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panel(3) Library calls panel(3)

panel - panel stack extension for curses

#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);

Panels are curses(3) 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 curses(3), make only high-level curses calls, and work anywhere terminfo curses does.

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

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

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

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

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(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(3), to move a panel window.

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(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.

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

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

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

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(3). It does not change the position of the panel in the stack.

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

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 pan on top of all panels in the stack. See COMPATIBILITY below.

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

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

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(3), and will return an error if mvwin returns an error.

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.

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).

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:

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.

panel.h interface for the panels library

libpanel.a the panels library itself

curses(3), curs_variables(3),

This describes ncurses version 6.4 (patch 20230826).

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.

2023-08-19 ncurses 6.4