# panel 3x

    panel(3x)                                                            panel(3x)

## 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);

## DESCRIPTION

           Panels  are  curses(3x) windows with the added feature of depth.  Panel
           functions allow the use of stacked windows and ensure the  proper  por-
           tions  of  each  window and the curses stdscr window are hidden or dis-
           played 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  curses(3x),  make  only
           high-level curses calls, and work anywhere terminfo curses does.

## FUNCTIONS

           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.

           update_panels
                  refreshes  the  virtual  screen to reflect the relations between
                  the panels in the stack, but does not call doupdate  to  refresh
                  the  physical  screen.   Use  this  function and not wrefresh or
                  wnoutrefresh.  update_panels may be called more than once before
                  a call to doupdate, but doupdate is the function responsible for
                  updating the physical screen.

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

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

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

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

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

           move_panel(pan,starty,startx)
                  moves the given panel 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, to  move  a
                  panel window.

           replace_panel(pan,window)
                  replaces  the  current  window of panel with window (useful, for
                  example if you want to resize a panel; if you're using  ncurses,
                  you  can  call  replace_panel on the output of wresize(3x)).  It
                  does not change the position of the panel in the stack.

           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(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.

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

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

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

## 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 suc-
           cessfully and ERR if not.

## 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 cau-
           tioned not to directly use PANEL fields.

           The functions show_panel and top_panel are identical in this  implemen-
           tation,  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 compat-
           ibility 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.

           Aside  from  ncurses,  only  systems  based  on SVr4 source code, e.g.,
           Solaris provide this library.

## FILES

           panel.h interface for the panels library

           libpanel.a the panels library itself

## SEE ALSO

           curses(3x), curs_variables(3x),

           This describes ncurses version 6.2 (patch 20200212).

## AUTHOR

           Originally written by Warren Tucker <wht@n4hgf.mt-park.ga.us>,  primar-
           ily  to  assist  in  porting u386mon to systems without a native panels
           library.  Repackaged for ncurses by Zeyd ben-Halim.

                                                                         panel(3x)