Add reset option (activated with -x) that removes any color adjustments

 applied to the screen. Based on patch by Dan Helfman.

1 files changed, 98 insertions, 55 deletions

diff --git a/src/redshift.c b/src/redshift.c
index bb418c7..18cc2c5 100644
--- a/src/redshift.c
+++ b/src/redshift.c
@@ -128,7 +128,7 @@ static const gamma_method_t gamma_methods[] = {
 		(gamma_method_set_temperature_func *)w32gdi_set_temperature
 	},
 #endif
-	{ NULL, NULL, NULL, NULL, NULL }
+	{ NULL }
 };
 
 
@@ -169,7 +169,7 @@ static const location_provider_t location_providers[] = {
 		(location_provider_get_location_func *)
 		location_manual_get_location
 	},
-	{ NULL, NULL, NULL, NULL }
+	{ NULL }
 };
 
 /* Bounds for parameters. */
@@ -187,6 +187,9 @@ static const location_provider_t location_providers[] = {
 #define DEFAULT_NIGHT_TEMP  3700
 #define DEFAULT_GAMMA        1.0
 
+/* The color temperature when no adjustment is applied. */
+#define NEUTRAL_TEMP  6500
+
 /* Angular elevation of the sun at which the color temperature
    transition period starts and ends (in degress).
    Transition during twilight, and while the sun is lower than
@@ -194,6 +197,13 @@ static const location_provider_t location_providers[] = {
 #define TRANSITION_LOW     SOLAR_CIVIL_TWILIGHT_ELEV
 #define TRANSITION_HIGH    3.0
 
+/* Program modes. */
+typedef enum {
+	PROGRAM_MODE_CONTINUAL,
+	PROGRAM_MODE_ONE_SHOT,
+	PROGRAM_MODE_RESET
+} program_mode_t;
+
 
 #ifdef HAVE_SYS_SIGNAL_H
 
@@ -284,6 +294,7 @@ print_help(const char *program_name)
 		"  \t\t(Type `list' to see available methods)\n"
 		"  -o\t\tOne shot mode (do not continously adjust"
 		" color temperature)\n"
+		"  -x\t\tReset mode (remove adjustment from screen)\n"
 		"  -r\t\tDisable temperature transitions\n"
 		"  -t DAY:NIGHT\tColor temperature to set at daytime/night\n"),
 	      stdout);
@@ -466,13 +477,13 @@ main(int argc, char *argv[])
 	char *provider_args = NULL;
 
 	int transition = 1;
-	int one_shot = 0;
+	program_mode_t mode = PROGRAM_MODE_CONTINUAL;
 	int verbose = 0;
 	char *s;
 
 	/* Parse arguments. */
 	int opt;
-	while ((opt = getopt(argc, argv, "g:hl:m:ort:v")) != -1) {
+	while ((opt = getopt(argc, argv, "g:hl:m:ort:vx")) != -1) {
 		switch (opt) {
 		case 'g':
 			s = strchr(optarg, ':');
@@ -594,7 +605,7 @@ main(int argc, char *argv[])
 			}
 			break;
 		case 'o':
-			one_shot = 1;
+			mode = PROGRAM_MODE_ONE_SHOT;
 			break;
 		case 'r':
 			transition = 0;
@@ -615,6 +626,9 @@ main(int argc, char *argv[])
 		case 'v':
 			verbose = 1;
 			break;
+		case 'x':
+			mode = PROGRAM_MODE_RESET;
+			break;
 		case '?':
 			fputs(_("Try `-h' for more information.\n"), stderr);
 			exit(EXIT_FAILURE);
@@ -626,66 +640,77 @@ main(int argc, char *argv[])
 	   try all providers until one that works is found. */
 	location_state_t location_state;
 
-	if (provider != NULL) {
-		/* Use provider specified on command line. */
-		r = provider_try_start(provider, &location_state,
-			provider_args);
-		if (r < 0) exit(EXIT_FAILURE);
-	} else {
-		/* Try all providers, use the first that works. */
-		for (int i = 0; location_providers[i].name != NULL; i++) {
-			const location_provider_t *p = &location_providers[i];
-			r = provider_try_start(p, &location_state, NULL);
-			if (r < 0) {
-				fputs(_("Trying other provider...\n"), stderr);
-				continue;
-			}
+	/* Location is not needed for reset mode. */
+	if (mode != PROGRAM_MODE_RESET) {
+		if (provider != NULL) {
+			/* Use provider specified on command line. */
+			r = provider_try_start(provider, &location_state,
+					       provider_args);
+			if (r < 0) exit(EXIT_FAILURE);
+		} else {
+			/* Try all providers, use the first that works. */
+			for (int i = 0;
+			     location_providers[i].name != NULL; i++) {
+				const location_provider_t *p =
+					&location_providers[i];
+				r = provider_try_start(p, &location_state,
+						       NULL);
+				if (r < 0) {
+					fputs(_("Trying other provider...\n"),
+					      stderr);
+					continue;
+				}
 
