//
// System.Globalization.StringInfo.cs
//
// Author:
// Dick Porter (dick@ximian.com)
//
// (C) 2002 Ximian, Inc.
// (C) 2004 Novell, Inc.
//
//
// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System.Collections;
using System.Runtime.InteropServices;
namespace System.Globalization{
[Serializable]
[ComVisible(true)]
public class StringInfo {
public StringInfo () : this (string.Empty)
{
}
string s;
int length;
public StringInfo (string value)
{
// Argument check in property
String = value;
}
[ComVisible (false)]
public override bool Equals (object value)
{
StringInfo other = value as StringInfo;
return other != null && s == other.s;
}
[ComVisible (false)]
public override int GetHashCode ()
{
return s.GetHashCode ();
}
public int LengthInTextElements {
get {
if (length < 0) {
length = 0;
for (int idx = 0; idx < s.Length; length++)
idx += GetNextTextElementLength (s, idx);
}
return length;
}
}
public string String {
get { return s; }
set {
if (value == null)
throw new ArgumentNullException ("value");
length = -1;
s = value;
}
}
public string SubstringByTextElements (int startingTextElement)
{
if (startingTextElement < 0 || s.Length == 0)
throw new ArgumentOutOfRangeException ("startingTextElement");
int idx = 0;
for (int i = 0; i < startingTextElement; i++) {
if (idx >= s.Length)
throw new ArgumentOutOfRangeException ("startingTextElement");
idx += GetNextTextElementLength (s, idx);
}
return s.Substring (idx);
}
public string SubstringByTextElements (int startingTextElement, int lengthInTextElements)
{
if (startingTextElement < 0 || s.Length == 0)
throw new ArgumentOutOfRangeException ("startingTextElement");
if (lengthInTextElements < 0)
throw new ArgumentOutOfRangeException ("lengthInTextElements");
int idx = 0;
for (int i = 0; i < startingTextElement; i++) {
if (idx >= s.Length)
throw new ArgumentOutOfRangeException ("startingTextElement");
idx += GetNextTextElementLength (s, idx);
}
int start = idx;
for (int i = 0; i < lengthInTextElements; i++) {
if (idx >= s.Length)
throw new ArgumentOutOfRangeException ("lengthInTextElements");
idx += GetNextTextElementLength (s, idx);
}
return s.Substring (start, idx - start);
}
public static string GetNextTextElement(string str)
{
if(str == null || str.Length == 0) {
throw new ArgumentNullException("string is null");
}
return(GetNextTextElement (str, 0));
}
public static string GetNextTextElement(string str, int index)
{
int len = GetNextTextElementLength (str, index);
return len != 1 ? str.Substring (index, len) : new string (str [index], 1);
}
static int GetNextTextElementLength(string str, int index)
{
if(str == null) {
throw new ArgumentNullException("string is null");
}
if(index >= str.Length)
return 0;
if(index < 0)
throw new ArgumentOutOfRangeException ("Index is not valid");
/* Find the next base character, surrogate
* pair or combining character sequence
*/
char ch = str[index];
UnicodeCategory cat = char.GetUnicodeCategory (ch);
if (cat == UnicodeCategory.Surrogate) {
/* Check that it's a high surrogate
* followed by a low surrogate
*/
if (ch >= 0xD800 && ch <= 0xDBFF) {
if ((index + 1) < str.Length &&
str[index + 1] >= 0xDC00 &&
str[index + 1] <= 0xDFFF) {
/* A valid surrogate pair */
return 2;
} else {
/* High surrogate on its own */
return 1;
}
} else {
/* Low surrogate on its own */
return 1;
}
} else {
/* Look for a base character, which
* may or may not be followed by a
* series of combining characters
*/
if (cat == UnicodeCategory.NonSpacingMark ||
cat == UnicodeCategory.SpacingCombiningMark ||
cat == UnicodeCategory.EnclosingMark) {
/* Not a base character */
return 1;
}
int count = 1;
while (index + count < str.Length) {
cat = char.GetUnicodeCategory (str[index + count]);
if (cat != UnicodeCategory.NonSpacingMark &&
cat != UnicodeCategory.SpacingCombiningMark &&
cat != UnicodeCategory.EnclosingMark) {
/* Finished the sequence */
break;
}
count++;
}
return count;
}
}
public static TextElementEnumerator GetTextElementEnumerator(string str)
{
if(str == null || str.Length == 0) {
throw new ArgumentNullException("string is null");
}
return(new TextElementEnumerator (str, 0));
}
public static TextElementEnumerator GetTextElementEnumerator(string str, int index)
{
if(str == null) {
throw new ArgumentNullException("string is null");
}
if(index < 0 || index >= str.Length) {
throw new ArgumentOutOfRangeException ("Index is not valid");
}
return(new TextElementEnumerator (str, index));
}
public static int[] ParseCombiningCharacters(string str)
{
if(str == null) {
throw new ArgumentNullException("string is null");
}
ArrayList indices = new ArrayList (str.Length);
TextElementEnumerator tee = GetTextElementEnumerator (str);
tee.Reset ();
while(tee.MoveNext ()) {
indices.Add (tee.ElementIndex);
}
return((int[])indices.ToArray (typeof (int)));
}
}
}
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