1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/textandloc/fontservices/textbase/tgdi/TBiDi.h Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,280 @@
1.4 +// Copyright (c) 2003-2010 Nokia Corporation and/or its subsidiary(-ies).
1.5 +// All rights reserved.
1.6 +// This component and the accompanying materials are made available
1.7 +// under the terms of "Eclipse Public License v1.0"
1.8 +// which accompanies this distribution, and is available
1.9 +// at the URL "http://www.eclipse.org/legal/epl-v10.html".
1.10 +//
1.11 +// Initial Contributors:
1.12 +// Nokia Corporation - initial contribution.
1.13 +//
1.14 +// Contributors:
1.15 +//
1.16 +// Description:
1.17 +//
1.18 +
1.19 +#ifndef __TBIDI_H__
1.20 +#define __TBIDI_H__
1.21 +
1.22 +#include "TGraphicsHarness.h"
1.23 +
1.24 +
1.25 +inline TBool IsSupplementary(TUint aChar)
1.26 +/**
1.27 +@param aChar The 32-bit code point value of a Unicode character.
1.28 +
1.29 +@return True, if aChar is supplementary character; false, otherwise.
1.30 +*/
1.31 + {
1.32 + return (aChar > 0xFFFF);
1.33 + }
1.34 +
1.35 +inline TBool IsHighSurrogate(TText16 aInt16)
1.36 +/**
1.37 +@return True, if aText16 is high surrogate; false, otherwise.
1.38 +*/
1.39 + {
1.40 + return (aInt16 & 0xFC00) == 0xD800;
1.41 + }
1.42 +
1.43 +inline TBool IsLowSurrogate(TText16 aInt16)
1.44 +/**
1.45 +@return True, if aText16 is low surrogate; false, otherwise.
1.46 +*/
1.47 + {
1.48 + return (aInt16 & 0xFC00) == 0xDC00;
1.49 + }
1.50 +
1.51 +inline TUint JoinSurrogate(TText16 aHighSurrogate, TText16 aLowSurrogate)
1.52 +/**
1.53 +Combine a high surrogate and a low surrogate into a supplementary character.
1.54 +
1.55 +@return The 32-bit code point value of the generated Unicode supplementary
1.56 + character.
1.57 +*/
1.58 + {
1.59 + return ((aHighSurrogate - 0xD7F7) << 10) + aLowSurrogate;
1.60 + }
1.61 +
1.62 +inline TText16 GetHighSurrogate(TUint aChar)
1.63 +/**
1.64 +Retrieve the high surrogate of a supplementary character.
1.65 +
1.66 +@param aChar The 32-bit code point value of a Unicode character.
1.67 +
1.68 +@return High surrogate of aChar, if aChar is a supplementary character;
1.69 + aChar itself, if aChar is not a supplementary character.
1.70 +*/
1.71 + {
1.72 + return STATIC_CAST(TText16, 0xD7C0 + (aChar >> 10));
1.73 + }
1.74 +
1.75 +inline TText16 GetLowSurrogate(TUint aChar)
1.76 +/**
1.77 +Retrieve the low surrogate of a supplementary character.
1.78 +
1.79 +@param aChar The 32-bit code point value of a Unicode character.
1.80 +
1.81 +@return Low surrogate of aChar, if aChar is a supplementary character;
1.82 + zero, if aChar is not a supplementary character.
1.83 +*/
1.84 + {
1.85 + return STATIC_CAST(TText16, 0xDC00 | (aChar & 0x3FF));
1.86 + }
1.87 +
1.88 +void AppendCharacter(HBufC *aDes, TUint aChar);
1.89 +void AppendCharacter(TBuf<24> *aDes, TUint aChar);
1.90 +
1.91 +
1.92 +// Class to implement a wrapping iterator meant for extracting 16 bit characters
1.93 +// from a block of text
1.94 +// This class can handle surrogate pairs correctly.
