TStaticText: add Unicode support

README.md

@@ -318,7 +318,7 @@ void TDrawBuffer::moveBuf(ushort indent, const TScreenCell *source, ushort count
 ```
 In case you happen to have an array of `TScreenCell`, this method allows you to copy them into a `TDrawBuffer`.
 
-There are other useful unicode-aware functions:
+There are other useful Unicode-aware functions:
 
 ```c++
 int cstrlen(const char *s);
@@ -339,7 +339,7 @@ The functions above depend on the following lower-level functions. You will need
 ```c++
 size_t TText::next(TStringView text);
 size_t TText::prev(TStringView text, size_t index);
-size_t TText::wseek(TStringView text, int count);
+size_t TText::wseek(TStringView text, int count, Boolean incRemainder=True);
 #ifndef __BORLANDC__
 void TText::eat(TScreenCell *cell, size_t n, size_t &width, TStringView text, size_t &bytes);
 void TText::next(TStringView text, size_t &bytes, size_t &width);
@@ -429,6 +429,7 @@ The overload of `moveStr` used here is `TDrawBuffer::moveStr(ushort indent, TStr
 Support for creating Unicode-aware views is in place, but some views that are part of the original Turbo Vision library have not been adapted to handle Unicode.
 
 * At least `TFrame`, `THistoryViewer`, `TListViewer` and `TMenuBox` are able to display Unicode text properly.
-* Automatic shortcuts in `TMenuBox` won't work with Unicode text, as shortcuts are still compared against `event.keyDown.charScan.charCode`.
 * `TInputLine` can display and process Unicode text.
+* Word wrapping in `TStaticText` is Unicode-aware.
+* Automatic shortcuts in `TMenuBox` won't work with Unicode text, as shortcuts are still compared against `event.keyDown.charScan.charCode`.
 * `TEditor` assumes a single-byte encoding both when handling input events and when displaying text. So it won't display UTF-8 but at least it has a consistent behaviour.

include/tvision/ttext.h

@@ -122,7 +122,7 @@ class TText {
 
     static size_t next(TStringView text);
     static size_t prev(TStringView text, size_t index);
-    static size_t wseek(TStringView text, int count);
+    static size_t wseek(TStringView text, int count, Boolean incRemainder=True);
 
 #ifndef __BORLANDC__
     static void eat(TScreenCell *cell, size_t n, size_t &width, TStringView text, size_t &bytes);
@@ -139,14 +139,14 @@ inline size_t TText::next(TStringView text)
     return text.size() ? 1 : 0;
 }
 
-inline size_t TText::prev(TStringView text, size_t index)
+inline size_t TText::prev(TStringView, size_t index)
 {
     return index ? 1 : 0;
 }
 
-inline size_t TText::wseek(TStringView text, int count)
+inline size_t TText::wseek(TStringView text, int count, Boolean)
 {
-    return count > 0 ? count : 0;
+    return count > 0 ? min(count, text.size()) : 0;
 }
 
 #else
@@ -182,13 +182,16 @@ inline size_t TText::prev(TStringView text, size_t index)
     return 0;
 }
 
-inline size_t TText::wseek(TStringView text, int count)
+inline size_t TText::wseek(TStringView text, int count, Boolean incRemainder)
 // Seeks a string by an amount of display columns ('count'). If that amount
-// partially overlaps a multi-column character, the whole character is included.
+// partially overlaps a multi-column character, the whole character is included,
+// unless 'incRemainder' is False.
 // Returns the number of bytes seeked.
 {
     size_t index = 0, remainder = 0;
     wseek(text, index, remainder, count);
+    if (!incRemainder && remainder)
+        index -= TText::prev(text, index);
     return index;
 }
 
@@ -277,14 +280,19 @@ inline void TText::wseek(TStringView text, size_t &index, size_t &remainder, int
 // * count: number of columns to seek.
 {
     if (count > 0) {
-        while (count > 0 && index < text.size()) {
+        while (index < text.size()) {
             size_t width = 0;
             TText::next({&text[index], text.size() - index}, index, width);
             count -= width;
+            if (count <= 0) {
+                // Immediately return when the requested width is exceeded.
+                remainder = -count;
+                return;
+            }
         }
-        remainder = -count;
-    } else
-        remainder = 0;
+    }
+    // No remainder when the end of string was reached.
+    remainder = 0;
 }
 
 #endif // __BORLANDC__

source/tvision/tstatict.cpp

@@ -65,25 +65,27 @@ void TStaticText::draw()
                 ++p;
                 }
             i = p;
+            int last = i + TText::wseek(TStringView(&s[i], l-i), size.x, False);
             do {
                j = p;
                while ((p < l) && (s[p] == ' '))
                    ++p;
                while ((p < l) && (s[p] != ' ') && (s[p] != '\n'))
-                   ++p;
-               } while ((p < l) && (p < i + size.x) && (s[p] != '\n'));
-            if (p > i + size.x)
+                   p += TText::next(TStringView(&s[p], l-p));
+               } while ((p < l) && (p < last) && (s[p] != '\n'));
+            if (p > last)
                 {
                 if (j > i)
                     p = j;
                 else
-                    p = i + size.x;
+                    p = last;
                 }
+            int width = strwidth(TStringView(&s[i], p-i));
             if (center == True)
-               j = (size.x - p + i) / 2 ;
+               j = (size.x - width) / 2 ;
             else
                j = 0;
-            b.moveBuf(j, &s[i], color, (p - i));
+            b.moveStr(j, TStringView(&s[i], l-i), color, (ushort) width);
             while ((p < l) && (s[p] == ' '))
                 p++;
             if ((p < l) && (s[p] == '\n'))