parse_color: return success + drop fallback color

This is the first in a series of commits to refactor the color handling
in sway. This changes parse_color to return whether it was success and
no longer uses 0xFFFFFFFF as the fallback color. This also verifies that
the string actually contains a valid hexadecimal number along with
the length checks.

In the process of altering the calls to parse_color, I also took the
opportunity to heavily refactor swaybar's ipc_parse_colors function.
This allowed for several lines of duplicated code to be removed.

7 files changed, 76 insertions, 142 deletions

diff --git a/common/util.c b/common/util.c
index c0324b2f..84ebab99 100644
--- a/common/util.c
+++ b/common/util.c
@@ -1,4 +1,5 @@
 #define _POSIX_C_SOURCE 200809L
+#include <ctype.h>
 #include <float.h>
 #include <fcntl.h>
 #include <math.h>
@@ -13,21 +14,21 @@ int wrap(int i, int max) {
 	return ((i % max) + max) % max;
 }
 
-uint32_t parse_color(const char *color) {
+bool parse_color(const char *color, uint32_t *result) {
 	if (color[0] == '#') {
 		++color;
 	}
-
 	int len = strlen(color);
-	if (len != 6 && len != 8) {
-		sway_log(SWAY_DEBUG, "Invalid color %s, defaulting to color 0xFFFFFFFF", color);
-		return 0xFFFFFFFF;
+	if ((len != 6 && len != 8) || !isxdigit(color[0]) || !isxdigit(color[1])) {
+		return false;
 	}
-	uint32_t res = (uint32_t)strtoul(color, NULL, 16);
-	if (strlen(color) == 6) {
-		res = (res << 8) | 0xFF;
+	char *ptr;
+	uint32_t parsed = strtoul(color, &ptr, 16);
+	if (*ptr != '\0') {
+		return false;
 	}
-	return res;
+	*result = len == 6 ? ((parsed << 8) | 0xFF) : parsed;
+	return true;
 }
 
 bool parse_boolean(const char *boolean, bool current) {
diff --git a/include/swaybar/i3bar.h b/include/swaybar/i3bar.h
index 5b6001ce..0b3bee21 100644
--- a/include/swaybar/i3bar.h
+++ b/include/swaybar/i3bar.h
@@ -9,7 +9,8 @@ struct i3bar_block {
 	int ref_count;
 	char *full_text, *short_text, *align, *min_width_str;
 	bool urgent;
-	uint32_t *color;
+	uint32_t color;
+	bool color_set;
 	int min_width;
 	char *name, *instance;
 	bool separator;
diff --git a/include/util.h b/include/util.h
index 3cba49f0..931ac691 100644
--- a/include/util.h
+++ b/include/util.h
@@ -11,10 +11,11 @@
 int wrap(int i, int max);
 
 /**
- * Given a string that represents an RGB(A) color, return a uint32_t
- * version of the color.
+ * Given a string that represents an RGB(A) color, result will be set to a
+ * uint32_t version of the color, as long as it is valid. If it is invalid,
+ * then false will be returned and result will be untouched.
  */
-uint32_t parse_color(const char *color);
+bool parse_color(const char *color, uint32_t *result);
 
