Improve libfonts_get_default_font_name and draft implementation of libfonts_get_default_font

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 210 insertions, 0 deletions

diff --git a/libfonts_get_default_font.c b/libfonts_get_default_font.c
new file mode 100644
index 0000000..d27e661
--- /dev/null
+++ b/libfonts_get_default_font.c
@@ -0,0 +1,210 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+static char *
+find(const char *dir_part1, const char *dir_part2, const char *dir_part3)
+{
+	return NULL; /* TODO */
+}
+
+static char *
+gethome(void)
+{
+	uid_t uid = getuid();
+	size_t size = 512;
+	char *buf = NULL, *new;
+	char *ret = NULL;
+	struct passwd pw, *pwp;
+	int err;
+
+	goto beginning;
+
+	do {
+		if (size > SIZE_MAX / 2)
+			goto enomem;
+		size *= 2;
+	beginning:
+		new = realloc(buf, size);
+		if (!new) {
+		enomem:
+			free(buf);
+			errno = ENOMEM;
+			return NULL;
+		}
+		buf = new;
+	} while ((err = getpwuid_r(uid, &pw, buf, size, &pwp)) == ERANGE);
+	if (err) {
+		free(buf);
+		return NULL;
+	}
+
+	if (pwp && pwp->pw_dir)
+		ret = strdup(pwp->pw_dir);
+	free(buf);
+	return ret;
+}
+
+static char *
+getn(const char *file_part1, size_t file_part1_len, const char *file_part2, const char *name)
+{
+	size_t file_part2_len = strlen(file_part2);
+	char *path;
+
+	if (file_part1_len > SIZE_MAX - file_part2_len - 1)
+		goto enomem;
+
+	path = malloc(file_part1_len + file_part2_len + 1);
+	if (!path) {
+	enomem:
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	memcpy(path, file_part1, file_part1_len);
+	memcpy(&path[file_part1_len], file_part2, file_part2_len + 1);
+
+	/* TODO
+	 *     sans-serif = $FONTNAME
+	 *     serif = $FONTNAME
+	 *     monospace = $FONTNAME
+	 */
+
+	free(path);
+	return NULL;
+}
+
+static char *
+get(const char *file_part1, const char *file_part2, const char *name)
+{
+	return getn(file_part1, strlen(file_part1), file_part2, name);
+}
+
+char *
+libfonts_get_default_font(enum libfonts_default_font font)
+{
+	const char *env, *var, *next;
+	char *ret, *home = NULL;
+	int saved_errno = errno;
+	size_t len;
+
+	if (font == LIBFONTS_DEFAULT_SANS_SERIF) {
+		env = "LIBFONTS_DEFAULT_SANS_SERIF";
+		var = "sans-serif";
+	} else if (font == LIBFONTS_DEFAULT_SERIF) {
+		env = "LIBFONTS_DEFAULT_SERIF";
+		var = "serif";
+	} else if (font == LIBFONTS_DEFAULT_MONOSPACE) {
+		env = "LIBFONTS_DEFAULT_MONOSPACE";
+		var = "monospace";
+	} else {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	ret = getenv(env);
+	if (ret && *ret)
+		return strdup(ret);
+
+	env = getenv("XDG_CONFIG_HOME");
+	if (env && *env) {
+		ret = get(env, "/libfonts/default-fonts.conf", var);
+		if (ret)
+			goto out;
+	}
+
+	env = getenv("HOME");
+	if (env && *env) {
+		ret = get(env, "/.config/libfonts/default-fonts.conf", var);
+		if (ret)
+			goto out;
+		ret = get(env, "/.libfonts/default-fonts.conf", var);
+		if (ret)
+			goto out;
+	}
+
+	home = gethome();
+	if (home && *home) {
+		ret = get(home, "/.config/libfonts/default-fonts.conf", var);
+		if (ret)
+			goto out;
+		ret = get(home, "/.libfonts/default-fonts.conf", var);
+		if (ret)
+			goto out;
+	}
+
+	env = getenv("XDG_CONFIG_HOME");
+	if (env && *env) {
+		ret = find(env, "/libfonts/", var);
+		if (ret)
+			goto out;
+	}
+
+	env = getenv("HOME");
+	if (env && *env) {
+		ret = find(env, "/.config/libfonts/", var);
+		if (ret)
+			goto out;
+		ret = find(env, "/.libfonts/", var);
+		if (ret)
+			goto out;
+	}
+
+	if (home && *home) {
+		ret = find(env, "/.config/libfonts/", var);
+		if (ret)
+			goto out;
+		ret = find(env, "/.libfonts/", var);
+		if (ret)
+			goto out;
+	}
+
+	env = getenv("XDG_CONFIG_DIRS");
+	if (env && *env) {
+		do {
+			next = strchr(&env[1], ':');
+			len = next ? (size_t)(next - env) : strlen(env);
+			if (len) {
+				ret = getn(env, len, "/libfonts/default-fonts.conf", var);
+				if (ret)
+					goto out;
+			}
+			env += len + 1;
+		} while (next);
+	}
+
+	ret = get("/etc", "/libfonts/default-fonts.conf", var);
+	if (ret)
+		goto out;
+
+	ret = find("/etc", "/libfonts/", var);
+	if (ret)
+		goto out;
+
+	/* TODO 
+	 * as a last resort look around for some
+	 * font that matches the specification as
+	 * well as possible
+	 */
+
+	ret = NULL;
+
+out:
+	free(home);
+	errno = saved_errno;
+	return ret;
+}
+
+
+#else
+
+
+int
+main(void)
+{
+	return 0; /* TODO add test */
+}
+
+
+#endif