examples/Base/ArraysAndLists/linkedlist/dbllist/src/mystringreverse.cpp

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// Copyright (c) 2008-2009 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:
// Contains definition of functions defined in the CMyStringReverse class.
// 
//

#include "mystringreverse.h"

CMyStringReverse* CMyStringReverse::NewL(CConsoleBase* aConsole)
        {
        CMyStringReverse* self = new (ELeave)CMyStringReverse(aConsole);
        self->AddToScheduler();
        return self;
        }

void CMyStringReverse::AddToScheduler()
        {
        CActiveScheduler::Add(this);
        }

CMyStringReverse::CMyStringReverse(CConsoleBase* aConsole):
                                                                                                                // Constructor of the base class.
                                                                                                                CActive(CActive::EPriorityUserInput),
                                                                                                                // Create the linked list.
                                                                                                                iString(_FOFF(TLetter,iDLink)),
                                                                                                                // Initialize iterators.
                                                                                                                iIteratorString(iString),
                                                                                                                iConsole(aConsole)
        {
        }

void CMyStringReverse::RunL()
        {
        // Get the key code.
        TUint8 option = iConsole->KeyCode();
        // Print the selected option.
        _LIT(KTextFormat,"%c\n");
        iConsole->Printf(KTextFormat,option);

        // Check if a numeric key is pressed.
        TInt number = option - (TUint)'0';
        if(number <10 && number > -1)
                {
                // Handle the numeric key press.
                switch(number)
                        {
                        case 1:
                                {
                                // The iString.AddFirst() function needs to be called.
                                // Read the character to be added to the list.
                                iTask = ETaskStringAddFirst;
                                ReadChar();
                                }
                                break;
                        case 2:
                                {
                                // The iString.AddLast() function needs to be called.
                                // Read the character to be added to the list.
                                iTask = ETaskStringAddLast;
                                ReadChar();
                                }
                                break;
                        default:
                                // Stop the active scheduler.
                                CActiveScheduler::Stop();
                        }
                }
        else
                {
                // An alphabetic key is pressed.
                // Check the action to be performed.
                switch(iTask)
                        {
                        case ETaskNone:
                                _LIT(KInvalidOption,"Invalid Option!\n");
                                iConsole->Printf(KInvalidOption);
                                break;
                        // The iString.AddFirst() function needs to be called.
                        case ETaskStringAddFirst:
                                {
                                // Create an object of the TLetter class.
                                TLetter* letter = new (ELeave) TLetter(option);
                                // Add the TLetter object into the list.
                                iString.AddFirst(*letter);
                                iTask = ETaskNone;
                                // Print the data in iString and iReverseString.
                                PrintStrings();
                                }
                                break;
                        case ETaskStringAddLast:
                                {
                                // Create an object of the TLetter class.
                                TLetter* letter = new (ELeave) TLetter(option);
                                // Add the TLetter object into the list.
                                iString.AddLast(*letter);
                                iTask = ETaskNone;
                                // Print the data in iString and iReverseString.
                                PrintStrings();         
                                }
                                break;
                        default:
                                iTask = ETaskNone;
                                break;
                        }
                // Generate an asynchronous read request.
                ReadOption();
                }
        }

void CMyStringReverse::ReadFunc()
        {
        // Wait for a key press event.
        iConsole->Read(iStatus);
        SetActive();
        }

void CMyStringReverse::ReadOption()
        {
        // Print the menu.
        _LIT(KTextMenu,"\nEnter\n1-> Add a character to the beginning of the string\n2-> Add a character to the end of the string\nAny other NUMBER to stop\n");
        iConsole->Printf(KTextMenu);
        // Generate an asynchronous read request.
        ReadFunc();
        }

void CMyStringReverse::ReadChar()
        {
        _LIT(KTextReadChar,"\nEnter a character\n");
        iConsole->Printf(KTextReadChar);
        // Generate an asynchronous read request.
        ReadFunc();
        }

void CMyStringReverse::PrintStrings()
        {
        _LIT(KTextSrcString,"Source String: ");
        iConsole->Printf(KTextSrcString);
        // Initialize the iterator.
        iIteratorString.SetToFirst();

        // Iterate iString.
        while(iIteratorString != NULL)
                {
                // Get the TLetter object pointed to by the iterator.
                TLetter letter = *iIteratorString;
                // Print the character value of the TLetter object.
                _LIT(KTextChar,"%c");
                iConsole->Printf(KTextChar,TUint(letter.iChar));
                // Set the iterator to point to the next element.
                iIteratorString++;
                }

        _LIT(KTextRevString,"\nReverse of the String: ");
        iConsole->Printf(KTextRevString);
        // Initialize the iterator.
        iIteratorString.SetToLast();

        // Iterate iReverseString.
        while(iIteratorString != NULL)
                {
                // Get the TLetter object pointed to by the iterator.
                TLetter letter = *iIteratorString;
                // Print the character value of the TLetter object.
                _LIT(KTextChar,"%c");
                iConsole->Printf(KTextChar,TUint(letter.iChar));
                // Set the iterator to point to the next element.
                iIteratorString--;
                }
        iConsole->Printf(KTextNewLine);
        }

void CMyStringReverse::DoCancel()
        {
        if(IsActive())
                {
                // Cancel any outstanding read requests.
                iConsole->ReadCancel();
                }
        }

CMyStringReverse::~CMyStringReverse()
        {
        // Delete the elements from the list.           
                iIteratorString.SetToFirst();
                // Iterate the list and delete all TLetter objects.
                TLetter* ptr = iIteratorString++;
                while (ptr != NULL)
                        {
                        delete ptr;
                        ptr = iIteratorString++;
                        }       
        }

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