Support for DELAY as a floating point number including less than 1

second while maintaining backward compatibiitiy with integer
arguments.

image.c

@@ -74,8 +74,8 @@ void img_init(img_t *img, win_t *win)
 	imlib_context_set_color_modifier(img->cmod);
 	img->gamma = MIN(MAX(options->gamma, -GAMMA_RANGE), GAMMA_RANGE);
 
-	img->ss.on = options->slideshow > 0;
-	img->ss.delay = options->slideshow > 0 ? options->slideshow : SLIDESHOW_DELAY;
+	img->ss.on = options->slideshow > 0.0;
+	img->ss.delay = options->slideshow > 0.0 ? options->slideshow : SLIDESHOW_DELAY;
 }
 
 #if HAVE_LIBEXIF

image.h

@@ -60,7 +60,7 @@ typedef struct {
 
 	struct {
 		bool on;
-		int delay;
+		float delay;
 	} ss;
 
 	multi_img_t multi;

main.c

@@ -372,7 +372,7 @@ void update_info(void)
 	} else {
 		bar_put(r, "%s", mark);
 		if (img.ss.on)
-			bar_put(r, "%ds | ", img.ss.delay);
+			bar_put(r, "%2.1fs | ", img.ss.delay);
 		if (img.gamma != 0)
 			bar_put(r, "G%+d | ", img.gamma);
 		bar_put(r, "%3d%% | ", (int) (img.zoom * 100.0));

options.c

@@ -44,6 +44,7 @@ void print_version(void)
 void parse_options(int argc, char **argv)
 {
 	int n, opt;
+	float f;
 	char *end, *s;
 	const char *scalemodes = "dfwh";
 
@@ -59,7 +60,7 @@ void parse_options(int argc, char **argv)
 	_options.zoom = 1.0;
 	_options.animate = false;
 	_options.gamma = 0;
-	_options.slideshow = 0;
+	_options.slideshow = 0.0;
 
 	_options.fullscreen = false;
 	_options.embed = 0;
@@ -128,10 +129,10 @@ void parse_options(int argc, char **argv)
 				_options.recursive = true;
 				break;
 			case 'S':
-				n = strtol(optarg, &end, 0);
-				if (*end != '\0' || n <= 0)
+				f = (float) strtof(optarg, &end);
+				if (*end != '\0' || f <= 0.0)
 					error(EXIT_FAILURE, 0, "Invalid argument for option -S: %s", optarg);
-				_options.slideshow = n;
+				_options.slideshow = (float) f;
 				break;
 			case 's':
 				s = strchr(scalemodes, optarg[0]);

options.h

@@ -36,7 +36,7 @@ typedef struct {
 	float zoom;
 	bool animate;
 	int gamma;
-	int slideshow;
+	float slideshow;
 
 	/* window: */
 	bool fullscreen;

sxiv.1

@@ -81,7 +81,7 @@ Be quiet, disable warnings to standard error stream.
 Search the given directories recursively for images to view.
 .TP
 .BI "\-S " DELAY
-Start in slideshow mode. Set the delay between images to DELAY seconds.
+Start in slideshow mode. Set the delay between images to DELAY (float, e.g. 1, 3.1, 0.01) seconds.
 .TP
 .BI "\-s " MODE
 Set scale mode according to MODE character. Supported modes are: [d]own, 
@@ -330,7 +330,7 @@ Toggle visibility of alpha-channel, i.e. image transparency.
 .TP
 .B s
 Toggle slideshow mode and/or set the delay between images to
-.I count
+.I count (integer prefix only)
 seconds.
 .SH MOUSE COMMANDS
 The following mouse mappings are available in image mode: