/*

* Copyright (c) 2007 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:  Software Installer plug-in usb handler

*

*/

// INCLUDE FILES

#include "chswiusbhandler.h"

#include "chswiplugin.h"

#include "chswimassmodeobserver.h"

// CONSTANTS

const TInt KCallBackDelay = 5000000;

// ----------------------------------------------------------------------------

// CCHSwiUsbHandler::NewL()

// two-phase constructor

// ----------------------------------------------------------------------------

//

CCHSwiUsbHandler* CCHSwiUsbHandler::NewL(

		MCHSwiMassModeObserver* aMassModeObserver,

		RFs& aFs )

    {

    CCHSwiUsbHandler* self =

        new(ELeave) CCHSwiUsbHandler( aMassModeObserver, aFs );

    CleanupStack::PushL( self );

    self->ConstructL();

    CleanupStack::Pop( self );

    return self;

    }

// ----------------------------------------------------------------------------

// CCHSwiUsbHandler::CCHSwiUsbHandler()

// C++ default constructor

// ----------------------------------------------------------------------------

//

CCHSwiUsbHandler::CCHSwiUsbHandler( MCHSwiMassModeObserver* aMassModeObserver,

        RFs& aFs )

    : CActive( CActive::EPriorityUserInput ),

      iLastDriveScanError( KErrNone ),

      iMassModeObserver( aMassModeObserver ),

      iFs( aFs ),

      iDriveFlags( 0 )

    {

    CActiveScheduler::Add( this );

    }

// ----------------------------------------------------------------------------

// CCHSwiUsbHandler::ConstructL()

// Symbian default constructor

// ----------------------------------------------------------------------------

//

void CCHSwiUsbHandler::ConstructL()

    {

    User::LeaveIfError( iTimer.CreateLocal() );

    iLastDriveScanError = ScanDrivesAndUpdateFlag( EFalse );

    if ( iLastDriveScanError != KErrNone )

    	{

    	HandleDriveError();

    	}

    }

// ----------------------------------------------------------------------------

// CCHSwiUsbHandler::~CCHSwiUsbHandler()

// destructor

// ----------------------------------------------------------------------------

//

CCHSwiUsbHandler::~CCHSwiUsbHandler()

    {

    Cancel();

    iTimer.Close();

    }

// ----------------------------------------------------------------------------

// CCHSwiUsbHandler::SynchronousDriveScan()

// Performs synchronous drive scan. Checks whether Mass Drive is available

// and updates the flag in observer.

// ----------------------------------------------------------------------------

//

void CCHSwiUsbHandler::SynchronousDriveScan()

	{

    iLastDriveScanError = ScanDrivesAndUpdateFlag( iLastDriveScanError == KErrNone );

    if ( iLastDriveScanError != KErrNone )

    	{

    	HandleDriveError();

    	}

	}

// ----------------------------------------------------------------------------

// CCHSwiUsbHandler::PostponedDriveScan()

// Starts postponed drive scan. 

// ----------------------------------------------------------------------------

//

void CCHSwiUsbHandler::PostponedDriveScan()

	{

	Cancel();

	iTimer.After( iStatus, KCallBackDelay ); 

	SetActive();

	}

// ----------------------------------------------------------------------------

// CCHSwiUsbHandler::RunL()

// Handles postponed drive scan. 

// Executed either after call to PostponedDriveScan or in case of drive reading

// errors in SynchronousDriveScan or ConstructL.

// ----------------------------------------------------------------------------

//

void CCHSwiUsbHandler::RunL()

    {

    TBool massModeBeforeScan = iMassModeObserver->IsMassStorageMode();

    TInt errorBeforeScan = iLastDriveScanError;

    SynchronousDriveScan();

    if ( iLastDriveScanError == KErrNone )

		{

		iMassModeObserver->HandleSuccessfulAsynchDriveScan();

		// CCHSwiUsbObserver can't detect app uninstall when app had been installed on removable 

		// memory card, the memory card was removed during mass mode, and then mass 

		// mode was deactivated.

	    // Additionaly, we need to update widgets when recovering from error.

		if ( !iMassModeObserver->IsMassStorageMode() && 

			( massModeBeforeScan || errorBeforeScan != KErrNone ) )

			{

			iMassModeObserver->HandleMassStorageModeEndEvent();

			}

		}   

    }

// ----------------------------------------------------------------------------

// CCHSwiUsbHandler::HandleDriveError()

// Handles drive access errors by launching new postponed scan.