-			provider = p;
-			break;
-		}
+				provider = p;
+				break;
+			}
 
-		/* Failure if no providers were successful at this point. */
-		if (provider == NULL) {
-			fputs(_("No more location providers to try.\n"),
-			      stderr);
-			exit(EXIT_FAILURE);
+			/* Failure if no providers were successful at this
+			   point. */
+			if (provider == NULL) {
+				fputs(_("No more location providers"
+					" to try.\n"), stderr);
+				exit(EXIT_FAILURE);
+			}
 		}
 	}
 
 	float lat = NAN;
 	float lon = NAN;
 
-	/* Get current location. */
-	r = provider->get_location(&location_state, &lat, &lon);
-	if (r < 0) {
-		fputs(_("Unable to get location from provider.\n"), stderr);
-		exit(EXIT_FAILURE);
-	}
+	if (mode != PROGRAM_MODE_RESET) {
+		/* Get current location. */
+		r = provider->get_location(&location_state, &lat, &lon);
+		if (r < 0) {
+			fputs(_("Unable to get location from provider.\n"),
+			      stderr);
+			exit(EXIT_FAILURE);
+		}
 
-	provider->free(&location_state);
+		provider->free(&location_state);
 
-	if (verbose) {
-		/* TRANSLATORS: Append degree symbols if possible. */
-		printf(_("Location: %f, %f\n"), lat, lon);
-	}
+		if (verbose) {
+			/* TRANSLATORS: Append degree symbols if possible. */
+			printf(_("Location: %f, %f\n"), lat, lon);
+		}
 
-	/* Latitude */
-	if (lat < MIN_LAT || lat > MAX_LAT) {
-		/* TRANSLATORS: Append degree symbols if possible. */
-		fprintf(stderr,
-			_("Latitude must be between %.1f and %.1f.\n"),
-			MIN_LAT, MAX_LAT);
-		exit(EXIT_FAILURE);
-	}
+		/* Latitude */
+		if (lat < MIN_LAT || lat > MAX_LAT) {
+			/* TRANSLATORS: Append degree symbols if possible. */
+			fprintf(stderr,
+				_("Latitude must be between %.1f and %.1f.\n"),
+				MIN_LAT, MAX_LAT);
+			exit(EXIT_FAILURE);
+		}
 
-	/* Longitude */
-	if (lon < MIN_LON || lon > MAX_LON) {
-		/* TRANSLATORS: Append degree symbols if possible. */
-		fprintf(stderr,
-			_("Longitude must be between %.1f and %.1f.\n"),
-			MIN_LON, MAX_LON);
-		exit(EXIT_FAILURE);
+		/* Longitude */
+		if (lon < MIN_LON || lon > MAX_LON) {
+			/* TRANSLATORS: Append degree symbols if possible. */
+			fprintf(stderr,
+				_("Longitude must be between"
+				  " %.1f and %.1f.\n"), MIN_LON, MAX_LON);
+			exit(EXIT_FAILURE);
+		}
 	}
 
 	/* Color temperature at daytime */
@@ -748,7 +773,9 @@ main(int argc, char *argv[])
 		}
 	}
 
-	if (one_shot) {
+	switch (mode) {
+	case PROGRAM_MODE_ONE_SHOT:
+	{
 		/* Current angular elevation of the sun */
 		double now;
 		r = systemtime_get_time(&now);
@@ -778,7 +805,21 @@ main(int argc, char *argv[])
 			method->free(&state);
 			exit(EXIT_FAILURE);
 		}
-	} else {
+	}
+	break;
+	case PROGRAM_MODE_RESET:
+	{
+		/* Reset screen */
+		r = method->set_temperature(&state, NEUTRAL_TEMP, gamma);
+		if (r < 0) {
+			fputs(_("Temperature adjustment failed.\n"), stderr);
+			method->free(&state);
+			exit(EXIT_FAILURE);
+		}
+	}
+	break;
+	case PROGRAM_MODE_CONTINUAL:
+	{
 		/* Transition state */
 		double short_trans_end = 0;
 		int short_trans = 0;
@@ -955,6 +996,8 @@ main(int argc, char *argv[])
 		/* Restore saved gamma ramps */
 		method->restore(&state);
 	}
+	break;
+	}
 
 	/* Clean up gamma adjustment state */
 	method->free(&state);