graphicsdeviceinterface/gdi/tgdi/TBiDi.h
changeset 0 5d03bc08d59c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graphicsdeviceinterface/gdi/tgdi/TBiDi.h	Tue Feb 02 01:47:50 2010 +0200
@@ -0,0 +1,280 @@
+// Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies).
+// All rights reserved.
+// This component and the accompanying materials are made available
+// under the terms of "Eclipse Public License v1.0"
+// which accompanies this distribution, and is available
+// at the URL "http://www.eclipse.org/legal/epl-v10.html".
+//
+// Initial Contributors:
+// Nokia Corporation - initial contribution.
+//
+// Contributors:
+//
+// Description:
+//
+
+#ifndef __TBIDI_H__
+#define __TBIDI_H__
+
+#include "TGraphicsHarness.h"
+
+
+inline TBool IsSupplementary(TUint aChar)
+/**
+@param aChar The 32-bit code point value of a Unicode character.
+
+@return True, if aChar is supplementary character; false, otherwise.
+*/
+	{
+	return (aChar > 0xFFFF);
+	}
+
+inline TBool IsHighSurrogate(TText16 aInt16)
+/**
+@return True, if aText16 is high surrogate; false, otherwise.
+*/
+	{
+	return (aInt16 & 0xFC00) == 0xD800;
+	}
+
+inline TBool IsLowSurrogate(TText16 aInt16)
+/**
+@return True, if aText16 is low surrogate; false, otherwise.
+*/
+	{
+	return (aInt16 & 0xFC00) == 0xDC00;
+	}
+
+inline TUint JoinSurrogate(TText16 aHighSurrogate, TText16 aLowSurrogate)
+/**
+Combine a high surrogate and a low surrogate into a supplementary character.
+
+@return The 32-bit code point value of the generated Unicode supplementary
+        character.
+*/
+	{
+	return ((aHighSurrogate - 0xD7F7) << 10) + aLowSurrogate;
+	}
+
+inline TText16 GetHighSurrogate(TUint aChar)
+/**
+Retrieve the high surrogate of a supplementary character.
+
+@param aChar The 32-bit code point value of a Unicode character.
+
+@return High surrogate of aChar, if aChar is a supplementary character; 
+        aChar itself, if aChar is not a supplementary character.
+*/
+	{
+	return STATIC_CAST(TText16, 0xD7C0 + (aChar >> 10));
+	}
+
+inline TText16 GetLowSurrogate(TUint aChar)
+/**
+Retrieve the low surrogate of a supplementary character.
+
+@param aChar The 32-bit code point value of a Unicode character.
+
+@return Low surrogate of aChar, if aChar is a supplementary character; 
+        zero, if aChar is not a supplementary character.
+*/
+	{
+	return STATIC_CAST(TText16, 0xDC00 | (aChar & 0x3FF));
+	}
+
+void AppendCharacter(HBufC *aDes, TUint aChar);
+void AppendCharacter(TBuf<24> *aDes, TUint aChar);
+
+
+// Class to implement a wrapping iterator meant for extracting 16 bit characters
+// from a block of text
+// This class can handle surrogate pairs correctly.
+class TextIterator
+	{
+public:
+	TextIterator(const TText16* aData, const TInt aLength) : 
+	  iData(aData), iLength(aLength), iIndex(0), iWrapped(EFalse), iCombineSurrogatePairs(ETrue)
+		{
+		}	
+	TextIterator(const TText16* aData, const TInt aLength, const TInt aIndex) : 
+		iData(aData), iLength(aLength), iIndex(aIndex), iWrapped(EFalse), iCombineSurrogatePairs(ETrue)
+		{
+		}
+	TextIterator(const TText16* aData, const TInt aLength, const TInt aIndex, TBool aCombineSurrogatePairs) : 
+		iData(aData), iLength(aLength), iIndex(aIndex), iWrapped(EFalse), iCombineSurrogatePairs(aCombineSurrogatePairs)
+		{
+		}
+	// Next character from data - wrap pointer to keep within data.
+	// Get current char, then move the internal pointer forward to next char.
+	TUint NextChar()
+		{
+		TUint ch = Char();
+		if (iCombineSurrogatePairs && IsSupplementary(ch))
+			iIndex += 2;
+		else
+			iIndex += 1;
+		// wrap
+		if (iIndex >= iLength)
+			{
+			iIndex = 0;
+			iWrapped = ETrue;
+			}
+		return ch;
+		}
+	// Move the internal pointer backward, then return the char pointed by internal char.
+	// Panic if iIndex already = 0.
