XRandR: Allow multiple but not all CRTCs to be redshifted

Previously only one CRTC could be set in the configuration file for
redshifting when XRandR mechanism was being used. That is fine for
a setup with two displays but breaks when three or more displays
are in use and one of those shouldn't be redshifted (e.g. two
computer displays and one TV connected to the computer).

The config value 'crtc' for method xrandr can now be entered as
comma separated list of multiple CRTCs. All CRTCs in the list will
be redshifted while all those not in the list will not be touched.

Signed-off-by: Lennart Sauerbeck <devel@lennart.sauerbeck.org>

src/gamma-randr.c

@@ -21,6 +21,7 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
+#include <errno.h>
 
 #ifdef ENABLE_NLS
 # include <libintl.h>
@@ -45,8 +46,9 @@ randr_init(randr_state_t *state)
 {
 	/* Initialize state. */
 	state->screen_num = -1;
-	state->crtc_num = -1;
+	state->crtc_num = NULL;
 
+	state->crtc_num_count = 0;
 	state->crtc_count = 0;
 	state->crtcs = NULL;
 
@@ -260,6 +262,7 @@ randr_free(randr_state_t *state)
 		free(state->crtcs[i].saved_ramps);
 	}
 	free(state->crtcs);
+	free(state->crtc_num);
 
 	/* Close connection */
 	xcb_disconnect(state->conn);
@@ -274,7 +277,7 @@ randr_print_help(FILE *f)
 	/* TRANSLATORS: RANDR help output
 	   left column must not be translated */
 	fputs(_("  screen=N\tX screen to apply adjustments to\n"
-		"  crtc=N\tCRTC to apply adjustments to\n"), f);
+		"  crtc=N\tList of comma separated CRTCs to apply adjustments to\n"), f);
 	fputs("\n", f);
 }
 
@@ -284,7 +287,37 @@ randr_set_option(randr_state_t *state, const char *key, const char *value)
 	if (strcasecmp(key, "screen") == 0) {
 		state->screen_num = atoi(value);
 	} else if (strcasecmp(key, "crtc") == 0) {
-		state->crtc_num = atoi(value);
+		char *tail;
+
+		/* Check how many crtcs are configured */
+		char *local_value_marker = value;
+		while (*local_value_marker != 0) {
+			if (strncmp(local_value_marker, ",", 1) == 0)
+				++local_value_marker;
+			if (*local_value_marker == 0)
+				break;
+
+			errno = 0;
+			strtol(local_value_marker, &tail, 0);
+			if (!errno)
+				++(state->crtc_num_count);
+			local_value_marker = tail;
+		}
+
+		/* Configure all given crtcs */
+		state->crtc_num = calloc(state->crtc_num_count, sizeof(int));
+		local_value_marker = value;
+		for (int i = 0; i < state->crtc_num_count; ++i)
+		{
+			if (strncmp(local_value_marker, ",", 1) == 0)
+				++local_value_marker;
+
+			errno = 0;
+			int parsed = strtol(local_value_marker, &tail, 0);
+			if (!errno)
+				state->crtc_num[i] = parsed;
+			local_value_marker = tail;
+		}
 	} else {
 		fprintf(stderr, _("Unknown method parameter: `%s'.\n"), key);
 		return -1;
@@ -301,7 +334,7 @@ randr_set_temperature_for_crtc(randr_state_t *state, int crtc_num, int temp,
 
 	if (crtc_num >= state->crtc_count || crtc_num < 0) {
 		fprintf(stderr, _("CRTC %d does not exist. "),
-			state->crtc_num);
+			crtc_num);
 		if (state->crtc_count > 1) {
 			fprintf(stderr, _("Valid CRTCs are [0-%d].\n"),
 				state->crtc_count-1);
@@ -354,18 +387,21 @@ randr_set_temperature(randr_state_t *state, int temp, float brightness,
 {
 	int r;
 
-	/* If no CRTC number has been specified,
+	/* If no CRTC numbers have been specified,
 	   set temperature on all CRTCs. */
-	if (state->crtc_num < 0) {
+	if (state->crtc_num_count == 0) {
 		for (int i = 0; i < state->crtc_count; i++) {
 			r = randr_set_temperature_for_crtc(state, i,
 							   temp, brightness,
 							   gamma);
 			if (r < 0) return -1;
 		}
 	} else {
-		return randr_set_temperature_for_crtc(state, state->crtc_num,
-						      temp, brightness, gamma);
+		for (int i = 0; i < state->crtc_num_count; ++i) {
+			r = randr_set_temperature_for_crtc(state, state->crtc_num[i],
+								temp, brightness, gamma);
+			if (r < 0) return -1;
+		}
 	}
 
 	return 0;

src/gamma-randr.h

@@ -40,7 +40,8 @@ typedef struct {
 	xcb_screen_t *screen;
 	int preferred_screen;
 	int screen_num;
-	int crtc_num;
+	int crtc_num_count;
+	int* crtc_num;
 	unsigned int crtc_count;
 	randr_crtc_state_t *crtcs;
 } randr_state_t;