summaryrefslogtreecommitdiff
path: root/xbacklight.c
blob: df99905a3787ed8e71daab3c68ffdeb46595c206 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
#include <stdio.h>
#include <stdlib.h>
#include <X11/Xatom.h>
#include <X11/Xlib.h>
#include <X11/extensions/Xrandr.h>

typedef enum { Get, Set, Inc, Dec } op_t;

static char *program_name;

static Atom backlight;

static void
usage (void)
{
    fprintf(stderr, "usage: %s [options]\n", program_name);
    fprintf(stderr, "  where options are:\n");
    fprintf(stderr, "  -display <display> or -d <display>\n");
    fprintf(stderr, "  -help\n");
    fprintf(stderr, "  -set <percentage> or = <percentage>\n");
    fprintf(stderr, "  -inc <percentage> or + <percentage>\n");
    fprintf(stderr, "  -dec <percentage> or - <percentage>\n");
    fprintf(stderr, "  -get\n");
    /*NOTREACHED*/
    exit (1);
}

static long
backlight_get (Display *dpy, RROutput output)
{
    unsigned long   nitems;
    unsigned long   bytes_after;
    unsigned char   *prop;
    Atom	    actual_type;
    int		    actual_format;
    long	    value;
    
    if (XRRGetOutputProperty (dpy, output, backlight,
			      0, 4, False, False, None,
			      &actual_type, &actual_format,
			      &nitems, &bytes_after, &prop) != Success)
	return -1;
    if (actual_type != XA_INTEGER || nitems != 1 || actual_format != 32)
	value = -1;
    else
	value = *((long *) prop);
    XFree (prop);
    return value;
}

static void
backlight_set (Display *dpy, RROutput output, long value)
{
    XRRChangeOutputProperty (dpy, output, backlight, XA_INTEGER, 32,
			     PropModeReplace, (unsigned char *) &value, 1);
}

int
main (int argc, char **argv)
{
    char    *dpy_name = NULL;
    Display *dpy;
    int	    screen;
    int	    major, minor;
    op_t    op = Get;
    int	    value = 0;
    int	    i;

    program_name = argv[0];

    for (i = 1; i < argc; i++)
    {
	if (!strcmp (argv[i], "-display") || !strcmp ("-d", argv[i]))
	{
	    if (++i >= argc) usage();
	    dpy_name = argv[i];
	    continue;
	}
	if (!strcmp (argv[i], "-set") || !strcmp (argv[i], "="))
	{
	    if (++i >= argc) usage();
	    op = Set;
	    value = atoi (argv[i]);
	    continue;
	}
	if (argv[i][0] == '=' && isdigit (argv[i][1]))
	{
	    op = Set;
	    value = atoi (argv[i] + 1);
	    continue;
	}
	if (!strcmp (argv[i], "-inc") || !strcmp (argv[i], "+"))
	{
	    if (++i >= argc) usage();
	    op = Inc;
	    value = atoi (argv[i]);
	    continue;
	}
	if (argv[i][0] == '+' && isdigit (argv[i][1]))
	{
	    op = Inc;
	    value = atoi (argv[i] + 1);
	    continue;
	}
	if (!strcmp (argv[i], "-dec") || !strcmp (argv[i], "-"))
	{
	    if (++i >= argc) usage();
	    op = Dec;
	    value = atoi (argv[i]);
	    continue;
	}
	if (argv[i][0] == '-' && isdigit (argv[i][1]))
	{
	    op = Dec;
	    value = atoi (argv[i] + 1);
	    continue;
	}
	if (!strcmp (argv[i], "-get") || !strcmp (argv[i], "-g"))
	{
	    op = Get;
	    continue;
	}
	if (!strcmp (argv[i], "-help") || !strcmp (argv[i], "-?"))
	{
	    usage ();
	}
    }
    dpy = XOpenDisplay (dpy_name);
    if (!dpy)
    {
	fprintf (stderr, "Cannot open display \"%s\"\n",
		 XDisplayName (dpy_name));
	exit (1);
    }
    if (!XRRQueryVersion (dpy, &major, &minor))
    {
	fprintf (stderr, "RandR extension missing\n");
	exit (1);
    }
    if (major < 1 || (major == 1 && minor < 2))
    {
	fprintf (stderr, "RandR version %d.%d too old\n", major, minor);
	exit (1);
    }
    backlight = XInternAtom (dpy, "BACKLIGHT", True);
    if (backlight == None)
    {
	fprintf (stderr, "No outputs have backlight property\n");
	exit (1);
    }
    for (screen = 0; screen < ScreenCount (dpy); screen++)
    {
	Window		    root = RootWindow (dpy, screen);
	XRRScreenResources  *resources = XRRGetScreenResources (dpy, root);
	int		    o;
	
	if (!resources) continue;
	for (o = 0; o < resources->noutput; o++)
	{
	    RROutput	output = resources->outputs[o];
	    XRRPropertyInfo *info;
	    double    	cur, new, step;
	    double	min, max;
	    double	set;

	    cur = backlight_get (dpy, output);
	    if (cur != -1)
	    {
		info = XRRQueryOutputProperty (dpy, output, backlight);
		if (info)
		{
		    if (info->range && info->num_values == 2)
		    {
			min = info->values[0];
			max = info->values[1];
			if (op == Get) {
			    printf ("%f\n", (cur - min) * 100 / (max - min));
			} else {
			    set = value * (max - min) / 100;
			    switch (op) {
			    case Set:
				new = min + set;
				break;
			    case Inc:
				new = cur + set;
				break;
			    case Dec:
				new = cur - set;
				break;
			    }
			    if (new > max) new = max;
			    if (new < min) new = min;
			    step = (new - cur) / 50;
			    for (i = 0; i < 50; i++)
			    {
				if (i == 49)
				    cur = new;
				else
				    cur += step;
				backlight_set (dpy, output, (long) cur);
				XFlush (dpy);
				usleep (10 * 1000);
			    }
			}
		    }
		    XFree (info);
		}
	    }
	}
							   
	XRRFreeScreenResources (resources);
    }
    XSync (dpy, False);
}