/*

* Copyright (c) 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:  Gesture helper implementation

*

*/

#include "gesturehelperimpl.h"

#include <alf/alfevent.h>

#include <e32base.h>

#include <w32std.h>

#include "gesture.h"

#include "gesturedefs.h"

#include "pointercapturer.h"

using namespace GestureHelper;

namespace GestureHelper

{

/// type of function in gesture helper to be called by the timer

/// when timer triggers

typedef void (CGestureHelperImpl::*CallbackFunctionL)();

NONSHARABLE_CLASS( CCallbackTimer ) : public CTimer

    {

public:

    /** Two-phase constructor */

    static CCallbackTimer* NewL( CGestureHelperImpl& aHelper, 

            CallbackFunctionL aCallbackFunctionL, TInt aDelay, TBool aIsEnabled )

        {

        CCallbackTimer* self = new ( ELeave ) CCallbackTimer( aHelper, 

            aCallbackFunctionL, aDelay, aIsEnabled );

        CleanupStack::PushL( self );

        self->ConstructL(); // construct base class

        CActiveScheduler::Add( self );

        CleanupStack::Pop( self );

        return self;

        }

    /** Destructor */

    ~CCallbackTimer()

        {

        Cancel();

        }

    /** Set whether sending holding events is currently enabled */

    void SetEnabled( TBool aEnabled )

        {

        iIsEnabled = aEnabled;

        // cancel in case hold timer is already running

        Cancel();

        }

    /** @return whether sending holding events is currently enabled */

    TBool IsEnabled() const

        {

        return iIsEnabled;

        }

    /** Start the timer. Calls CGestureHelperImpl::StartHoldingL upon completion */

    void Start()

        {

        // if sending hold events is disabled, do not ever start the hold timer, and 

        // hence hold events will never be triggered

        if ( iIsEnabled ) 

            {

            Cancel();

            After( iDelay );

            }

        }    

private:    

    /** Constructor */

    CCallbackTimer( CGestureHelperImpl& aHelper,

        CallbackFunctionL aCallbackFunctionL, TInt aDelay, TBool aIsEnabled )

            : CTimer( EPriorityUserInput - 1 ), // give higher priority to new pointer events with - 1

                iHelper( aHelper ), iCallbackFunctionL( aCallbackFunctionL ), 

                    iDelay( aDelay ), iIsEnabled( aIsEnabled ) 

        {

        }

    void RunL() // From CActive

        {

        (iHelper.*iCallbackFunctionL)();

        }

private:

    /// helper object that will be called back when timer is triggered

    CGestureHelperImpl& iHelper;

    /// Function in the iHelper object call 

    CallbackFunctionL iCallbackFunctionL;

    /// How long a time to wait befor calling back after Start()

    TInt iDelay;

    /// whether sending holding events is currently enabled

    TBool iIsEnabled;

    };

} // namespace GestureHelper

/** 

 * @return position from event. Use this instead of using aEvent direction to

 *         avoid accidentally using TPointerEvent::iPosition

 */

inline TPoint Position( const TPointerEvent& aEvent )

    {

    // use parent position, since the capturer is using full screen area,

    // and because the (Alfred) drag events are not local to visual even when

    // coming from the client

    return aEvent.iParentPosition;

    }

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

// Two-phase constructor

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

//

CGestureHelperImpl* CGestureHelperImpl::NewL( MGestureObserver& aObserver )

    {

    CGestureHelperImpl* self = new ( ELeave ) CGestureHelperImpl( );

    CleanupStack::PushL( self );

    self->iDoubleTapTimer = CCallbackTimer::NewL( *self, EmitFirstTapEventL, 

        KMaxDoubleTapDuration, EFalse ); // double tap is disabled by default

    self->iHoldingTimer = CCallbackTimer::NewL( *self, StartHoldingL, 

        KHoldDuration, ETrue ); // holding is enabled by default

    self->iGesture = new ( ELeave ) CGesture();

    self->iUnusedGesture = new ( ELeave ) CGesture();

    self->iPointerCapturer = CPointerCapturer::NewL();

    self->iPointerCount = 0;

    self->iObserver = &aObserver;

