How to implement a recent array

Consider the following two scenarios

We need a list of the recent URL's that the user entered OR
We need a list of recent search keywords that the user entered.

There can be many more like this, these keywords/URL's/Files opened etc... can be sorted in the recent used order in an array.

The following class is very handy in such situations, not only it maintains a recent list it also stores it into a file so that the recent list is available the next time the application starts.

Header File

Recent.h #ifndef        _RECENTH_
#define       _RECENTH_
class CRecent : public CBase
{
public:
        virtual ~CRecent();
        void ReadFromFileL();
        void WriteToFileL();
        CRecent();
        TInt RecentCount();
        void AppendToRecTitle(TDesC& aUrl);
        void RecentSelected(TInt aIndex, TDes& aRet);
        void MoveArrayElementsL(TDesC& aUrl);
        TBool ResetAll();
        TBool ItemElseWhere(TDesC& aUrl);
        TBool ItemAtZeroth(TDesC& aUrl);
        void SetFile(TFileName& aFile);
private:
        void ConstructL();
private:
   CDesCArray *iRecent;
   TUint iRCount;
   TFileName iFile;
};

#endif

Cpp File

Recent.cpp #include <bautils.h>
#include <s32file.h>
#include <eikspane.h>
#include <akntitle.h>
#include <avkon.hrh>
#include "Recent.h"

_LIT(KFile,".dat");

_LIT(KFormat,"%S");
const TInt KMax = 5;

CRecent::CRecent()
{
        iRecent = new (ELeave) CDesCArrayFlat(10);

}

void CRecent::SetFile(TFileName& aFile)
{
        iFile.Copy(aFile);
        iFile.Append(KFile);
        ReadFromFileL();
}

//clean up
CRecent::~CRecent()
{
        delete iRecent;

}

//read recent urls line by line from file
void CRecent::ReadFromFileL()
{
        RFs aFs;
        User::LeaveIfError(aFs.Connect());
        CleanupClosePushL(aFs);

        TBool iBool;
        iBool=BaflUtils::FileExists(aFs,iFile);

        if(iBool)
        {
               iRecent->Reset();


               TBuf<128> urlbuf;
               RFileReadStream fRead;
               User::LeaveIfError(fRead.Open(aFs,iFile, EFileRead));
               CleanupClosePushL(fRead);
               TInt count = fRead.ReadInt16L();
               iRCount=count; //added now
               for(TInt i=0;i<count;i++)

Unknown macro: { HBufC *url = HBufC}

               CleanupStack::PopAndDestroy(&fRead);
        }
        else

Unknown macro: { iRCount = 0; }

        aFs.Close();
        CleanupStack::PopAndDestroy(&aFs);
}

//write files line by line to the file
void CRecent::WriteToFileL()
{
        RFs aFs;
        User::LeaveIfError(aFs.Connect());
        CleanupClosePushL(aFs);
        aFs.Delete(iFile);
        RFileWriteStream fWrite;
        User::LeaveIfError(fWrite.Create(aFs, iFile, EFileWrite));
        CleanupClosePushL(fWrite);

        fWrite.WriteInt16L( static_cast<TInt16>(iRecent->Count() ) );
        for(TInt i =0 ; i < iRecent->Count() ; i++)

Unknown macro: { fWrite << iRecent->MdcaPoint(i); // Warning, this _CAN_ leave }

        fWrite.CommitL();
        CleanupStack::PopAndDestroy(&fWrite);
        CleanupStack::PopAndDestroy(&aFs);
}

TInt CRecent::RecentCount()
{
        return iRCount;
}

//new file to list
void CRecent::AppendToRecTitle(TDesC& aUrl)
{
        //the first element is selected , dont do anything
        if(ItemAtZeroth(aUrl))
               return;

        //a file that already exists in the list , bring it to top
        if(ItemElseWhere(aUrl))
               return;

        //else append to recent list
        if(iRecent->Count() == KMax)
               MoveArrayElementsL(aUrl);
        else
               iRCount++;

        iRecent->AppendL(aUrl);
        WriteToFileL();
        ReadFromFileL();
}

//a file that already exists in the list , bring it to top
TBool CRecent::ItemElseWhere(TDesC& aUrl)
{
        TBuf<128> iCompStr;
        TInt iIndex;
        TBool iFound;
        iFound = EFalse;
        for(TInt i=0; i < iRecent->Count();i++)
        {
               iCompStr.Zero();
               iCompStr.Copy(iRecent->MdcaPoint

);
               TInt comp =iCompStr.Compare(aUrl);
               if(comp == 0)

Unknown macro: { iFound=ETrue; iIndex = i; break; }

        }
        if(iFound)

Unknown macro: { TBuf<128> item; item.Copy(iRecent->MdcaPoint(iIndex)); iRecent->Delete(iIndex); iRecent->AppendL(item); WriteToFileL(); ReadFromFileL(); return ETrue; }

        else
               return EFalse;
}

//item already is at the recent position or not
TBool CRecent::ItemAtZeroth(TDesC& aUrl)
{
        if(iRecent->Count() > 0 )

Unknown macro: { TBuf<128> iCompStr; if(iRecent->Count() == 1) iCompStr.Copy(iRecent->MdcaPoint(0)); else iCompStr.Copy(iRecent->MdcaPoint(iRCount-1)); TInt comp =iCompStr.Compare(aUrl); if(comp != 0) return EFalse; else return ETrue; }

else

Unknown macro: { return EFalse; }

}

//return selected item
void CRecent::RecentSelected(TInt aIndex, TDes& aRet)
{
        aRet.Copy(iRecent->MdcaPoint(aIndex));
}

//move elements in case of list full
void CRecent::MoveArrayElementsL(TDesC& aUrl)
{
        TInt i;
        CDesCArrayFlat* iTempRecentUrls = new (ELeave) CDesCArrayFlat(10);

        for( i=1 ; i <= KMax-1 ; i++ )

Unknown macro: { iTempRecentUrls->AppendL(iRecent->MdcaPoint(i)); }

        iRecent->Reset();

        for( i = 0 ; i <=KMax-2 ; i++)

Unknown macro: { iRecent->AppendL(iTempRecentUrls->MdcaPoint(i)); }

        delete iTempRecentUrls;
}

//reset all
TBool CRecent::ResetAll()
{
        RFs aFs;
        User::LeaveIfError(aFs.Connect());
        CleanupClosePushL(aFs);

        TBool iBool;
        iBool=BaflUtils::FileExists(aFs, iFile);
        if(iBool)

Unknown macro: { aFs.Delete(iFile); iRCount = 0 ; iRecent->Reset(); CleanupStack}

CleanupStack::PopAndDestroy(&aFs);
return EFalse;
}PS: The url/search mentioned in the above scenarios are not the external applications data,like the browsers urls , all scenarios are for the same applications data.

Name                    : Avinash
Surname              :Rathod
Email                    :avinashrathod@gmail.com
Article                   :How to implement a recent array
Address                :Western Rly. Colony,
                               175-15, S.V.Road,
                               Bandra(West)
                               Mumbai 400050.
                               Maharashtra.
                               India.
Date of Cr            : 20 Aug 2007