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//+-----------------------------------------------------------------------
//
// Microsoft Windows Client Platform
// Copyright (C) Microsoft Corporation, 2001
//
// File: Bidi.cs
//
// Contents: Bidi services
//
// Created: 9-9-2001 Worachai Chaoweeraprasit (wchao)
// Added BiDi Algorithm : 10-10-2001 Tarek Mahmoud Sayed (Microsoft)
//
//------------------------------------------------------------------------
using System.Windows;
using System;
using MS.Internal.TextFormatting;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Security.Permissions;
using System.Globalization;
using System.Security;
using System.Windows.Media.TextFormatting;
using MS.Internal;
namespace MS.Internal.TextFormatting
{
/// <Remark>
/// Bidi resolution services
/// </Remark>
internal static class Bidi
{
static private readonly StateMachineAction [,] Action;
static private readonly StateMachineState [,] NextState;
static private readonly byte [,] ImplictPush;
static private readonly byte [,] CharProperty;
static private readonly StateMachineState [] ClassToState;
static private readonly byte [] FastPathClass;
// Hidden char doesn't affect the relative ordering of surroudning characters.
// They are internally assigned to the class types of either the previous or following non-hidden text
static private char CharHidden = '\xFFFF';
static Bidi()
{
Action = new StateMachineAction[9, 11]
{
// L R AN EN AL ES CS ET NSM BN N
/*S_L*/ {StateMachineAction.ST_ST, StateMachineAction.ST_ST, StateMachineAction.ST_ST, StateMachineAction.EN_L, StateMachineAction.ST_ST, StateMachineAction.SEP_ST, StateMachineAction.SEP_ST, StateMachineAction.CS_NUM, StateMachineAction.NSM_ST, StateMachineAction.BN_ST, StateMachineAction.N_ST},
/*S_AL*/ {StateMachineAction.ST_ST, StateMachineAction.ST_ST, StateMachineAction.ST_ST, StateMachineAction.EN_AL, StateMachineAction.ST_ST, StateMachineAction.SEP_ST, StateMachineAction.SEP_ST, StateMachineAction.CS_NUM, StateMachineAction.NSM_ST, StateMachineAction.BN_ST, StateMachineAction.N_ST},
/*S_R*/ {StateMachineAction.ST_ST, StateMachineAction.ST_ST, StateMachineAction.ST_ST, StateMachineAction.ST_ST, StateMachineAction.ST_ST, StateMachineAction.SEP_ST, StateMachineAction.SEP_ST, StateMachineAction.CS_NUM, StateMachineAction.NSM_ST, StateMachineAction.BN_ST, StateMachineAction.N_ST},
/*S_AN*/ {StateMachineAction.ST_ST, StateMachineAction.ST_ST, StateMachineAction.ST_ST, StateMachineAction.NUM_NUM, StateMachineAction.ST_ST, StateMachineAction.ES_AN, StateMachineAction.CS_NUM, StateMachineAction.CS_NUM, StateMachineAction.NSM_ST, StateMachineAction.BN_ST, StateMachineAction.N_ST},
/*S_EN*/ {StateMachineAction.ST_ST, StateMachineAction.ST_ST, StateMachineAction.ST_ST, StateMachineAction.NUM_NUM, StateMachineAction.ST_ST, StateMachineAction.CS_NUM, StateMachineAction.CS_NUM, StateMachineAction.ET_EN, StateMachineAction.NSM_ST, StateMachineAction.BN_ST, StateMachineAction.N_ST},
/*S_ET*/ {StateMachineAction.ST_ET, StateMachineAction.ST_ET, StateMachineAction.ST_ET, StateMachineAction.EN_ET, StateMachineAction.ST_ET, StateMachineAction.SEP_ET, StateMachineAction.SEP_ET, StateMachineAction.ET_ET, StateMachineAction.NSM_ET, StateMachineAction.BN_ST, StateMachineAction.N_ET},
/*S_ANfCS*/{StateMachineAction.ST_NUMSEP, StateMachineAction.ST_NUMSEP, StateMachineAction.NUM_NUMSEP, StateMachineAction.ST_NUMSEP, StateMachineAction.ST_NUMSEP, StateMachineAction.SEP_NUMSEP, StateMachineAction.SEP_NUMSEP, StateMachineAction.ET_NUMSEP, StateMachineAction.SEP_NUMSEP, StateMachineAction.BN_ST, StateMachineAction.N_ST},
/*S_ENfCS*/{StateMachineAction.ST_NUMSEP, StateMachineAction.ST_NUMSEP, StateMachineAction.ST_NUMSEP, StateMachineAction.NUM_NUMSEP, StateMachineAction.ST_NUMSEP, StateMachineAction.SEP_NUMSEP, StateMachineAction.SEP_NUMSEP, StateMachineAction.ET_NUMSEP, StateMachineAction.SEP_NUMSEP, StateMachineAction.BN_ST, StateMachineAction.N_ST},
/*S_N*/ {StateMachineAction.ST_N, StateMachineAction.ST_N, StateMachineAction.ST_N, StateMachineAction.EN_N, StateMachineAction.ST_N, StateMachineAction.SEP_N, StateMachineAction.SEP_N, StateMachineAction.ET_N, StateMachineAction.NSM_ET, StateMachineAction.BN_ST, StateMachineAction.N_ET}
};
NextState = new StateMachineState[9, 11]
{
// L R AN EN AL ES CS ET NSM BN N
/*S_L*/ {StateMachineState.S_L, StateMachineState.S_R, StateMachineState.S_AN, StateMachineState.S_EN, StateMachineState.S_AL, StateMachineState.S_N, StateMachineState.S_N, StateMachineState.S_ET, StateMachineState.S_L, StateMachineState.S_L, StateMachineState.S_N},
/*S_AL*/ {StateMachineState.S_L, StateMachineState.S_R, StateMachineState.S_AN, StateMachineState.S_AN, StateMachineState.S_AL, StateMachineState.S_N, StateMachineState.S_N, StateMachineState.S_ET, StateMachineState.S_AL, StateMachineState.S_AL, StateMachineState.S_N},
/*S_R*/ {StateMachineState.S_L, StateMachineState.S_R, StateMachineState.S_AN, StateMachineState.S_EN, StateMachineState.S_AL, StateMachineState.S_N, StateMachineState.S_N, StateMachineState.S_ET, StateMachineState.S_R, StateMachineState.S_R, StateMachineState.S_N},
/*S_AN*/ {StateMachineState.S_L, StateMachineState.S_R, StateMachineState.S_AN, StateMachineState.S_EN, StateMachineState.S_AL, StateMachineState.S_N, StateMachineState.S_ANfCS, StateMachineState.S_ET, StateMachineState.S_AN, StateMachineState.S_AN, StateMachineState.S_N},
/*S_EN*/ {StateMachineState.S_L, StateMachineState.S_R, StateMachineState.S_AN, StateMachineState.S_EN, StateMachineState.S_AL, StateMachineState.S_ENfCS, StateMachineState.S_ENfCS, StateMachineState.S_EN, StateMachineState.S_EN, StateMachineState.S_EN, StateMachineState.S_N},
/*S_ET*/ {StateMachineState.S_L, StateMachineState.S_R, StateMachineState.S_AN, StateMachineState.S_EN, StateMachineState.S_AL, StateMachineState.S_N, StateMachineState.S_N, StateMachineState.S_ET, StateMachineState.S_ET, StateMachineState.S_ET, StateMachineState.S_N},
/*S_ANfCS*/ {StateMachineState.S_L, StateMachineState.S_R, StateMachineState.S_AN, StateMachineState.S_EN, StateMachineState.S_AL, StateMachineState.S_N, StateMachineState.S_N, StateMachineState.S_ET, StateMachineState.S_N, StateMachineState.S_ANfCS, StateMachineState.S_N},
/*S_ENfCS*/ {StateMachineState.S_L, StateMachineState.S_R, StateMachineState.S_AN, StateMachineState.S_EN, StateMachineState.S_AL, StateMachineState.S_N, StateMachineState.S_N, StateMachineState.S_ET, StateMachineState.S_N, StateMachineState.S_ENfCS, StateMachineState.S_N},
/*S_N*/ {StateMachineState.S_L, StateMachineState.S_R, StateMachineState.S_AN, StateMachineState.S_EN, StateMachineState.S_AL, StateMachineState.S_N, StateMachineState.S_N, StateMachineState.S_ET, StateMachineState.S_N, StateMachineState.S_N, StateMachineState.S_N}
};
ImplictPush = new byte[2,4]
{
// L, R, AN, EN
/*even*/ {0, 1, 2, 2},
/*odd*/ {1, 0, 1, 1}
};
CharProperty = new byte[6, (int) DirectionClass.ClassMax - 1]
{
//L R AN EN AL ES CS ET NSM BN N B LRE LRO RLE RLO PDF S WS ON
/*STRONG*/ { 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} ,
/*STRONG/NUMBER*/ { 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} ,
/*FIXED*/ { 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} ,
/*FINAL*/ { 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} ,
/*NUMBER*/ { 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} ,
/*VALID INDEX*/ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0}
};
ClassToState = new StateMachineState[(int) DirectionClass.ClassMax]
{
/* Left */ StateMachineState.S_L,
/* Right */ StateMachineState.S_R,
/* ArabicNumber */ StateMachineState.S_AN,
/* EuropeanNumber */ StateMachineState.S_EN,
/* ArabicLetter */ StateMachineState.S_AL,
/* EuropeanSeparator */ StateMachineState.S_L,
/* CommonSeparator */ StateMachineState.S_L,
/* EuropeanTerminator */ StateMachineState.S_L,
/* NonSpacingMark */ StateMachineState.S_L,
/* BoundaryNeutral */ StateMachineState.S_L,
/* GenericNeutral */ StateMachineState.S_L,
/* ParagraphSeparator */ StateMachineState.S_L,
/* LeftToRightEmbedding */ StateMachineState.S_L,
/* LeftToRightOverride */ StateMachineState.S_L,
/* RightToLeftEmbedding */ StateMachineState.S_L,
/* RightToLeftOverride */ StateMachineState.S_L,
/* PopDirectionalFormat */ StateMachineState.S_L,
/* SegmentSeparator */ StateMachineState.S_L,
/* WhiteSpace */ StateMachineState.S_L,
/* OtherNeutral */ StateMachineState.S_L,
/* ClassInvalid */ StateMachineState.S_L
};
// FastPathClass
// 0 means couldn't handle through the fast loop.
