theme: move more button fallback logic to theme.c

...and simplify button_xbm_load() by splitting it into one function that
loads an xbm file and another that creates an icon from a builtin
bitmap.

include/button/button-xbm.h

@@ -4,9 +4,19 @@
 
 struct lab_data_buffer;
 
+/**
+ * button_xbm_from_bitmap() - create button from monochrome bitmap
+ * @bitmap: bitmap data array in hexadecimal xbm format
+ * @buffer: cairo-surface-buffer to create
+ * @rgba: color
+ *
+ * Example bitmap: char button[6] = { 0x3f, 0x3f, 0x21, 0x21, 0x21, 0x3f };
+ */
+void button_xbm_from_bitmap(const char *bitmap, struct lab_data_buffer **buffer,
+	float *rgba);
+
 /* button_xbm_load - Convert xbm file to buffer with cairo surface */
-void button_xbm_load(const char *button_name, const char *alt_name,
+void button_xbm_load(const char *button_name, struct lab_data_buffer **buffer,
-	struct lab_data_buffer **buffer, const char *fallback_button,
 	float *rgba);
 
 #endif /* LABWC_BUTTON_XBM_H */

src/button/button-xbm.c

@@ -259,16 +259,29 @@ parse_xbm_builtin(const char *button, int size)
 }
 
 void
-button_xbm_load(const char *button_name, const char *alt_name,
+button_xbm_from_bitmap(const char *bitmap, struct lab_data_buffer **buffer,
-	struct lab_data_buffer **buffer, const char *fallback_button,
+		float *rgba)
-	float *rgba)
 {
 	struct pixmap pixmap = {0};
 	if (*buffer) {
 		wlr_buffer_drop(&(*buffer)->base);
 		*buffer = NULL;
 	}
+	color = u32(rgba);
+	pixmap = parse_xbm_builtin(bitmap, 6);
+	*buffer = buffer_create_wrap(pixmap.data, pixmap.width, pixmap.height,
+		pixmap.width * 4, /* free_on_destroy */ true);
+}
 
+void
+button_xbm_load(const char *button_name, struct lab_data_buffer **buffer,
+		float *rgba)
+{
+	struct pixmap pixmap = {0};
+	if (*buffer) {
+		wlr_buffer_drop(&(*buffer)->base);
+		*buffer = NULL;
+	}
 	color = u32(rgba);
 
 	/* Read file into memory as it's easier to tokenize that way */
@@ -283,20 +296,8 @@ button_xbm_load(const char *button_name, const char *alt_name,
 			free(tokens);
 		}
 	}
-	if (!pixmap.data && *alt_name) {
+	if (!pixmap.data) {
-		button_filename(alt_name, filename, sizeof(filename));
+		return;
-		char *token_buffer = grab_file(filename);
-		if (token_buffer) {
-			struct token *tokens = tokenize_xbm(token_buffer);
-			free(token_buffer);
-			pixmap = parse_xbm_tokens(tokens);
-			if (tokens) {
-				free(tokens);
-			}
-		}
-	}
-	if (!pixmap.data && fallback_button) {
-		pixmap = parse_xbm_builtin(fallback_button, 6);
 	}
 
 	/* Create buffer with free_on_destroy being true */

src/theme.c

@@ -219,21 +219,20 @@ load_buttons(struct theme *theme)
 	}, };
 
 	char filename[4096] = {0};
-	char alt_filename[4096] = {0};
 	for (size_t i = 0; i < ARRAY_SIZE(buttons); ++i) {
 		struct button *b = &buttons[i];
 
 		drop(b->active.buffer);
 		drop(b->inactive.buffer);
 
-		/* Try png icon first */
+		/* PNG */
 		snprintf(filename, sizeof(filename), "%s-active.png", b->name);
 		button_png_load(filename, b->active.buffer);
 		snprintf(filename, sizeof(filename), "%s-inactive.png", b->name);
 		button_png_load(filename, b->inactive.buffer);
 
 #if HAVE_RSVG
-		/* Then try svg icon */
+		/* SVG */
 		int size = theme->title_height - 2 * theme->padding_height;
 		if (!*b->active.buffer) {
 			snprintf(filename, sizeof(filename), "%s-active.svg", b->name);
@@ -245,19 +244,47 @@ load_buttons(struct theme *theme)
 		}
 #endif
 
-		/* If there were no png/svg buttons, use xbm */
+		/* XBM */
 		snprintf(filename, sizeof(filename), "%s.xbm", b->name);
-		alt_filename[0] = '\0';
-		if (b->alt_name) {
-			snprintf(alt_filename, sizeof(alt_filename), "%s.xbm", b->alt_name);
-		}
 		if (!*b->active.buffer) {
-			button_xbm_load(filename, alt_filename, b->active.buffer,
+			button_xbm_load(filename, b->active.buffer, b->active.rgba);
-				b->fallback_button, b->active.rgba);
 		}
 		if (!*b->inactive.buffer) {
-			button_xbm_load(filename, alt_filename, b->inactive.buffer,
+			button_xbm_load(filename, b->inactive.buffer, b->inactive.rgba);
-				b->fallback_button, b->inactive.rgba);
+		}
+
+		/*
+		 * XBM (alternative name)
+		 * For example max_hover_toggled instead of max_toggled_hover
+		 */
+		if (b->alt_name) {
+			snprintf(filename, sizeof(filename), "%s.xbm", b->name);
+		}  else {
+			filename[0] = '\0';
+		}
+		if (!*b->active.buffer) {
+			button_xbm_load(filename, b->active.buffer, b->active.rgba);
+		}
+		if (!*b->inactive.buffer) {
+			button_xbm_load(filename, b->inactive.buffer, b->inactive.rgba);
+		}
+
+		/*
+		 * Builtin bitmap
+		 *
+		 * Applicable to basic buttons such as max, max_toggled and
+		 * iconify. There are no bitmap fallbacks for *_hover icons.
+		 */
+		if (!b->fallback_button) {
+			continue;
+		}
+		if (!*b->active.buffer) {
+			button_xbm_from_bitmap(b->fallback_button,
+				b->active.buffer, b->active.rgba);
+		}
+		if (!*b->inactive.buffer) {
+			button_xbm_from_bitmap(b->fallback_button,
+				b->inactive.buffer, b->inactive.rgba);
 		}
 	}