// Copyright (c) 2002-2009 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 LINEBREAK_H_

#define LINEBREAK_H_

#include <e32def.h>

class MContingentLineBreaker;

class MContingentLineBreakerL;

class TDesC16;

class TUid;

/**

 This enumeration holds the possible panic codes that may be raised

 by the LineBreak API on detecting an unrecoverable error.

@publishedAll

@released

*/

enum TLineBreakPanic

	{

	/** Not used */

	ELineBreakPanic_Unknown				= 0,

	/** Internal error, error found in data table */

	ELineBreakPanic_BadTable			= 1,

	/** One or more of the input parameters to the interface were invalid */

	ELineBreakPanic_InvalidInputParam	= 2,

	/** Raised when an output parameter breaks an API condition */

	ELineBreakPanic_InvalidOutputParam	= 3,

	};

class MLineBreaker

/**

Customizes the Unicode line-breaking algorithm. 

@publishedAll

@released

*/

	{

public:

	/** The Unicode line breaking classes; see Unicode Technical Report 14.

	Not a named enumerated type, so that overriding classes may add new

	line breaking classes freely.

	The description of each constant gives the name of the line-breaking

	class, an example and a brief, imprecise description of the default

	behaviour of characters of that class.	 */

	enum

		{

		/** Opening Punctuation (e.g. '['). Breaking after prohibited. */

		EOpLineBreakClass,

		/** Closing Punctuation (e.g. ']'). Breaking before prohibited. */

		EClLineBreakClass,

		/** Ambiguous Quotes (e.g. '"'). Breaking before and after prohibited. */

		EQuLineBreakClass,

		/** Glue (e.g. Non-breaking space). Breaking before and after prohibited

		unless spaces are present. */

		EGlLineBreakClass,

		/** Non-Starter (e.g. small Japanese kana). Breaking before prohibited

		if no spaces present. */

		ENsLineBreakClass,

		/** Exclamation or Interrogation (e.g. '?'). Like closing punctuation

		except before Postfix or Non-starter. */

		EExLineBreakClass,

		/** Symbol (e.g. '/'. Like Alphabetic, but allows breaking before

		Alphabetic. */

		ESyLineBreakClass,

		/** Numeric Infix Separator (e.g. ','). Forbids breaking after any and before

		Numeric. */

		EIsLineBreakClass,

		/** Numeric Prefix (e.g. '$'). Forbids breaking before Numeric. */

		EPrLineBreakClass,

		/** Numeric Postfix (e.g. '%'). Forbids breaking after Numeric. */

		EPoLineBreakClass,

		/** Numeric (e.g. '1'). */

		ENuLineBreakClass,

		/** Alphabetic (e.g. 'a'). */

		EAlLineBreakClass,

		/** Ideographic (e.g. Japanese Kanji). Generally break before or after */

		EIdLineBreakClass,

		/** Inseparable (e.g. ellipsis). Forbid breaks between Inseparables. */

		EInLineBreakClass,

		/** Hyphen (e.g. '-'). Allows a break after except before Numeric. */

		EHyLineBreakClass,

		/** Break After. Generally allow a break after. Breaking between Break

		Afters not separated by spaces is prohibited. */

		EBaLineBreakClass,

		/** Break Before. Generally allow a break before. Breaking between Break

		Befores not separated by spaces is prohibited. */

		EBbLineBreakClass,

		/** Break Before and After. Generally allow a break before or after.

		Breaking between Break Before and Afters is prohibited, even if spaces

		are present. */

		EB2LineBreakClass,

		/** Zero-Width Space. Allow a break. */

		EZwLineBreakClass,

		/** Combining Mark. Takes on the class of its base class. */

		ECmLineBreakClass,

		/** Mandatory Break. */

		EBkLineBreakClass,

		/** Carriage Return. Break after unless part of a CRLF pair. */

		ECrLineBreakClass,

		/** Line Feed. Break after. */

		ELfLineBreakClass,

		/** Surrogate. Half of a surrogate pair. */

		ESgLineBreakClass,

		/** Contingent Break (e.g. embedded pictures). Uses external

		information */

		ECbLineBreakClass,

		/** Space. Intervening characters of class Space are indicated by

		aHaveSpaces in LineBreakPossible. */

		ESpLineBreakClass, 

		/** Complex Context (e.g. Thai). Runs of Complex Context are passed to

		GetLineBreakInContext. */

		ESaLineBreakClass,

		/** Ambiguous. Characters of ambiguous East Asian width are treated

		as Alphabetic, unless they are resolved as being "Wide", in which case

		they are treated as Ideographic. */

		EAiLineBreakClass,

		/** The Xx class is used when the class is unknown; e.g.; outside the provided context. */