// 1 means treat it as nuetral character.
// 2 means Left strong character.
// 3 Right strong character.
FastPathClass = new byte[(int) DirectionClass.ClassMax]
{
/* Left */ 2,
/* Right */ 3,
/* ArabicNumber */ 0,
/* EuropeanNumber */ 0,
/* ArabicLetter */ 3,
/* EuropeanSeparator */ 1,
/* CommonSeparator */ 1,
/* EuropeanTerminator */ 0,
/* NonSpacingMark */ 0,
/* BoundaryNeutral */ 0,
/* GenericNeutral */ 1,
/* ParagraphSeparator */ 0,
/* LeftToRightEmbedding */ 0,
/* LeftToRightOverride */ 0,
/* RightToLeftEmbedding */ 0,
/* RightToLeftOverride */ 0,
/* PopDirectionalFormat */ 0,
/* SegmentSeparator */ 0,
/* WhiteSpace */ 1,
/* OtherNeutral */ 1,
/* ClassInvalid */ 1
};
}
//
// Helper Class
//
private static class Helper
{
public static ulong LeftShift(ulong x, byte y)
{
return x << y;
}
public static ulong LeftShift(ulong x, int y)
{
return x << y;
}
public static void SetBit(ref ulong x, byte y)
{
x |= LeftShift(1,y);
}
public static void ResetBit(ref ulong x, int y)
{
x &= ~LeftShift(1,y);
}
public static bool IsBitSet(ulong x, byte y)
{
return ((x & LeftShift(1,y)) != 0);
}
public static bool IsBitSet(ulong x, int y)
{
return ((x & LeftShift(1,y)) != 0);
}
public static bool IsOdd(byte x)
{
return ((x & 1) != 0);
}
public static bool IsOdd(int x)
{
return ((x & 1) != 0);
}
}
//
// BidiStack class. It represents the level stack in bidi analysis
// The level stack is internally stored as a ulong. The Nth bit's value
// represents whether level N is on stack.
//
internal class BidiStack
{
private const byte EmbeddingLevelInvalid = 62;
public BidiStack()
{
currentStackLevel = 0;
}
public bool Init (ulong initialStack)
{
byte currentLevel = GetMaximumLevel(initialStack);
byte minimumLevel = GetMinimumLevel(initialStack);
if ((currentLevel >= EmbeddingLevelInvalid) || (minimumLevel < 0))
{
return false;
}
stack = initialStack;
currentStackLevel = currentLevel;
return true;
}
public bool Push(bool pushToGreaterEven)
{
byte newMaximumLevel;
if (!PushCore(ref stack, pushToGreaterEven, currentStackLevel, out newMaximumLevel))
return false;
currentStackLevel = newMaximumLevel;
return true;
}
public bool Pop()
{
byte newMaximumLevel;
if (!PopCore(ref stack, currentStackLevel, out newMaximumLevel))
return false;
currentStackLevel = newMaximumLevel;
return true;
}
public byte GetStackBottom()
{
return GetMinimumLevel(stack);
}
public byte GetCurrentLevel()
{
return currentStackLevel;
}
public ulong GetData()
{
return stack;
}
/// <summary>
/// Helper method to push to bidi stack. Bidi stack is a ulong, the value of the Nth bit inidcates whether
/// level N is on stack.
/// </summary>
internal static bool Push(ref ulong stack, bool pushToGreaterEven, out byte topLevel)
{
byte currentLevel = GetMaximumLevel(stack);
return PushCore(ref stack, pushToGreaterEven, currentLevel, out topLevel);
}
/// <summary>
/// Helper method to pop bidi stack. Bidi stack is a ulong, the value of the Nth bit inidcates whether
/// level N is on stack.
/// </summary>
internal static bool Pop(ref ulong stack, out byte topLevel)
{
byte currentLevel = GetMaximumLevel(stack);
return PopCore(ref stack, currentLevel, out topLevel);
}
/// <summary>
/// Helper method to get the top-most level of the bidi stack.
/// </summary>
internal static byte GetMaximumLevel(ulong inputStack)
{
byte maximumLevel = 0;
for (int counter=MaxLevel; counter>=0; counter--)
{
if (Helper.IsBitSet(inputStack, counter))
{
maximumLevel = (byte) counter;
break;
}
}
return maximumLevel;
}
private static bool PushCore(
ref ulong stack,
bool pushToGreaterEven,
byte currentStackLevel,
out byte newMaximumLevel
)
{
newMaximumLevel =
pushToGreaterEven ? GreaterEven(currentStackLevel) : GreaterOdd(currentStackLevel);
if (newMaximumLevel >= EmbeddingLevelInvalid)
{
newMaximumLevel = currentStackLevel;
return false;
}
Helper.SetBit(ref stack, newMaximumLevel);
return true;
}
private static bool PopCore(
ref ulong stack,
byte currentStackLevel,
out byte newMaximumLevel
)
{
newMaximumLevel = currentStackLevel;
if (currentStackLevel == 0 || ((currentStackLevel == 1) && ((stack & 1)==0)))
{
return false;
}
newMaximumLevel = Helper.IsBitSet(stack, currentStackLevel - 1) ?
(byte)(currentStackLevel - 1) : (byte)(currentStackLevel - 2);
Helper.ResetBit(ref stack, currentStackLevel);
return true;
}
private static byte GetMinimumLevel(ulong inputStack)
{
byte minimumLevel = 0xFF;
for (byte counter =0; counter<=MaxLevel; counter++)
{
if (Helper.IsBitSet(inputStack, counter))
{
minimumLevel = counter;
break;
}
}
return minimumLevel;
}
private static byte GreaterEven(byte level)
{
return Helper.IsOdd(level) ? (byte) (level + 1) : (byte) (level + 2);
}
private static byte GreaterOdd(byte level)
{
return Helper.IsOdd(level) ? (byte) (level + 2) : (byte) (level + 1);
}
private ulong stack;
private byte currentStackLevel;
};
#region Enumerations & Const
/// <Remark>
/// Bidi control flags
/// </Remark>
public enum Flags : uint
{
/// <Remark>
/// Paragraph direction defaults to left to right.
/// Ignored if ContinueAnalysis flag is set.
/// </Remark>
DirectionLeftToRight = 0x00000000,
/// <Remark>
/// Paragraph direction defaults to right to left.
/// Ignored if ContinueAnalysis flag is set.
/// </Remark>
DirectionRightToLeft = 0x00000001,
/// <Remark>
/// Paragragraph direction determined by scanning for the first strongly
/// directed character. If no strong character is found, defaults to
/// setting of DirectionRtl flag.
/// Ignored if ContinueAnalysis flag is set.
/// </Remark>
FirstStrongAsBaseDirection = 0x00000002,
/// <Remark>
/// Parse numbers as if the paragraph were preceeded by an Arabic letter.
/// Ignored if ContinueAnalysis flag is set.
/// </Remark>
PreviousStrongIsArabic = 0x00000004,
/// <Remark>
/// This analysis is a continuation. The 'state' parameter provides the
/// last state of the previously analyzed block. This flag causes
/// DirectionRtl, FirstStrongAsBaseDirection, and PreviousStrongIsArabic
/// flags to be ignored.
/// </Remark>
ContinueAnalysis = 0x00000008, // require state-in
/// <Remark>
/// Indicates that the input text may not end at a paragraph boundary,
/// and that futher calls to the API may be made for subsequent text to
/// come and thereby resolve trailing neutral characters. If this flag
/// is set, the 'state' and 'cchResolved' parameters are required.
/// </Remark>
IncompleteText = 0x00000010, // require state-out
/// <Remark>
/// The hint is given for the maximum number of character to be analyzed.
/// This is purely for performance optimization. If this flag is set,
/// the API will start attempting to stop the process at a proper character
/// position beginning at the position given by the 'cchTextMaxHint'
/// parameter.
/// </Remark>
MaximumHint = 0x00000020, // hint on upper bound limit
/// <Remark>
/// Indicate that direction controls (i.e. LRE, RLE, PDF, LRO and RLO) are not to
/// be processed in the analysis. These characters will be treated as neutrals and
/// and will not affect the bidi state.
/// </Remark>
IgnoreDirectionalControls = 0x00000040, // ignore all directional controls characters in input
/// <Remark>
/// By default Unicode Bidi Algorithm resolves European number based on preceding
/// character (Unciode Bidi Rule w2). When this flag is set, the API will ignore this rule and
/// use the input DirectionClass explicitly for European numbers (Unicode Bidi Rule HL2). The
/// valid DirectionClass for European number is either EuropeanNumber or ArabicNumber. This flag
/// doesn't affect non European number.
