NAME

       panel - panel stack extension for curses

SYNOPSIS

       #include <panel.h>

       cc [flags] sourcefiles -lpanel -lncurses

       PANEL *new_panel(WINDOW *win);

       int bottom_panel(PANEL *pan);
       int top_panel(PANEL *pan);
       int show_panel(PANEL *pan);
       void update_panels(void);
       int hide_panel(PANEL *pan);

       WINDOW *panel_window(const PANEL *pan);
       int replace_panel(PANEL *pan, WINDOW *window);
       int move_panel(PANEL *pan, int starty, int startx);
       int panel_hidden(const PANEL *pan);

       PANEL *panel_above(const PANEL *pan);
       PANEL *panel_below(const PANEL *pan);

       int set_panel_userptr(PANEL *pan, const void *ptr);
       const void *panel_userptr(const PANEL *pan);

       int del_panel(PANEL *pan);

       /* ncurses-extensions */
       PANEL *ground_panel(SCREEN *sp);
       PANEL *ceiling_panel(SCREEN *sp);

DESCRIPTION

       Panels  are  ncurses(3NCURSES)  windows  with the added feature of depth.  Panel functions
       allow the use of stacked windows and ensure the proper portions of  each  window  and  the
       curses  stdscr  window  are  hidden or displayed when panels are added, moved, modified or
       removed.  The set of currently visible panels is the stack of panels.  The  stdscr  window
       is beneath all panels, and is not considered part of the stack.

       A  window  is associated with every panel.  The panel routines enable you to create, move,
       hide, and show panels, as well as position a panel at any desired location in the stack.

       Panel routines are a functional layer added to  ncurses(3NCURSES),  make  only  high-level
       curses calls, and work anywhere terminfo curses does.

FUNCTIONS

   bottom_panel
       bottom_panel(pan) puts panel pan at the bottom of all panels.

   ceiling_panel
       ceiling_panel(sp) acts like panel_below(NULL), for the given SCREEN sp.

   del_panel
       del_panel(pan)  removes  the  given  panel  pan  from the  stack and deallocates the PANEL
       structure (but not its associated window).

   ground_panel
       ground_panel(sp) acts like panel_above(NULL), for the given SCREEN sp.

   hide_panel
       hide_panel(pan) removes the given panel pan from the panel stack and thus  hides  it  from
       view.  The PANEL structure is not lost, merely removed from the stack.

   move_panel
       move_panel(pan,starty,startx)  moves  the  given panel pan's window so that its upper-left
       corner is at starty, startx.  It does not change the position of the panel in  the  stack.
       Be sure to use this function, not mvwin(3X), to move a panel window.

   new_panel
       new_panel(win)  allocates  a  PANEL structure, associates it with win, places the panel on
       the top of the stack (causes  it to  be  displayed above any other panel)  and  returns  a
       pointer to the new panel.

   panel_above
       panel_above(pan)  returns  a  pointer  to  the  panel above pan.  If the panel argument is
       (PANEL *)0, it returns a pointer to the bottom panel in the stack.

   panel_below
       panel_below(pan) returns a pointer to the panel just below pan.  If the panel argument  is
       (PANEL *)0, it returns a pointer to the top panel in the stack.

   panel_hidden
       panel_hidden(pan) returns TRUE if the panel pan is in the panel stack, FALSE if it is not.
       If the panel is a null pointer, return ERR.

   panel_userptr
       panel_userptr(pan) returns the user pointer for a given panel pan.

   panel_window
       panel_window(pan) returns a pointer to the window of the given panel pan.

   replace_panel
       replace_panel(pan,window) replaces the current window of panel pan  with  window  This  is
       useful, for example if you want to resize a panel.  In ncurses, you can call replace_panel
       to resize a panel using a window resized with wresize(3NCURSES).  It does not  change  the
       position of the panel in the stack.

   set_panel_userptr
       set_panel_userptr(pan,ptr) sets the panel's user pointer.

   show_panel
       show_panel(pan)  makes  a  hidden  panel visible by placing it on top of the panels in the
       panel stack.  See COMPATIBILITY below.

   top_panel
       top_panel(pan) puts the given visible panel pan on top of all panels in  the  stack.   See
       COMPATIBILITY below.

   update_panels
       update_panels()  refreshes  the virtual screen to reflect the relations between the panels
       in the stack, but does not call doupdate(3X) to refresh the  physical  screen.   Use  this
       function and not wrefresh(3X) or wnoutrefresh(3X).

       update_panels  may be called more than once before a call to doupdate, but doupdate is the
       function responsible for updating the physical screen.

DIAGNOSTICS

       Each routine that returns a pointer returns NULL if an error occurs.   Each  routine  that
       returns an int value returns OK if it executes successfully and ERR if not.

       Except  as  noted,  the pan and window parameters must be non-null.  If those are null, an
       error is returned.

       The move_panel function uses mvwin(3X), and will return  an  error  if  mvwin  returns  an
       error.

COMPATIBILITY

       Reasonable care has been taken to  ensure  compatibility with  the  native  panel facility
       introduced in System V (inspection of the  SVr4  manual  pages  suggests  the  programming
       interface  is unchanged).  The PANEL data structures are merely  similar.  The  programmer
       is cautioned not to directly use PANEL fields.

       The functions show_panel and top_panel are identical  in  this  implementation,  and  work
       equally  well  with  displayed  or  hidden panels.  In the native System V implementation,
       show_panel is intended for making a hidden panel visible (at the top  of  the  stack)  and
       top_panel  is  intended  for making an already-visible panel move to the top of the stack.
       You are cautioned to use the correct function to ensure compatibility  with  native  panel
       libraries.

NOTE

       In  your  library  list, libpanel.a should be before libncurses.a; that is, you should say
       “-lpanel -lncurses”, not the other way around (which would give a link-error  with  static
       libraries).

PORTABILITY

       The  panel facility was documented in SVr4.2 in Character User Interface Programming (UNIX
       SVR4.2).

       It is not part of X/Open Curses.

       A few implementations exist:

       •   Systems based on SVr4 source code, e.g., Solaris, provide this library.

       •   ncurses (since version 0.6 in 1993) and PDCurses (since version 2.2 in 1995) provide a
           panel  library  whose  common  ancestor  was  a public domain implementation by Warren
           Tucker published in u386mon 2.20 (1990).

           According to Tucker, the SystemV panel library was first released  in  SVr3.2  (1988),
           and his implementation helped with a port to SVr3.1 (1987).

           Several  developers  have  improved  each  of  these;  they  are no longer the same as
           Tucker's implementation.

       •   NetBSD 8 (2018) has a panel library begun by Valery Ushakov in 2015.  This is based on
           the AT&T documentation.

FILES

       panel.h interface for the panels library

       libpanel.a the panels library itself

SEE ALSO

       ncurses(3NCURSES), curses_variables(3NCURSES),

       This describes ncurses version 6.4 (patch 20230625).

AUTHOR

       Originally  written  by  Warren  Tucker  <wht@n4hgf.mt-park.ga.us>, primarily to assist in
       porting u386mon to systems without a native panels library.

       Repackaged for ncurses by Zeyd ben-Halim.

       Juergen Pfeifer and Thomas E. Dickey revised/improved the library.