.\"
.\" 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.
.\"
.\" $FreeBSD$
.\"
.Dd October 2, 1998
.Dt DIALOG 3
.Os FreeBSD 2
.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 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 \fBdialog(1)\fR 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 \fBdialogMenuItem\fR structures,
giving the user much more control over the internal behavior of each
control.  The \fBdialogMenuItem\fR structure internals are public:

.nf
typedef struct _dmenu_item {
   char *\fBprompt\fR;
   char *\fBtitle\fR;
   int (*\fBchecked\fR)(struct _dmenu_item *self);
   int (*\fBfire\fR)(struct _dmenu_item *self);
   int (*\fBselected\fR)(struct _dmenu_item *self, int is_selected);
   void *\fBdata\fR;
   char \fBlbra\fR, \fBmark\fR, \fBrbra\fR;
} \fBdialogMenuItem\fR;
.fi

The \fBprompt\fR and \fBtitle\fR strings are pretty much self-explanatory,
and the \fBchecked\fR and \fBfire\fR function pointers provide optional
display and action hooks (the \fBdata\fR variable being available for
the convenience of those hooks) when more tightly coupled feedback between
a menu object and user code is required.  The \fBselected\fR 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 \fBlbra\fR
(default: '['), \fB\mark\fR (default: '*' for radio menus, 'X' for check menus)
and \fBrbra\fR (default: ']') and declaring a reasonable \fBchecked\fR hook,
which should return TRUE for the `marked' state and FALSE for `unmarked.'
If an item has a \fBfire\fR 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:
.nf

#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 */

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.

.fi

.Sh SYNOPSIS
.Fd #include <dialog.h>
.Ft "void"
.Fn draw_shadow "WINDOW *win" "int y" "int x" "int height" "int width"

Draws a shadow in curses window \fBwin\fR using the dimensions
of \fBx, y, width\fR and \fBheight\fR.  Returns 0 on success, -1 on failure.

.Ft "void"
.Fn draw_box "WINDOW *win" "int y" "int x" "int height" "int width" "chtype box" "chtype border"

Draws a bordered box using the dimensions of \fBx, y, width\fR and
\fBheight\fR.  The attributes from \fBbox\fR and \fBborder\fR are
used, if specified, while painting the box and border regions of the
object.

.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

Invoke a simple line editor with an edit box of dimensions \fBbox_x,
box_y\fR and \fBbox_width\fR.  The field length is constrained by
\fBflen\fR, starting at the \fBfirst\fR character specified and
optionally displayed with character attributes \fBattrs\fR.  The
string being edited is stored in \fBresult\fR.

Returns 0 on success, -1 on failure.

.Ft "int"
.Fn strheight "const char *p"

Returns the height of string in \fBp\fR, counting newlines.

.Ft "int"
.Fn strwidth "const char *p"

Returns the width of string in \fBp\fR, counting newlines.

.Ft "void"
.Fn dialog_create_rc "unsigned char *filename"

Dump dialog library settings into \fBfilename\fR for later retrieval
as defaults.  Returns 0 on success, -1 on failure.

.Ft "int"
.Fn dialog_yesno "unsigned char *title" "unsigned char *prompt" "int height" "int width"

Display a text box using \fBtitle\fR and \fBprompt\fR strings of dimensions
\fBheight\fR and \fBwidth\fR.  Also paint a pair of \fBYes\fR and \fBNo\fR
buttons at the bottom.  If the \fBYes\fR button is chosen, return FALSE.
If \fBNo\fR, return TRUE.

.Ft "int"
.Fn dialog_prgbox "unsigned char *title" "const unsigned char *line" "int height" "int width" "int pause" "int use_shell"

Display a text box of dimensions \fBheight\fR and \fBwidth\fR
containing the output of command \fBline\fR.  If \fBuse_shell\fR is
TRUE, \fBline\fR is passed as an argument to \fBsh(1)\fR, otherwise it
is simply passed to \fBexec(3)\fR.  If \fBpause\fR is TRUE, a final
confirmation requestor will be put up when execution terminates.

Returns 0 on success, -1 on failure.

.Ft "int"
.Fn dialog_textbox "unsigned char *title" "unsigned char *prompt" "int height" "int width"

Display a text box containing the contents of string \fBprompt\fR of dimensions
\fBheight\fR and \fBwidth\fR.

Returns 0 on success, -1 on failure.

