path: root/lib/libpanel/panel.3

.\" $OpenBSD: panel.3,v 1.11 2023/10/17 09:52:10 nicm Exp $
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.\" $Id: panel.3,v 1.11 2023/10/17 09:52:10 nicm Exp $
.TH panel 3 2023-08-19 "ncurses 6.4" "Library calls"
.ie \n(.g .ds `` \(lq
.el       .ds `` ``
.ie \n(.g .ds '' \(rq
.el       .ds '' ''
.de bP
.ie n  .IP \(bu 4
.el    .IP \(bu 2
..
.SH NAME
panel \- panel stack extension for curses
.SH SYNOPSIS
\fB#include <panel.h>\fP
.P
\fBcc [flags] sourcefiles \-lpanel \-lncurses\fP
.P
\fBPANEL *new_panel(WINDOW *\fIwin\fB);\fR
.sp
\fBint bottom_panel(PANEL *\fIpan\fB);\fR
.br
\fBint top_panel(PANEL *\fIpan\fB);\fR
.br
\fBint show_panel(PANEL *\fIpan\fB);\fR
.br
\fBvoid update_panels(void);\fP
.br
\fBint hide_panel(PANEL *\fIpan\fB);\fR
.sp
\fBWINDOW *panel_window(const PANEL *\fIpan\fB);\fR
.br
\fBint replace_panel(PANEL *\fIpan\fB, WINDOW *\fIwindow\fB);\fR
.br
\fBint move_panel(PANEL *\fIpan\fB, int \fIstarty\fB, int \fIstartx\fB);\fR
.br
\fBint panel_hidden(const PANEL *\fIpan\fB);\fR
.sp
\fBPANEL *panel_above(const PANEL *\fIpan\fB);\fR
.br
\fBPANEL *panel_below(const PANEL *\fIpan\fB);\fR
.sp
\fBint set_panel_userptr(PANEL *\fIpan\fB, const void *\fIptr\fB);\fR
.br
\fBconst void *panel_userptr(const PANEL *\fIpan\fB);\fR
.sp
\fBint del_panel(PANEL *\fIpan\fB);\fR
.sp
\fR/* ncurses-extensions */\fP
.br
\fBPANEL *ground_panel(SCREEN *\fIsp\fB);\fR
.br
\fBPANEL *ceiling_panel(SCREEN *\fIsp\fB);\fR
.br
.SH DESCRIPTION
Panels are \fBcurses\fP(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 \fBstdscr\fP 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
\fBstdscr\fP window is beneath all panels, and is not considered part
of the stack.
.P
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.
.P
Panel routines are a functional layer added to \fBcurses\fP(3), make only
high-level curses calls, and work anywhere terminfo curses does.
.SH FUNCTIONS
.\" ---------
.SS bottom_panel
\fBbottom_panel(\fIpan\fB)\fR
puts panel \fIpan\fP at the bottom of all panels.
.\" ---------
.SS ceiling_panel
\fBceiling_panel(\fIsp\fB)\fR
acts like \fBpanel_below(NULL)\fP, for the given \fBSCREEN\fP \fIsp\fP.
.\" ---------
.SS del_panel
\fBdel_panel(\fIpan\fB)\fR
removes the given panel \fIpan\fP from the  stack and deallocates the
\fBPANEL\fP structure (but not its associated window).
.\" ---------
.SS ground_panel
\fBground_panel(\fIsp\fB)\fR
acts like \fBpanel_above(NULL)\fP, for the given \fBSCREEN\fP \fIsp\fP.
.\" ---------
.SS hide_panel
\fBhide_panel(\fIpan\fB)\fR
removes the given panel \fIpan\fP from the panel stack
and thus hides it from view.
The \fBPANEL\fP structure is not lost, merely removed from the stack.
.\" ---------
.SS move_panel
\fBmove_panel(\fIpan\fB,\fIstarty\fB,\fIstartx\fB)\fR
moves the given panel \fIpan\fP's window so that its upper-left corner is at
\fIstarty\fP, \fIstartx\fP.
It does not change the position of the panel in the stack.
Be sure to use this function, not \fBmvwin\fP(3), to move a panel window.
.\" ---------
.SS new_panel
\fBnew_panel(\fIwin\fB)\fR allocates a \fBPANEL\fR structure,
associates it with \fIwin\fP, 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.
.\" ---------
.SS panel_above
\fBpanel_above(\fIpan\fB)\fR
returns a pointer to the panel above \fIpan\fP.
If the panel argument is
\fB(PANEL *)0\fP, it returns a pointer to the bottom panel in the stack.
.\" ---------
.SS panel_below
\fBpanel_below(\fIpan\fB)\fR
returns a pointer to the panel just below \fIpan\fP.
