Support using GetTextExtent() with empty string to get descent in wxOSX.

[wxWidgets.git] / include / wx / stringops.h

diff --git a/include/wx/stringops.h b/include/wx/stringops.h
index 6451275bb1d1a7460d36e8d61e490970a586d34c..c7eb83bc4b3190d18cd019ca4ca9892f37e55cb8 100644 (file)
--- a/include/wx/stringops.h
+++ b/include/wx/stringops.h
@@ -15,6 +15,7 @@
 #include "wx/chartype.h"
 #include "wx/stringimpl.h"
 #include "wx/unichar.h"
+#include "wx/buffer.h"
 
 // This header contains wxStringOperations "namespace" class that implements
 // elementary operations on string data as static methods; wxString methods and
@@ -27,25 +28,21 @@
 struct WXDLLIMPEXP_BASE wxStringOperationsWchar
 {
     // moves the iterator to the next Unicode character
-    static void IncIter(wxStringImpl::iterator& i) { ++i; }
-    static void IncIter(wxStringImpl::const_iterator& i) { ++i; }
+    template <typename Iterator>
+    static void IncIter(Iterator& i) { ++i; }
 
     // moves the iterator to the previous Unicode character
-    static void DecIter(wxStringImpl::iterator& i) { --i; }
-    static void DecIter(wxStringImpl::const_iterator& i) { --i; }
+    template <typename Iterator>
+    static void DecIter(Iterator& i) { --i; }
 
     // moves the iterator by n Unicode characters
-    static wxStringImpl::iterator AddToIter(const wxStringImpl::iterator& i, int n)
-        { return i + n; }
-    static wxStringImpl::const_iterator AddToIter(const wxStringImpl::const_iterator& i, int n)
+    template <typename Iterator>
+    static Iterator AddToIter(const Iterator& i, ptrdiff_t n)
         { return i + n; }
 
     // returns distance of the two iterators in Unicode characters
-    static int DiffIters(const wxStringImpl::iterator& i1,
-                         const wxStringImpl::iterator& i2)
-        { return i1 - i2; }
-    static int DiffIters(const wxStringImpl::const_iterator& i1,
-                         const wxStringImpl::const_iterator& i2)
+    template <typename Iterator>
+    static ptrdiff_t DiffIters(const Iterator& i1, const Iterator& i2)
         { return i1 - i2; }
 
     // encodes the character to a form used to represent it in internal
@@ -62,13 +59,15 @@ struct WXDLLIMPEXP_BASE wxStringOperationsWchar
 struct WXDLLIMPEXP_BASE wxStringOperationsUtf8
 {
     // checks correctness of UTF-8 sequence
-    static bool IsValidUtf8String(const char *c);
-#ifdef __WXDEBUG__
-    static bool IsValidUtf8LeadByte(unsigned char c);
-#endif
+    static bool IsValidUtf8String(const char *c,
+                                  size_t len = wxStringImpl::npos);
+    static bool IsValidUtf8LeadByte(unsigned char c)
+    {
+        return (c <= 0x7F) || (c >= 0xC2 && c <= 0xF4);
+    }
 
     // table of offsets to skip forward when iterating over UTF-8 sequence
-    static unsigned char ms_utf8IterTable[256];
+    static const unsigned char ms_utf8IterTable[256];
 
 
     template<typename Iterator>
@@ -95,18 +94,18 @@ struct WXDLLIMPEXP_BASE wxStringOperationsUtf8
     }
 
     template<typename Iterator>
-    static Iterator AddToIter(const Iterator& i, int n)
+    static Iterator AddToIter(const Iterator& i, ptrdiff_t n)
     {
         Iterator out(i);
 
         if ( n > 0 )
         {
-            for ( int j = 0; j < n; ++j )
+            for ( ptrdiff_t j = 0; j < n; ++j )
                 IncIter(out);
         }
         else if ( n < 0 )
         {
-            for ( int j = 0; j > n; --j )
+            for ( ptrdiff_t j = 0; j > n; --j )
                 DecIter(out);
         }
 
@@ -114,9 +113,9 @@ struct WXDLLIMPEXP_BASE wxStringOperationsUtf8
     }
 
     template<typename Iterator>
-    static int DiffIters(Iterator i1, Iterator i2)
+    static ptrdiff_t DiffIters(Iterator i1, Iterator i2)
     {
-        int dist = 0;
+        ptrdiff_t dist = 0;
 
         if ( i1 < i2 )
         {
@@ -138,15 +137,10 @@ struct WXDLLIMPEXP_BASE wxStringOperationsUtf8
         return dist;
     }
 
-    // buffer for single UTF-8 character
-    struct Utf8CharBuffer
-    {
-        char data[5];
-        operator const char*() const { return data; }
-    };
-
     // encodes the character as UTF-8:
-    static Utf8CharBuffer EncodeChar(const wxUniChar& ch);
+    typedef wxUniChar::Utf8CharBuffer Utf8CharBuffer;
+    static Utf8CharBuffer EncodeChar(const wxUniChar& ch)
+        { return ch.AsUTF8(); }
 
     // returns n copies of ch encoded in UTF-8 string
     static wxCharBuffer EncodeNChars(size_t n, const wxUniChar& ch);
@@ -159,7 +153,15 @@ struct WXDLLIMPEXP_BASE wxStringOperationsUtf8
     }
 
     // decodes single UTF-8 character from UTF-8 string
-    static wxUniChar DecodeChar(wxStringImpl::const_iterator i);
+    static wxUniChar DecodeChar(wxStringImpl::const_iterator i)
+    {
+        if ( (unsigned char)*i < 0x80 )
+            return (int)*i;
+        return DecodeNonAsciiChar(i);
+    }
+
+private:
+    static wxUniChar DecodeNonAsciiChar(wxStringImpl::const_iterator i);
 };
 #endif // wxUSE_UNICODE_UTF8