C++ nsString::Insert方法代码示例

// We have a serious problem!! I have this content type and the windows registry only gives me
// helper apps based on extension. Right now, we really don't have a good place to go for 
// trying to figure out the extension for a particular mime type....One short term hack is to look
// this information in 4.x (it's stored in the windows regsitry). 
static nsresult GetExtensionFrom4xRegistryInfo(const nsACString& aMimeType,
                                               nsString& aFileExtension)
{
  nsCOMPtr<nsIWindowsRegKey> regKey = 
    do_CreateInstance("@mozilla.org/windows-registry-key;1");
  if (!regKey) 
    return NS_ERROR_NOT_AVAILABLE;

  nsresult rv = regKey->
    Open(nsIWindowsRegKey::ROOT_KEY_CURRENT_USER,
         NS_LITERAL_STRING("Software\\Netscape\\Netscape Navigator\\Suffixes"),
         nsIWindowsRegKey::ACCESS_QUERY_VALUE);
  if (NS_FAILED(rv))
    return NS_ERROR_NOT_AVAILABLE;
   
  rv = regKey->ReadStringValue(NS_ConvertASCIItoUTF16(aMimeType),
                               aFileExtension);
  if (NS_FAILED(rv))
    return NS_OK;

  aFileExtension.Insert(char16_t('.'), 0);
      
  // this may be a comma separated list of extensions...just take the 
  // first one for now...

  int32_t pos = aFileExtension.FindChar(char16_t(','));
  if (pos > 0) {
    // we have a comma separated list of types...
    // truncate everything after the first comma (including the comma)
    aFileExtension.Truncate(pos); 
  }
   
  return NS_OK;
}

// EscapeStr takes the passed in string and
// escapes it IN PLACE.
void
mozTXTToHTMLConv::EscapeStr(nsString& aInString, bool inAttribute)
{
  // the replace substring routines
  // don't seem to work if you have a character
  // in the in string that is also in the replacement
  // string! =(
  //aInString.ReplaceSubstring("&", "&");
  //aInString.ReplaceSubstring("<", "&lt;");
  //aInString.ReplaceSubstring(">", "&gt;");
  for (uint32_t i = 0; i < aInString.Length();)
  {
    switch (aInString[i])
    {
    case '<':
      aInString.Cut(i, 1);
      aInString.Insert(NS_LITERAL_STRING("&lt;"), i);
      i += 4; // skip past the integers we just added
      break;
    case '>':
      aInString.Cut(i, 1);
      aInString.Insert(NS_LITERAL_STRING("&gt;"), i);
      i += 4; // skip past the integers we just added
      break;
    case '&':
      aInString.Cut(i, 1);
      aInString.Insert(NS_LITERAL_STRING("&amp;"), i);
      i += 5; // skip past the integers we just added
      break;
    case '"':
      if (inAttribute)
      {
        aInString.Cut(i, 1);
        aInString.Insert(NS_LITERAL_STRING("&quot;"), i);
        i += 6;
        break;
      }
      // else fall through
      MOZ_FALLTHROUGH;
    default:
      i++;
    }
  }
}

// XXX Code copied from nsHTMLContentSink. It should be shared.
void
nsRDFParserUtils::StripAndConvert(nsString& aResult)
{
    if ( !aResult.IsEmpty() ) {
      // Strip quotes if present
      PRUnichar first = aResult.First();
      if ((first == '"') || (first == '\'')) {
          if (aResult.Last() == first) {
              aResult.Cut(0, 1);
              PRInt32 pos = aResult.Length() - 1;
              if (pos >= 0) {
                  aResult.Cut(pos, 1);
              }
          } else {
              // Mismatched quotes - leave them in
          }
      }
    }

    // Reduce any entities
    // XXX Note: as coded today, this will only convert well formed
    // entities.  This may not be compatible enough.
    // XXX there is a table in navigator that translates some numeric entities
    // should we be doing that? If so then it needs to live in two places (bad)
    // so we should add a translate numeric entity method from the parser...
    char cbuf[100];
    PRUint32 i = 0;
    while (i < aResult.Length()) {
        // If we have the start of an entity (and it's not at the end of
        // our string) then translate the entity into it's unicode value.
        if ((aResult.CharAt(i++) == '&') && (i < aResult.Length())) {
            PRInt32 start = i - 1;
            PRUnichar e = aResult.CharAt(i);
            if (e == '#') {
                // Convert a numeric character reference
                i++;
                char* cp = cbuf;
                char* limit = cp + sizeof(cbuf) - 1;
                PRBool ok = PR_FALSE;
                PRUint32 slen = aResult.Length();
                while ((i < slen) && (cp < limit)) {
                    PRUnichar f = aResult.CharAt(i);
                    if (f == ';') {
                        i++;
                        ok = PR_TRUE;
                        break;
                    }
                    if ((f >= '0') && (f <= '9')) {
                        *cp++ = char(f);
                        i++;
                        continue;
                    }
                    break;
                }
                if (!ok || (cp == cbuf)) {
                    continue;
                }
                *cp = '\0';
                if (cp - cbuf > 5) {
                    continue;
                }
                PRInt32 ch = PRInt32( ::atoi(cbuf) );
                if (ch > 65535) {
                    continue;
                }

                // Remove entity from string and replace it with the integer
                // value.
                aResult.Cut(start, i - start);
                aResult.Insert(PRUnichar(ch), start);
                i = start + 1;
            }
            else if (((e >= 'A') && (e <= 'Z')) ||
                     ((e >= 'a') && (e <= 'z'))) {
                // Convert a named entity
                i++;
                char* cp = cbuf;
                char* limit = cp + sizeof(cbuf) - 1;
                *cp++ = char(e);
                PRBool ok = PR_FALSE;
                PRUint32 slen = aResult.Length();
                while ((i < slen) && (cp < limit)) {
                    PRUnichar f = aResult.CharAt(i);
                    if (f == ';') {
                        i++;
                        ok = PR_TRUE;
                        break;
                    }
                    if (((f >= '0') && (f <= '9')) ||
                        ((f >= 'A') && (f <= 'Z')) ||
                        ((f >= 'a') && (f <= 'z'))) {
                        *cp++ = char(f);
                        i++;
                        continue;
                    }
                    break;
                }
                if (!ok || (cp == cbuf)) {
                    continue;
//.........这里部分代码省略.........