//
// Titlecasing:
// -----------
// Titlecasing refers to a casing practice wherein the first letter of a word is an uppercase letter
// and the rest of the letters are lowercase. The choice of which words to titlecase in headings
// and titles is dependent on language and local conventions. For example, "The Merry Wives of Windor"
// is the appropriate titlecasing of that play's name in English, with the word "of" not titlecased.
// In German, however, the title is "Die lustigen Weiber von Windsor," and both "lustigen" and "von"
// are not titlecased. In French even fewer words are titlecased: "Les joyeuses commeres de Windsor."
//
// Moreover, the determination of what actually constitutes a word is language dependent, and this can
// influence which letter or letters of a "word" are uppercased when titlecasing strings. For example
// "l'arbre" is considered two words in French, whereas "can't" is considered one word in English.
//
public unsafe String ToTitleCase(String str)
{
if (str == null)
{
throw new ArgumentNullException(nameof(str));
}
Contract.EndContractBlock();
if (str.Length == 0)
{
return(str);
}
StringBuilder result = new StringBuilder();
string lowercaseData = null;
// Store if the current culture is Dutch (special case)
bool isDutchCulture = CultureName.StartsWith("nl-", StringComparison.OrdinalIgnoreCase);
for (int i = 0; i < str.Length; i++)
{
UnicodeCategory charType;
int charLen;
charType = CharUnicodeInfo.InternalGetUnicodeCategory(str, i, out charLen);
if (Char.CheckLetter(charType))
{
// Special case to check for Dutch specific titlecasing with "IJ" characters
// at the beginning of a word
if (isDutchCulture && i < str.Length - 1 && (str[i] == 'i' || str[i] == 'I') && (str[i + 1] == 'j' || str[i + 1] == 'J'))
{
result.Append("IJ");
i += 2;
}
else
{
// Do the titlecasing for the first character of the word.
i = AddTitlecaseLetter(ref result, ref str, i, charLen) + 1;
}
//
// Convert the characters until the end of the this word
// to lowercase.
//
int lowercaseStart = i;
//
// Use hasLowerCase flag to prevent from lowercasing acronyms (like "URT", "USA", etc)
// This is in line with Word 2000 behavior of titlecasing.
//
bool hasLowerCase = (charType == UnicodeCategory.LowercaseLetter);
// Use a loop to find all of the other letters following this letter.
while (i < str.Length)
{
charType = CharUnicodeInfo.InternalGetUnicodeCategory(str, i, out charLen);
if (IsLetterCategory(charType))
{
if (charType == UnicodeCategory.LowercaseLetter)
{
hasLowerCase = true;
}
i += charLen;
}
else if (str[i] == '\'')
{
i++;
if (hasLowerCase)
{
if (lowercaseData == null)
{
lowercaseData = this.ToLower(str);
}
result.Append(lowercaseData, lowercaseStart, i - lowercaseStart);
}
else
{
result.Append(str, lowercaseStart, i - lowercaseStart);
}
lowercaseStart = i;
hasLowerCase = true;
}
else if (!IsWordSeparator(charType))
{
// This category is considered to be part of the word.
// This is any category that is marked as false in wordSeprator array.
i += charLen;
}
else
{
// A word separator. Break out of the loop.
break;
}
}
int count = i - lowercaseStart;
if (count > 0)
{
if (hasLowerCase)
{
if (lowercaseData == null)
{
lowercaseData = this.ToLower(str);
}
result.Append(lowercaseData, lowercaseStart, count);
}
else
{
result.Append(str, lowercaseStart, count);
}
}
if (i < str.Length)
{
// not a letter, just append it
i = AddNonLetter(ref result, ref str, i, charLen);
}
}
else
{
// not a letter, just append it
i = AddNonLetter(ref result, ref str, i, charLen);
}
}
return(result.ToString());
}
//
// Titlecasing:
// -----------
// Titlecasing refers to a casing practice wherein the first letter of a word is an uppercase letter
// and the rest of the letters are lowercase. The choice of which words to titlecase in headings
// and titles is dependent on language and local conventions. For example, "The Merry Wives of Windor"
// is the appropriate titlecasing of that play's name in English, with the word "of" not titlecased.
// In German, however, the title is "Die lustigen Weiber von Windsor," and both "lustigen" and "von"
// are not titlecased. In French even fewer words are titlecased: "Les joyeuses commeres de Windsor."
//
// Moreover, the determination of what actually constitutes a word is language dependent, and this can
// influence which letter or letters of a "word" are uppercased when titlecasing strings. For example
// "l'arbre" is considered two words in French, whereas "can't" is considered one word in English.
//
//
// Differences between UNICODE 5.0 and the .NET Framework (
#if !FEATURE_CORECLR
public unsafe String ToTitleCase(String str)
{
if (str == null)
{
throw new ArgumentNullException("str");
}
Contract.EndContractBlock();
if (str.Length == 0)
{
return(str);
}
StringBuilder result = new StringBuilder();
String lowercaseData = null;
for (int i = 0; i < str.Length; i++)
{
UnicodeCategory charType;
int charLen;
charType = CharUnicodeInfo.InternalGetUnicodeCategory(str, i, out charLen);
if (Char.CheckLetter(charType))
{
// Do the titlecasing for the first character of the word.
i = AddTitlecaseLetter(ref result, ref str, i, charLen) + 1;
//
// Convert the characters until the end of the this word
// to lowercase.