/// </Remark>
OverrideEuropeanNumberResolution = 0x00000080,
}
private enum OverrideClass
{
OverrideClassNeutral,
OverrideClassLeft,
OverrideClassRight
};
private enum StateMachineState
{
S_L, // Left character
S_AL, // Arabic letter
S_R, // Right character
S_AN, // Arabic number
S_EN, // European number
S_ET, // Europen terminator
S_ANfCS, // Arabic number followed by common sperator
S_ENfCS, // European number followed by common sperator
S_N // Neutral character
};
private enum StateMachineAction
{
ST_ST, // Strong followed by strong
ST_ET, // ET followed by Strong
ST_NUMSEP, // Number followed by sperator follwed by strong
ST_N, // Neutral followed by strong
SEP_ST, // Strong followed by sperator
CS_NUM, // Number followed by CS
SEP_ET, // ET followed by sperator
SEP_NUMSEP, // Number follwed by sperator follwed by number
SEP_N, // Neutral followed by sperator
ES_AN, // Arabic Number followed by European sperator
ET_ET, // European terminator follwed by a sperator
ET_NUMSEP, // Number followed by sperator followed by ET
ET_EN, // European number follwed by European terminator
ET_N, // Neutral followed by European Terminator
NUM_NUMSEP, // Number followed by sperator followed by number
NUM_NUM, // Number followed by number
EN_L, // Left followed by EN
EN_AL, // AL followed by EN
EN_ET, // ET followed by EN
EN_N, // Neutral followed by EN
BN_ST, // ST followed by BN
NSM_ST, // ST followed by NSM
NSM_ET, // ET followed by NSM
N_ST, // ST followed by neutral
N_ET // ET followed by neutral
};
#endregion
#region Public API
/// <summary>
/// GetLastStongAndNumberClass is used to get the last strong character class and last number
/// class. if numberClass is not equal DirectionClass.ClassInvalid then we are interested in
/// last strong class only otherwise we are interested in both last strong and number class.
/// this method is useful while implementing the derived Bidi.State properties Bidi.LastNumberClass
/// and Bidi.LastStrongClass.
/// </summary>
static internal bool GetLastStongAndNumberClass(
CharacterBufferRange charString,
ref DirectionClass strongClass,
ref DirectionClass numberClass)
{
int wordCount;
DirectionClass currentClass;
int i = charString.Length - 1;
while (i >= 0)
{
int intChar = charString[i];
wordCount = 1;
if (((charString[i] & 0xFC00) == 0xDC00) && (i > 0) && ((charString[i-1] & 0xFC00) == 0xD800))
{
intChar = (((charString[i-1] & 0x03ff) << 10) | (charString[i] & 0x3ff)) + 0x10000;
wordCount = 2;
}
currentClass = Classification.CharAttributeOf((int) Classification.GetUnicodeClass(intChar)).BiDi;
// Stop scaning backwards in this character buffer once and ParagraphSeperator is encountered.
// Bidi algorithm works strictly within a paragraph.
if (currentClass == DirectionClass.ParagraphSeparator)
{
return false; // stop scaning as paragraph separator is encountered before seeing last strong/number.
}
if (CharProperty[1, (int) currentClass] == 1)
{
if (numberClass == DirectionClass.ClassInvalid )
{
numberClass = currentClass;
}
if (currentClass != DirectionClass.EuropeanNumber)
{
strongClass = currentClass;
break;
}
}
i -= wordCount;
}
return true; // Finish scanning all the input characters
}
/// <Remark>
/// Bidi state
/// </Remark>
internal class State
{
/// <Remark>
/// Constructor
/// </Remark>
public State(bool isRightToLeft)
{
OverrideLevels = 0;
Overflow = 0;
NumberClass = DirectionClass.Left;
StrongCharClass = DirectionClass.Left;
LevelStack = isRightToLeft ? Bidi.StackRtl : Bidi.StackLtr;
}
#region Overridable methods
/// <Remark>
/// This method should return one of the following values:
/// Left, Right, or ArabicLetter.
/// </Remark>
public virtual DirectionClass LastStrongClass
{
get { return StrongCharClass; }
set { StrongCharClass = value;}
}
/// <Remark>
/// Last number character
/// </Remark>
public virtual DirectionClass LastNumberClass
{
get { return NumberClass; }
set { NumberClass = value; }
}
#endregion
/// <Remark>
/// Bidi level stack
/// </Remark>
public ulong LevelStack
{
get { return m_levelStack; }
set { m_levelStack = value; }
}
/// <Remark>
/// Bidi override status
/// </Remark>
public ulong OverrideLevels
{
get { return m_overrideLevels; }
set { m_overrideLevels = value; }
}
/// <Remark>
/// Overflow counter
/// </Remark>
public ushort Overflow
{
get { return m_overflow; }
set { m_overflow = value; }
}
ulong m_levelStack;
ulong m_overrideLevels;
/// <Remark>
/// holding the last number class from the analysis
/// </Remark>
protected DirectionClass NumberClass;
/// <Remark>
/// holding the last strong class from the analysis
/// </Remark>
protected DirectionClass StrongCharClass;
ushort m_overflow;
}
#endregion
//
// Bidi class constants
//
private const byte ParagraphTerminatorLevel = 0xFF;
private const int PositionInvalid = -1;
private const byte BaseLevelLeft = 0;
private const byte BaseLevelRight = 1;
private const uint EmptyStack = 0; // no stack
private const uint StackLtr = 1; // left to right
private const uint StackRtl = 2; // right to left
private const int MaxLevel = 63; // right to left
//
// Start BiDi class implementation
//
static private bool GetFirstStrongCharacter(
CharacterBuffer charBuffer,
int ichText,
int cchText,
ref DirectionClass strongClass)
{
DirectionClass currentClass = DirectionClass.ClassInvalid;
int counter = 0;
int wordCount;
while (counter<cchText)
{
int intChar = charBuffer[ichText + counter];
wordCount = 1;
if ((intChar & 0xFC00) == 0xD800)
{
intChar = DoubleWideChar.GetChar(charBuffer, ichText, cchText, counter, out wordCount);
}
currentClass = Classification.CharAttributeOf((int) Classification.GetUnicodeClass(intChar)).BiDi;
if (CharProperty[0, (int) currentClass]==1 || currentClass == DirectionClass.ParagraphSeparator)
{
break;
}
counter += wordCount;
}
if (CharProperty[0, (int) currentClass]==1)
{
strongClass = currentClass;
return true;
}
return false;
}
static private void ResolveNeutrals(
IList<DirectionClass> characterClass, // [IN / OUT]
int classIndex, // [IN]
int count, // [IN]
DirectionClass startClass, // [IN]
DirectionClass endClass, // [IN]
byte runLevel // [IN]
)
{
DirectionClass startType;
DirectionClass endType;
DirectionClass resolutionType;
if ((characterClass == null) || (count == 0))
{
return;
}
Debug.Assert(CharProperty[1, (int) startClass]==1 || (startClass == DirectionClass.ArabicLetter),
("Cannot use non strong type to resolve neutrals"));
Debug.Assert(CharProperty[1, (int) endClass]==1, ("Cannot use non strong type to resolve neutrals"));
startType = ((startClass == DirectionClass.EuropeanNumber) ||
(startClass == DirectionClass.ArabicNumber) ||
(startClass == DirectionClass.ArabicLetter)) ? DirectionClass.Right : startClass;
endType = ((endClass == DirectionClass.EuropeanNumber) ||
(endClass == DirectionClass.ArabicNumber) ||
(endClass == DirectionClass.ArabicLetter)) ? DirectionClass.Right : endClass;
if (startType == endType)
{
resolutionType = startType;
}
else
{
resolutionType = Helper.IsOdd(runLevel) ? DirectionClass.Right : DirectionClass.Left;
}
for (int counter = 0; counter < count; counter++)
{
// We should never be changing a fixed type here
Debug.Assert(CharProperty[2, (int) characterClass[counter + classIndex]]==0,
"Resolving fixed class as being neutral: " +
characterClass[counter + classIndex].ToString());
characterClass[counter + classIndex] = resolutionType;
}
}
static private void ChangeType(
IList<DirectionClass> characterClass, // [IN / OUT]
int classIndex,
int count, // [IN]
DirectionClass newClass // [IN]
)
{
if ((characterClass == null) || (count == 0))
{
return;
}
for (int counter = 0; counter < count; counter++)
{
// We should never be changing a fixed type here
Debug.Assert(CharProperty[2, (int) characterClass[counter + classIndex]]==0, "Changing class of a fixed class");
characterClass[counter + classIndex] = newClass;
}
}
static private int ResolveNeutralAndWeak(
IList<DirectionClass> characterClass, // [IN / OUT]
int classIndex, // [IN]
int runLength, // [IN]
DirectionClass sor, // [IN]
DirectionClass eor, // [IN]
byte runLevel, // [IN]
State stateIn, // [IN], [OPTIONAL]
State stateOut, // [OUT],[OPTIONAL]
bool previousStrongIsArabic,// [IN], OPTIONAL
Flags flags // [IN]
)
{
int startOfNeutrals = PositionInvalid;
int startOfDelayed = PositionInvalid;
DirectionClass lastClass = DirectionClass.ClassInvalid;
DirectionClass lastStrongClass = DirectionClass.ClassInvalid;
DirectionClass lastNumericClass = DirectionClass.ClassInvalid;
DirectionClass startingClass = DirectionClass.ClassInvalid;
DirectionClass currentClass = DirectionClass.ClassInvalid;
StateMachineState state;
bool previousClassIsArabic = false;
bool ArabicNumberAfterLeft = false;
int lengthResolved = 0;
if (runLength == 0)
{
return 0;
}
if (stateIn != null)
{
lastStrongClass = stateIn.LastStrongClass;
if (stateIn.LastNumberClass != DirectionClass.ClassInvalid)
{
lastNumericClass = startingClass =
lastClass =
stateIn.LastNumberClass;
}
else
{
startingClass = lastClass = lastStrongClass;
}
}
else if (previousStrongIsArabic)
{
startingClass = DirectionClass.ArabicLetter;
lastClass = lastStrongClass = sor;
previousClassIsArabic = true;
}
else
{
startingClass = lastClass = lastStrongClass = sor;
}
state = ClassToState[(int) startingClass];
// We have two types of classes that needs delayed resolution:
// Neutrals and other classes such as CS, ES, ET, BN, NSM that needs look ahead.
