/*

* Copyright (c) 2004-2008 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: 

*

*/

using System;

using System.Text;

using System.Collections;

using SymBuildParsingLib.Lexer;

using SymBuildParsingLib.Utils;

namespace SymBuildParsingLib.Lexer

{

	public class SymLexerWorkerLine : SymLexerWorker, ISymLexerPositionProvider

	{

		#region Constructors & destructor

		public SymLexerWorkerLine( SymLexer aLexer )

			: base( aLexer )

		{

		}

		#endregion

		#region Properties

		public char LastCharacter

		{

			get { return iLastCharacter; }

			set { iLastCharacter = value; }

		}

		#endregion

		#region SymLexerWorker Members

		public override bool ProcessCharacter( char aCharacter )

		{

			bool consumed = false;

			// At the end of a line if we see 0x0A or then 0x0D and the next character is not 0x0A

			if	( aCharacter == KSymLineFeed || aCharacter == KSymCarriageReturn )

			{

				if	( aCharacter == KSymLineFeed )

				{

					// This is definitely the end of a line. If the last

					// character was a carriage return, then we mark

					// the start of the end-of-line as the previous

					// character. Otherwise, its this one.

					AddNewEndOfLinePosition();

				}

				else

				{

					// Its a CR (0x0D) but it might be followed by a LF

					// so don't do anything yet.

					LastCharacter = aCharacter;

				}

				consumed = true;

			}

			else if ( LastCharacter == KSymCarriageReturn )

			{

				// The current character is not a line feed, but the last

				// char was a carriage return => implicitly, the last

				// character was an end of line.

				AddNewEndOfLinePosition();

			}

			else

			{

				iCurrentPosition.Inc();

				LastCharacter = aCharacter;

			}

			return consumed;

		}

		public override void StartedNewLine( SymTextPosition aEOLPosition )

		{

		}

		#endregion

		#region ISymLexerPositionProvider Members

		public SymTextPosition CurrentPosition

		{

			get

			{

				return new SymTextPosition( iCurrentPosition );

			}

		}

		public void SetObserver( ISymLexerPositionObserver aObserver )

		{

		}

		#endregion

		#region Internal methods

		private void AddNewEndOfLinePosition()

		{

			iLineEndingPositions.Add( iCurrentPosition );

			Lexer.HandleEndOfLineDetected( iCurrentPosition );

			iCurrentPosition.NewLine();

			iLastCharacter = '\0';

		}

		#endregion

		#region Internal constants

		const int KSymLineFeed = 0xA;

		const int KSymCarriageReturn = 0xD;

		#endregion

		#region Data members

		private char iLastCharacter = '\0';

		private ArrayList iLineEndingPositions = new ArrayList( 1024 );

		private SymTextPosition iCurrentPosition = new SymTextPosition();

		#endregion

	}

}