Category : C Source Code
Archive   : WTWG12B.ZIP
Filename : WPICK.C

/* WPICKLIST.C
*
* General-purpose menu.
*
* displays a menu, which may be multiple pages (scrolling)
* gets user input.
*
*
*
* PARAMETERS:
* char *title = title for menu.
* char *list[] = array of string pointers to choices.
* terminated by NULL
*
* RETURNS:
* N, the number of the choice, ranges from 0 to last on list
* if user hit ESCAPE, N will indicate the terminal NULL
*
* NOTE: in the large memory model, be sure you've NORMALIZED the list
* otherwise list[N] may be garbage.
*
*/


#include "wsys.h"



#define MAX_WIDTH 20
#define MIN_WIDTH 5
#define MAX_N 10


static void W_NEAR draw_menu ( char **list, int nfirst, int nlast, int npick );


/* draw the '#nnn/nnnn' at bottom */
static void W_NEAR draw_npick ( int width, int npick );



/* draw one line of the menu
*/
static void W_NEAR draw_one_line (char **list, int nfirst, int n,
unsigned char attr );


int wpicklist ( char *title, char **list )
{
int more =1,
width =MIN_WIDTH, /* menu choices, screen dimensions */
n, w, /* scratch */
ntotal, /* total # of choices */
nfirst =0, /* number of first on-screen choice */
nlast, /* number of last on-screen choice */
nvisible, /* number of choices onscreen */
npick =0, /* number of currently highlighted choice */
newpick=0, /* number of next choice */
up_buttons =0, /* are PageUp buttons being displayed ? */
dn_buttons =0, /* are PageDn ... */
redraw =0, /* need to rewrite list of choices */
have_scrollbar =0; /* have ascrollbar onscreen */


WINDOW *bigW, *smallW; /* onscreen windows */
int l,t, ncols ; /* window postions */
int extra =0; /* extra columns on right ? */

WBUTTON *scrollbar; /* mouse-able scrollbar */

int key; /* user input */


/* letter typing buffer for matching to strings.
* note that initializing type_len to MAX_WIDTH
* forces matching routine to initialize the buffer.
*/
int type_len = MAX_WIDTH;
char typematch [ MAX_WIDTH+1 ];
int type_cnt;

_NORMALIZE (list);


/* count lines and find widest line
*/
for ( ntotal = 0; list[ntotal] != NULL; ++ntotal )
{
w = strlen ( list[ntotal] );

width = max ( width, w );
}

if ( title )
{
width = max (width, strlen (title) +2 );
}



width = min ( width, MAX_WIDTH ) +2; /* extra for frames R */



/* decide if menu is shorter than 1 page...
*/
if ( ntotal <= MAX_N )
{
nlast = ntotal;
}
else
{
nlast = MAX_N;
extra = 4; /* enable extra for right-side buttons */
}
nvisible = nlast;


/* pick window position
*/
ncols = width + extra ;
wlocate ( &l, &t, ncols, nlast );



bigW = wopen ( l, t, ncols, nlast, wmenuattr,
DOUBLE_BORDER, wmenuattr, 1 );
w0-> winputstyle = (0xFF - WPUTWRAP - WPUTSCROLL );


/* create scrollbar
*/
if ( nlast > 4 )
{
have_scrollbar =1;
scrollbar = wscrollbar_add ( -1, width-1, 0, nlast-1, ntotal-1, 0 );
}


/* actual number of text columns is width -1 (for border)
*/
smallW = wopen ( l,t, width-1, nlast, wmenuattr, NO_BORDER, 0, 0);
w0-> winputstyle = (0xFF - WPUTWRAP - WPUTSCROLL );






wreopen ( bigW );
if ( title )
{
wtitle ( title );
}

if ( extra )
{
wbutton_add ("END ", width, nvisible-1, 5, END, 0);
wbutton_add ("HOME", width, 0, 5, HOME, 0);
}

newpick = npick;
redraw = ON;