// We keep a separate pointer for the start of neutrals and another pointer
// for the those other classes (if needed since its resolution might be delayed).
// Also, we need the last strong class for neutral resolution and the last
// general class (that is not BN or MSM) for NSM resolution.
// The simple idea of all actions is that we always resolve neutrals starting
// from 'startOfNeutrals' and when we are sure about delayed weak type
// resolution, we resolve it starting from 'startOfDelayed' else we point by
// 'startOfNeutrals' as resolve it as neutral.
int counter = 0;
for (counter = 0; counter < runLength; counter++)
{
currentClass = characterClass[counter + classIndex];
// We index action and next state table by class.
// If we got a calss that should have been resolved already or a bogus
// value, return what we were able to resolve so far.
if (CharProperty[5, (int) currentClass]==0)
{
return lengthResolved;
}
StateMachineAction action = Action[(int) state, (int)currentClass];
// Need to record last numeric type so that when
// we continue from a previous call, we can correctly resolve something
// like L AN at the end of the first call and EN at the start of the
// next call.
if (CharProperty[4, (int) currentClass]==1)
{
lastNumericClass = currentClass;
}
// If we have previousClassIsArabic flag set, we need its efect to
// last only till the first strong character in the run.
if(CharProperty[0, (int) currentClass]==1)
{
previousClassIsArabic = false;
}
switch (action)
{
case StateMachineAction.ST_ST:
Debug.Assert(startOfNeutrals == PositionInvalid,
"Cannot have unresolved neutrals. State: " +
state.ToString() +
", Class: " + currentClass.ToString());
if (currentClass == DirectionClass.ArabicLetter)
{
characterClass[counter + classIndex] = DirectionClass.Right;
}
if (startOfDelayed != PositionInvalid)
{
startOfNeutrals = startOfDelayed;
ResolveNeutrals(characterClass,
classIndex + startOfNeutrals,
counter - startOfNeutrals,
ArabicNumberAfterLeft ? DirectionClass.ArabicNumber : lastStrongClass,
characterClass[counter + classIndex],
runLevel);
startOfNeutrals = startOfDelayed = PositionInvalid;
}
if ((currentClass != DirectionClass.ArabicNumber) ||
((currentClass == DirectionClass.ArabicNumber) &&
(lastStrongClass == DirectionClass.Right)))
{
lastStrongClass = currentClass;
}
if ((currentClass == DirectionClass.ArabicNumber) &&
(lastStrongClass == DirectionClass.Left))
{
ArabicNumberAfterLeft = true;
}
else
{
ArabicNumberAfterLeft = false;
}
lastClass = currentClass;
break;
case StateMachineAction.ST_ET:
Debug.Assert(startOfDelayed != PositionInvalid,
"Must have delayed weak classes. State: " +
state.ToString() +
", Class: "+ currentClass.ToString());
if (startOfNeutrals == PositionInvalid)
{
startOfNeutrals = startOfDelayed;
}
if (currentClass == DirectionClass.ArabicLetter)
{
characterClass[counter + classIndex] = DirectionClass.Right;
}
ResolveNeutrals(characterClass,
classIndex + startOfNeutrals,
counter - startOfNeutrals,
ArabicNumberAfterLeft ? DirectionClass.ArabicNumber : lastStrongClass,
characterClass[counter + classIndex],
runLevel);
startOfNeutrals = startOfDelayed = PositionInvalid;
if ((currentClass != DirectionClass.ArabicNumber) ||
((currentClass == DirectionClass.ArabicNumber) &&
(lastStrongClass == DirectionClass.Right)))
{
lastStrongClass = currentClass;
}
if ((currentClass == DirectionClass.ArabicNumber) &&
(lastStrongClass == DirectionClass.Left))
{
ArabicNumberAfterLeft = true;
}
else
{
ArabicNumberAfterLeft = false;
}
lastClass = currentClass;
break;
case StateMachineAction.ST_NUMSEP:
{
Debug.Assert(startOfNeutrals == PositionInvalid,
"Cannot have unresolved neutrals. State: " +
state.ToString() +
", Class: "+ currentClass.ToString());
Debug.Assert(startOfDelayed != PositionInvalid,
"Must have delayed weak classes. State: " +
state.ToString() +
" Class: "+ currentClass.ToString());
bool processed = false;
if (currentClass == DirectionClass.ArabicLetter)
{
// Rule W3, change all AL to R.
characterClass[counter + classIndex] = DirectionClass.Right;
}
if (((lastStrongClass == DirectionClass.ArabicLetter) || previousClassIsArabic) &&
((currentClass == DirectionClass.EuropeanNumber && (flags & Flags.OverrideEuropeanNumberResolution) == 0) ||
(currentClass == DirectionClass.ArabicNumber)))
{
// Rule W2: Change EN to AN if it follows AL.
characterClass[counter + classIndex] = DirectionClass.ArabicNumber;
bool commonSeparator = true;
int commonSeparatorCount = 0;
for (int i = startOfDelayed; i < counter; i++)
{
if (characterClass[i + classIndex] != DirectionClass.CommonSeparator &&
characterClass[i + classIndex] != DirectionClass.BoundaryNeutral)
{
commonSeparator = false;
break;
}
if (characterClass[i + classIndex] == DirectionClass.CommonSeparator )
{
commonSeparatorCount++;
}
}
if (commonSeparator && (commonSeparatorCount == 1))
{
// Rule W4: In sequence of AN CS AN, change CS to AN.
ChangeType(characterClass,
classIndex + startOfDelayed,
counter - startOfDelayed,
characterClass[counter + classIndex]);
processed = true;
}
}
else if ((lastStrongClass == DirectionClass.Left) &&
(currentClass == DirectionClass.EuropeanNumber))
{
// Rule W7: Change EN to L if it follows L.
characterClass[counter + classIndex] = DirectionClass.Left;
}
if (!processed)
{
startOfNeutrals = startOfDelayed;
ResolveNeutrals(characterClass,
classIndex + startOfNeutrals,
counter - startOfNeutrals,
ArabicNumberAfterLeft ? DirectionClass.ArabicNumber : lastStrongClass,
characterClass[counter + classIndex],
runLevel);
}
startOfNeutrals = startOfDelayed = PositionInvalid;
if ((currentClass != DirectionClass.ArabicNumber) ||
((currentClass == DirectionClass.ArabicNumber) &&
(lastStrongClass == DirectionClass.Right)))
{
if (!(((lastStrongClass == DirectionClass.Left) ||
(lastStrongClass == DirectionClass.ArabicLetter)) &&
(currentClass == DirectionClass.EuropeanNumber)))
{
lastStrongClass = currentClass;
}
}
if ((currentClass == DirectionClass.ArabicNumber) &&
(lastStrongClass == DirectionClass.Left))
{
ArabicNumberAfterLeft = true;
}
else
{
ArabicNumberAfterLeft = false;
}
lastClass = currentClass;
if (characterClass[counter + classIndex] == DirectionClass.ArabicNumber)
{
currentClass = DirectionClass.ArabicNumber;
}
}
break;
case StateMachineAction.ST_N:
Debug.Assert(startOfNeutrals != PositionInvalid,
"Must have unresolved neutrals. State: " +
state.ToString() +", Class: "+
currentClass.ToString());
if (currentClass == DirectionClass.ArabicLetter)
{
characterClass[counter + classIndex] = DirectionClass.Right;
}
ResolveNeutrals(characterClass,
classIndex + startOfNeutrals,
counter - startOfNeutrals,
ArabicNumberAfterLeft ? DirectionClass.ArabicNumber : lastStrongClass,
characterClass[counter + classIndex],
runLevel);
startOfNeutrals = startOfDelayed = PositionInvalid;
if ((currentClass != DirectionClass.ArabicNumber) ||
((currentClass == DirectionClass.ArabicNumber) &&
(lastStrongClass == DirectionClass.Right)))
{
lastStrongClass = currentClass;
}
if ((currentClass == DirectionClass.ArabicNumber) &&
(lastStrongClass == DirectionClass.Left))
{
ArabicNumberAfterLeft = true;
}
else
{
ArabicNumberAfterLeft = false;
}
lastClass = currentClass;
break;
case StateMachineAction.EN_N:
Debug.Assert(startOfNeutrals != PositionInvalid,
"Must have unresolved neutrals. State: " +
state.ToString() + ", Class: "+
currentClass.ToString());
if ((flags & Flags.OverrideEuropeanNumberResolution) == 0 &&
((lastStrongClass == DirectionClass.ArabicLetter) ||
previousClassIsArabic)
)
{
// Rule W2: EN changes to AN if it follows AL.
characterClass[counter + classIndex] = DirectionClass.ArabicNumber;
currentClass = DirectionClass.ArabicNumber;
}
else if (lastStrongClass == DirectionClass.Left)
{
// Rule W7: EN changes to L if it follows L.