 /**
  * Given a string that represents a boolean, return the boolean value. This
diff --git a/swaybar/i3bar.c b/swaybar/i3bar.c
index 43e2fe2d..5c8b87a2 100644
--- a/swaybar/i3bar.c
+++ b/swaybar/i3bar.c
@@ -24,7 +24,6 @@ void i3bar_block_unref(struct i3bar_block *block) {
 		free(block->min_width_str);
 		free(block->name);
 		free(block->instance);
-		free(block->color);
 		free(block);
 	}
 }
@@ -70,8 +69,11 @@ static void i3bar_parse_json(struct status_line *status,
 		block->short_text = short_text ?
 			strdup(json_object_get_string(short_text)) : NULL;
 		if (color) {
-			block->color = malloc(sizeof(uint32_t));
-			*block->color = parse_color(json_object_get_string(color));
+			const char *hexstring = json_object_get_string(color);
+			block->color_set = parse_color(hexstring, &block->color);
+			if (!block->color_set) {
+				sway_log(SWAY_ERROR, "Invalid block color: %s", hexstring);
+			}
 		}
 		if (min_width) {
 			json_type type = json_object_get_type(min_width);
@@ -98,10 +100,14 @@ static void i3bar_parse_json(struct status_line *status,
 		block->separator_block_width = separator_block_width ?
 			json_object_get_int(separator_block_width) : 9;
 		// Airblader features
-		block->background = background ?
-			parse_color(json_object_get_string(background)) : 0;
-		block->border = border ? 
-			parse_color(json_object_get_string(border)) : 0;
+		const char *hex = background ? json_object_get_string(background) : NULL;
+		if (hex && !parse_color(hex, &block->background)) {
+			sway_log(SWAY_ERROR, "Ignoring invalid block background: %s", hex);
+		}
+		hex = border ? json_object_get_string(border) : NULL;
+		if (hex && !parse_color(hex, &block->border)) {
+			sway_log(SWAY_ERROR, "Ignoring invalid block border: %s", hex);
+		}
 		block->border_top = border_top ? json_object_get_int(border_top) : 1;
 		block->border_bottom = border_bottom ?
 			json_object_get_int(border_bottom) : 1;
diff --git a/swaybar/ipc.c b/swaybar/ipc.c
index afaffb04..cca510c6 100644
--- a/swaybar/ipc.c
+++ b/swaybar/ipc.c
@@ -55,117 +55,42 @@ char *parse_font(const char *font) {
 
