.\"
.\" Copyright (c) 1995, Jordan Hubbard
.\"
.\" All rights reserved.
.\"
.\" This manual page may be used, modified, copied, distributed, and
.\" sold, in both source and binary form provided that the above
.\" copyright and these terms are retained, verbatim, as the first
.\" lines of this file.  Under no circumstances is the author
.\" responsible for the proper functioning of the software described herein
.\" nor does the author assume any responsibility for damages incurred with
.\" its use.
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.\" $FreeBSD$
.\"
.Dd January 1, 2000
.Dt DIALOG 3
.Os FreeBSD
.Sh NAME
.Nm draw_shadow ,
.Nm draw_box ,
.Nm line_edit ,
.Nm strheight ,
.Nm strwidth ,
.Nm dialog_create_rc ,
.Nm dialog_yesno ,
.Nm dialog_prgbox ,
.Nm dialog_msgbox ,
.Nm dialog_textbox ,
.Nm dialog_menu ,
.Nm dialog_checklist ,
.Nm dialog_radiolist ,
.Nm dialog_inputbox ,
.Nm dialog_clear_norefresh ,
.Nm dialog_clear ,
.Nm dialog_update ,
.Nm dialog_fselect ,
.Nm dialog_notify ,
.Nm dialog_mesgbox ,
.Nm dialog_gauge ,
.Nm init_dialog ,
.Nm end_dialog ,
.Nm use_helpfile ,
.Nm use_helpline ,
.Nm get_helpline ,
.Nm restore_helpline ,
.Nm dialog_ftree ,
.Nm dialog_tree
.Nd provide a simple ncurses-based GUI interface.
.Sh SYNOPSIS
.Fd #include <dialog.h>
.Ft "void"
.Fn draw_shadow "WINDOW *win" "int y" "int x" "int height" "int width"
.Ft "void"
.Fn draw_box "WINDOW *win" "int y" "int x" "int height" "int width" "chtype box" "chtype border"
.Ft "int"
.Fo line_edit
.Fa "WINDOW *dialog"
.Fa "int box_y"
.Fa "int box_x"
.Fa "int flen"
.Fa "int box_width"
.Fa "chtype attrs"
.Fa "int first"
.Fa "unsigned char *result"
.Fa "int attr_mask"
.Fc
.Ft "int"
.Fn strheight "const char *p"
.Ft "int"
.Fn strwidth "const char *p"
.Ft "void"
.Fn dialog_create_rc "unsigned char *filename"
.Ft "int"
.Fn dialog_yesno "unsigned char *title" "unsigned char *prompt" "int height" "int width"
.Ft "int"
.Fn dialog_prgbox "unsigned char *title" "const unsigned char *line" "int height" "int width" "int pause" "int use_shell"
.Ft "int"
.Fn dialog_textbox "unsigned char *title" "unsigned char *prompt" "int height" "int width"
.Ft "int"
.Fn dialog_menu "unsigned char *title" "unsigned char *prompt" "int height" "int width" "int menu_height" "int item_no" "void *itptr" "unsigned char *result, int *ch, int *sc"
.Ft "int"
.Fn dialog_checklist "unsigned char *title" "unsigned char *prompt" "int height" "int width" "int m_height" "int item_no" "void *itptr" "unsigned char *result"
.Ft "int"
.Fn dialog_radiolist "unsigned char *title" "unsigned char *prompt" "int height" "int width" "int m_height" "int item_no" "void *it" "unsigned char *result"
.Ft "int"
.Fn dialog_inputbox "unsigned char *title" "unsigned char *prompt" "int height" "int width" "unsigned char *result"
.Ft "char *"
.Fn dialog_fselect "char *dir" "char *fmask"
.Ft "int"
.Fn dialog_dselect "char *dir" "char *fmask"
.Ft "void"
.Fn dialog_notify "char *msg"
.Ft "int"
.Fn dialog_mesgbox "unsigned char *title" "unsigned char *prompt" "int height" "int width"
.Ft "void"
.Fn dialog_gauge "char *title" "char *prompt" "int y" "int x" "int height" "int width" "int perc"
.Ft "void"
.Fn use_helpfile "char *helpfile"
.Ft "void"
.Fn use_helpline "char *helpline"
.Ft "char *"
.Fn get_helpline "void"
.Ft "void"
.Fn dialog_clear_norefresh "void"
.Ft "void"
.Fn dialog_clear "void"
.Ft "void"
.Fn dialog_update "void"
.Ft "void"
.Fn init_dialog "void"
.Ft "void"
.Fn end_dialog "void"
.Ft "int"
.Fn dialog_ftree "unsigned char *filename" "unsigned char FS" "unsigned char *title" "unsigned char *prompt" "int height" "int width" "int menu_height" "unsigned char **result"
.Ft "int" 
.Fo dialog_tree 
.Fa "unsigned char **names" 
.Fa "int size"
.Fa "unsigned char FS" 
.Fa "unsigned char *title" 
.Fa "unsigned char *prompt"
.Fa "int height" 
.Fa "int width" 
.Fa "int menu_height"
.Fa "unsigned char **result"
.Fc
.Sh DESCRIPTION
The dialog library attempts to provide a fairly simplistic set of
fixed-presentation menus, input boxes, gauges, file requestors and
other general purpose GUI (a bit of a stretch, since it uses
ncurses) objects.  Since the library also had its roots in a
shell-script writer's utility (see the
.Xr dialog 1
command), the
early API was somewhat primitively based on strings being passed in or
out and parsed.  This API was later extended to take either the
original arguments or arrays of
.Va dialogMenuItem
structures,
giving the user much more control over the internal behavior of each
control.  The
.Va dialogMenuItem
structure internals are public:
.Bd -literal -offset indent
typedef struct _dmenu_item {
   char *prompt;
   char *title;
   int (*checked)(struct _dmenu_item *self);
   int (*fire)(struct _dmenu_item *self);
   int (*selected)(struct _dmenu_item *self, int is_selected);
   void *data;
   char lbra, mark, rbra;
} dialogMenuItem;
.Ed

