/*

* Copyright (c) 2002 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:           

*

*/

// CAknFepInlineTextDecorator class

//

#include <aknenv.h>

#include "AknFepInlineTextDecorator.h"

#include "AknFepManager.h"

#ifdef _DEBUG

#include "AknFepPanic.h"

#endif

void CAknFepInlineTextDecorator::DecorateInlineText(

	const TDesC& aInlineText,

	TDes& aDecoratedText,

	TInt& aPositionOfInsertionPointInInlineText,

	TChar aPreviousCharacter,

	TBool aRTLParagraph,

    TBool aInputDirectionIsRTL)

	{

	DecorateNeutralCharacters(aInlineText, aDecoratedText, aPositionOfInsertionPointInInlineText, 

                              aPreviousCharacter, aRTLParagraph, aInputDirectionIsRTL);

	}

/**

* This routine performs a consolidation of directional markers in the region around text being committed.

* It returns EFalse if no change has been made to the buffer.

*/

TBool CAknFepInlineTextDecorator::ResolveDecoratedText(

	TDes& aDecoratedTextPlusSurroundings,

	TCursorSelection aDecoratedTextSpan)

	{

	TBool needsResolving(EFalse); // Return value

    // Note that this is a copy of a part of the buffer and that aNewTextSpan is relative to this

    // new buffer, not the whole text buffer.

    // aNewTextSpan must fit within the descriptor; that is from 0 to length-1

    // But remember that span is a span; indices refer to positions between characters. 0 is position just before 0

    // 1 is a position between 0 and character 1.  

    __ASSERT_DEBUG(aDecoratedTextSpan.LowerPos() >= 0, 

                   AknFepPanic(EAknFepPanicCharPosOutOfRange) );

    __ASSERT_DEBUG(aDecoratedTextSpan.HigherPos() <= aDecoratedTextPlusSurroundings.Length(), 

                   AknFepPanic(EAknFepPanicCharPosOutOfRange) );

    // Examine the decorated text for real content

    TBool cont = EFalse;

	TInt ii = 0;

	for (ii = aDecoratedTextSpan.LowerPos(); ii < aDecoratedTextSpan.HigherPos(); ii++)

		{

		if (!CharacterIsDirectionalMarker(aDecoratedTextPlusSurroundings[ii]))

			cont = ETrue;

		}

	// if all we have entered are directional markers we want

	// to keep them so do nothing and return

	if (!cont)

		return needsResolving; // Uses initialized value of return value. Please maintain.

	ii = 0;

	while (ii < aDecoratedTextPlusSurroundings.Length())

		{

		TChar prevCh = ENullChar;

		if (ii > 0)

			prevCh = aDecoratedTextPlusSurroundings[ii-1];

		TChar ch = aDecoratedTextPlusSurroundings[ii];

		TChar nextCh = ENullChar;

		if (ii <  aDecoratedTextPlusSurroundings.Length()-1)

			nextCh = aDecoratedTextPlusSurroundings[ii+1];

		if (CharacterIsDirectionalMarker(ch))

			{

			// Remove a marker if :

			//

			// 1. previous character is strong and has the same directionality

			// 2. next character is a marker of the same type (remove both)

			// 3. next character is strong and has the same directionality

			//

			if (CharactersHaveSameStrongDirection(ch, prevCh))

				{

				aDecoratedTextPlusSurroundings.Delete(ii, ESingleCharacter);

				ii--;

				needsResolving = ETrue;

				}

			else if (CharacterIsDirectionalMarker(nextCh) && CharactersHaveSameStrongDirection(ch, nextCh))

				{

				aDecoratedTextPlusSurroundings.Delete(ii, ETwoCharacters);

				ii--;

				needsResolving = ETrue;

				}

			else if (CharactersHaveSameStrongDirection(ch, nextCh))

				{

				aDecoratedTextPlusSurroundings.Delete(ii, ESingleCharacter);

				ii--;

				needsResolving = ETrue;

				}

			}

		ii++;

		}

    return needsResolving;

	}

TBool CAknFepInlineTextDecorator::CharacterIsDirectionalMarker(TChar aChar)

	{

	return (aChar == ELeftToRightMark || aChar == ERightToLeftMark);

	}

TBool CAknFepInlineTextDecorator::CharacterIsStrongLeftToRight(TChar aChar)