.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"

Display a menu of dimensions \fBheight\fR and \fBwidth\fR with an
optional internal menu height of \fBmenu_height\fR.  The \fBitem_no\fR
and \fBitptr\fR arguments are of particular importance since they,
together, determine which of the 2 available APIs to use.  To use the
older and traditional interface, \fBitem_no\fR should be a positive
integer representing the number of string pointer pairs to find in
\fBitptr\fR (which should be of type \fBchar **\fR), the strings are
expected to be in prompt and title order for each item and the
\fBresult\fR parameter is expected to point to an array where the
prompt string of the item selected will be copied.  To use the newer
interface, \fBitem_no\fR should be a \fInegative\fR integer
representing the number of \fBdialogMenuItem\fR structures pointed to
by \fBitptr\fR (which should be of type \fBdialogMenuItem *\fR), one
structure per item.  In the new interface, the \fBresult\fR variable
is used as a simple boolean (not a pointer) and should be NULL if
\fBitptr\fR only points to menu items and the default \fBOK\fR and
\fBCancel\fR buttons are desired.  If \fBresult\fR is non-NULL, then
\fBitptr\fR is actually expected to point 2 locations \fBpast\fR the
start of the menu item list.  \fBitptr\fR[-1] is then expected to
point to an item representing the \fBCancel\fR button, from which the
\fBprompt\fR and \fBfire\fR actions are used to override the default
behavior, and \fBitptr\fR[-2] to the same for the \fBOK\fR button.

Using either API behavior, the \fBch\fR and \fBsc\fR 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.

.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"

Display a menu of dimensions \fBheight\fR and \fBwidth\fR with an
optional internal menu height of \fBmenu_height\fR.  The \fBitem_no\fR
and \fBitptr\fR arguments are of particular importance since they,
together, determine which of the 2 available APIs to use.  To use the
older and traditional interface, \fBitem_no\fR should be a positive
integer representing the number of string pointer tuples to find in
\fBitptr\fR (which should be of type \fBchar **\fR), the strings are
expected to be in prompt, title and state ("on" or "off") order for
each item and the \fBresult\fR 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, \fBitem_no\fR should be a
\fInegative\fR integer representing the number of \fBdialogMenuItem\fR
structures pointed to by \fBitptr\fR (which should be of type
\fBdialogMenuItem *\fR), one structure per item. In the new interface,
the \fBresult\fR variable is used as a simple boolean (not a pointer)
and should be NULL if \fBitptr\fR only points to menu items and the
default \fBOK\fR and \fBCancel\fR buttons are desired.  If
\fBresult\fR is non-NULL, then \fBitptr\fR is actually expected to
point 2 locations \fBpast\fR the start of the menu item list.
\fBitptr\fR[-1] is then expected to point to an item representing the
\fBCancel\fR button, from which the \fBprompt\fR and \fBfire\fR
actions are used to override the default behavior, and \fBitptr\fR[-2]
to the same for the \fBOK\fR 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 \fBresult\fR 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 \fBdialog_checklist\fR over
\fBdialog_radiolist\fR 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.

.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"

Display a menu of dimensions \fBheight\fR and \fBwidth\fR with an
optional internal menu height of \fBmenu_height\fR.  The \fBitem_no\fR
and \fBitptr\fR arguments are of particular importance since they,
together, determine which of the 2 available APIs to use.  To use the
older and traditional interface, \fBitem_no\fR should be a positive
integer representing the number of string pointer tuples to find in
\fBitptr\fR (which should be of type \fBchar **\fR), the strings are
expected to be in prompt, title and state ("on" or "off") order for
each item and the \fBresult\fR 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, \fBitem_no\fR should be a
\fInegative\fR integer representing the number of \fBdialogMenuItem\fR
structures pointed to by \fBitptr\fR (which should be of type
\fBdialogMenuItem *\fR), one structure per item. In the new interface,
the \fBresult\fR variable is used as a simple boolean (not a pointer)
and should be NULL if \fBitptr\fR only points to menu items and the
default \fBOK\fR and \fBCancel\fR buttons are desired.  If
\fBresult\fR is non-NULL, then \fBitptr\fR is actually expected to
point 2 locations \fBpast\fR the start of the menu item list.
\fBitptr\fR[-1] is then expected to point to an item representing the
\fBCancel\fR button, from which the \fBprompt\fR and \fBfire\fR
actions are used to override the default behavior, and \fBitptr\fR[-2]
does the same for the traditional \fBOK\fR 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 \fBresult\fR 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 \fBdialog_radiolist\fR over
\fBdialog_checklistlist\fR in the new API model is to inherit the base
behavior.