The
.Dv prompt
and
.Dv title
strings are pretty much self-explanatory,
and the
.Va checked
and
.Va fire
function pointers provide optional
display and action hooks (the
.Dv data
variable being available for
the convenience of those hooks) when more tightly coupled feedback between
a menu object and user code is required.  The
.Va selected
hook also
allows you to verify whether or not a given item is selected (the cursor is
over it) for implementing pretty much any possible context-sensitive
behavior. A number of clever tricks for simulating various kinds of item
types can also be done by adjusting the values of
.Va lbra
(default: '['),
.Va mark
(default: '*' for radio menus, 'X' for check menus)
and
.Va rbra
(default: ']') and declaring a reasonable
.Va checked
hook,
which should return TRUE for the
.Dq marked
state and FALSE for
.Dq unmarked .
If an item has a
.Va fire
hook associated with it, it will also be called
whenever the item is "toggled" in some way and should return one of the
following codes:

.Bd -literal -offset 4n
#define DITEM_SUCCESS            0    /* Successful completion */
#define DITEM_FAILURE           -1    /* Failed to "fire" */
#define DITEM_LEAVE_MENU        -2    /* Treat selection as "Ok" */
#define DITEM_REDRAW            -3    /* Menu has changed, redraw it */
.Ed

Two special globals also exist for putting a dialog at any arbitrary
X,Y location (the early designers rather short-sightedly made no provisions
for this).  If set to zero, the default centering behavior will be in
effect.
.Pp
Below is a short description of the various functions:
.Pp
.Fn draw_shadow
draws a shadow in curses window
.Va win
using the dimensions of
.Va x , y , width
and
.Va height .
Returns 0 on success, -1 on failure.
.Pp
.Fn draw_box
draws a bordered box using the dimensions of
.Va x , y , width
and
.Va height .
The attributes from
.Va box
and
.Va border
are used, if specified, while painting the box and border regions of the
object.
.Pp
.Fn line_edit
invoke a simple line editor with an edit box of dimensions
.Va box_x , box_y
and
.Va box_width .
The field length is constrained by
.Va flen ,
starting at the
.Va first
character specified and
optionally displayed with character attributes
.Va attrs .
The string being edited is stored in
.Va result .
Returns 0 on success, -1 on failure.
.Pp
.Fn strheight
returns the height of string in
.Va p ,
counting newlines.
.Pp
.Fn strwidth
returns the width of string in
.Va p ,
counting newlines.
.Pp
.Fn dialog_create_rc
dump dialog library settings into
.Pa filename
for later retrieval as defaults.  Returns 0 on success, -1 on failure.
.Pp
.Fn dialog_yesno
display a text box using
.Va title
and
.Va prompt
strings of dimensions
.Va height
and
.Va width .
Also paint a pair of
.Em Yes
and
.Em \&No
buttons at the bottom.  If the
.Em Yes
button is chosen, return FALSE.  If
.Em \&No ,
return TRUE.
.Pp
.Fn dialog_prgbox
display a text box of dimensions
.Va height
and
.Va width
containing the output of command
.Va line .
If
.Va use_shell
is TRUE,
.Va line
is passed as an argument to
.Xr sh 1 ,
otherwise it is simply passed to
.Xr exec 3 .
If
.Va pause
is TRUE, a final confirmation requestor will be put up when execution
terminates.  Returns 0 on success, -1 on failure.
.Pp
