Add support for surrogate pairs to TQChar API.

This relates to issue #162.
The new code is partially taken from Qt4 but with some local rework.

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>
(cherry picked from commit c5cda03125a6d34c179d968011083bceb87976bd)

1 files changed, 8 insertions, 14 deletions

diff --git a/src/tools/qstring.cpp b/src/tools/qstring.cpp
index a7256e354..82ae39a0e 100644
--- a/src/tools/qstring.cpp
+++ b/src/tools/qstring.cpp
@@ -6019,13 +6019,10 @@ TQCString TQString::utf8() const
  	    if ( u < 0x0800 ) {
 		*cursor++ = 0xc0 | ((uchar) (u >> 6));
  	    } else {
-		if (u >= 0xd800 && u < 0xdc00 && i < l-1) {
-		    unsigned short low = ch[1].unicode();
-		    if (low >= 0xdc00 && low < 0xe000) {
-			++ch;
-			++i;
-			u = (u - 0xd800)*0x400 + (low - 0xdc00) + 0x10000;
-		    }
+		if (ch[0].isHighSurrogate() && i < (l - 1) && ch[1].isLowSurrogate()) {
+		    u = TQChar::surrogateToUcs4(ch[0], ch[1]);
+		    ++ch;
+		    ++i;
 		}
 		if (u > 0xffff) {
 		    // if people are working in utf8, but strings are encoded in eg. latin1, the resulting
@@ -6104,15 +6101,12 @@ TQString TQString::fromUtf8( const char* utf8, int len )
 		uc = (uc << 6) | (ch & 0x3f);
 		need--;
 		if ( !need ) {
-		    if (uc > 0xffff) {
+		    if (TQChar::requiresSurrogates(uc)) {
 			// surrogate pair
-			uc -= 0x10000;
-			unsigned short high = uc/0x400 + 0xd800;
-			unsigned short low = uc%0x400 + 0xdc00;
-			*qch++ = TQChar(high);
-			*qch++ = TQChar(low);
+			*qch++ = TQChar(TQChar::highSurrogate(uc));
+			*qch++ = TQChar(TQChar::lowSurrogate(uc));
 		    } else if (uc < min_uc || (uc >= 0xd800 && uc <= 0xdfff) || (uc >= 0xfffe)) {
-			// overlong seqence, UTF16 surrogate or BOM
+			// overlong sequence, UTF16 surrogate or BOM
                         i = error;
                         qch = addOne(qch, result);
                         *qch++ = TQChar(0xdbff);