characterClass[counter + classIndex] = DirectionClass.Left;
}
ResolveNeutrals(characterClass,
classIndex + startOfNeutrals,
counter - startOfNeutrals,
ArabicNumberAfterLeft ? DirectionClass.ArabicNumber : lastStrongClass,
characterClass[counter + classIndex],
runLevel);
startOfNeutrals = startOfDelayed = PositionInvalid;
ArabicNumberAfterLeft = false;
lastClass = currentClass;
break;
case StateMachineAction.SEP_ST:
Debug.Assert(startOfNeutrals == PositionInvalid,
"Cannot have unresolved neutrals. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
if (startOfDelayed != PositionInvalid)
{
startOfNeutrals = startOfDelayed;
startOfDelayed = PositionInvalid;
}
else
{
startOfNeutrals = counter;
}
lastClass = currentClass;
break;
case StateMachineAction.CS_NUM:
Debug.Assert(startOfNeutrals == PositionInvalid,
"Cannot have unresolved neutrals. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
if (startOfDelayed == PositionInvalid)
{
startOfDelayed = counter;
}
lastClass = currentClass;
break;
case StateMachineAction.SEP_ET:
Debug.Assert(startOfDelayed != PositionInvalid,
"Must have delayed weak classes. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
if (startOfNeutrals == PositionInvalid)
{
startOfNeutrals = startOfDelayed;
}
startOfDelayed = PositionInvalid;
lastClass = DirectionClass.GenericNeutral;
break;
case StateMachineAction.SEP_NUMSEP:
Debug.Assert(startOfNeutrals == PositionInvalid,
"Cannot have unresolved neutrals. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
Debug.Assert(startOfDelayed != PositionInvalid,
"Must have delayed weak classes. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
startOfNeutrals = startOfDelayed;
startOfDelayed = PositionInvalid;
lastClass = DirectionClass.GenericNeutral;
break;
case StateMachineAction.SEP_N:
Debug.Assert(startOfNeutrals != PositionInvalid,
"Must have unresolved neutrals. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
startOfDelayed = PositionInvalid;
break;
case StateMachineAction.ES_AN:
Debug.Assert(startOfNeutrals == PositionInvalid,
"Cannot have unresolved neutrals. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
if (startOfDelayed != PositionInvalid)
{
startOfNeutrals = startOfDelayed;
startOfDelayed = PositionInvalid;
}
else
{
startOfNeutrals = counter;
}
lastClass = DirectionClass.GenericNeutral;
break;
case StateMachineAction.ET_ET:
Debug.Assert(startOfDelayed != PositionInvalid,
"Must have delayed weak classes. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
Debug.Assert(lastClass == DirectionClass.EuropeanTerminator,
"Last class must be ET. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
break;
case StateMachineAction.ET_NUMSEP:
Debug.Assert(startOfNeutrals == PositionInvalid,
"Cannot have unresolved neutrals. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
Debug.Assert(startOfDelayed != PositionInvalid,
"Must have delayed weak classes. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
startOfNeutrals = startOfDelayed;
startOfDelayed = counter;
lastClass = currentClass;
break;
case StateMachineAction.ET_EN:
if (startOfDelayed == PositionInvalid)
{
startOfDelayed = counter;
}
if (!((lastStrongClass == DirectionClass.ArabicLetter) || previousClassIsArabic))
{
if (lastStrongClass == DirectionClass.Left)
{
characterClass[counter + classIndex] = DirectionClass.Left;
}
else
{
characterClass[counter + classIndex] = DirectionClass.EuropeanNumber;
}
ChangeType(characterClass,
classIndex + startOfDelayed,
counter - startOfDelayed,
characterClass[counter + classIndex]);
startOfDelayed = PositionInvalid;
}
lastClass = DirectionClass.EuropeanNumber;
// According to the rules W4, W5, and W6 If we have a sequence EN ET ES EN
// we should treat ES as ON
if ( counter<runLength-1 &&
(characterClass[counter + 1 + classIndex] == DirectionClass.EuropeanSeparator||
characterClass[counter + 1 + classIndex] == DirectionClass.CommonSeparator))
{
characterClass[counter + 1 + classIndex] = DirectionClass.GenericNeutral;
}
break;
case StateMachineAction.ET_N:
Debug.Assert(startOfNeutrals != PositionInvalid,
"Must have unresolved neutrals. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
if (startOfDelayed == PositionInvalid)
{
startOfDelayed = counter;
}
lastClass = currentClass;
break;
case StateMachineAction.NUM_NUMSEP:
Debug.Assert(startOfNeutrals == PositionInvalid,
"Cannot have unresolved neutrals. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
Debug.Assert(startOfDelayed != PositionInvalid,
"Must have delayed weak classes. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
if ((lastStrongClass == DirectionClass.ArabicLetter) ||
previousClassIsArabic || ArabicNumberAfterLeft)
{
if ((flags & Flags.OverrideEuropeanNumberResolution) == 0)
{
characterClass[counter + classIndex] = DirectionClass.ArabicNumber;
}
}
else if (lastStrongClass == DirectionClass.Left)
{
characterClass[counter + classIndex] = DirectionClass.Left;
}
else
{
lastStrongClass = currentClass;
}
ChangeType(characterClass,
classIndex + startOfDelayed,
counter - startOfDelayed,
characterClass[counter + classIndex]);
startOfDelayed = PositionInvalid;
lastClass = currentClass;
break;
case StateMachineAction.EN_L:
Debug.Assert(startOfNeutrals == PositionInvalid,
"Cannot have unresolved neutrals. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
if (lastStrongClass == DirectionClass.Left)
{
characterClass[counter + classIndex] = DirectionClass.Left;
}
if (startOfDelayed != PositionInvalid)
{
startOfNeutrals = startOfDelayed;
ResolveNeutrals(characterClass,
classIndex + startOfNeutrals,
counter - startOfNeutrals,
ArabicNumberAfterLeft ? DirectionClass.ArabicNumber : lastStrongClass,
characterClass[counter + classIndex],
runLevel);
startOfNeutrals = startOfDelayed = PositionInvalid;
}
lastClass = currentClass;
break;
case StateMachineAction.NUM_NUM:
Debug.Assert(startOfNeutrals == PositionInvalid,
"Cannot have unresolved neutrals. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
if ((flags & Flags.OverrideEuropeanNumberResolution) == 0 &&
(lastStrongClass == DirectionClass.ArabicLetter || previousClassIsArabic)
)
{
// W2: EN changes to AN if it follows AL.
characterClass[counter + classIndex] = DirectionClass.ArabicNumber;
currentClass = DirectionClass.ArabicNumber;
}
else if (lastStrongClass == DirectionClass.Left)
{
characterClass[counter + classIndex] = DirectionClass.Left;
}
if (startOfDelayed != PositionInvalid)
{
startOfNeutrals = startOfDelayed;
ResolveNeutrals(characterClass,
classIndex + startOfNeutrals,
counter - startOfNeutrals,
ArabicNumberAfterLeft ? DirectionClass.ArabicNumber : lastStrongClass,
characterClass[counter + classIndex],
runLevel);
startOfNeutrals = startOfDelayed = PositionInvalid;
}
if ( (currentClass == DirectionClass.ArabicNumber) &&
(lastStrongClass == DirectionClass.Left))
{
ArabicNumberAfterLeft = true;
}
else
{
ArabicNumberAfterLeft = false;
}
lastClass = currentClass;
break;
case StateMachineAction.EN_AL:
Debug.Assert(startOfNeutrals == PositionInvalid,
"Cannot have unresolved neutrals. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
if ((flags & Flags.OverrideEuropeanNumberResolution) == 0)
{
// W2: EN changes to AN if it follows AL.
// We will go onto Arabic number state (S_AN).
characterClass[counter + classIndex] = DirectionClass.ArabicNumber;
}
else
{
// Change the current state such that we will go onto European number state (S_EN)
// instead of Arabic number state (S_AN). As rule W2 is ignored, "EN following AL"
// is the same as "EN following L".
state = StateMachineState.S_L;
}
if (startOfDelayed != PositionInvalid)
{
startOfNeutrals = startOfDelayed;
ResolveNeutrals(characterClass,
classIndex + startOfNeutrals,
counter - startOfNeutrals,
ArabicNumberAfterLeft ? DirectionClass.ArabicNumber : lastStrongClass,
characterClass[counter + classIndex],
runLevel);
startOfNeutrals = startOfDelayed = PositionInvalid;
}
lastClass = characterClass[counter + classIndex];
break;
case StateMachineAction.EN_ET:
Debug.Assert(startOfDelayed != PositionInvalid,
"Must have delayed weak classes. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
if ((lastStrongClass == DirectionClass.ArabicLetter) ||
previousClassIsArabic)
{
if ((flags & Flags.OverrideEuropeanNumberResolution) == 0)
{
// W2: EN changes to AN if it follows AL
characterClass[counter + classIndex] = DirectionClass.ArabicNumber;
currentClass = DirectionClass.ArabicNumber;
}
if (startOfNeutrals == PositionInvalid)
{
ResolveNeutrals(characterClass,
classIndex + startOfDelayed,
counter - startOfDelayed,
ArabicNumberAfterLeft ? DirectionClass.ArabicNumber : lastStrongClass,
characterClass[counter + classIndex],
runLevel);
}
else
{
ResolveNeutrals(characterClass,
classIndex + startOfNeutrals,
counter - startOfNeutrals,
ArabicNumberAfterLeft ? DirectionClass.ArabicNumber : lastStrongClass,
characterClass[counter + classIndex],
runLevel);
}
}
else if (lastStrongClass == DirectionClass.Left)
{
characterClass[counter + classIndex] = DirectionClass.Left;
ChangeType(characterClass,
classIndex + startOfDelayed,
counter - startOfDelayed,
characterClass[counter + classIndex]);
if (startOfNeutrals != PositionInvalid)
{
ResolveNeutrals(characterClass,
classIndex + startOfNeutrals,
startOfDelayed - startOfNeutrals,
ArabicNumberAfterLeft ? DirectionClass.ArabicNumber : lastStrongClass,
characterClass[counter + classIndex],
runLevel);
}
ArabicNumberAfterLeft = false;
}
else
{
ChangeType(characterClass,
classIndex + startOfDelayed,
counter - startOfDelayed,
DirectionClass.EuropeanNumber);
if (startOfNeutrals != PositionInvalid)
{
ResolveNeutrals(characterClass,
classIndex + startOfNeutrals,
startOfDelayed - startOfNeutrals,
ArabicNumberAfterLeft ? DirectionClass.ArabicNumber : lastStrongClass,
currentClass,
runLevel);
}
}
startOfNeutrals = startOfDelayed = PositionInvalid;
lastClass = currentClass;
break;
case StateMachineAction.BN_ST:
if (startOfDelayed == PositionInvalid)
{
startOfDelayed = counter;
}
break;
case StateMachineAction.NSM_ST:
// Here is an NSM (non-space-mark) followed by a Strong.