		EXxLineBreakClass,

		/** The number of Unicode line break classes. */

		ELineBreakClasses

		};

	IMPORT_C virtual TUint LineBreakClass(TUint aCode,

		TUint& aRangeStart, TUint& aRangeEnd) const;

	IMPORT_C virtual TBool LineBreakPossible(TUint aPrevClass, TUint aNextClass,

		TBool aHaveSpaces) const;

	IMPORT_C virtual TBool GetLineBreakInContext(const TDesC16& aText,

		TInt aMinBreakPos, TInt aMaxBreakPos, TBool aForwards,

		TInt& aBreakPos) const;

	IMPORT_C virtual TBool IsHangingCharacter(TUint aChar) const;

	IMPORT_C TBool GetLineBreak(const TDesC16& aText,

		TInt aMinBreakPos, TInt aMaxBreakPos, TBool aForwards,

		MContingentLineBreaker* aCbDelegate,

		TInt& aBreakPos, TInt& aBreakPosAfterSpaces) const;

	IMPORT_C TBool GetLineBreakL(const TDesC16& aText,

		TInt aMinBreakPos, TInt aMaxBreakPos, TBool aForwards,

		MContingentLineBreakerL* aCbDelegate,

		TInt& aBreakPos, TInt& aBreakPosAfterSpaces) const;

	IMPORT_C virtual void* ExtendedInterface(TUid& aUid) const;

	};

class MContingentLineBreaker

/**

Used to determine the line breaks around pictures and other characters with 

the CB (contingent line break) class in situations where this operation cannot 

leave. 

@publishedAll

@released

*/

	{

public:

	/** Determines if a break is legal before the picture at aTextPosition. 

	@param aTextPosition The position of a character of line breaking class ECbLineBreakClass 

	in the text as supplied to MLineBreaker::GetLineBreak(), which may refer to 

	a picture.

	@param aPrecedingClass The class of the character preceding aTextPosition.

	@param aHasSpaces ETrue if spaces separate the preceding class from this.

	@return ETrue if a line break is legal here. */

	virtual TBool IsLegalBreakBefore(TInt aTextPosition, TInt aPrecedingClass,

		TBool aHasSpaces) = 0;

	/** Determines if a break is legal after the picture at aTextPosition. 

	@param aTextPosition The position of a character of line breaking class ECbLineBreakClass 

	in the text as supplied to MLineBreaker::GetLineBreak, which may refer to 

	a picture.

	@param aFollowingClass The class of the character immediately following aTextPosition.

	@param aHasSpaces ETrue if spaces separate the following class from this.

	@return ETrue if a line break is legal here. */

	virtual TBool IsLegalBreakAfter(TInt aTextPosition, TInt aFollowingClass,

		TBool aHasSpaces) = 0;

	};

class MContingentLineBreakerL

/**

Used to determine the line breaks around pictures and other characters with 

the CB (contingent line break) class in situations where this operation may 

leave. 

@publishedAll

@released

*/

	{

public:

	/** Determines if a break is legal before the picture at aTextPosition. 

	@param aTextPosition The position of a character of line breaking class ECbLineBreakClass 

	in the text as supplied to MLineBreaker::GetLineBreak(), which may refer to 

	a picture.

	@param aPrecedingClass The class of the character preceding aTextPosition.

	@param aHasSpaces ETrue if spaces separate the preceding class from this.

	@return ETrue if a line break is legal here. */

	virtual TBool IsLegalBreakBeforeL(TInt aTextPosition, TInt aPrecedingClass,

		TBool aHasSpaces) = 0;

	/** Determines if a break is legal after the picture at aTextPosition. 

	@param aTextPosition The position of a character of line breaking class ECbLineBreakClass 

	in the text as supplied to MLineBreaker::GetLineBreak(), which may refer to 

	a picture.

	@param aFollowingClass The class of the character immediately following aTextPosition.

	@param aHasSpaces ETrue if spaces separate the preceding class from this.

	@return ETrue if a line break is legal here. */

	virtual TBool IsLegalBreakAfterL(TInt aTextPosition, TInt aFollowingClass,

		TBool aHasSpaces) = 0;

	};

#endif