//
int lowercaseStart = i;
//
// Use hasLowerCase flag to prevent from lowercasing acronyms (like "URT", "USA", etc)
// This is in line with Word 2000 behavior of titlecasing.
//
bool hasLowerCase = (charType == UnicodeCategory.LowercaseLetter);
// Use a loop to find all of the other letters following this letter.
while (i < str.Length)
{
charType = CharUnicodeInfo.InternalGetUnicodeCategory(str, i, out charLen);
if (IsLetterCategory(charType))
{
if (charType == UnicodeCategory.LowercaseLetter)
{
hasLowerCase = true;
}
i += charLen;
}
else if (str[i] == '\'')
{
//
i++;
if (hasLowerCase)
{
if (lowercaseData == null)
{
lowercaseData = this.ToLower(str);
}
result.Append(lowercaseData, lowercaseStart, i - lowercaseStart);
}
else
{
result.Append(str, lowercaseStart, i - lowercaseStart);
}
lowercaseStart = i;
hasLowerCase = true;
}
else if (!IsWordSeparator(charType))
{
// This category is considered to be part of the word.
// This is any category that is marked as false in wordSeprator array.
i += charLen;
}
else
{
// A word separator. Break out of the loop.
break;
}
}
int count = i - lowercaseStart;
if (count > 0)
{
if (hasLowerCase)
{
if (lowercaseData == null)
{
lowercaseData = this.ToLower(str);
}
result.Append(lowercaseData, lowercaseStart, count);
}
else
{
result.Append(str, lowercaseStart, count);
}
}
if (i < str.Length)
{
// not a letter, just append it
i = AddNonLetter(ref result, ref str, i, charLen);
}
}
else
{
// not a letter, just append it
i = AddNonLetter(ref result, ref str, i, charLen);
}
}
return(result.ToString());
}
public unsafe String ToTitleCase(String str)
{
if (str == null)
{
throw new ArgumentNullException("str");
}
int len = str.Length;
if (len == 0)
{
return(str);
}
int i;
StringBuilder result = new StringBuilder();
String lowercaseData = null;
for (i = 0; i < len; i++)
{
UnicodeCategory charType;
int charLen;
charType = CharUnicodeInfo.InternalGetUnicodeCategory(str, i, out charLen);
if (Char.CheckLetter(charType))
{
// Do the uppercasing for the first character of the word.
// There are titlecase characters that need to be special treated.
if (charLen == 1)
{
result.Append(nativeGetTitleCaseChar(m_pNativeTextInfo, str[i]));
}
else
{
//
// ASSUMPTION: There is no titlecase char in the surrogate.
//
char resultHighSurrogate;
char resultLowSurrogate;
ChangeCaseSurrogate(str[i], str[i + 1], out resultHighSurrogate, out resultLowSurrogate, true);
result.Append(resultHighSurrogate);
result.Append(resultLowSurrogate);
}
i += charLen;
//
// Convert the characters until the end of the this word
// to lowercase.
//
int lowercaseStart = i;
//
// Use hasLowerCase flag to prevent from lowercasing acronyms (like "URT", "USA", etc)
// This is in line with Word 2000 behavior of titilecasing.
//
bool hasLowerCase = (charType == UnicodeCategory.LowercaseLetter);
// Use a loop to find all of the other letters following this letter.
while (i < len)
{
charType = CharUnicodeInfo.InternalGetUnicodeCategory(str, i, out charLen);
if (IsLetterCategory(charType))
{
if (charType == UnicodeCategory.LowercaseLetter)
{
hasLowerCase = true;
}
i += charLen;
}
else if (str[i] == '\'')
{
// Special case for APOSTROPHE. It should be considered part of the word. E.g. "can't".
i++;
if (hasLowerCase)
{
if (lowercaseData == null)
{
lowercaseData = this.ToLower(str);
}
result.Append(lowercaseData, lowercaseStart, i - lowercaseStart);
}
else
{
result.Append(str, lowercaseStart, i - lowercaseStart);
}
lowercaseStart = i;
hasLowerCase = true;
}
else if (!IsWordSeparator(charType))
{
// This category is considered to be part of the word.
// This is any category that is marked as false in wordSeprator array.
i += charLen;
}
else
{
// A word separator. Break out of the loop.
break;
}
}
int count = i - lowercaseStart;
if (count > 0)
{
if (hasLowerCase)
{
if (lowercaseData == null)
{
lowercaseData = this.ToLower(str);
}
result.Append(lowercaseData, lowercaseStart, count);
}
else
{
result.Append(str, lowercaseStart, count);
}
}
if (i < len)
{
// Add the non-letter character.
if (charLen == 1)
{
result.Append(str[i]);
}
else
{
// Surrogate.
result.Append(str[i++]);
result.Append(str[i]);
}
}
}
else
{
//
// Not a letter, just append them.
//
if (charLen == 1)
{
result.Append(str[i]);
}
else
{
// Surrogate.
result.Append(str[i++]);
result.Append(str[i]);
}
}
}
return(result.ToString());
}