Move isIVSSelector, isCJKIVSCharacter to i18nutil/unicode.hxx

6a7db071c75609093fc3a9cbc297b8069726a33e "tdf#125497 allow backspace to remove
CJK IVS" had moved these functions from sw/source/uibase/wrtsh/delete.cxx to
rtl/character.hxx, but the latter appears to be a less than ideal home for them:
For one, it is part of the stable URE interface, which makes it harder to
maintain (e.g., later versions of Unicode have added CJK Extension C--F code
blocks, which the current implementation of isCJKIVSCharacter does not reflect).
And for another, besides details of legacy/ubiquitous ASCII, it only deals with
the "hard" structure of Unicode (isUnicodeCodePoint, isSurrogate, etc.), not
with any specific code blocks or character classifications (which can change
over time).  Internal i18nutil/unicode.hxx appears to be better suited.

Change-Id: I88b3e4e2488411f988c1a20f79b8a58626d93dce
Reviewed-on: https://gerrit.libreoffice.org/73873
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/include/i18nutil/unicode.hxx b/include/i18nutil/unicode.hxx
index b3563e529a38..c0b20a33cba8 100644
--- a/include/i18nutil/unicode.hxx
+++ b/include/i18nutil/unicode.hxx
@@ -47,6 +47,31 @@ public:
     static bool isSpace( const sal_Unicode ch);
     static bool isWhiteSpace( const sal_Unicode ch);
 
+    /** Check for Unicode variation sequence selectors
+
+        @param nCode  A Unicode code point.
+
+        @return  True if code is an Unicode variation sequence selector.
+     */
+    static bool isIVSSelector(sal_uInt32 nCode)
+    {
+        return (nCode >= 0xFE00 && nCode <= 0xFE0F)   // Variation Selectors block
+            || (nCode >= 0xE0100 && nCode <= 0xE01EF);// Variation Selectors Supplement block
+    }
+
+    /** Check for base characters of a CJK ideographic variation sequence (IVS)
+
+        @param nCode  A Unicode code point.
+
+        @return  True if code is an Unicode base character part of CJK IVS
+     */
+    static bool isCJKIVSCharacter(sal_uInt32 nCode)
+    {
+        return (nCode >= 0x4E00 && nCode <= 0x9FFF)       // CJK Unified Ideographs
+            || (nCode >= 0x3400 && nCode <= 0x4DBF)       // CJK Unified Ideographs Extension A
+            || (nCode >= 0x20000 && nCode <= 0x2A6DF);    // CJK Unified Ideographs Extension B
+    }
+
     //Map an ISO 15924 script code to Latin/Asian/Complex/Weak
     static sal_Int16 getScriptClassFromUScriptCode(UScriptCode eScript);