+	TUint PreviousChar()
+		{
+		ASSERT(iIndex > 0);
+		iIndex--;
+		if (iCombineSurrogatePairs && IsLowSurrogate(iData[iIndex]))
+			{
+			ASSERT(iIndex > 0);
+			iIndex--;
+			ASSERT(IsHighSurrogate(iData[iIndex]));
+			}
+		else if (iCombineSurrogatePairs && IsHighSurrogate(iData[iIndex]))
+			{
+			ASSERT(EFalse);
+			}
+		else
+			{
+			// do nothing
+			}
+		return Char();
+		}
+	//Reset the iterator to the original values
+	void Reset()
+		{
+		iIndex = 0;
+		iWrapped = EFalse;
+		}
+	void SetIndex(const TInt aIndex)
+		{
+		iIndex = aIndex;
+		iWrapped = EFalse;
+		}
+	//Has the iterator wrapped back to the start of the buffer at least once?
+	TBool Wrapped() const
+		{
+		return iWrapped;
+		}
+	//Where is the current buffer index?
+	TInt Index() const
+		{
+		return iIndex;
+		}
+	//Return pointer to data
+	const TText16* Ptr() const
+		{
+		return iData;
+		}
+	//Get length of data
+	TInt Length() const
+		{
+		return iLength;
+		}
+	//Get character at current index
+	TUint Char() const
+		{
+		TUint ch = 0xFFFF;
+		TText16 i16 = iData[iIndex];
+		if (iCombineSurrogatePairs && IsHighSurrogate(i16))
+			{
+			ASSERT(iIndex+1 < iLength);
+			TText16 low = iData[iIndex+1];
+			ch = JoinSurrogate(i16, low);
+			}
+		else if (iCombineSurrogatePairs && IsLowSurrogate(i16))
+			{
+			ASSERT(EFalse);
+			}
+		else
+			{
+			ch = i16;
+			}
+		return ch;
+		}
+	// Fill aBuffer with a char, fill at aIndex, guarded by aMaxIndex (excluded).
+	// After return, aIndex points to the next position, if aUpdate_aIndex=ETrue.
+	// aUpdate_aIndex: do you want to update the parameter aIndex?
+	// aUpdate_iIndex: do you want to update the member variable iIndex?
+	// aChar: [out] current char
+	TBool NextCharInto(TDes &aBuffer, TInt &aIndex, TInt aMaxIndex=-1, TBool aUpdate_aIndex=ETrue, TBool aUpdate_iIndex=ETrue, TUint *aChar=NULL)
+		{
+		if (aMaxIndex < 0)
+			aMaxIndex = aBuffer.Length();
+		if (aIndex >= aMaxIndex)
+			return EFalse;
+
+		TUint ch = Char();
+		if (iCombineSurrogatePairs && IsSupplementary(ch))
+			{
+			if (aIndex+1 >= aMaxIndex)
+				return EFalse;
+			aBuffer[aIndex] = GetHighSurrogate(ch);
+			aBuffer[aIndex+1] = GetLowSurrogate(ch);
+			if (aUpdate_aIndex)
+				aIndex += 2;
+			}
+		else
+			{
+			aBuffer[aIndex] = (TText16)ch;
+			if (aUpdate_aIndex)
+				aIndex++;
+			}
+		if (aChar)
+			*aChar = ch;
+		if (aUpdate_iIndex)
+			{
+			if (iCombineSurrogatePairs && IsSupplementary(ch))
+				iIndex += 2;
+			else
+				iIndex += 1;
+			if (iIndex >= iLength)
+				{
+				iIndex = 0;
+				iWrapped = ETrue;
+				}
+			}
+		return ETrue;
+		}
+	// Fill aBuffer from aIndex to aMaxIndex (excluded).
+	// aMaxIndex=-1 means fill to index=aBuffer.Length.
+	// After return, aIndex points to the next position, if aUpdate_aIndex=ETrue.
+	TBool FillInto(TDes &aBuffer, TInt &aIndex, TInt aMaxIndex=-1)
+		{
+		if (aMaxIndex == -1)
+			aMaxIndex = aBuffer.Length();
+		while (aIndex < aMaxIndex)
+			{
+			TBool b = NextCharInto(aBuffer, aIndex, aMaxIndex);
+			if (!b)
+				{
+				return ETrue;
+				}
+			}
+		return ETrue;
+		}
+
+private:
+	const TText16* iData;
+	TInt  iLength;
+	TInt  iIndex;
+	TBool iWrapped;
+	TBool iCombineSurrogatePairs;	// ETrue = combine surrogates; EFalse = take single surrogate as character
+	};
+
+class CTBiDiStep : public CTGraphicsStep
+	{
+public:
+	CTBiDiStep();
+protected:	
+	//from CTGraphicsStep
+	virtual CTGraphicsBase* CreateTestL();
+	};
+
+_LIT(KTBiDiStep,"TBiDi");
+
+
+#endif