.Fn dialog_textbox
display a text box containing the contents of string
.Va prompt
of dimensions
.Va height
and
.Va width .
Returns 0 on success, -1 on failure.
.Pp
.Fn dialog_menu
display a menu of dimensions
.Va height
and
.Va width
with an optional internal menu height of
.Va menu_height .
The
.Va item_no
and
.Va itptr
arguments are of particular importance since they,
together, determine which of the 2 available APIs to use.  To use the
older and traditional interface,
.Va item_no
should be a positive
integer representing the number of string pointer pairs to find in
.Va itptr
(which should be of type
.Ft char "**" ),
the strings are
expected to be in prompt and title order for each item and the
.Va result
parameter is expected to point to an array where the
prompt string of the item selected will be copied.  To use the newer
interface,
.Va item_no
should be a
.Va negative
integer representing the number of
.Va dialogMenuItem
structures pointed to by
.Va itptr
(which should be of type
.Va dialogMenuItem "*" ),
one structure per item.  In the new interface, the
.Va result
variable is used as a simple boolean (not a pointer) and should be NULL if
.Va itptr
only points to menu items and the default OK and Cancel buttons are desired.  If
.Va result
is non-NULL, then
.Va itptr
is actually expected to point 2 locations
.Va past
the start of the menu item list.
.Va itptr
is then expected to
point to an item representing the Cancel button, from which the
.Va prompt
and
.Va fire
actions are used to override the default behavior, and
.Va itptr
to the same for the OK button.

Using either API behavior, the
.Va ch
and
.Va sc
values may be passed in to preserve current
item selection and scroll position values across calls.

Returns 0 on success, 1 on Cancel and -1 on failure or ESC.

.Fn dialog_checklist
display a menu of dimensions
.Va height
and
.Va width
with an
optional internal menu height of
.Va menu_height .
The
.Va item_no
and
.Va itptr
arguments are of particular importance since they,
together, determine which of the 2 available APIs to use.  To use the
older and traditional interface,
.Va item_no
should be a positive
integer representing the number of string pointer tuples to find in
.Va itptr
(which should be of type
.Ft "char **" ),
the strings are
expected to be in prompt, title and state ("on" or "off") order for
each item and the
.Va result
parameter is expected to point to an
array where the prompt string of the item(s) selected will be
copied.  To use the newer interface,
.Va item_no
should be a
.Em negative
integer representing the number of
.Ft dialogMenuItem
structures pointed to by
.Va itptr
(which should be of type
.Ft "dialogMenuItem *" ),
one structure per item. In the new interface,
the
.Va result
variable is used as a simple boolean (not a pointer)
and should be NULL if
.Va itptr
only points to menu items and the default OK and Cancel
buttons are desired.  If
.Va result
is non-NULL, then
.Va itptr
is actually expected to
point 2 locations
.Va past
the start of the menu item list.
.Va itptr
is then expected to point to an item representing the Cancel
button, from which the
.Va prompt
and
.Va fire
actions are used to override the default behavior, and
.Va itptr
to the same for the OK button.

