panels();
> >         }
> >         endwin( );
> >         return(0);
> >     }
> > ```
> >
> > > >
> > > >    It occurs to me to wonder : is the panel library warranteed to w=
ork
> > if
> > > > you feed it a pad (or subpad or sub-window) instead of a plain old
> > window?
> > > > I've never tried it.
> >
> > Had the same thoughts, never tried it too.
> >
> > > >
> > > >    Is there a use case for calling new_panel( ) with a pad?
> >
> > Pads are really useful with anything involving scrollable text (such as
> > logs, lists, fancy-tuifimanager stuff etc.).
> >
> > As you already know, the main appeal of panels is the fact that they
> > solve the flickering issue of stacked windows in a more elegant way
> > than manually doing so.
> >
> > Therefore pads with panels are practically useful for anything that
> > already previously involved plain old stacked-windows but with
> > too-much text.
> >
> > A few practical examples I can think of using pads with panels are
> > thinks like:
> > - https://www.reddit.com/r/neovim/comments/1u49mnw/
> > - https://www.reddit.com/r/commandline/comments/1tbfeua/
> > - https://github.com/reekta92/graf
> > - plus, fancy modern-TUI animations?
> >
> >
> > >
> > > maybe - but pads differ from windows by being more readily movable
> > >
> > > >
> > > > -- Bill
> > > >
> > > > > > -- Bill
> > > > > >
> > > > > > On 6/15/26 14:20, Giorgos Xou wrote:
> > > > > > > move_panel internally uses mvwin, which doesn't work with pads
> > (pdcurses
> > > > > > > seems to be affected by this as well). Maybe pnoutrefresh cou=
ld
> > be used
> > > > > > > internally for that specific case or some kind of an alternat=
ive
> > new
> > > > > > > mvpad function?
> > > > > > >
> > > > > > > (It just happened that I was again looking deep into how pane=
ls
> > work
> > > > > > > internally and just happened to stumble upon this issue.)
> > > > > > >
> > > > > > > *Cross-refs: *
> > > > > > > 3. ncurses 6.3 - patch 20211106 <
> > https://github.com/mirror/ncurses/commit/f399f54c6c4ea2143afcbf704ce9af=
0be52b63fc
> > >
> > > > > > > 2. hide_panel/show_panel not working with pads.
> > > > > > > <
> > https://lists.gnu.org/archive/html/bug-ncurses/2021-10/msg00037.html>
> > > > > > > 1. https://github.com/wmcbrine/PDCurses/issues/124
> > > > > > > <https://github.com/wmcbrine/PDCurses/issues/124>
> > > > > >
> > > > > >
> > > > >
> > > >
> > >
> > > --
> > > Thomas E. Dickey <[email protected]>
> > > https://invisible-island.net
> >
> >
> > PS. For some reason html "reply via email to" didn't work and I had to
> > figure out how (this cool thing that is called) neomutt works. so I've
> > no idea how this mail will be sent or if it actually was sent
> > correctly.
> >
> >

--=20
Thomas E. Dickey <[email protected]>
https://invisible-island.net

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