1.95 +class TextIterator
1.96 + {
1.97 +public:
1.98 + TextIterator(const TText16* aData, const TInt aLength) :
1.99 + iData(aData), iLength(aLength), iIndex(0), iWrapped(EFalse), iCombineSurrogatePairs(ETrue)
1.100 + {
1.101 + }
1.102 + TextIterator(const TText16* aData, const TInt aLength, const TInt aIndex) :
1.103 + iData(aData), iLength(aLength), iIndex(aIndex), iWrapped(EFalse), iCombineSurrogatePairs(ETrue)
1.104 + {
1.105 + }
1.106 + TextIterator(const TText16* aData, const TInt aLength, const TInt aIndex, TBool aCombineSurrogatePairs) :
1.107 + iData(aData), iLength(aLength), iIndex(aIndex), iWrapped(EFalse), iCombineSurrogatePairs(aCombineSurrogatePairs)
1.108 + {
1.109 + }
1.110 + // Next character from data - wrap pointer to keep within data.
1.111 + // Get current char, then move the internal pointer forward to next char.
1.112 + TUint NextChar()
1.113 + {
1.114 + TUint ch = Char();
1.115 + if (iCombineSurrogatePairs && IsSupplementary(ch))
1.116 + iIndex += 2;
1.117 + else
1.118 + iIndex += 1;
1.119 + // wrap
1.120 + if (iIndex >= iLength)
1.121 + {
1.122 + iIndex = 0;
1.123 + iWrapped = ETrue;
1.124 + }
1.125 + return ch;
1.126 + }
1.127 + // Move the internal pointer backward, then return the char pointed by internal char.
1.128 + // Panic if iIndex already = 0.
1.129 + TUint PreviousChar()
1.130 + {
1.131 + ASSERT(iIndex > 0);
1.132 + iIndex--;
1.133 + if (iCombineSurrogatePairs && IsLowSurrogate(iData[iIndex]))
1.134 + {
1.135 + ASSERT(iIndex > 0);
1.136 + iIndex--;
1.137 + ASSERT(IsHighSurrogate(iData[iIndex]));
1.138 + }
1.139 + else if (iCombineSurrogatePairs && IsHighSurrogate(iData[iIndex]))
1.140 + {
1.141 + ASSERT(EFalse);
1.142 + }
1.143 + else
1.144 + {
1.145 + // do nothing
1.146 + }
1.147 + return Char();
1.148 + }
1.149 + //Reset the iterator to the original values
1.150 + void Reset()
1.151 + {
1.152 + iIndex = 0;
1.153 + iWrapped = EFalse;
1.154 + }
1.155 + void SetIndex(const TInt aIndex)
1.156 + {
1.157 + iIndex = aIndex;
1.158 + iWrapped = EFalse;
1.159 + }
1.160 + //Has the iterator wrapped back to the start of the buffer at least once?
1.161 + TBool Wrapped() const
1.162 + {
1.163 + return iWrapped;
1.164 + }
1.165 + //Where is the current buffer index?
1.166 + TInt Index() const
1.167 + {
1.168 + return iIndex;
1.169 + }
1.170 + //Return pointer to data
1.171 + const TText16* Ptr() const
1.172 + {
1.173 + return iData;
1.174 + }
1.175 + //Get length of data
1.176 + TInt Length() const
1.177 + {
1.178 + return iLength;
1.179 + }
1.180 + //Get character at current index
1.181 + TUint Char() const
1.182 + {
1.183 + TUint ch = 0xFFFF;
1.184 + TText16 i16 = iData[iIndex];
1.185 + if (iCombineSurrogatePairs && IsHighSurrogate(i16))
1.186 + {
1.187 + ASSERT(iIndex+1 < iLength);
1.188 + TText16 low = iData[iIndex+1];
1.189 + ch = JoinSurrogate(i16, low);
1.190 + }
1.191 + else if (iCombineSurrogatePairs && IsLowSurrogate(i16))
1.192 + {
1.193 + ASSERT(EFalse);
1.194 + }
1.195 + else
1.196 + {
1.197 + ch = i16;
1.198 + }
1.199 + return ch;
1.200 + }
1.201 + // Fill aBuffer with a char, fill at aIndex, guarded by aMaxIndex (excluded).