In the standard API model, the menu supports the selection of multiple items,
each of which is marked with an `X' character to denote selection.  When
the OK button is selected, the prompt values for all items selected are
concatenated into the
.Va result
string.

In the new API model, it is not actually necessary to preserve
"checklist" semantics at all since practically everything about how
each item is displayed or marked as "selected" is fully configurable.
You could have a single checklist menu that actually contained a group
of items with "radio" behavior, "checklist" behavior and standard menu
item behavior.  The only reason to call
.Fn dialog_checklist
over
.Fn dialog_radiolist
in the new API model is to inherit the base
behavior, you're no longer constrained by it.

Returns 0 on success, 1 on Cancel and -1 on failure or ESC.

.Fn dialog_radiolist
display a menu of dimensions
.Va height
and
.Va width
with an
optional internal menu height of
.Va menu_height .
The
.Va item_no
and
.Va itptr
arguments are of particular importance since they,
together, determine which of the 2 available APIs to use.  To use the
older and traditional interface,
.Va item_no
should be a positive
integer representing the number of string pointer tuples to find in
.Va itptr
(which should be of type
.Ft "char **" ),
the strings are
expected to be in prompt, title and state ("on" or "off") order for
each item and the
.Va result
parameter is expected to point to an
array where the prompt string of the item(s) selected will be
copied.  To use the newer interface,
.Va item_no
should be a
.Dv negative
integer representing the number of
.Ft dialogMenuItem
structures pointed to by
.Va itptr
(which should be of type
.Ft "dialogMenuItem *" ,
one structure per item. In the new interface,
the
.Va result
variable is used as a simple boolean (not a pointer)
and should be NULL if
.Va itptr
only points to menu items and the default OK and Cancel
buttons are desired.  If
.Va result
is non-NULL, then
.Va itptr
is actually expected to point 2 locations
.Va past
the start of the menu item list.
.Va itptr
is then expected to point to an item representing the Cancel
button, from which the
.Va prompt
and
.Va fire
actions are used to override the default behavior, and
.Va itptr
does the same for the traditional OK button.

In the standard API model, the menu supports the selection of only one
of multiple items, the currently active item marked with an `*'
character to denote selection.  When the OK button is selected, the
prompt value for this item is copied into the
.Va result
string.

In the new API model, it is not actually necessary to preserve
"radio button" semantics at all since practically everything about how
each item is displayed or marked as "selected" is fully configurable.
You could have a single radio menu that actually contained a group
of items with "checklist" behavior, "radio" behavior and standard menu
item behavior.  The only reason to call
.Fn dialog_radiolist
over
.Fn dialog_checklistlist
in the new API model is to inherit the base
behavior.

Returns 0 on success, 1 on Cancel and -1 on failure or ESC.

.Fn dialog_inputbox
displays a single-line text input field in a box displaying
.Va title
and
.Va prompt
of dimensions
.Va height
and
.Va width .
The field entered is stored in
.Va result .

Returns 0 on success, -1 on failure or ESC.

.Fn dialog_fselect
brings up a file selector dialog starting at
.Va dir
and showing only those file names
matching
.Va fmask .

Returns filename selected or NULL.

.Fn dialog_dselect
brings up a directory selector dialog starting at
.Va dir
and showing only those directory names
matching
.Va fmask .

Returns directory name selected or NULL.

.Fn dialog_notify
brings up a generic "hey, you!" notifier dialog containing
.Va msg .

.Fn dialog_mesgbox
like a notifier dialog, but with more control over
.Va title ,
.Va prompt ,
.Va width
and
.Va height .
This object will also wait for user confirmation, unlike
.Fn dialog_notify .

Returns 0 on success, -1 on failure.

.Fn dialog_gauge
displays a horizontal bar-graph style gauge.  A value of
.Em 100
for
.Em perc
constitutes a full gauge, a value of
.Em 0
an empty one.

.Fn use_helpfile
for any menu supporting context sensitive help, invoke the text box
object on this file whenever the
.Em F1
key is pressed.

.Fn use_helpline
displays this line of helpful text below any menu being displayed.

.Fn get_helpline
get the current value of the helpful text line.

.Fn dialog_clear_norefresh
clear the screen back to the dialog background color, but don't refresh the
contents just yet.