// We can always resolve the NSM to its final class
if ((lastStrongClass == DirectionClass.ArabicLetter))
{
if (lastClass == DirectionClass.EuropeanNumber)
{
if ((flags & Flags.OverrideEuropeanNumberResolution) == 0)
{
// Applying rule W1 & W2
// W1: NSM changes to the class of previous char
// W2: EN following AL changes to AN
characterClass[counter + classIndex] = DirectionClass.ArabicNumber;
}
else
{
// Just apply rule W1.
characterClass[counter + classIndex] = DirectionClass.EuropeanNumber;
}
}
else if (lastClass != DirectionClass.ArabicNumber)
{
// Rule W3: AL is considered as R.
characterClass[counter + classIndex] = DirectionClass.Right;
}
else
{
// last char is an AN.
characterClass[counter + classIndex] = DirectionClass.ArabicNumber;
}
}
else
{
characterClass[counter + classIndex] = ArabicNumberAfterLeft
|| lastClass == DirectionClass.ArabicNumber ?
DirectionClass.ArabicNumber :
lastClass==DirectionClass.EuropeanNumber &&
lastStrongClass != DirectionClass.Left
? DirectionClass.EuropeanNumber : lastStrongClass;
}
if (startOfDelayed != PositionInvalid)
{
// Resolve delayed characters. This happens when
// there is BN in between of last strong and this NSM
ChangeType(characterClass,
classIndex + startOfDelayed,
counter - startOfDelayed,
characterClass[counter + classIndex]);
startOfDelayed = PositionInvalid;
}
break;
case StateMachineAction.NSM_ET:
characterClass[counter + classIndex] = lastClass;
break;
case StateMachineAction.N_ST:
Debug.Assert(startOfNeutrals == PositionInvalid,
"Cannot have unresolved neutrals. State: " +
state.ToString() + ", Class: " +
currentClass.ToString());
if (startOfDelayed != PositionInvalid)
{
startOfNeutrals = startOfDelayed;
startOfDelayed = PositionInvalid;
}
else
{
startOfNeutrals = counter;
}
lastClass = currentClass;
break;
case StateMachineAction.N_ET:
// Note that this state is used for N_N as well.
if (startOfNeutrals == PositionInvalid)
{
if (startOfDelayed != PositionInvalid)
{
startOfNeutrals = startOfDelayed;
}
}
startOfDelayed = PositionInvalid;
lastClass = currentClass;
break;
};
// Fetch next state.
state = NextState[(int)state, (int)currentClass];
lengthResolved = Math.Max(startOfNeutrals, startOfDelayed) == PositionInvalid ?
counter + 1 :
((Math.Min(startOfNeutrals, startOfDelayed) == PositionInvalid) ?
(Math.Max(startOfNeutrals, startOfDelayed)) :
(Math.Min(startOfNeutrals, startOfDelayed)));
}
// If the caller flagged this run as incomplete
// return the maximun that we could resolve so far and the last strong (fixed)
// class saved
if (stateOut != null)
{
stateOut.LastStrongClass = lastStrongClass;
stateOut.LastNumberClass = lastNumericClass;
return lengthResolved;
}
// Else, resolve remaining neutrals or delayed classes.
// Resolve as neutrals based on eor.
else
{
if (lengthResolved != counter)
ResolveNeutrals(characterClass,
classIndex + lengthResolved,
counter - lengthResolved,
ArabicNumberAfterLeft ? DirectionClass.ArabicNumber : lastStrongClass,
eor,
runLevel);
return counter;
}
}
static private void ResolveImplictLevels(
IList<DirectionClass> characterClass, // [IN / OUT]
CharacterBuffer charBuffer, // [IN]
int ichText, // [IN]
int runLength, // [IN]
IList<byte> levels, // [IN / OUT]
int index,
byte paragraphEmbeddingLevel // [IN] Paragraph base level
)
{
if (runLength == 0)
{
return;
}
int counter = 0;
for (counter = runLength -1; counter >= 0; counter--)
{
Invariant.Assert(CharProperty[3, (int) characterClass[counter+index]]==1,
("Cannot have unresolved classes during implict levels resolution"));
int intChar = charBuffer[ichText + index+counter];
int wordCount = 1;
if (((intChar & 0xFC00) == 0xDC00) && counter > 0)
{
if ((charBuffer[ichText + index+counter-1] & 0xFC00) == 0xD800)
{
intChar = ((((charBuffer[ichText + index+counter-1] & 0x03ff) << 10) | (charBuffer[ichText + index+counter] & 0x3ff)) + 0x10000);
wordCount = 2;
}
}
DirectionClass directionClass;
directionClass = Classification.CharAttributeOf((int) Classification.GetUnicodeClass(intChar)).BiDi;
if (directionClass == DirectionClass.ParagraphSeparator ||
directionClass == DirectionClass.SegmentSeparator)
{
// Rule L1: segment separator and paragraph separator should use paragraph embedding level
levels[counter+index] = paragraphEmbeddingLevel;
}
else
{
levels[counter+index] =
(byte)((ImplictPush[Helper.IsOdd(levels[counter+index]) ? 1 : 0,
(int)characterClass[index+counter]]) + levels[counter+index]);
}
if (wordCount > 1)
{
levels[counter+index-1] = levels[counter+index];
counter--;
}
}
}
/// <Remark>
/// Analyze() is created to serve the testing only. it is protected by security attribute to insure
/// that BidiTest application only can call this method. the public key in the security attribute is
/// generated from the BidiTest assembly by the command "sn -Tp biditest.exe"
/// </Remark>
static public bool Analyze(
char [] chars, // input text to be analyzed
int cchText, // number of input char
int cchTextMaxHint, // hint maximum number of char processed
Flags flags, // control flags
State state, // bidi state in, out or both
out byte[] levels, // resolved level per char
out int cchResolved // number of char resolved
)
{
DirectionClass[] characterClass = new DirectionClass[cchText];
levels = new byte[cchText];
return Bidi.BidiAnalyzeInternal(
new CharArrayCharacterBuffer(chars),
0,
cchText,
cchTextMaxHint,
flags,
state,
levels,
new PartialArray<DirectionClass>(characterClass),
out cchResolved
);
}
static internal bool BidiAnalyzeInternal(
CharacterBuffer charBuffer, // character buffer
int ichText, // offset to first char in the buffer
int cchText, // number of input char
int cchTextMaxHint, // hint maximum number of char processed
Flags flags, // control flags
State state, // bidi state in, out or both
IList<byte> levels, // [IN/OUT] resolved level per char
IList<DirectionClass> characterClass, // [IN/OUT] direction class of each char
out int cchResolved // number of char resolved
)
{
DirectionClass tempClass;
int [] runLimits;
State stateIn = null, stateOut = null; // both can point into state parameter
ulong overrideStatus;
OverrideClass overrideClass;
ushort stackOverflow;
byte baseLevel;
byte lastRunLevel;
byte lastNonBnLevel;
int counter;
int codePoint;
int lengthUnresolved = 0;
int controlStack = 0;
int runCount = 0;
int wordCount;
Invariant.Assert(levels != null && levels.Count >= cchText);
Invariant.Assert(characterClass != null && characterClass.Count >= cchText);
cchResolved = 0;
// Verifying input parameters.
if(charBuffer == null || (cchText <= 0) || (charBuffer.Count < cchText) ||
((((flags & Flags.ContinueAnalysis)!=0) || ((flags & Flags.IncompleteText)!=0)) && (state == null)))
{
return false;
}
// try to be smart to get the maximum we need to process.
if ((flags & Flags.MaximumHint) != 0 && cchTextMaxHint>0 && cchTextMaxHint < cchText)
{
if (cchTextMaxHint>1 && (charBuffer[ichText + cchTextMaxHint-2] & 0xFC00) == 0xD800)
{
// it might be surrogate pair
cchTextMaxHint--;
}
int index = cchTextMaxHint-1;
int intChar = charBuffer[ichText + index];
wordCount = 1;
if ((intChar & 0xFC00) == 0xD800)
{
intChar = DoubleWideChar.GetChar(charBuffer, ichText, cchText, index, out wordCount);
}
tempClass = Classification.CharAttributeOf((int) Classification.GetUnicodeClass(intChar)).BiDi;
index += wordCount;
if (CharProperty[1, (int) tempClass]==1)
{
// if we got more than 20 same strong charcaters class, we give up. we might
// get this case with Thai script.
while (index<cchText && index-cchTextMaxHint<20)
{
intChar = charBuffer[ichText + index];
wordCount = 1;
if ((intChar & 0xFC00) == 0xD800)
{
intChar = DoubleWideChar.GetChar(charBuffer, ichText, cchText, index, out wordCount);
}
if (tempClass != Classification.CharAttributeOf((int) Classification.GetUnicodeClass(intChar)).BiDi)
{
break;
}
else
{
index += wordCount;
}
}
}
else
{
// we got neutral try to get first strong character.