1.202 + // After return, aIndex points to the next position, if aUpdate_aIndex=ETrue.
1.203 + // aUpdate_aIndex: do you want to update the parameter aIndex?
1.204 + // aUpdate_iIndex: do you want to update the member variable iIndex?
1.205 + // aChar: [out] current char
1.206 + TBool NextCharInto(TDes &aBuffer, TInt &aIndex, TInt aMaxIndex=-1, TBool aUpdate_aIndex=ETrue, TBool aUpdate_iIndex=ETrue, TUint *aChar=NULL)
1.207 + {
1.208 + if (aMaxIndex < 0)
1.209 + aMaxIndex = aBuffer.Length();
1.210 + if (aIndex >= aMaxIndex)
1.211 + return EFalse;
1.212 +
1.213 + TUint ch = Char();
1.214 + if (iCombineSurrogatePairs && IsSupplementary(ch))
1.215 + {
1.216 + if (aIndex+1 >= aMaxIndex)
1.217 + return EFalse;
1.218 + aBuffer[aIndex] = GetHighSurrogate(ch);
1.219 + aBuffer[aIndex+1] = GetLowSurrogate(ch);
1.220 + if (aUpdate_aIndex)
1.221 + aIndex += 2;
1.222 + }
1.223 + else
1.224 + {
1.225 + aBuffer[aIndex] = (TText16)ch;
1.226 + if (aUpdate_aIndex)
1.227 + aIndex++;
1.228 + }
1.229 + if (aChar)
1.230 + *aChar = ch;
1.231 + if (aUpdate_iIndex)
1.232 + {
1.233 + if (iCombineSurrogatePairs && IsSupplementary(ch))
1.234 + iIndex += 2;
1.235 + else
1.236 + iIndex += 1;
1.237 + if (iIndex >= iLength)
1.238 + {
1.239 + iIndex = 0;
1.240 + iWrapped = ETrue;
1.241 + }
1.242 + }
1.243 + return ETrue;
1.244 + }
1.245 + // Fill aBuffer from aIndex to aMaxIndex (excluded).
1.246 + // aMaxIndex=-1 means fill to index=aBuffer.Length.
1.247 + // After return, aIndex points to the next position, if aUpdate_aIndex=ETrue.
1.248 + TBool FillInto(TDes &aBuffer, TInt &aIndex, TInt aMaxIndex=-1)
1.249 + {
1.250 + if (aMaxIndex == -1)
1.251 + aMaxIndex = aBuffer.Length();
1.252 + while (aIndex < aMaxIndex)
1.253 + {
1.254 + TBool b = NextCharInto(aBuffer, aIndex, aMaxIndex);
1.255 + if (!b)
1.256 + {
1.257 + return ETrue;
1.258 + }
1.259 + }
1.260 + return ETrue;
1.261 + }
1.262 +
1.263 +private:
1.264 + const TText16* iData;
1.265 + TInt iLength;
1.266 + TInt iIndex;
1.267 + TBool iWrapped;
1.268 + TBool iCombineSurrogatePairs; // ETrue = combine surrogates; EFalse = take single surrogate as character
1.269 + };
1.270 +
1.271 +class CTBiDiStep : public CTGraphicsStep
1.272 + {
1.273 +public:
1.274 + CTBiDiStep();
1.275 +protected:
1.276 + //from CTGraphicsStep
1.277 + virtual CTGraphicsBase* CreateTestL();
1.278 + };
1.279 +
1.280 +_LIT(KTBiDiStep,"TBiDi");
1.281 +
1.282 +
1.283 +#endif