 static void ipc_parse_colors(
 		struct swaybar_config *config, json_object *colors) {
-	json_object *background, *statusline, *separator;
-	json_object *focused_background, *focused_statusline, *focused_separator;
-	json_object *focused_workspace_border, *focused_workspace_bg, *focused_workspace_text;
-	json_object *inactive_workspace_border, *inactive_workspace_bg, *inactive_workspace_text;
-	json_object *active_workspace_border, *active_workspace_bg, *active_workspace_text;
-	json_object *urgent_workspace_border, *urgent_workspace_bg, *urgent_workspace_text;
-	json_object *binding_mode_border, *binding_mode_bg, *binding_mode_text;
-	json_object_object_get_ex(colors, "background", &background);
-	json_object_object_get_ex(colors, "statusline", &statusline);
-	json_object_object_get_ex(colors, "separator", &separator);
-	json_object_object_get_ex(colors, "focused_background", &focused_background);
-	json_object_object_get_ex(colors, "focused_statusline", &focused_statusline);
-	json_object_object_get_ex(colors, "focused_separator", &focused_separator);
-	json_object_object_get_ex(colors, "focused_workspace_border", &focused_workspace_border);
-	json_object_object_get_ex(colors, "focused_workspace_bg", &focused_workspace_bg);
-	json_object_object_get_ex(colors, "focused_workspace_text", &focused_workspace_text);
-	json_object_object_get_ex(colors, "active_workspace_border", &active_workspace_border);
-	json_object_object_get_ex(colors, "active_workspace_bg", &active_workspace_bg);
-	json_object_object_get_ex(colors, "active_workspace_text", &active_workspace_text);
-	json_object_object_get_ex(colors, "inactive_workspace_border", &inactive_workspace_border);
-	json_object_object_get_ex(colors, "inactive_workspace_bg", &inactive_workspace_bg);
-	json_object_object_get_ex(colors, "inactive_workspace_text", &inactive_workspace_text);
-	json_object_object_get_ex(colors, "urgent_workspace_border", &urgent_workspace_border);
-	json_object_object_get_ex(colors, "urgent_workspace_bg", &urgent_workspace_bg);
-	json_object_object_get_ex(colors, "urgent_workspace_text", &urgent_workspace_text);
-	json_object_object_get_ex(colors, "binding_mode_border", &binding_mode_border);
-	json_object_object_get_ex(colors, "binding_mode_bg", &binding_mode_bg);
-	json_object_object_get_ex(colors, "binding_mode_text", &binding_mode_text);
-	if (background) {
-		config->colors.background = parse_color(
-				json_object_get_string(background));
-	}
-	if (statusline) {
-		config->colors.statusline = parse_color(
-				json_object_get_string(statusline));
-	}
-	if (separator) {
-		config->colors.separator = parse_color(
-				json_object_get_string(separator));
-	}
-	if (focused_background) {
-		config->colors.focused_background = parse_color(
-				json_object_get_string(focused_background));
-	}
-	if (focused_statusline) {
-		config->colors.focused_statusline = parse_color(
-				json_object_get_string(focused_statusline));
-	}
-	if (focused_separator) {
-		config->colors.focused_separator = parse_color(
-				json_object_get_string(focused_separator));
-	}
-	if (focused_workspace_border) {
-		config->colors.focused_workspace.border = parse_color(
-				json_object_get_string(focused_workspace_border));
-	}
-	if (focused_workspace_bg) {
-		config->colors.focused_workspace.background = parse_color(
-				json_object_get_string(focused_workspace_bg));
-	}
-	if (focused_workspace_text) {
-		config->colors.focused_workspace.text = parse_color(
-				json_object_get_string(focused_workspace_text));
-	}
-	if (active_workspace_border) {
-		config->colors.active_workspace.border = parse_color(
-				json_object_get_string(active_workspace_border));
-	}
-	if (active_workspace_bg) {
-		config->colors.active_workspace.background = parse_color(
-				json_object_get_string(active_workspace_bg));
-	}
-	if (active_workspace_text) {
-		config->colors.active_workspace.text = parse_color(
-				json_object_get_string(active_workspace_text));
-	}
-	if (inactive_workspace_border) {
-		config->colors.inactive_workspace.border = parse_color(
-				json_object_get_string(inactive_workspace_border));
-	}
-	if (inactive_workspace_bg) {
-		config->colors.inactive_workspace.background = parse_color(
-				json_object_get_string(inactive_workspace_bg));
-	}
-	if (inactive_workspace_text) {
-		config->colors.inactive_workspace.text = parse_color(
-				json_object_get_string(inactive_workspace_text));
-	}
-	if (urgent_workspace_border) {
-		config->colors.urgent_workspace.border = parse_color(
-				json_object_get_string(urgent_workspace_border));
-	}
-	if (urgent_workspace_bg) {
-		config->colors.urgent_workspace.background = parse_color(
-				json_object_get_string(urgent_workspace_bg));
-	}
-	if (urgent_workspace_text) {
-		config->colors.urgent_workspace.text = parse_color(
-				json_object_get_string(urgent_workspace_text));
-	}
-	if (binding_mode_border) {
-		config->colors.binding_mode.border = parse_color(
-				json_object_get_string(binding_mode_border));
-	}
-	if (binding_mode_bg) {
-		config->colors.binding_mode.background = parse_color(
-				json_object_get_string(binding_mode_bg));
-	}
-	if (binding_mode_text) {
-		config->colors.binding_mode.text = parse_color(
-				json_object_get_string(binding_mode_text));
+	struct {
+		const char *name;
+		uint32_t *color;
+	} properties[] = {
+		{ "background", &config->colors.background },
+		{ "statusline", &config->colors.statusline },
+		{ "separator", &config->colors.separator },
+		{ "focused_background", &config->colors.focused_background },
+		{ "focused_statusline", &config->colors.focused_statusline },
+		{ "focused_separator", &config->colors.focused_separator },
+		{ "focused_workspace_border", &config->colors.focused_workspace.border },
+		{ "focused_workspace_bg", &config->colors.focused_workspace.background },
+		{ "focused_workspace_text", &config->colors.focused_workspace.text },
+		{ "active_workspace_border", &config->colors.active_workspace.border },
+		{ "active_workspace_bg", &config->colors.active_workspace.background },
+		{ "active_workspace_text", &config->colors.active_workspace.text },
+		{ "inactive_workspace_border", &config->colors.inactive_workspace.border },
+		{ "inactive_workspace_bg", &config->colors.inactive_workspace.background },
+		{ "inactive_workspace_text", &config->colors.inactive_workspace.text },
+		{ "urgent_workspace_border", &config->colors.urgent_workspace.border },
+		{ "urgent_workspace_bg", &config->colors.urgent_workspace.background },
+		{ "urgent_workspace_text", &config->colors.urgent_workspace.text },
+		{ "binding_mode_border", &config->colors.binding_mode.border },
+		{ "binding_mode_bg", &config->colors.binding_mode.background },
+		{ "binding_mode_text", &config->colors.binding_mode.text },
+	};
+
+	for (size_t i = 0; i < sizeof(properties) / sizeof(properties[i]); i++) {
+		json_object *object;
+		if (json_object_object_get_ex(colors, properties[i].name, &object)) {
+			const char *hexstring = json_object_get_string(object);
+			if (!parse_color(hexstring, properties[i].color)) {
+				sway_log(SWAY_ERROR, "Ignoring invalid %s: %s",
+						properties[i].name, hexstring);
+			}
+		}
 	}
 }
 
