1 /* Public Domain Curses */
2
3 #include <curspriv.h>
4
5 RCSID("$Id: color.c,v 1.83 2008/07/13 16:08:18 wmcbrine Exp $")
6
7 /*man-start**************************************************************
8
9 Name: color
10
11 Synopsis:
12 int start_color(void);
13 int init_pair(short pair, short fg, short bg);
14 int init_color(short color, short red, short green, short blue);
15 bool has_colors(void);
16 bool can_change_color(void);
17 int color_content(short color, short *red, short *green, short *blue);
18 int pair_content(short pair, short *fg, short *bg);
19
20 int assume_default_colors(int f, int b);
21 int use_default_colors(void);
22
23 int PDC_set_line_color(short color);
24
25 Description:
26 To use these routines, start_color() must be called, usually
27 immediately after initscr(). Colors are always used in pairs,
28 referred to as color-pairs. A color-pair consists of a
29 foreground color and a background color. A color-pair is
30 initialized via init_pair(). After initialization, COLOR_PAIR(n)
31 can be used like any other video attribute.
32
33 start_color() initializes eight basic colors (black, red, green,
34 yellow, blue, magenta, cyan, and white), and two global
35 variables; COLORS and COLOR_PAIRS (respectively defining the
36 maximum number of colors and color-pairs the terminal is capable
37 of displaying).
38
39 init_pair() changes the definition of a color-pair. It takes
40 three arguments: the number of the color-pair to be redefined,
41 and the new values of the foreground and background colors. The
42 pair number must be between 0 and COLOR_PAIRS - 1, inclusive.
43 The foreground and background must be between 0 and COLORS - 1,
44 inclusive. If the color pair was previously initialized, the
45 screen is refreshed, and all occurrences of that color-pair are
46 changed to the new definition.
47
48 has_colors() indicates if the terminal supports, and can
49 maniplulate color. It returns TRUE or FALSE.
50
51 can_change_color() indicates if the terminal has the capability
52 to change the definition of its colors.
53
54 pair_content() is used to determine what the colors of a given
55 color-pair consist of.
56
57 assume_default_colors() and use_default_colors() emulate the
58 ncurses extensions of the same names. assume_default_colors(f,
59 b) is essentially the same as init_pair(0, f, b) (which isn't
60 allowed); it redefines the default colors. use_default_colors()
61 allows the use of -1 as a foreground or background color with
62 init_pair(), and calls assume_default_colors(-1, -1); -1
63 represents the foreground or background color that the terminal
64 had at startup. If the environment variable PDC_ORIGINAL_COLORS
65 is set at the time start_color() is called, that's equivalent to
66 calling use_default_colors().
67
68 PDC_set_line_color() is used to set the color, globally, for
69 the color of the lines drawn for the attributes: A_UNDERLINE,
70 A_OVERLINE, A_LEFTLINE and A_RIGHTLINE. A value of -1 (the
71 default) indicates that the current foreground color should be
72 used.
73
74 NOTE: COLOR_PAIR() and PAIR_NUMBER() are implemented as macros.
75
76 Return Value:
77 All functions return OK on success and ERR on error, except for
78 has_colors() and can_change_colors(), which return TRUE or FALSE.
79
80 Portability X/Open BSD SYS V
81 start_color Y - 3.2
82 init_pair Y - 3.2
83 init_color Y - 3.2
84 has_colors Y - 3.2
85 can_change_color Y - 3.2
86 color_content Y - 3.2
87 pair_content Y - 3.2
88 assume_default_colors - - -
89 use_default_colors - - -
90 PDC_set_line_color - - -
91
92 **man-end****************************************************************/
93
94 #include <stdlib.h>
95 #include <string.h>
96
97 int COLORS = 0;
98 int COLOR_PAIRS = PDC_COLOR_PAIRS;
99
100 bool pdc_color_started = FALSE;
101
102 /* pair_set[] tracks whether a pair has been set via init_pair() */
103
104 static bool pair_set[PDC_COLOR_PAIRS];
105 static bool default_colors = FALSE;
106 static short first_col = 0;
107
start_color(void)108 int start_color(void)
109 {
110 PDC_LOG(("start_color() - called\n"));
111
112 if (SP->mono)
113 return ERR;
114
115 pdc_color_started = TRUE;
116
117 PDC_set_blink(FALSE); /* Also sets COLORS, to 8 or 16 */
118
119 if (!default_colors && SP->orig_attr && getenv("PDC_ORIGINAL_COLORS"))
120 default_colors = TRUE;
121
122 PDC_init_atrtab();
123
124 memset(pair_set, 0, PDC_COLOR_PAIRS);
125
126 return OK;
127 }
128
_normalize(short * fg,short * bg)129 static void _normalize(short *fg, short *bg)
130 {
131 if (*fg == -1)
132 *fg = SP->orig_attr ? SP->orig_fore : COLOR_WHITE;
133
134 if (*bg == -1)
135 *bg = SP->orig_attr ? SP->orig_back : COLOR_BLACK;
136 }
137
init_pair(short pair,short fg,short bg)138 int init_pair(short pair, short fg, short bg)
139 {
140 PDC_LOG(("init_pair() - called: pair %d fg %d bg %d\n", pair, fg, bg));
141
142 if (!pdc_color_started || pair < 1 || pair >= COLOR_PAIRS ||
143 fg < first_col || fg >= COLORS || bg < first_col || bg >= COLORS)
144 return ERR;
145
146 _normalize(&fg, &bg);
147
148 /* To allow the PDC_PRESERVE_SCREEN option to work, we only reset
149 curscr if this call to init_pair() alters a color pair created by
150 the user. */
151
152 if (pair_set[pair])
153 {
154 short oldfg, oldbg;
155
156 PDC_pair_content(pair, &oldfg, &oldbg);
157
158 if (oldfg != fg || oldbg != bg)
159 curscr->_clear = TRUE;
160 }
161
162 PDC_init_pair(pair, fg, bg);
163
164 pair_set[pair] = TRUE;
165
166 return OK;
167 }
168
has_colors(void)169 bool has_colors(void)
170 {
171 PDC_LOG(("has_colors() - called\n"));
172
173 return !(SP->mono);
174 }
175
init_color(short color,short red,short green,short blue)176 int init_color(short color, short red, short green, short blue)
177 {
178 PDC_LOG(("init_color() - called\n"));
179
180 if (color < 0 || color >= COLORS || !PDC_can_change_color() ||
181 red < 0 || red > 1000 || green < 0 || green > 1000 ||
182 blue < 0 || blue > 1000)
183 return ERR;
184
185 return PDC_init_color(color, red, green, blue);
186 }
187
color_content(short color,short * red,short * green,short * blue)188 int color_content(short color, short *red, short *green, short *blue)
189 {
190 PDC_LOG(("color_content() - called\n"));
191
192 if (color < 0 || color >= COLORS || !red || !green || !blue)
193 return ERR;
194
195 if (PDC_can_change_color())
196 return PDC_color_content(color, red, green, blue);
197 else
198 {
199 /* Simulated values for platforms that don't support palette
200 changing */
201
202 short maxval = (color & 8) ? 1000 : 680;
203
204 *red = (color & COLOR_RED) ? maxval : 0;
205 *green = (color & COLOR_GREEN) ? maxval : 0;
206 *blue = (color & COLOR_BLUE) ? maxval : 0;
207
208 return OK;
209 }
210 }
211
can_change_color(void)212 bool can_change_color(void)
213 {
214 PDC_LOG(("can_change_color() - called\n"));
215
216 return PDC_can_change_color();
217 }
218
pair_content(short pair,short * fg,short * bg)219 int pair_content(short pair, short *fg, short *bg)
220 {
221 PDC_LOG(("pair_content() - called\n"));
222
223 if (pair < 0 || pair >= COLOR_PAIRS || !fg || !bg)
224 return ERR;
225
226 return PDC_pair_content(pair, fg, bg);
227 }
228
assume_default_colors(int f,int b)229 int assume_default_colors(int f, int b)
230 {
231 PDC_LOG(("assume_default_colors() - called: f %d b %d\n", f, b));
232
233 if (f < -1 || f >= COLORS || b < -1 || b >= COLORS)
234 return ERR;
235
236 if (pdc_color_started)
237 {
238 short fg, bg, oldfg, oldbg;
239
240 fg = f;
241 bg = b;
242
243 _normalize(&fg, &bg);
244
245 PDC_pair_content(0, &oldfg, &oldbg);
246
247 if (oldfg != fg || oldbg != bg)
248 curscr->_clear = TRUE;
249
250 PDC_init_pair(0, fg, bg);
251 }
252
253 return OK;
254 }
255
use_default_colors(void)256 int use_default_colors(void)
257 {
258 PDC_LOG(("use_default_colors() - called\n"));
259
260 default_colors = TRUE;
261 first_col = -1;
262
263 return assume_default_colors(-1, -1);
264 }
265
PDC_set_line_color(short color)266 int PDC_set_line_color(short color)
267 {
268 PDC_LOG(("PDC_set_line_color() - called: %d\n", color));
269
270 if (color < -1 || color >= COLORS)
271 return ERR;
272
273 SP->line_color = color;
274
275 return OK;
276 }
277
PDC_init_atrtab(void)278 void PDC_init_atrtab(void)
279 {
280 int i;
281 short fg, bg;
282
283 if (pdc_color_started && !default_colors)
284 {
285 fg = COLOR_WHITE;
286 bg = COLOR_BLACK;
287 }
288 else
289 fg = bg = -1;
290
291 _normalize(&fg, &bg);
292
293 for (i = 0; i < PDC_COLOR_PAIRS; i++)
294 PDC_init_pair(i, fg, bg);
295 }
296