while (index<cchText)
{
intChar = charBuffer[ichText + index];
wordCount = 1;
if ((intChar & 0xFC00) == 0xD800)
{
intChar = DoubleWideChar.GetChar(charBuffer, ichText, cchText, index, out wordCount);
}
if (CharProperty[1,
(int) Classification.CharAttributeOf((int) Classification.GetUnicodeClass(intChar)).BiDi] == 1)
break;
index += wordCount;
}
index++; // include the first strong character to be able to resolve the neutrals
}
cchText = Math.Min(cchText, index);
}
// If the last character in the string is a paragraph terminator,
// we can analyze the whole string, No need to use state parameter
// for output
BidiStack levelsStack = new BidiStack();
if ((flags & Flags.IncompleteText) != 0)
{
codePoint = charBuffer[ichText + cchText -1];
if((cchText > 1) && ((charBuffer[ichText + cchText -2] & 0xFC00 ) == 0xD800) && ((charBuffer[ichText + cchText - 1] & 0xFC00) == 0xDC00))
{
codePoint = 0x10000 + (((charBuffer[ichText + cchText -2] & 0x3ff) << 10) | (charBuffer[ichText + cchText - 1] & 0x3ff));
}
if (DirectionClass.ParagraphSeparator != Classification.CharAttributeOf((int) Classification.GetUnicodeClass(codePoint)).BiDi)
{
stateOut = state;
}
}
if ((flags & Flags.ContinueAnalysis) != 0)
{
// try to see if we have enough information to start the analysis or we need to get more.
codePoint = charBuffer[ichText + 0];
if((cchText > 1) && ((charBuffer[ichText + 0] & 0xFC00 ) == 0xD800) && ((charBuffer[ichText + 1] & 0xFC00) == 0xDC00))
{
codePoint = 0x10000 + (((charBuffer[ichText + 0] & 0x3ff) << 10) | (charBuffer[ichText + 1] & 0x3ff));
}
tempClass = Classification.CharAttributeOf((int) Classification.GetUnicodeClass(codePoint)).BiDi;
// state can be used as in/out parameter
stateIn = state;
// Note: use the state instant to call LastStrongClass or LastStrongOrNumberClass
// which should be overrided by the caller.
switch (tempClass)
{
case DirectionClass.Left:
case DirectionClass.Right:
case DirectionClass.ArabicNumber:
case DirectionClass.ArabicLetter:
stateIn.LastNumberClass = tempClass;
stateIn.LastStrongClass = tempClass;
break;
case DirectionClass.EuropeanNumber:
stateIn.LastNumberClass = tempClass;
break;
}
}
// Done with the state
if (stateIn != null)
{
if (!levelsStack.Init(stateIn.LevelStack))
{
cchResolved = 0;
return false;
}
baseLevel = levelsStack.GetCurrentLevel();
stackOverflow = stateIn.Overflow;
overrideStatus = stateIn.OverrideLevels;
overrideClass = (Helper.IsBitSet(overrideStatus, baseLevel)) ?
(Helper.IsOdd(baseLevel) ?
OverrideClass.OverrideClassRight :
OverrideClass.OverrideClassLeft):
OverrideClass.OverrideClassNeutral;
}
else
{
baseLevel = BaseLevelLeft;
if ((flags & Flags.FirstStrongAsBaseDirection) != 0)
{
// Find strong character in the first paragraph
// This might cause a complete pass over the input string
// but we must get it before we start.
DirectionClass firstStrong = DirectionClass.ClassInvalid;
if (GetFirstStrongCharacter(charBuffer, ichText, cchText, ref firstStrong))
{
if (firstStrong != DirectionClass.Left)
{
baseLevel = BaseLevelRight;
}
}
}
else if ((flags & Flags.DirectionRightToLeft) != 0)
{
baseLevel = BaseLevelRight;
}
levelsStack.Init((ulong) baseLevel + 1);
stackOverflow = 0;
// Initialize to neutral
overrideStatus = 0;
overrideClass = OverrideClass.OverrideClassNeutral;
}
byte paragraphEmbeddingLevel = levelsStack.GetStackBottom();
//
// try to optimize through a fast path.
//
int neutralIndex = -1;
byte bidiLevel, nonBidiLevel;
byte lastPathClass;
byte basePathClass;
byte neutralLevel;
DirectionClass lastStrongClass;
if (Helper.IsOdd(baseLevel))
{
bidiLevel = baseLevel;
nonBidiLevel = (byte) (baseLevel + 1);
lastPathClass = basePathClass = 3;
if (stateIn != null )
lastStrongClass = stateIn.LastStrongClass;
else
lastStrongClass = DirectionClass.Right;
}
else
{
nonBidiLevel = baseLevel;
bidiLevel = (byte) (baseLevel + 1);
lastPathClass = basePathClass = 2;
if (stateIn != null )
lastStrongClass = stateIn.LastStrongClass;
else
lastStrongClass = DirectionClass.Left;
}
if (stateIn != null )
{
if ((FastPathClass[(int) lastStrongClass] & 0x02) == 0x02) // Strong Left or Right
{
lastPathClass = FastPathClass[(int) lastStrongClass];
}
}
//
// Hidden text do not affect the relative order of surrounding text. We do that by
// assigning them to the class type of either the preceding or following non-hidden text
// so that they won't cause additional transitions of Bidi levels.
//
DirectionClass hiddenCharClass = DirectionClass.GenericNeutral;
counter = 0;
wordCount = 1;
// In case the input starts with hidden characters, we will assign them to the class of the following
// non-hidden cp. The for-loop scans forward till the 1st non-hidden cp and remembers its bidi class
// to be used in case there are hidden cp at the beginning of the input.
for (int i = counter; i < cchText; i += wordCount)
{
int intChar = charBuffer[ichText + i];
if ((intChar & 0xFC00) == 0xD800)
{
intChar = DoubleWideChar.GetChar(charBuffer, ichText, cchText, counter, out wordCount);
}
if (intChar != CharHidden)
{
hiddenCharClass = Classification.CharAttributeOf((int)Classification.GetUnicodeClass(intChar)).BiDi;
if ( hiddenCharClass == DirectionClass.EuropeanNumber
&& (flags & Flags.OverrideEuropeanNumberResolution) != 0)
{
hiddenCharClass = characterClass[i]; // In case EN resolution is overridden.
}
break;
}
}
while (counter < cchText)
{
// Account for surrogate characters
wordCount = 1;
codePoint = DoubleWideChar.GetChar(charBuffer, ichText, cchText, counter, out wordCount);
tempClass = Classification.CharAttributeOf((int) Classification.GetUnicodeClass(codePoint)).BiDi;
if (codePoint == CharHidden)
{
tempClass = hiddenCharClass;
}
if (FastPathClass[(int) tempClass] == 0)
break;
// The directional class can be processed in fast path. It will not be EN or AN and hence not
// overridable.
characterClass[counter] = tempClass;
hiddenCharClass = tempClass;
if (FastPathClass[(int) tempClass] == 1) // Neutral
{
if (tempClass != DirectionClass.EuropeanSeparator && tempClass != DirectionClass.CommonSeparator)
characterClass[counter] = DirectionClass.GenericNeutral;
if (neutralIndex == -1)
neutralIndex = counter;
}
else // strong class (2, 3, or 4)
{
if (neutralIndex != -1) // resolve the neutral
{
if (lastPathClass != FastPathClass[(int) tempClass])
{
neutralLevel = baseLevel;
}
else
{
neutralLevel = lastPathClass == 2 ? nonBidiLevel : bidiLevel;
}
while (neutralIndex < counter)
{
levels[neutralIndex] = neutralLevel;
neutralIndex++;
}
neutralIndex = -1;
}
lastPathClass = FastPathClass[(int) tempClass];
levels[counter] = lastPathClass == 2 ? nonBidiLevel : bidiLevel;
if (wordCount == 2)
{
// Higher and Lower surrogate should have the same bidi level.
levels[counter + 1] = levels[counter];
}
lastStrongClass = tempClass;
}
counter = counter + wordCount;
}
if (counter < cchText) // couldn't optimize.
{
// reset the levels
for (int j=0; j<counter; j++)
levels[j] = baseLevel;
}
else
{
cchResolved = cchText;
if (state != null)
{
state.LastStrongClass = lastStrongClass;
}
if (neutralIndex != -1) // resolve the neutral
{
if ((flags & Flags.IncompleteText) == 0)
{
if (lastPathClass != basePathClass)
{
neutralLevel = baseLevel;
}
else
{
neutralLevel = lastPathClass == 2 ? nonBidiLevel : bidiLevel;
}
while (neutralIndex < cchText)
{
levels[neutralIndex] = neutralLevel;
neutralIndex++;
}
}
else
{
cchResolved = neutralIndex;
}
}
return true;
}
//
// end fast path
//
// Get character classifications.
// Resolve explicit embedding levels.
// Record run limits (either due to a level change or due to new paragraph)
lastNonBnLevel = baseLevel;
// for the worst case of all paragraph terminators string.
runLimits = new int[cchText];
// counter is already initialized in the fast path
while (counter < cchText)
{
int intChar = charBuffer[ichText + counter];
wordCount = 1;
if ((intChar & 0xFC00) == 0xD800)
{
intChar = DoubleWideChar.GetChar(charBuffer, ichText, cchText, counter, out wordCount);
}
DirectionClass currentClass;
currentClass = Classification.CharAttributeOf((int) Classification.GetUnicodeClass(intChar)).BiDi;
levels[counter] = levelsStack.GetCurrentLevel();
if (intChar == CharHidden)
{
currentClass = hiddenCharClass;
}
switch(currentClass)
{
case DirectionClass.ParagraphSeparator:
// mark output level array with a special mark
// to seperate between paragraphs
levels[counter] = ParagraphTerminatorLevel;
runLimits[runCount] = counter;
if (counter != cchText-1)
{
runCount++;
}
levelsStack.Init((ulong) baseLevel + 1);
overrideStatus = 0;
overrideClass = OverrideClass.OverrideClassNeutral;
stackOverflow = 0;
controlStack = 0;
goto case DirectionClass.OtherNeutral;
// Fall through
// We keep our Unicode classification table stictly following Unicode
// regarding neutral types (B, S, WS, ON), change all to generic N.
