Move get_colorpixel to libi3, use it everywhere else

libi3/get_colorpixel.c

@@ -0,0 +1,39 @@
+/*
+ * vim:ts=4:sw=4:expandtab
+ *
+ * i3 - an improved dynamic tiling window manager
+ *
+ * © 2009-2011 Michael Stapelberg and contributors
+ *
+ * See file LICENSE for license information.
+ *
+ */
+#include <stdlib.h>
+#include <stdint.h>
+
+#include "libi3.h"
+
+/*
+ * Returns the colorpixel to use for the given hex color (think of HTML). Only
+ * works for true-color (vast majority of cases) at the moment, avoiding a
+ * roundtrip to X11.
+ *
+ * The hex_color has to start with #, for example #FF00FF.
+ *
+ * NOTE that get_colorpixel() does _NOT_ check the given color code for validity.
+ * This has to be done by the caller.
+ *
+ * NOTE that this function may in the future rely on a global xcb_connection_t
+ * variable called 'conn' to be present.
+ *
+ */
+uint32_t get_colorpixel(const char *hex) {
+    char strgroups[3][3] = {{hex[1], hex[2], '\0'},
+                            {hex[3], hex[4], '\0'},
+                            {hex[5], hex[6], '\0'}};
+    uint8_t r = strtol(strgroups[0], NULL, 16);
+    uint8_t g = strtol(strgroups[1], NULL, 16);
+    uint8_t b = strtol(strgroups[2], NULL, 16);
+
+    return (r << 16 | g << 8 | b);
+}