diff --git a/swaybar/render.c b/swaybar/render.c
index 0d6bb354..06efb53c 100644
--- a/swaybar/render.c
+++ b/swaybar/render.c
@@ -265,7 +265,7 @@ static uint32_t render_status_block(cairo_t *cairo,
 	}
 	double text_y = height / 2.0 - text_height / 2.0;
 	cairo_move_to(cairo, offset, (int)floor(text_y));
-	uint32_t color = block->color ?  *block->color : config->colors.statusline;
+	uint32_t color = block->color_set ? block->color : config->colors.statusline;
 	color = block->urgent ? config->colors.urgent_workspace.text : color;
 	cairo_set_source_u32(cairo, color);
 	pango_printf(cairo, config->font, output->scale,
diff --git a/swaynag/config.c b/swaynag/config.c
index 2fa7cb61..f1161b39 100644
--- a/swaynag/config.c
+++ b/swaynag/config.c
@@ -221,28 +221,28 @@ int swaynag_parse_options(int argc, char **argv, struct swaynag *swaynag,
 			fprintf(stdout, "swaynag version " SWAY_VERSION "\n");
 			return -1;
 		case TO_COLOR_BACKGROUND: // Background color
-			if (type) {
-				type->background = parse_color(optarg);
+			if (type && !parse_color(optarg, &type->background)) {
+				fprintf(stderr, "Invalid background color: %s", optarg);
 			}
 			break;
 		case TO_COLOR_BORDER: // Border color
-			if (type) {
-				type->border = parse_color(optarg);
+			if (type && !parse_color(optarg, &type->border)) {
+				fprintf(stderr, "Invalid border color: %s", optarg);
 			}
 			break;
 		case TO_COLOR_BORDER_BOTTOM: // Bottom border color
-			if (type) {
-				type->border_bottom = parse_color(optarg);
+			if (type && !parse_color(optarg, &type->border_bottom)) {
+				fprintf(stderr, "Invalid border bottom color: %s", optarg);
 			}
 			break;
 		case TO_COLOR_BUTTON:  // Button background color
-			if (type) {
-				type->button_background = parse_color(optarg);
+			if (type && !parse_color(optarg, &type->button_background)) {
+				fprintf(stderr, "Invalid button background color: %s", optarg);
 			}
 			break;
 		case TO_COLOR_TEXT:  // Text color
-			if (type) {
-				type->text = parse_color(optarg);
+			if (type && !parse_color(optarg, &type->text)) {
+				fprintf(stderr, "Invalid text color: %s", optarg);
 			}
 			break;
 		case TO_THICK_BAR_BORDER:  // Bottom border thickness