keysym: add xkb_keysym_to_{lower,upper} to public API

These can be useful in some odd cases.

There is already an implementation (+ tests) for internal use, so all
that's needed is to export them.

If xkbcommon were to provide a way to convert a Unicode codepoint to a
keysym, this could have been implemented externally as follows:

    uint32_t codepoint = xkb_keysym_to_utf32(keysym);
    uint32_t upper_codepoint = my_unicode_library_to_upper(codepoint);
    xkb_keysym_t upper_keysym = theoretical_xkb_keysym_from_utf32(upper_codepoint);

However keysym -> codepoint is not injective so such a function is not
possible strictly speaking.

Signed-off-by: Ran Benita <ran234@gmail.com>

NEWS

@@ -1,3 +1,16 @@
+libxkbcommon 0.8.0 - UNRELEASED
+
+- Add xkb_keysym_to_{upper,lower} to perform case-conversion directly on
+  keysyms. This is useful in some odd cases, but working with the Unicode
+  representations should be preferred when possible.
+
+- Added Unicode conversion rules for the signifblank and permille keysyms.
+
+- New API:
+  xkb_keysym_to_upper()
+  xkb_keysym_to_lower()
+
+==================
 libxkbcommon 0.7.2 - 2017-08-04
 ==================
 

src/keysym.c

@@ -264,7 +264,7 @@ xkb_keysym_is_upper(xkb_keysym_t ks)
     return (ks == upper ? true : false);
 }
 
-xkb_keysym_t
+XKB_EXPORT xkb_keysym_t
 xkb_keysym_to_lower(xkb_keysym_t ks)
 {
     xkb_keysym_t lower, upper;
@@ -274,7 +274,7 @@ xkb_keysym_to_lower(xkb_keysym_t ks)
     return lower;
 }
 
-xkb_keysym_t
+XKB_EXPORT xkb_keysym_t
 xkb_keysym_to_upper(xkb_keysym_t ks)
 {
     xkb_keysym_t lower, upper;

src/keysym.h

@@ -62,10 +62,4 @@ xkb_keysym_is_keypad(xkb_keysym_t keysym);
 bool
 xkb_keysym_is_modifier(xkb_keysym_t keysym);
 
-xkb_keysym_t
-xkb_keysym_to_upper(xkb_keysym_t ks);
-
-xkb_keysym_t
-xkb_keysym_to_lower(xkb_keysym_t ks);
-
 #endif

xkbcommon.map

@@ -97,3 +97,9 @@ global:
 	xkb_state_key_get_consumed_mods2;
 	xkb_state_mod_index_is_consumed2;
 } V_0.6.0;
+
+V_0.8.0 {
+global:
+	xkb_keysym_to_lower;
+	xkb_keysym_to_upper;
+} V_0.7.0;

xkbcommon/xkbcommon.h

@@ -493,6 +493,26 @@ xkb_keysym_to_utf8(xkb_keysym_t keysym, char *buffer, size_t size);
 uint32_t
 xkb_keysym_to_utf32(xkb_keysym_t keysym);
 
+/**
+ * Convert a keysym to its uppercase form.
+ *
+ * If there is no such form, the keysym is returned unchanged.
+ *
+ * The conversion rules may be incomplete; prefer to work with the Unicode
+ * representation instead, when possible.
+ */
+xkb_keysym_t
+xkb_keysym_to_upper(xkb_keysym_t ks);
+
+/**
+ * Convert a keysym to its lowercase form.
+ *
+ * The conversion rules may be incomplete; prefer to work with the Unicode
+ * representation instead, when possible.
+ */
+xkb_keysym_t
+xkb_keysym_to_lower(xkb_keysym_t ks);
+
 /** @} */
 
 /**