DIALOG(3)

NAME
draw_shadow, draw_box, line_edit, strheight, strwidth, dialog_create_rc, dialog_yesno, dialog_prgbox, dialog_msgbox, dialog_textbox, dialog_menu, dialog_checklist, dialog_radiolist, dialog_inputbox, dialog_clear_norefresh, dialog_clear, dialog_update, dialog_fselect, dialog_notify, dialog_mesgbox, dialog_gauge, init_dialog, end_dialog, use_helpfile, use_helpline, get_helpline, restore_helpline, dialog_ftree, dialog_tree - provide a simple ncurses-based GUI interface.

SYNOPSIS
#include <dialog.h>
void
draw_shadow(WINDOW *win, int y, int x, int height, int width);
void
draw_box(WINDOW *win, int y, int x, int height, int width, chtype box, chtype border);
int
line_edit(WINDOW *dialog, int box_y, int box_x, int flen, int box_width, chtype attrs, int first, unsigned char *result, int attr_mask);
int
strheight(const char *p);
int
strwidth(const char *p);
void
dialog_create_rc(unsigned char *filename);
int
dialog_yesno(unsigned char *title, unsigned char *prompt, int height, int width);
int
dialog_prgbox(unsigned char *title, const unsigned char *line, int height, int width, int pause, int use_shell);
int
dialog_textbox(unsigned char *title, unsigned char *prompt, int height, int width);
int
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);
int
dialog_checklist(unsigned char *title, unsigned char *prompt, int height, int width, int m_height, int item_no, void *itptr, unsigned char *result);
int
dialog_radiolist(unsigned char *title, unsigned char *prompt, int height, int width, int m_height, int item_no, void *it, unsigned char *result);
int
dialog_inputbox(unsigned char *title, unsigned char *prompt, int height, int width, unsigned char *result);
char *
dialog_fselect(char *dir, char *fmask);
int
dialog_dselect(char *dir, char *fmask);
void
dialog_notify(char *msg);
int
dialog_mesgbox(unsigned char *title, unsigned char *prompt, int height, int width);
void
dialog_gauge(char *title, char *prompt, int y, int x, int height, int width, int perc);
void
use_helpfile(char *helpfile);
void
use_helpline(char *helpline);
char *
get_helpline(void);
void
dialog_clear_norefresh(void);
void
dialog_clear(void);
void
dialog_update(void);
void
init_dialog(void);
void
end_dialog(void);
int
dialog_ftree(unsigned char *filename, unsigned char FS, unsigned char *title, unsigned char *prompt, int height, int width, int menu_height, unsigned char **result);
int
dialog_tree(unsigned char **names, int size, unsigned char FS, unsigned char *title, unsigned char *prompt, int height, int width, int menu_height, unsigned char **result);

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 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 dialogMenuItem structures, giving the user much more control over the internal behavior of each control. The dialogMenuItem structure internals are public:

    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;

The prompt and title strings are pretty much self-explanatory, and the checked and fire function pointers provide optional display and action hooks (the 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 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 lbra (default: '['), mark (default: '*' for radio menus, 'X' for check menus) and rbra (default: ']') and declaring a reasonable checked hook, which should return TRUE for the “marked” state and FALSE for “unmarked”. If an item has a 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:

    #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.

Below is a short description of the various functions:

draw_shadow() draws a shadow in curses window win using the dimensions of x, y, width and height. Returns 0 on success, -1 on failure.

draw_box() draws a bordered box using the dimensions of x, y, width and height. The attributes from box and border are used, if specified, while painting the box and border regions of the object.

line_edit() invoke a simple line editor with an edit box of dimensions box_x, box_y and box_width. The field length is constrained by flen, starting at the first character specified and optionally displayed with character attributes attrs. The string being edited is stored in result. Returns 0 on success, -1 on failure.

strheight() returns the height of string in p, counting newlines.

strwidth() returns the width of string in p, counting newlines.

dialog_create_rc() dump dialog library settings into filename for later retrieval as defaults. Returns 0 on success, -1 on failure.

dialog_yesno() display a text box using title and prompt strings of dimensions height and width. Also paint a pair of Yes and buttons at the bottom. If the Yes button is chosen, return FALSE. If, return TRUE.

dialog_prgbox() display a text box of dimensions height and width containing the output of command line. If use_shell is TRUE, line is passed as an argument to sh(1), otherwise it is simply passed to exec(3). If pause is TRUE, a final confirmation requestor will be put up when execution terminates. Returns 0 on success, -1 on failure.

dialog_textbox() display a text box containing the contents of string prompt of dimensions height and width. Returns 0 on success, -1 on failure.

