Center correctly multi-chars letters in the text interface

dic/encoding.cpp

@@ -279,6 +279,40 @@ string padAndConvert(const wstring &iWstr, unsigned int iLength,
 }
 
 
+string centerAndConvert(const wstring &iWstr, unsigned int iLength, char c)
+{
+    int width = 0;
+    for (unsigned int i = 0; i < iWstr.size(); ++i)
+    {
+        int n = wcwidth(iWstr[i]);
+        if (n == -1)
+        {
+            ostringstream ss;
+            ss << "padAndConvert: non printable character: " << iWstr[i];
+            // XXX: Should we throw an exception instead? Just ignore the problem?
+            cerr << ss.str() << endl;;
+            //throw DicException(ss.str());
+            return convertToMb(iWstr);
+        }
+        width += n;
+    }
+
+    if ((unsigned int)width >= iLength)
+        return convertToMb(iWstr);
+    else
+    {
+        // Padding is needed
+        string s((iLength - width) / 2, c);
+        string res = s + convertToMb(iWstr) + s;
+        // If the string cannot be centered perfectly, pad again on the right
+        // (arbitrary; if needed, we could take the iLeftPad argument)
+        if (res.size() != iLength)
+            s.append(1, c);
+        return res;
+    }
+}
+
+
 unsigned int readFromUTF8(wchar_t *oString, unsigned int iWideSize,
                           const char *iBuffer, unsigned int iBufSize,
                           const string &iContext)

dic/encoding.h

@@ -74,6 +74,15 @@ string truncOrPad(const string &iStr, unsigned int iWidth, char iChar = ' ');
 string padAndConvert(const wstring &iWstr, unsigned int iLength,
                      bool iLeftPad = true, char c = ' ');
 
+/**
+ * Convert the given string into a multi-byte one. If the number of columns
+ * needed to display the resulting string is less than iLength, pad it with
+ * the given character (defaulting to space) on both left and right, trying
+ * to keep the string centered
+ */
+string centerAndConvert(const wstring &iWstr, unsigned int iLength,
+                        char c = ' ');
+
 /**
  * Utility function to convert a char* buffer encoded in UTF-8 into a
  * wchar_t* string

utils/game_io.cpp

@@ -53,7 +53,7 @@ void GameIO::printBoard(ostream &out, const PublicGame &iGame)
             if (iGame.getBoard().isVacant(row, col))
                 out << " - ";
             else
-                out << padAndConvert(iGame.getBoard().getDisplayStr(row, col), 3);
+                out << centerAndConvert(iGame.getBoard().getDisplayStr(row, col), 3);
         }
         out << endl;
     }