	{

	return (aChar.GetBdCategory() == TChar::ELeftToRight ||

			   aChar == ELeftToRightMark);

	}

TBool CAknFepInlineTextDecorator::CharacterIsStrongRightToLeft(TChar aChar)

	{

	return ((aChar.GetBdCategory() == TChar::ERightToLeft) || 

			(aChar.GetBdCategory() == TChar::ERightToLeftArabic) ||

			aChar == ERightToLeftMark);

	}

TBool CAknFepInlineTextDecorator::CharactersHaveSameStrongDirection(TChar aCh1, TChar aCh2)

	{

	return ((CharacterIsStrongLeftToRight(aCh1) && CharacterIsStrongLeftToRight(aCh2)) ||

				(CharacterIsStrongRightToLeft(aCh1) && CharacterIsStrongRightToLeft(aCh2)));

	}

TBool CAknFepInlineTextDecorator::CharacterIsWeaklyDirectional(TChar aChar)

	{

	return ((aChar.GetBdCategory() == TChar::EEuropeanNumber) ||

			(aChar.GetBdCategory() == TChar::EEuropeanNumberSeparator) ||

			(aChar.GetBdCategory() == TChar::EEuropeanNumberTerminator) ||

			(aChar.GetBdCategory() == TChar::EArabicNumber) ||

			(aChar.GetBdCategory() == TChar::ECommonNumberSeparator));

	}

TBool CAknFepInlineTextDecorator::CharacterIsSeparator(TChar aChar)

	{

	return ((aChar.GetBdCategory() == TChar::EParagraphSeparator) || 

			(aChar.GetBdCategory() == TChar::ESegmentSeparator));

	}

TBool CAknFepInlineTextDecorator::CharacterIsNeutral(TChar aChar)

	{

	return ((aChar.GetBdCategory() == TChar::EWhitespace) || 

			(aChar.GetBdCategory() == TChar::EOtherNeutral));

	}

void CAknFepInlineTextDecorator::DecorateNeutralCharacters(

	const TDesC& aInlineText,

	TDes& aDecoratedText,

	TInt& aPositionOfInsertionPointInInlineText,

	TChar aPreviousCharacter,

	TBool aRTLParagraph,

    TBool aInputDirectionIsRTL)

	{

	TChar curCh;

	TChar prevCh = aPreviousCharacter;

	TBuf<ESingleCharacter> insertBuf(ESingleCharacter);

	for (TInt ii = 0; ii < aInlineText.Length(); ii++)

		{

		curCh = aInlineText[ii];

		aDecoratedText.Append(curCh);

		if (CharacterIsNeutral(curCh))

			{

			// mark the neutral character with appropriate direction markers if :

			//

			// 1. the input mode (lang) is opposed to the paragraph direction and 

			//     previous character is not neutral

			// 2. the input mode (lang) is opposed to the previous char direction

			//     (=> charcater is entered inside existing block)

			//

			// Note that we need to increment the insertion point by 2 if the

			// markers are inserted before it

			//

			if ((aInputDirectionIsRTL && !aRTLParagraph && !CharacterIsNeutral(prevCh)) ||

				(aInputDirectionIsRTL &&  CharacterIsStrongLeftToRight(prevCh)))

				{ // mark neutral with RLM

				insertBuf[0]=ERightToLeftMark;

				aDecoratedText.Insert(aDecoratedText.Length() -1, insertBuf);

				aDecoratedText.Append(insertBuf);

				if (aPositionOfInsertionPointInInlineText > ii)

					aPositionOfInsertionPointInInlineText+=ETwoCharacters;

				}

			else if ((!aInputDirectionIsRTL && aRTLParagraph && !CharacterIsNeutral(prevCh)) ||

					 (!aInputDirectionIsRTL && CharacterIsStrongRightToLeft(prevCh)))

				{ // mark neutral with LRM

				insertBuf[0]=ELeftToRightMark;

				aDecoratedText.Insert(aDecoratedText.Length() -1, insertBuf);

				aDecoratedText.Append(insertBuf);

				if (aPositionOfInsertionPointInInlineText > ii)

					aPositionOfInsertionPointInInlineText+=ETwoCharacters;

				}

			}

		prevCh = curCh;

		}

	}