// ----------------------------------------------------------------------------

void CCHSwiUsbHandler::HandleDriveError()

	{

	Cancel();

	iMassModeObserver->SetMassStorageMode( ETrue );

	iTimer.After( iStatus, KCallBackDelay ); 

	SetActive();

	}

// ----------------------------------------------------------------------------

// CCHSwiUsbHandler::ScanDrivesAndUpdateFlag()

// Scans drives and updates Mass Mode flag in the observer. 

// ----------------------------------------------------------------------------

TInt CCHSwiUsbHandler::ScanDrivesAndUpdateFlag( TBool aFlagsValid )

	{

	TInt error( KErrNone );

	if( aFlagsValid )

		{

		// iDriveFlags is valid, we can use deltaDriveFlags to avoid

		// unnecessary calls to DriveInfo::GetDriveStatus

		TInt driveFlags = 0;

		TInt deltaDriveFlags = 0;

		error = ScanDrives( driveFlags );

		if ( error == KErrNone )

			{

			deltaDriveFlags = iDriveFlags ^ driveFlags;

			iDriveFlags = driveFlags;

			}

		if ( deltaDriveFlags )

			{ 

			error = UpdateMassModeFlag();

			}

		}

	else

		{

		error = ScanDrives( iDriveFlags );

		if ( error == KErrNone )

			{

			error = UpdateMassModeFlag();

			}   

		}

	return error;

	}

// ----------------------------------------------------------------------------

// CCHSwiUsbHandler::UpdateMassModeFlag()

// Updates Mass Mode flag in the observer. 

// ----------------------------------------------------------------------------

TInt CCHSwiUsbHandler::UpdateMassModeFlag()

	{

    TInt flags = iDriveFlags;

    TBool massMemoryPresent = EFalse;

    for( TInt DriveNo = EDriveA + 1 ; DriveNo <= EDriveY; DriveNo++ )

    	{   

    	flags = flags >> 1;

        if( flags & 01 )

            {

            TUint status( 0 );

            TInt error = DriveInfo::GetDriveStatus( iFs, DriveNo, status );

            if( error != KErrNone )

            	{

            	return error;

            	}

            if( ( status & DriveInfo::EDriveExternallyMountable ) 

            		&& ( status & DriveInfo::EDriveInternal ) )

                {

                // Internal Memory

                massMemoryPresent = ETrue;

                break;

                }

            }            

        }

    iMassModeObserver->SetMassStorageMode( !massMemoryPresent );            

    return KErrNone;

	}

// ----------------------------------------------------------------------------

// CCHSwiUsbHandler::RunError()

// Ignore errors from RunL.

// ----------------------------------------------------------------------------

//

TInt CCHSwiUsbHandler::RunError( TInt /* aError */ )

    {

    return KErrNone; // indicates error was handled

    }

// ----------------------------------------------------------------------------

// CCHSwiUsbHandler::DoCancel()

// Cancel the MMC event handler

// ----------------------------------------------------------------------------

void CCHSwiUsbHandler::DoCancel()

    {

    iTimer.Cancel();

    }

// ----------------------------------------------------------------------------

// CCHSwiUsbHandler::ScanDrives( TInt& aDriveFlags )

// Scans drives and records a bit flag for those that exist and are

// suitable for installing widgets to.

// ----------------------------------------------------------------------------

//

TInt CCHSwiUsbHandler::ScanDrives( TInt& aDriveFlags )

    {

    // List all drives in the system

    TDriveList driveList;

    TInt error = iFs.DriveList( driveList );

    if ( KErrNone == error )

        {

        for ( TInt driveNumber = EDriveY;

              driveNumber >= EDriveA;

              driveNumber-- )

            {

            // The drives that will be filtered out are the same ones that

            // WidgetInstaller filters out in CWidgetUIHandler::SelectDriveL()

            if ( (EDriveD == driveNumber)

                 || !driveList[driveNumber] )

                {

                // EDriveD is a temporary drive usually a RAM disk

                continue;

                }

            TVolumeInfo volInfo;

            if ( iFs.Volume( volInfo, driveNumber ) != KErrNone )

                {

                // volume is not usable (e.g. no media card inserted)

                continue;

                }

            if ( (volInfo.iDrive.iType == EMediaNotPresent) ||

                 (volInfo.iDrive.iType == EMediaRom) ||

                 (volInfo.iDrive.iType == EMediaRemote) ||

                 (volInfo.iDrive.iDriveAtt & KDriveAttRom) ||

                 (volInfo.iDrive.iDriveAtt & KDriveAttSubsted) )

                {

                // not a suitable widget install drive

                continue;

                }

            // found a usable drive

            aDriveFlags |= (1 << driveNumber);

            }

        }

    return error;

    }