case DirectionClass.SegmentSeparator:
case DirectionClass.WhiteSpace:
case DirectionClass.OtherNeutral:
characterClass[counter] = DirectionClass.GenericNeutral;
if (counter>0 && characterClass[counter-1] == DirectionClass.BoundaryNeutral)
{
if (levels[counter-1] < levels[counter] && levels[counter] != ParagraphTerminatorLevel)
{
levels[counter-1] = levels[counter];
}
}
controlStack = 0;
break;
case DirectionClass.LeftToRightEmbedding:
case DirectionClass.RightToLeftEmbedding:
characterClass[counter] = DirectionClass.BoundaryNeutral;
if ((flags & Flags.IgnoreDirectionalControls) != 0)
break; // Ignore directional controls. They won't affect bidi state
// If we overflowed the stack, keep track of this in order to know when you hit
// a PDF if you should pop or not.
if(!levelsStack.Push(currentClass == DirectionClass.LeftToRightEmbedding ? true : false))
{
stackOverflow++;
}
else
{
runLimits[runCount] = counter;
if (counter != cchText-1)
{
runCount++;
}
controlStack++;
}
overrideClass = OverrideClass.OverrideClassNeutral;
levels[counter] = lastNonBnLevel;
break;
case DirectionClass.LeftToRightOverride:
case DirectionClass.RightToLeftOverride:
characterClass[counter] = DirectionClass.BoundaryNeutral;
if ((flags & Flags.IgnoreDirectionalControls) != 0)
break; // Ignore directional controls. They won't affect bidi state
if(!levelsStack.Push(currentClass == DirectionClass.LeftToRightOverride ? true : false))
{
stackOverflow++;
}
else
{
// Set the matching bit of 'overrideStatus' to one
// in order to know when you pop if you're in override state or not.
Helper.ResetBit(ref overrideStatus, levelsStack.GetCurrentLevel());
overrideClass = (currentClass == DirectionClass.LeftToRightOverride) ?
OverrideClass.OverrideClassLeft : OverrideClass.OverrideClassRight;
runLimits[runCount] = counter;
if (counter != cchText-1)
{
runCount++;
}
controlStack++;
}
levels[counter] = lastNonBnLevel;
break;
case DirectionClass.PopDirectionalFormat:
characterClass[counter] = DirectionClass.BoundaryNeutral;
if ((flags & Flags.IgnoreDirectionalControls) != 0)
break; // Ignore directional controls. They won't affect bidi state
if (stackOverflow != 0)
{
stackOverflow--;
}
else
{
if (levelsStack.Pop())
{
int newLevel = levelsStack.GetCurrentLevel();
// Override state being left or right is determined
// from the new level being even or odd.
overrideClass = (Helper.IsBitSet(overrideStatus, newLevel)) ? (Helper.IsOdd(newLevel) ?
OverrideClass.OverrideClassRight : OverrideClass.OverrideClassLeft):
OverrideClass.OverrideClassNeutral;
if (controlStack > 0)
{
runCount--;
controlStack--;
}
else
{
runLimits[runCount] = counter;
if (counter != cchText-1)
{
runCount++;
}
}
}
}
levels[counter] = lastNonBnLevel;
break;
default:
controlStack = 0;
if ( currentClass == DirectionClass.EuropeanNumber
&& (flags & Flags.OverrideEuropeanNumberResolution) != 0)
{
// Use the input DirectionClass explictly for EN. We don't
// need to copy the the Unicode classification data into it.
// However, assert that the input DirectionClass must be either be AN or EN
Invariant.Assert(characterClass[counter] == DirectionClass.ArabicNumber || characterClass[counter] == DirectionClass.EuropeanNumber);
}
else
{
// Non EuropeanNumber is not affected by the input DirectionClass.
characterClass[counter] = currentClass;
}
if(overrideClass != OverrideClass.OverrideClassNeutral)
{
characterClass[counter] = (overrideClass == OverrideClass.OverrideClassLeft) ?
DirectionClass.Left : DirectionClass.Right;
}
if (counter>0 && characterClass[counter-1]==DirectionClass.BoundaryNeutral)
{
if (levels[counter-1] < levels[counter])
{
levels[counter-1] = levels[counter];
}
}
break;
}
lastNonBnLevel = levels[counter];
if (wordCount > 1)
{
levels[counter+1] = levels[counter];
characterClass[counter+1] = characterClass[counter];
}
hiddenCharClass = characterClass[counter];
counter += wordCount;
}
runCount++;
if (stateOut != null)
{
stateOut.LevelStack = levelsStack.GetData();
stateOut.OverrideLevels = overrideStatus;
stateOut.Overflow = stackOverflow;
}
// Resolve neutral and weak types.
// Resolve implict levels.
// The lastRunLevel will hold the level of last processed run to be used
// to determine the sor of the next run. we can't depend on the level array
// because it can be changed in case of numerics. so level of the numerics
// will be increased by one or two.
lastRunLevel = baseLevel;
bool currenLimitIsParagraphTerminator;
bool previousLimitIsParagraphTerminator = false;
for(counter = 0; counter < runCount; counter++)
{
DirectionClass sor;
DirectionClass eor;
currenLimitIsParagraphTerminator = (levels[runLimits[counter]] == ParagraphTerminatorLevel);
if (currenLimitIsParagraphTerminator)
levels[runLimits[counter]] = baseLevel;
int runStart = (counter == 0) ? 0 : runLimits[counter - 1] + 1;
// If the level transition was due to a new paragraph
// we don't want pass the paragraph terminator position.
int offset = (counter != (runCount - 1)) ? (currenLimitIsParagraphTerminator ? 1 : 0) : 0;
int runLength = (counter == (runCount - 1)) ?
(int) ((cchText - runStart) - offset):
(int) (runLimits[counter] - runStart) + 1 - offset;
// See if we need to provide state information from a previous call
// or need to save it for a possible next call
bool incompleteRun = ((runCount - 1) == counter) && ((flags & Flags.IncompleteText) != 0)
&& (stateOut != null);
bool continuingAnalysis = (counter == 0) && (stateIn != null);
int runLengthResolved;
// First run or a run after paragraph terminator.
if ((counter == 0) || previousLimitIsParagraphTerminator)
{
sor = Helper.IsOdd(Math.Max(baseLevel, levels[runStart])) ?
DirectionClass.Right : DirectionClass.Left;
}
else
{
sor = Helper.IsOdd(Math.Max(lastRunLevel, levels[runStart])) ?
DirectionClass.Right : DirectionClass.Left;
}
lastRunLevel = levels[runStart];
// Last run or a run just before paragraph terminator.
if( ((runCount - 1) == counter) || currenLimitIsParagraphTerminator)
{
eor = Helper.IsOdd(Math.Max(levels[runStart], baseLevel)) ?
DirectionClass.Right : DirectionClass.Left;
}
else
{
// we will try to get first run which doesn't have just one
// control char like LRE,RLE,... and so on
int runNumber = counter+1;
while ( runNumber<runCount - 1 &&
runLimits[runNumber]-runLimits[runNumber-1]==1 &&
characterClass[runLimits[runNumber]] == DirectionClass.BoundaryNeutral)
{
runNumber++;
}
eor = Helper.IsOdd(Math.Max(levels[runStart], levels[runLimits[runNumber-1] + 1])) ?
DirectionClass.Right : DirectionClass.Left;
}
// If it is a continuation from a previous call, set sor
// to the last stron type saved in the input state parameter.
runLengthResolved = ResolveNeutralAndWeak(characterClass,
runStart,
runLength,
sor,
eor,
levels[runStart],
continuingAnalysis ? stateIn: null,
incompleteRun ? stateOut: null,
((counter == 0) && (stateIn == null)) ?
((flags & Flags.PreviousStrongIsArabic)!=0):
false,
flags);
if (!incompleteRun)
{
// If we in a complete run, we should be able to resolve everything
// unless we passed a corrupted data
Debug.Assert(runLengthResolved == runLength,
"Failed to resolve neutrals and weaks. Run#:" +
counter.ToString(CultureInfo.InvariantCulture));
}
else
{
lengthUnresolved = (runLength - runLengthResolved);
}
// Resolve implict levels.
// Also, takes care of Rule L1 (segment separators, paragraph separator,
// white spaces at the end of the line.
ResolveImplictLevels(characterClass,
charBuffer,
ichText,
runLength - lengthUnresolved,
levels,
runStart,
paragraphEmbeddingLevel);
previousLimitIsParagraphTerminator = currenLimitIsParagraphTerminator;
}
cchResolved = cchText - lengthUnresolved;
// if the charBuffer ended with paragraph seperator then we need to reset the Bidi state
if (((flags & Flags.IncompleteText) != 0) && (stateOut == null))
{
state.OverrideLevels = 0;
state.Overflow = 0;
if ((paragraphEmbeddingLevel & 1) != 0)
{
state.LastStrongClass = DirectionClass.Right;
state.LastNumberClass = DirectionClass.Right;
state.LevelStack = Bidi.StackRtl;
}
else
{
state.LastStrongClass = DirectionClass.Left;
state.LastNumberClass = DirectionClass.Left;
state.LevelStack = Bidi.StackLtr;
}
}
return true;
}
}
/// <summary>
/// DoubleWideChar convert word char into int char (handle Surrogate).
/// </summary>
internal static class DoubleWideChar
{
static internal int GetChar(
CharacterBuffer charBuffer,
int ichText,
int cchText,
int charNumber,
out int wordCount)
{
if (charNumber < cchText-1 &&
((charBuffer[ichText + charNumber] & 0xFC00) == 0xD800) &&
((charBuffer[ichText + charNumber+1] & 0xFC00) == 0xDC00))
{
wordCount = 2;
return ((((charBuffer[ichText + charNumber] & 0x03ff) << 10) | (charBuffer[ichText + charNumber+1] & 0x3ff)) + 0x10000);
}
wordCount = 1;
return ((int) charBuffer[ichText + charNumber]);
}
}
}
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