.Fn dialog_clear
clear the screen back to the dialog background color immediately.

.Fn dialog_update
do any pending screen refreshes now.

.Fn init_dialog
initialize the dialog library (call this routine before any other dialog
API calls).

.Fn end_dialog
shut down the dialog library (call this if you need to get back to sanity).

.Fn dialog_ftree
shows a tree described by the data from the file
.Pa filename .
The data in the file should look like
.Xr find 1
output.
For the
.Xr find 1
output, the field separator
.Va FS
will be
.Dq \&/ .
If
.Va height
and
.Va width
are positive numbers, they set the absolute
size of the whole
.Fn dialog_ftree
box. If
.Va height
and
.Va width
are negative numbers, the size of the
.Fn dialog_ftree
box will be calculated automatically.
.Va menu_height
sets the height of the tree subwindow inside the
.Fn dialog_ftree
box and must be set. 
.Va title
is shown centered on the upper border of the
.Fn dialog_ftree
box.
.Va prompt
is shown inside the
.Fn dialog_ftree
box above the tree subwindow and can contain
.Ql \e\&n
to split lines.  One can navigate in
the tree by pressing UP/DOWN or
.Sm off
.So \&+ Sc \&/ So \&- Sc ,
.Sm on
PG_UP/PG_DOWN or
.Sm off
.So b Sc \&/SPACE
.Sm on
and
HOME/END or
.Sm off
.So g Sc \&/ So G Sc .
A leaf of the
tree is selected by pressing TAB or LEFT/RIGHT the OK
button and pressing ENTER. filename may contain data like
.Xr find 1
output, as well as like the output of
.Xr find 1
with
.Fl d
option. Some of the transient paths to the leaves of the tree may
be absent. Such data is corrected when fed from filename.

The function returns 0 and a pointer to the selected leaf (to the path to
the leaf from the root of the tree) into result, if the OK button was
selected. The memory allocated for the building of the tree is freed on
exiting
.Fn dialog_ftree .
The memory for the result line should be freed
later manually, if necessary. If the Cancel button was selected, the
function returns 1. In case of exiting
.Fn dialog_ftree
on ESC, the function returns -1.

.Fn dialog_tree 
function returns the same results as
.Fn dialog_ftree .
If 0 is returned, result will contain a pointer from the array
.Va names .
.\" \fBdialog_tree\fR displays the tree very much like \fBdialog_ftree\fR does,
.\" with some exceptions. The source data for the building of the tree is an
.\" array \fBnames\fR of paths to the leaves (should be similar to \fBfind(1)\fR
.\" output) of the size \fBsize\fR. However, there is no correction of data like
.\" in \fBdialog_ftree\fR. Thus, to display a correct tree, the array must
.\" already contain correct data. Besides, in each session every unique use of
.\" \fBdialog_tree\fR is kept in memory, and later, when calling
.\" \fBdialog_tree\fR with the same \fBnames\fR, \fBsize\fR, \fBFS\fR,
.\" \fBheight\fR, \fBwidth\fR and \fBmenu_height\fR the position of the cursor
.\" in the tree subwindow is restored.
.Sh SEE ALSO
.Xr dialog 1 ,
.Xr ncurses 3
.Sh AUTHORS
The primary author would appear to be
.An Savio Lam Aq lam836@cs.cuhk.hk
with contributions over the years by
.An Stuart Herbert Aq S.Herbert@sheffield.ac.uk ,
.An Marc van Kempen Aq wmbfmk@urc.tue.nl ,
.An Andrey Chernov Aq ache@FreeBSD.org ,
.An Jordan Hubbard Aq jkh@FreeBSD.org
and
.An Anatoly A. Orehovsky Aq tolik@mpeks.tomsk.su .
.Sh HISTORY
These functions appeared in
.Fx 2.0
as the
.Xr dialog 1
command and were soon split into a separate library
and command by
.An Andrey Chernov.
.An Marc van Kempen implemented most of the
extra controls and objects,
.An Jordan Hubbard
added the dialogMenuItem renovations and this man page and
.An Anatoly A. Orehovsky
implemented
.Fn dialog_ftree
and
.Fn dialog_tree .
.Sh BUGS
Sure!