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)

2 files changed, 9 insertions, 11 deletions

diff --git a/src/kernel/qfontengine_x11.cpp b/src/kernel/qfontengine_x11.cpp
index 539b14aed..084b830ba 100644
--- a/src/kernel/qfontengine_x11.cpp
+++ b/src/kernel/qfontengine_x11.cpp
@@ -1531,16 +1531,15 @@ static glyph_t getAdobeCharIndex(XftFont *font, int cmap, uint ucs4)
     return g;
 }
 
-static uint getChar(const TQChar *str, int &i, const int len)
+static uint getUnicode(const TQChar *str, int &i, const int len)
 {
-    uint uc = str[i].unicode();
-    if (uc >= 0xd800 && uc < 0xdc00 && i < len-1) {
-	uint low = str[++i].unicode();
-	if (low >= 0xdc00 && low < 0xe000) {
-	    uc = (uc - 0xd800)*0x400 + (low - 0xdc00) + 0x10000;
-	}
+    if (str[i].isHighSurrogate() && i < (len - 1) && str[i + 1].isLowSurrogate())
+    {
+	++i; // Don't delete this: it is required for correct
+	     // advancement when handling surrogate pairs
+	return TQChar::surrogateToUcs4(str[i - 1], str[i]);
     }
-    return uc;
+    return str[i].unicode();
 }
 
 TQFontEngine::Error TQFontEngineXft::stringToCMap( const TQChar *str, int len, glyph_t *glyphs, advance_t *advances, int *nglyphs, bool mirrored ) const
@@ -1552,7 +1551,7 @@ TQFontEngine::Error TQFontEngineXft::stringToCMap( const TQChar *str, int len, g
 
     int glyph_pos = 0;
     for ( int i = 0; i < len; ++i ) {
-	uint uc = getChar(str, i, len);
+	uint uc = getUnicode(str, i, len);
 	if ( uc == 0xa0 )
 	    uc = 0x20;
 	if ( mirrored )
diff --git a/src/kernel/qtextengine.cpp b/src/kernel/qtextengine.cpp
index f527cd86a..7ada261e9 100644
--- a/src/kernel/qtextengine.cpp
+++ b/src/kernel/qtextengine.cpp
@@ -819,8 +819,7 @@ static void calcLineBreaks(const TQString &str, TQCharAttributes *charAttributes
         
         if (category == TQChar::Other_Surrogate) {
             // char stop only on first pair
-            if (uc[i].unicode() >= 0xd800 && uc[i].unicode() < 0xdc00 && i < len-1
-                && uc[i+1].unicode() >= 0xdc00 && uc[i+1].unicode() < 0xe000)
+            if (uc[i].isHighSurrogate() && i < (len - 1) && uc[i + 1].isLowSurrogate())
                 goto nsm;
             // ### correctly handle second surrogate
         }