/* loop thru user input.
*/
while ( more )
{
/*next line added for protection from wmsdrag() hotkey
* mouse may move the bigW during a wgetc() call,
* so may need to re-align positions of the 2 windows.
*/
smallW->winleft = bigW->winleft; smallW->wintop = bigW->wintop;
wreopen (smallW);

if ( redraw )
{
draw_menu ( list, nfirst, nlast, newpick );
redraw = OFF;
}
else
if ( npick != newpick )
{
/* only thing changed is line# picked
* the other lines haven't changed
* so redraw old line, draw new one highlighted.
*/
draw_one_line(list, nfirst, npick, wmenuattr);
draw_one_line(list, nfirst, newpick,wbuttonattr);
}
wreopen (bigW);

if ( npick != newpick )
{
npick = newpick;
if ( have_scrollbar )
{
wscrollbar_reset ( scrollbar, npick );
}
}



if ( extra )
{
draw_npick ( width, npick ); /* '#nnn' */

/* handle the 'dn' buttons, if need to change them
*/
if ( nlast != ntotal )
{
if ( ! dn_buttons )
{
/* not at bottom, so draw 'down' buttons
*/
wbutton_add ("PgDn", width,
nvisible-2,5,PAGE_DN, 0);
wbutton_add ("Dn 1", width,
nvisible-3,5,CTRL_PAGE_DN,0);
dn_buttons = ON;
}
}
else
{
/* (nlast == ntotal )
*/
if ( dn_buttons )
{
/* if reached end of list,
* and dn_buttons are on,
* then need to erase them
*/
wbutton_delete ( PAGE_DN, 0 );
wbutton_delete ( CTRL_PAGE_DN, 0 );
dn_buttons = OFF;
}
}

/* now the 'up' buttons, if need to change them
*/
if ( nfirst > 0 )
{
if ( ! up_buttons )
{
/* not at bottom, so draw 'down' buttons
*/
wbutton_add ("PgUp", width, 1, 5,
PAGE_UP, 0 );
wbutton_add ("Up 1", width, 2, 5,
CTRL_PAGE_UP, 0 );
up_buttons = ON;
}
}
else
{
/* (nfirst == 0 )
*/
if ( up_buttons )
{
/* if reached top of list,
* and up_buttons are on,
* then need to erase them
*/
wbutton_delete ( PAGE_UP, 0 );
wbutton_delete ( CTRL_PAGE_UP, 0 );
up_buttons = OFF;
}
}
}



key = wgetc ();


/* did user type value to match ?
*/
if ( isascii(key) && isprint(key) )
{
if ( type_len == MAX_WIDTH )
{
/* filled type match buffer, restart from 0
*/
memset (typematch, 0, sizeof (typematch) );
type_len = 0;
}
/* insert typed char in match buffer
* & add one to length of buffer.
* start search from current position
*/
typematch [type_len++] = key;
for (type_cnt =npick; type_cnt < ntotal; ++type_cnt)
{
if (0==memicmp
(list[type_cnt],typematch, type_len))
{
newpick = type_cnt;
redraw = ON;
nfirst = max (0,newpick-1);
nlast = nfirst + nvisible;
if ( nlast > ntotal)
{
nlast = ntotal;
nfirst = nlast - nvisible;
}
break; /* break from for(...) */
}
}


} /* end of printable char match */
else
if ( type_len > 0 )
{
/* match buffer has characters in it,
* but user is no longer trying to match
*/
memset (typematch, 0, sizeof (typematch) );
type_len = 0;
}



/* used mouse to make a selection on menu ?
*/
if ( ( key == MOUSE )
&& ( wmouse.wms_inwindow )
&& ( wmouse.wms_x < width ) /* in a line l to r*/
&& ( wmouse.wms_y < (nlast-nfirst) ) /* on a line t to b*/
)
{
n = nfirst + wmouse.wms_y; /* menu line # chosen */
if ( n != npick )
{
newpick = n;

