input and displaying of Unicode characters is now possible (refs #5)

* All non-ASCII characters are inserted as Unicode.
  On Curses, this also requires a properly set up locale.
* We still do not need any widechar Curses, as waddch() handles
  multibyte characters on ncurses.
  We will see whether there is any Curses variant that strictly requires
  wadd_wch().
  If this will be an exception, we might keep both widechar and non-widechar
  support.
* By convention gsize is used exclusively for byte sizes.
  Character offsets or lengths use int or long.

1 files changed, 58 insertions, 12 deletions

diff --git a/src/interface-curses/curses-utils.c b/src/interface-curses/curses-utils.c
index e7c8659..c751afd 100644
--- a/src/interface-curses/curses-utils.c
+++ b/src/interface-curses/curses-utils.c
@@ -29,7 +29,21 @@
 #include "string-utils.h"
 #include "curses-utils.h"
 
-gsize
+/**
+ * Render UTF-8 string with TECO character representations.
+ *
+ * Strings are cut off with `...` at the end if necessary.
+ * The mapping is similar to teco_view_set_representations().
+ *
+ * @param win The Curses window to write to.
+ * @param str The string to format.
+ * @param len The length of the string in bytes.
+ * @param max_width The maximum width to consume in
+ *   the window in characters. If smaller 0, take the
+ *   entire remaining space in the window.
+ * @return Number of characters actually written.
+ */
+guint
 teco_curses_format_str(WINDOW *win, const gchar *str, gsize len, gint max_width)
 {
 	int old_x, old_y;
@@ -42,6 +56,12 @@ teco_curses_format_str(WINDOW *win, const gchar *str, gsize len, gint max_width)
 
 	while (len > 0) {
 		/*
+		 * NOTE: It shouldn't be possible to meet any string,
+		 * that is not valid UTF-8.
+		 */
+		gsize clen = g_utf8_next_char(str) - str;
+
+		/*
 		 * NOTE: This mapping is similar to
 		 * teco_view_set_representations().
 		 */
@@ -85,12 +105,18 @@ teco_curses_format_str(WINDOW *win, const gchar *str, gsize len, gint max_width)
 				chars_added++;
 				if (chars_added > max_width)
 					goto truncate;
-				waddch(win, *str);
+				/*
+				 * FIXME: This works with UTF-8 on ncurses,
+				 * since it detects multi-byte characters.
+				 * However on other platforms wadd_wch() may be
+				 * necessary, which requires a widechar Curses variant.
+				 */
+				waddnstr(win, str, clen);
 			}
 		}
 
-		str++;
-		len--;
+		str += clen;
+		len -= clen;
 	}
 
 	return getcurx(win) - old_x;
@@ -108,23 +134,43 @@ truncate:
 	return getcurx(win) - old_x;
 }
 
-gsize
-teco_curses_format_filename(WINDOW *win, const gchar *filename,
-                            gint max_width)
+/**
+ * Render UTF-8 filename.
+ *
+ * This cuts of overlong filenames with `...` at the beginning,
+ * possibly skipping any drive letter.
+ * Control characters are escaped, but not highlighted.
+ *
+ * @param win The Curses window to write to.
+ * @param filename Null-terminated filename to render.
+ * @param max_width The maximum width to consume in
+ *   the window in characters. If smaller 0, take the
+ *   entire remaining space in the window.
+ * @return Number of characters actually written.
+ */
+guint
+teco_curses_format_filename(WINDOW *win, const gchar *filename, gint max_width)
 {
 	int old_x = getcurx(win);
 
 	g_autofree gchar *filename_printable = teco_string_echo(filename, strlen(filename));
-	size_t filename_len = strlen(filename_printable);
+	glong filename_len = g_utf8_strlen(filename_printable, -1);
 
 	if (max_width < 0)
 		max_width = getmaxx(win) - old_x;
 
-	if (filename_len <= (size_t)max_width) {
+	if (filename_len <= max_width) {
+		/*
+		 * FIXME: This works with UTF-8 on ncurses,
+		 * since it detects multi-byte characters.
+		 * However on other platforms wadd_wch() may be
+		 * necessary, which requires a widechar Curses variant.
+		 */
 		waddstr(win, filename_printable);
-	} else {
-		const gchar *keep_post = filename_printable + filename_len -
-		                         max_width + 3;
+	} else if (filename_len >= 3) {
+		const gchar *keep_post;
+		keep_post = g_utf8_offset_to_pointer(filename_printable + strlen(filename_printable),
+		                                     -max_width + 3);
 
 #ifdef G_OS_WIN32
 		const gchar *keep_pre = g_path_skip_root(filename_printable);