/* PDCurses */
#include <curspriv.h>
/*man-start**************************************************************
color
-----
### Synopsis
bool has_colors(void);
int start_color(void);
int init_pair(short pair, short fg, short bg);
int pair_content(short pair, short *fg, short *bg);
bool can_change_color(void);
int init_color(short color, short red, short green, short blue);
int color_content(short color, short *red, short *green, short *blue);
int alloc_pair(int fg, int bg);
int assume_default_colors(int f, int b);
int find_pair(int fg, int bg);
int free_pair(int pair);
int use_default_colors(void);
int PDC_set_line_color(short color);
### Description
To use these routines, first, call start_color(). Colors are always
used in pairs, referred to as color-pairs. A color-pair is created by
init_pair(), and consists of a foreground color and a background
color. After initialization, COLOR_PAIR(n) can be used like any other
video attribute.
has_colors() reports whether the terminal supports color.
start_color() initializes eight basic colors (black, red, green,
yellow, blue, magenta, cyan, and white), and two global variables:
COLORS and COLOR_PAIRS (respectively defining the maximum number of
colors and color-pairs the terminal is capable of displaying).
init_pair() changes the definition of a color-pair. It takes three
arguments: the number of the color-pair to be redefined, and the new
values of the foreground and background colors. The pair number must
be between 0 and COLOR_PAIRS - 1, inclusive. The foreground and
background must be between 0 and COLORS - 1, inclusive. If the color
pair was previously initialized, the screen is refreshed, and all
occurrences of that color-pair are changed to the new definition.
pair_content() is used to determine what the colors of a given color-
pair consist of.
can_change_color() indicates if the terminal has the capability to
change the definition of its colors.
init_color() is used to redefine a color, if possible. Each of the
components -- red, green, and blue -- is specified in a range from 0
to 1000, inclusive.
color_content() reports the current definition of a color in the same
format as used by init_color().
assume_default_colors() and use_default_colors() emulate the ncurses
extensions of the same names. assume_default_colors(f, b) is
essentially the same as init_pair(0, f, b) (which isn't allowed); it
redefines the default colors. use_default_colors() allows the use of
-1 as a foreground or background color with init_pair(), and calls
assume_default_colors(-1, -1); -1 represents the foreground or
background color that the terminal had at startup. If the environment
variable PDC_ORIGINAL_COLORS is set at the time start_color() is
called, that's equivalent to calling use_default_colors().
alloc_pair(), find_pair() and free_pair() are also from ncurses.
free_pair() marks a pair as unused; find_pair() returns an existing
pair with the specified foreground and background colors, if one
exists. And alloc_pair() returns such a pair whether or not it was
previously set, overwriting the oldest initialized pair if there are
no free pairs.
PDC_set_line_color() is used to set the color, globally, for the
color of the lines drawn for the attributes: A_UNDERLINE, A_LEFT and
A_RIGHT. A value of -1 (the default) indicates that the current
foreground color should be used.
NOTE: COLOR_PAIR() and PAIR_NUMBER() are implemented as macros.
### Return Value
Most functions return OK on success and ERR on error. has_colors()
and can_change_colors() return TRUE or FALSE. alloc_pair() and
find_pair() return a pair number, or -1 on error.
### Portability
X/Open ncurses NetBSD
has_colors Y Y Y
start_color Y Y Y
init_pair Y Y Y
pair_content Y Y Y
can_change_color Y Y Y
init_color Y Y Y
color_content Y Y Y
alloc_pair - Y -
assume_default_colors - Y Y
find_pair - Y -
free_pair - Y -
use_default_colors - Y Y
PDC_set_line_color - - -
**man-end****************************************************************/
#include <stdlib.h>
#include <string.h>
int COLORS = 0;
int COLOR_PAIRS = PDC_COLOR_PAIRS;
static bool default_colors = FALSE;