}
else
{
/* double_click means accept */
if ( wmouse.wms_used & WMS_LEFT_RLS )
{
key = ENTER;
}
}
}
else
if ( key == UP_ARROW )
{
/* no on_screen buttons for up arrow
* so have to handle it here
*/
--newpick;
if ( newpick < 0 )
{
newpick =0;
}

if ( newpick < nfirst )
{
/* have moved offscreen */
nfirst = newpick;
nlast = nfirst + nvisible;
redraw = ON;
}
}
else
if ( key == DN_ARROW )
{
/* no on_screen buttons for dnup arrow
*/
++newpick;
if ( newpick >= ntotal )
{
newpick = ntotal-1;
}
if ( newpick >= nlast )
{
/* have moved down offscreen */
nlast = newpick +1;
nfirst = nlast-nvisible;
redraw = ON;
}

}




switch ( key )
{
/* NOTE ESCAPE falls through to ENTER,
* there is no break
*/
case (ESCAPE):
npick = ntotal; /* offset to NULL string */
case (ENTER):
more = 0;
break;

case ( HOME ):
nfirst = 0;
nlast = nvisible;
newpick= 0;
redraw = ON;
break;

case ( END ):
nlast = ntotal;
nfirst = nlast - nvisible;
newpick= nlast -1;
redraw = ON;
break;

case ( PAGE_DN ):
if ( dn_buttons )
{
/* dn_buttons are onscreen,
* implies valid choice
*/
nlast += nvisible;
if ( nlast > ntotal )
{
nlast = ntotal;
}
nfirst = nlast - nvisible;
newpick = nfirst;
redraw = ON;
}
break;

case ( PAGE_UP ):
if ( up_buttons )
{
nfirst -= nvisible;
if ( nfirst < 0 )
{
nfirst = 0;
}
nlast = nfirst + nvisible;
newpick = nlast -1;
redraw = ON;
}
break;




case ( CTRL_PAGE_UP ):
if ( up_buttons )
{
nfirst -= 1;
if ( nfirst < 0 )
{
nfirst = 0;
}
nlast = nfirst + nvisible;

if ( npick >= nlast )
{
newpick = nlast-1;
}

redraw = ON;
}
break;


case ( CTRL_PAGE_DN ):
if ( dn_buttons )
{
nlast += 1;
if ( nlast >ntotal )
{
nlast = ntotal;
}
nfirst = nlast - nvisible;
if ( npick < nfirst )
{
newpick = nfirst;
}
redraw = ON;
}
break;


case ( -1 ):
/* scrollbar was selected.
*/
newpick = wscrollbar_scroll ( scrollbar );
if ( newpick < nfirst )
{
redraw = ON;
nfirst = newpick;
nlast = nfirst + nvisible;
}
else
if ( newpick >= nlast )
{
redraw = ON;
nlast = newpick +1;
nfirst = nlast - nvisible;
}
break;

} /* end switch on key */



} /* end while ... more */






/* close the small window first, then the big window
*/
wreopen ( smallW );
wabandon ();
wclose ();

return (npick); /* wmenu */
}



static void W_NEAR draw_npick ( int width, int npick )
{
wgoto ( width, (w0->winymax)/2 );
wprintf ( "#%-3.3i" , npick+1 );
return;
}



static void W_NEAR draw_menu ( char **list, int nfirst, int nlast, int npick )
{
int n;
unsigned char attr;

for ( n= nfirst; n {
if ( n==npick )
{
attr = wbuttonattr;
}
else
{
attr = wmenuattr;
}

draw_one_line ( list, nfirst, n, attr );
}

return;
}




/* draw one line of the menu */
static void W_NEAR draw_one_line (char **list, int nfirst, int n,
unsigned char attr )
{

wgoto ( 0, n-nfirst );
wsetattr ( attr );
wclearline ();
wputs ( list[n] );
wsetattr (wmenuattr);

return;
}




/*--------------------------- end of WPICK.C -------------------------*/