slang: Use index-based color identifiers

Don't pass color names like "black", "red" to slang, instead pass
index-based identifiers like "color0", "color1" etc.

This is in preparation for the next commit in which mc will diverge
from slang's color names.

Signed-off-by: Egmont Koblinger <egmont@gmail.com>

Author: egmontkob

lib/tty/color-internal.c

@@ -161,33 +161,6 @@ parse_256_or_true_color_name (const char *color_name)
 /*** public functions ****************************************************************************/
 /* --------------------------------------------------------------------------------------------- */
 
-const char *
-tty_color_get_name_by_index (int idx)
-{
-    int i;
-
-    // Find the real English name of the first 16 colors,
-    // as well as the A_* special values.
-    for (i = 0; color_table[i].name != NULL; i++)
-        if (idx == color_table[i].value)
-            return color_table[i].name;
-
-    // Create and return the strings in "colorNNN" or "#rrggbb" format.
-    if ((idx >= 16 && idx < 256) || (idx & FLAG_TRUECOLOR) != 0)
-    {
-        char name[9];
-
-        if (idx < 256)
-            g_snprintf (name, sizeof (name), "color%d", idx);
-        else
-            g_snprintf (name, sizeof (name), "#%06X", (unsigned int) idx & 0xFFFFFF);
-        return g_intern_string (name);
-    }
-    return "default";
-}
-
-/* --------------------------------------------------------------------------------------------- */
-
 int
 tty_color_get_index_by_name (const char *color_name)
 {

lib/tty/color-internal.h

@@ -43,7 +43,6 @@ extern gboolean need_convert_256color;
 
 /*** declarations of public functions ************************************************************/
 
-const char *tty_color_get_name_by_index (int idx);
 int tty_color_get_index_by_name (const char *color_name);
 int tty_attr_get_bits (const char *attrs);
 int convert_256color_to_truecolor (int color);

lib/tty/color-slang.c

@@ -128,6 +128,24 @@ tty_color_deinit_lib (void)
 
 /* --------------------------------------------------------------------------------------------- */
 
+static const char *
+tty_color_get_name_by_index (int idx)
+{
+    if (idx >= 0 && (idx < 256 || (idx & FLAG_TRUECOLOR) != 0))
+    {
+        char name[9];
+
+        if (idx < 256)
+            g_snprintf (name, sizeof (name), "color%d", idx);
+        else
+            g_snprintf (name, sizeof (name), "#%06X", (unsigned int) idx & 0xFFFFFF);
+        return g_intern_string (name);
+    }
+    return "default";
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
 void
 tty_color_try_alloc_lib_pair (tty_color_lib_pair_t *mc_color_pair)
 {