dialog_menu() display a menu of dimensions height and width with an optional internal menu height of menu_height. The item_no and 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, item_no should be a positive integer representing the number of string pointer pairs to find in itptr (which should be of type char ** ), the strings are expected to be in prompt and title order for each item and the 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, item_no should be a negative integer representing the number of dialogMenuItem structures pointed to by itptr (which should be of type dialogMenuItem * ), one structure per item. In the new interface, the result variable is used as a simple boolean (not a pointer) and should be NULL if itptr only points to menu items and the default OK and Cancel buttons are desired. If result is non-NULL, then itptr is actually expected to point 2 locations past the start of the menu item list. itptr is then expected to point to an item representing the Cancel button, from which the prompt and fire actions are used to override the default behavior, and itptr to the same for the OK button. Using either API behavior, the ch and 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. dialog_checklist() display a menu of dimensions height and width with an optional internal menu height of menu_height. The item_no and 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, item_no should be a positive integer representing the number of string pointer tuples to find in itptr (which should be of type char ** ), the strings are expected to be in prompt, title and state ("on" or "off") order for each item and the 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, item_no should be a negative integer representing the number of dialogMenuItem structures pointed to by itptr (which should be of type dialogMenuItem * ), one structure per item. In the new interface, the result variable is used as a simple boolean (not a pointer) and should be NULL if itptr only points to menu items and the default OK and Cancel buttons are desired. If result is non-NULL, then itptr is actually expected to point 2 locations past the start of the menu item list. itptr is then expected to point to an item representing the Cancel button, from which the prompt and fire actions are used to override the default behavior, and 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 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 dialog_checklist() over 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. dialog_radiolist() display a menu of dimensions height and width with an optional internal menu height of menu_height. The item_no and 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, item_no should be a positive integer representing the number of string pointer tuples to find in itptr (which should be of type char ** ), the strings are expected to be in prompt, title and state ("on" or "off") order for each item and the 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, item_no should be a negative integer representing the number of dialogMenuItem structures pointed to by itptr (which should be of type dialogMenuItem *, one structure per item. In the new interface, the result variable is used as a simple boolean (not a pointer) and should be NULL if itptr only points to menu items and the default OK and Cancel buttons are desired. If result is non-NULL, then itptr is actually expected to point 2 locations past the start of the menu item list. itptr is then expected to point to an item representing the Cancel button, from which the prompt and fire actions are used to override the default behavior, and 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 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 dialog_radiolist() over 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. dialog_inputbox() displays a single-line text input field in a box displaying title and prompt of dimensions height and width. The field entered is stored in result. Returns 0 on success, -1 on failure or ESC. dialog_fselect() brings up a file selector dialog starting at dir and showing only those file names matching fmask. Returns filename selected or NULL. dialog_dselect() brings up a directory selector dialog starting at dir and showing only those directory names matching fmask. Returns directory name selected or NULL. dialog_notify() brings up a generic "hey, you!" notifier dialog containing msg. dialog_mesgbox() like a notifier dialog, but with more control over title, prompt, width and height. This object will also wait for user confirmation, unlike dialog_notify(). Returns 0 on success, -1 on failure. dialog_gauge() displays a horizontal bar-graph style gauge. A value of 100 for perc constitutes a full gauge, a value of 0 an empty one. use_helpfile() for any menu supporting context sensitive help, invoke the text box object on this file whenever the F1 key is pressed. use_helpline() displays this line of helpful text below any menu being displayed. get_helpline() get the current value of the helpful text line. dialog_clear_norefresh() clear the screen back to the dialog background color, but don't refresh the contents just yet. dialog_clear() clear the screen back to the dialog background color immediately. dialog_update() do any pending screen refreshes now. init_dialog() initialize the dialog library (call this routine before any other dialog API calls). end_dialog() shut down the dialog library (call this if you need to get back to sanity). dialog_ftree() shows a tree described by the data from the file filename. The data in the file should look like find(1) output. For the find(1) output, the field separator FS will be “/”. If height and width are positive numbers, they set the absolute size of the whole dialog_ftree() box. If height and width are negative numbers, the size of the dialog_ftree() box will be calculated automatically. menu_height sets the height of the tree subwindow inside the dialog_ftree() box and must be set. title is shown centered on the upper border of the dialog_ftree() box. prompt is shown inside the dialog_ftree() box above the tree subwindow and can contain ‘\n’ to split lines. One can navigate in the tree by pressing UP/DOWN or ‘+’/‘-’, PG_UP/PG_DOWN or ‘b’/SPACE and HOME/END or ‘g’/‘G’. A leaf of the tree is selected by pressing TAB or LEFT/RIGHT the OK button and pressing ENTER. filename may contain data like find(1) output, as well as like the output of find(1) with -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 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 dialog_ftree() on ESC, the function returns -1. dialog_tree() function returns the same results as dialog_ftree(). If 0 is returned, result will contain a pointer from the array names.

SEE ALSO
dialog(1), ncurses(3)

AUTHORS
The primary author would appear to be SavioLam<lam836@cs.cuhk.hk> with contributions over the years by StuartHerbert<S.Herbert@sheffield.ac.uk>, MarcvanKempen<wmbfmk@urc.tue.nl>, AndreyChernov<ache@FreeBSD.org>, JordanHubbard<jkh@FreeBSD.org> and AnatolyA.Orehovsky<tolik@mpeks.tomsk.su>.

HISTORY
These functions appeared in FreeBSD2.0 as the dialog(1) command and were soon split into a separate library and command by AndreyChernov. MarcvanKempenimplementedmostofthe extra controls and objects, JordanHubbard added the dialogMenuItem renovations and this man page and AnatolyA.Orehovsky implemented dialog_ftree() and dialog_tree().

BUGS
Sure!