If the panel argument
is \fB(PANEL *)0\fP, it returns a pointer to the top panel in the stack.
.\" ---------
.SS panel_hidden
\fBpanel_hidden(\fIpan\fB)\fR
returns \fBFALSE\fP if the panel \fIpan\fP is in the panel stack,
\fBTRUE\fP if it is not.
If the panel is a null pointer, return \fBERR\fP.
.\" ---------
.SS panel_userptr
\fBpanel_userptr(\fIpan\fB)\fR
returns the user pointer for a given panel \fIpan\fP.
.\" ---------
.SS panel_window
\fBpanel_window(\fIpan\fB)\fR
returns a pointer to the window of the given panel \fIpan\fP.
.\" ---------
.SS replace_panel
\fBreplace_panel(\fIpan\fB,\fIwindow\fB)\fR
replaces the current window of panel \fIpan\fP with \fIwindow\fP
This is useful, for example if you want to resize a panel.
In \fBncurses\fP, you can call \fBreplace_panel\fP
to resize a panel using a window resized with \fBwresize\fP(3).
It does not change the position of the panel in the stack.
.\" ---------
.SS set_panel_userptr
\fBset_panel_userptr(\fIpan\fB,\fIptr\fB)\fR
sets the panel's user pointer.
.\" ---------
.SS show_panel
\fBshow_panel(\fIpan\fB)\fR
makes a hidden panel visible by placing it on top of the panels in the
panel stack.
See \fBCOMPATIBILITY\fP below.
.\" ---------
.SS top_panel
\fBtop_panel(\fIpan\fB)\fR
puts the given visible panel \fIpan\fP on top of all panels in the stack.
See \fBCOMPATIBILITY\fP below.
.\" ---------
.SS update_panels
\fBupdate_panels()\fR
refreshes the \fIvirtual screen\fP to reflect the relations between the
panels in the stack, but does not call \fBdoupdate\fP(3) to refresh the
\fIphysical screen\fP.
Use this function and not \fBwrefresh\fP(3) or \fBwnoutrefresh\fP(3).
.PP
\fBupdate_panels\fP may be called more than once before a call to
\fBdoupdate\fP, but \fBdoupdate\fP is the function responsible for updating
the \fIphysical screen\fP.
.SH DIAGNOSTICS
Each routine that returns a pointer returns \fBNULL\fP if an error
occurs.
Each routine that returns an int value returns \fBOK\fP if it
executes successfully and \fBERR\fP if not.
.PP
Except as noted, the \fIpan\fP and \fIwindow\fP parameters must be non-null.
If those are null, an error is returned.
.PP
The \fBmove_panel\fP function uses \fBmvwin\fP(3),
and will return an error if \fBmvwin\fP returns an error.
.SH 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 \fBPANEL\fP data structures are merely  similar.
The  programmer
is cautioned not to directly use \fBPANEL\fP fields.
.P
The functions \fBshow_panel\fP and \fBtop_panel\fP are identical
in this implementation, and work equally well with displayed or hidden
panels.
In the native System V implementation, \fBshow_panel\fP is
intended for making a hidden panel visible (at the top of the stack)
and \fBtop_panel\fP 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.
.SH 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).
.SH PORTABILITY
The panel facility was documented in SVr4.2 in
\fICharacter User Interface Programming (UNIX SVR4.2)\fP.
.PP
It is not part of X/Open Curses.
.PP
A few implementations exist:
.bP
Systems based on SVr4 source code,
e.g., Solaris, provide this library.
.bP
\fBncurses\fP (since version 0.6 in 1993)
and \fBPDCurses\fP (since version 2.2 in 1995)
provide a panel library whose common ancestor
was a public domain implementation by Warren Tucker
published in \fIu386mon\fP 2.20 (1990).
.IP
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).
.IP
Several developers have improved each of these;
they are no longer the same as Tucker's implementation.
.bP
NetBSD 8 (2018)
has a panel library begun by Valery Ushakov in 2015.
This is based on the AT&T documentation.
.SH FILES
panel.h
interface for the panels library
.P
libpanel.a
the panels library itself
.SH SEE ALSO
\fBcurses\fP(3),
\fBcurs_variables\fP(3),
.PP
This describes \fBncurses\fP
version 6.4 (patch 20230826).
.SH AUTHOR
Originally written by Warren Tucker <wht@n4hgf.mt-park.ga.us>,
primarily to assist in porting \fIu386mon\fP to systems without a native
panels library.
.PP
Repackaged for ncurses by Zeyd ben-Halim.
.PP
Juergen Pfeifer and Thomas E. Dickey revised/improved the library.