Simplify and merge {config,theme}-dir.c

src/common/dir.c

@@ -0,0 +1,135 @@
+/*
+ * Find the configuration and theme directories
+ *
+ * Copyright Johan Malm 2020
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <stdbool.h>
+#include <glib.h>
+
+#include "common/dir.h"
+
+struct dir {
+	const char *prefix;
+	const char *path;
+};
+
+/* clang-format off */
+static struct dir config_dirs[] = {
+	{ "XDG_CONFIG_HOME", "labwc" },
+	{ "HOME", ".config/labwc" },
+	{ "XDG_CONFIG_DIRS", "labwc" },
+	{ NULL, "/etc/xdg/labwc" },
+	{ "XDG_CONFIG_HOME", "openbox" },
+	{ "HOME", ".config/openbox" },
+	{ "XDG_CONFIG_DIRS", "openbox" },
+	{ NULL, "/etc/xdg/openbox" },
+	{ NULL, NULL }
+};
+
+static struct dir theme_dirs[] = {
+	{ "XDG_DATA_HOME", "themes" },
+	{ "HOME", ".local/share/themes" },
+	{ "HOME", ".themes" },
+	{ "XDG_DATA_DIRS", "themes" },
+	{ NULL, "/usr/share/themes" },
+	{ NULL, "/usr/local/share/themes" },
+	{ NULL, "opt/share/themes" },
+	{ NULL, NULL }
+};
+/* clang-format on */
+
+static bool isdir(const char *path)
+{
+	struct stat st;
+	return (!stat(path, &st) && S_ISDIR(st.st_mode));
+}
+
+struct ctx {
+	void (*build_path_fn)(struct ctx *ctx, char *prefix, const char *path);
+	char *buf;
+	size_t len;
+	struct dir *dirs;
+	const char *theme_name;
+};
+
+static void build_config_path(struct ctx *ctx, char *prefix, const char *path)
+{
+	if (!prefix)
+		snprintf(ctx->buf, ctx->len, "%s", path);
+	else
+		snprintf(ctx->buf, ctx->len, "%s/%s", prefix, path);
+}
+
+static void build_theme_path(struct ctx *ctx, char *prefix, const char *path)
+{
+	if (!prefix)
+		snprintf(ctx->buf, ctx->len, "%s/%s/openbox-3", path,
+			 ctx->theme_name);
+	else
+		snprintf(ctx->buf, ctx->len, "%s/%s/%s/openbox-3", prefix, path,
+			 ctx->theme_name);
+}
+
+char *find_dir(struct ctx *ctx)
+{
+	char *debug = getenv("LABWC_DEBUG_DIR_CONFIG_AND_THEME");
+
+	for (int i = 0; ctx->dirs[i].path; i++) {
+		struct dir d = ctx->dirs[i];
+		if (!d.prefix) {
+			/* handle /etc/xdg... */
+			ctx->build_path_fn(ctx, NULL, d.path);
+			if (debug)
+				fprintf(stderr, "DEBUG: %s\n", ctx->buf);
+			if (isdir(ctx->buf))
+				return ctx->buf;
+		} else {
+			/* handle $HOME/.config/... and $XDG_* */
+			char *prefix = getenv(d.prefix);
+			if (!prefix)
+				continue;
+			gchar **prefixes = g_strsplit(prefix, ":", -1);
+			for (gchar **p = prefixes; *p; p++) {
+				ctx->build_path_fn(ctx, *p, d.path);
+				if (debug)
+					fprintf(stderr, "DEBUG: %s\n",
+						ctx->buf);
+				if (isdir(ctx->buf))
+					return ctx->buf;
+			}
+		}
+	}
+	/* no directory was found */
+	ctx->buf[0] = '.';
+	ctx->buf[1] = '\0';
+	return ctx->buf;
+}
+
+char *config_dir(void)
+{
+	static char buf[4096] = { 0 };
+	if (buf[0] != '\0')
+		return buf;
+	struct ctx ctx = { .build_path_fn = build_config_path,
+			   .buf = buf,
+			   .len = sizeof(buf),
+			   .dirs = config_dirs };
+	return find_dir(&ctx);
+}
+
+char *theme_dir(const char *theme_name)
+{
+	static char buf[4096] = { 0 };
+	if (buf[0] != '\0')
+		return buf;
+	struct ctx ctx = { .build_path_fn = build_theme_path,
+			   .buf = buf,
+			   .len = sizeof(buf),
+			   .dirs = theme_dirs,
+			   .theme_name = theme_name };
+	return find_dir(&ctx);
+}