static short first_col = 0;
static int allocnum = 0;
int start_color(void)
{
PDC_LOG(("start_color() - called\n"));
if (!SP || SP->mono)
return ERR;
SP->color_started = TRUE;
PDC_set_blink(FALSE); /* Also sets COLORS */
if (!default_colors
&& SP
->orig_attr
&& getenv("PDC_ORIGINAL_COLORS")) default_colors = TRUE;
PDC_init_atrtab();
return OK;
}
static void _normalize(short *fg, short *bg)
{
if (*fg == -1)
*fg = SP->orig_attr ? SP->orig_fore : COLOR_WHITE;
if (*bg == -1)
*bg = SP->orig_attr ? SP->orig_back : COLOR_BLACK;
}
static void _init_pair_core(short pair, short fg, short bg)
{
PDC_PAIR *p = SP->atrtab + pair;
_normalize(&fg, &bg);
/* To allow the PDC_PRESERVE_SCREEN option to work, we only reset
curscr if this call to init_pair() alters a color pair created by
the user. */
if (p->set)
{
if (p->f != fg || p->b != bg)
curscr->_clear = TRUE;
}
p->f = fg;
p->b = bg;
p->count = allocnum++;
p->set = TRUE;
}
int init_pair(short pair, short fg, short bg)
{
PDC_LOG(("init_pair() - called: pair %d fg %d bg %d\n", pair, fg, bg));
if (!SP || !SP->color_started || pair < 1 || pair >= COLOR_PAIRS ||
fg < first_col || fg >= COLORS || bg < first_col || bg >= COLORS)
return ERR;
_init_pair_core(pair, fg, bg);
return OK;
}
bool has_colors(void)
{
PDC_LOG(("has_colors() - called\n"));
return SP ? !(SP->mono) : FALSE;
}
int init_color(short color, short red, short green, short blue)
{
PDC_LOG(("init_color() - called\n"));
if (!SP || color < 0 || color >= COLORS || !PDC_can_change_color() ||
red < -1 || red > 1000 || green < -1 || green > 1000 ||
blue < -1 || blue > 1000)
return ERR;
SP->dirty = TRUE;
return PDC_init_color(color, red, green, blue);
}
int color_content(short color, short *red, short *green, short *blue)
{
PDC_LOG(("color_content() - called\n"));
if (color < 0 || color >= COLORS || !red || !green || !blue)
return ERR;
if (PDC_can_change_color())
return PDC_color_content(color, red, green, blue);
else
{
/* Simulated values for platforms that don't support palette
changing */
short maxval = (color & 8) ? 1000 : 680;
*red = (color & COLOR_RED) ? maxval : 0;
*green = (color & COLOR_GREEN) ? maxval : 0;
*blue = (color & COLOR_BLUE) ? maxval : 0;
return OK;
}
}
bool can_change_color(void)
{
PDC_LOG(("can_change_color() - called\n"));
return PDC_can_change_color();
}
int pair_content(short pair, short *fg, short *bg)
{
PDC_LOG(("pair_content() - called\n"));
if (pair < 0 || pair >= COLOR_PAIRS || !fg || !bg)
return ERR;
*fg = SP->atrtab[pair].f;
*bg = SP->atrtab[pair].b;
return OK;
}
int assume_default_colors(int f, int b)
{
PDC_LOG(("assume_default_colors() - called: f %d b %d\n", f, b));
if (f < -1 || f >= COLORS || b < -1 || b >= COLORS)
return ERR;
if (SP->color_started)
_init_pair_core(0, f, b);
return OK;
}
int use_default_colors(void)
{
PDC_LOG(("use_default_colors() - called\n"));
default_colors = TRUE;
first_col = -1;
return assume_default_colors(-1, -1);
}
int PDC_set_line_color(short color)
{
PDC_LOG(("PDC_set_line_color() - called: %d\n", color));
if (!SP || color < -1 || color >= COLORS)
return ERR;
SP->line_color = color;
return OK;
}
void PDC_init_atrtab(void)
{
PDC_PAIR *p = SP->atrtab;
short i, fg, bg;
if (SP->color_started && !default_colors)
{
fg = COLOR_WHITE;
bg = COLOR_BLACK;
}
else
fg = bg = -1;
_normalize(&fg, &bg);
for (i = 0; i < PDC_COLOR_PAIRS; i++)
{
p[i].f = fg;
p[i].b = bg;
p[i].set = FALSE;
}
}
int free_pair(int pair)
{
if (pair < 1 || pair >= PDC_COLOR_PAIRS || !(SP->atrtab[pair].set))
return ERR;
SP->atrtab[pair].set = FALSE;
return OK;
}
int find_pair(int fg, int bg)
{
int i;
PDC_PAIR *p = SP->atrtab;
for (i = 0; i < PDC_COLOR_PAIRS; i++)
if (p[i].set && p[i].f == fg && p[i].b == bg)
return i;
return -1;
}
static int _find_oldest()
{
int i, lowind = 0, lowval = 0;
PDC_PAIR *p = SP->atrtab;
for (i = 1; i < PDC_COLOR_PAIRS; i++)
{
if (!p[i].set)
return i;
if (!lowval || (p[i].count < lowval))
{
lowind = i;
lowval = p[i].count;
}
}
return lowind;
}
int alloc_pair(int fg, int bg)
{
int i = find_pair(fg, bg);
if (-1 == i)
{
i = _find_oldest();
if (ERR == init_pair(i, fg, bg))
return -1;
}
return i;
}