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

.Ft "int"
.Fn dialog_inputbox "unsigned char *title" "unsigned char *prompt" "int height" "int width" "unsigned char *result"

Displays a single-line text input field in a box displaying \fBtitle\fR and \fBprompt\fR
of dimensions \fBheight\fR and \fBwidth\fR.  The field entered is stored in \fBresult\fR.

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

.Ft "char *"
.Fn dialog_fselect "char *dir" "char *fmask"

Brings up a file selector dialog starting at \fBdir\fR and showing only those file names
matching \fBfmask\fR.

Returns filename selected or NULL.

.Ft "int"
.Fn dialog_dselect "char *dir" "char *fmask"

Brings up a directory selector dialog starting at \fBdir\fR and showing only those directory names
matching \fBfmask\fR.

Returns directory name selected or NULL.

.Ft "void"
.Fn dialog_notify "char *msg"

Bring up a generic "hey, you!" notifier dialog containing \fBmsg\fR.

.Ft "int"
.Fn dialog_mesgbox "unsigned char *title" "unsigned char *prompt" "int height" "int width"

Like a notifier dialog, but with more control over \fBtitle\fR, \fBprompt\fR, \fBwidth\fR and
\fBheight\fR.  This object will also wait for user confirmation, unlike \fBdialog_notify\fR.

Returns 0 on success, -1 on failure.

.Ft "void"
.Fn dialog_gauge "char *title" "char *prompt" "int y" "int x" "int height" "int width" "int perc"

Display a horizontal bar-graph style gauge.  A value of \fB100\fR for \fBperc\fR constitutes
a full gauge, a value of \fB0\fR an empty one.

.Ft "void"
.Fn use_helpfile "char *helpfile"

For any menu supporting context sensitive help, invoke the text box
object on this file whenever the \fBF1\fR key is pressed.


.Ft "void"
.Fn use_helpline "char *helpline"

Display this line of helpful text below any menu being displayed.

.Ft "char *"
.Fn get_helpline "void"

Get the current value of the helpful text line.

.Ft "void"
.Fn dialog_clear_norefresh "void"

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

.Ft "void"
.Fn dialog_clear "void"

Clear the screen back to the dialog background color immediately.

.Ft "void"
.Fn dialog_update "void"

Do any pending screen refreshes now.

.Ft "void"
.Fn init_dialog "void"

Initialize the dialog library (call this routine before any other dialog API calls).

.Ft "void"
.Fn end_dialog "void"

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

.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"

\fBdialog_ftree\fR shows a tree described by the data from the file
\fBfilename\fR.  The data in the file should look like \fBfind(1)\fR output.
For the \fBfind(1)\fR output, the field separator \fBFS\fR will be \fB\'/\'\fR.  If
\fBheight\fR and \fBwidth\fR are positive numbers, they set the absolute
size of the whole \fBdialog_ftree\fR box. If \fBheight\fR and
\fBwidth\fR are negative numbers, the size of the \fBdialog_ftree\fR box
will be calculated automatically. \fBmenu_height\fR sets the height of the
tree subwindow inside the \fBdialog_ftree\fR box and must be set. 
\fBtitle\fR is shown centered on the upper border of the \fBdialog_ftree\fR
box.  \fBprompt\fR is shown inside the \fBdialog_ftree\fR box above the tree
subwindow and can contain \fB\'\\n\'\fR to split lines.  One can navigate in
the tree by pressing \fBUP/DOWN\fR or \fB\'+\'/\'-\'\fR, \fBPG_UP/PG_DOWN\fR or
\fB\'b\'/SPACE\fR and \fBHOME/END\fR or \fB\'g\'/\'G\'\fR. A leaf of the
tree is selected by pressing \fBTAB\fR or \fBLEFT/RIGHT\fR the \fBOK\fR
button and pressing \fBENTER\fR. filename may contain data like
\fBfind(1)\fR output, as well as like the output of \fBfind(1)\fR with
\fB-d\fR 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 \fBOK\fR button was
selected. The memory allocated for the building of the tree is freed on
exiting \fBdialog_ftree\fR. The memory for the result line should be freed
later manually, if necessary. If the \fBCancel\fR button was selected, the
function returns 1. In case of exiting \fBdialog_ftree\fR on \fBESC\fR, the
function returns -1.

.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

\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.

The function returns the same results as \fBdialog_ftree\fR. If 0 is
returned, result will contain a pointer from the array \fBnames\fR.

.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 Andrey Chernov.  Marc van Kempen implemented most of the
extra controls and objects, Jordan Hubbard added the dialogMenuItem
renovations and this man page and Anatoly A. Orehovsky implemented
dialog_ftree() and dialog_tree().
.Sh BUGS
Sure!