    CleanupStack::Pop( self );

    return self;

    }

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

// Destructor

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

//

CGestureHelperImpl::~CGestureHelperImpl()

    {

    delete iDoubleTapTimer;

    delete iHoldingTimer;

    delete iGesture;

    delete iPreviousTapGesture;

    delete iUnusedGesture;

    delete iPointerCapturer;

    }

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

// SetHoldingEnabled

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

//

void CGestureHelperImpl::SetHoldingEnabled( TBool aEnabled )

    {

    iHoldingTimer->SetEnabled( aEnabled );

    }

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

// IsHoldingEnabled

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

//

TBool CGestureHelperImpl::IsHoldingEnabled() const

    {

    return iHoldingTimer->IsEnabled();

    }

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

// SetHoldingEnabled

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

//

void CGestureHelperImpl::SetDoubleTapEnabled( TBool aEnabled )

    {

    iDoubleTapTimer->SetEnabled( aEnabled );

    }

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

// IsHoldingEnabled

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

//

TBool CGestureHelperImpl::IsDoubleTapEnabled() const

    {

    return iDoubleTapTimer->IsEnabled();

    }

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

// InitAlfredPointerEventCaptureL

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

//

void CGestureHelperImpl::InitAlfredPointerCaptureL( CAlfEnv& aEnv, 

        CAlfDisplay& aDisplay, TInt aFreeControlGroupId )

    {

    iPointerCapturer->InitForAlfredL(*this, aEnv, aDisplay, aFreeControlGroupId );

    }

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

// Reset state

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

//

void CGestureHelperImpl::Reset()

    {

    iHoldingTimer->Cancel();

    iGesture->Reset();

    iPointerCapturer->Stop();

    iPointerCount=0;

    iCurrentPointer = -1;

    }

/** 

 * Helper function that calls Reset on the pointer to CGestureHelperImpl

 */

static void ResetHelper( TAny* aHelper )

    {

    static_cast< CGestureHelperImpl* >( aHelper )->Reset();

    }

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

// Handle a pointer event

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

//

TBool CGestureHelperImpl::HandlePointerEventL( const TPointerEvent& aEvent )

    {     

    return HandlePointerEventL( aEvent, NULL );

    }

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

// OfferEventL

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

//

TBool CGestureHelperImpl::OfferEventL( const TAlfEvent& aEvent )

    {

    if ( aEvent.IsPointerEvent() )

        {

        return HandlePointerEventL( aEvent.PointerEvent(), aEvent.Visual() );

        }

    return EFalse;

    }

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

// Handle a pointer event

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

//

TBool CGestureHelperImpl::HandlePointerEventL( const TPointerEvent& aEvent,

        CAlfVisual* aVisual )

    {  

    TInt pointerNumber = GestureHelper::TGestureRecogniser().PointerNumber( aEvent );

    if( !ValidatePointer( aEvent, pointerNumber ) )

        {

        return EFalse; // don't consume

        }

    switch ( aEvent.iType )

        {

        case TPointerEvent::EButton1Down:            

		    // Error handling for recieveing a button down on the pointer which

            // is already touched down

            // Here the pointer number shouldnot be considered for validtaing.

            // We should consider which pointer is currently touched down

            // It can so happen that user has touched was doing pinch and then released his

            // 1st finger. and starts to do panning with the second finger still touched down.

            // Then again when he touches the first finger, in that case you should be validating these pointers w.r.t

            // the pointer numbers of the last touched finger

            // we shouldnot consider pointer number here. If pointer 1 is

            // already touched and dragging and we recieve a down of pointer 0     

            if( iPointerCount == 1 )

                {

                if(iCurrentPointer == pointerNumber )

                    {

                    TRAP_IGNORE( EmitCancelEventL() );

                    Reset();

                    }

                }

            else if( iPointerCount == 2 )

                {

                // if pointer count is already 2, then reset the array of pointer for 

                // which a down event is recieved, and continue handling in normal way

                iPointerCount = 1; 

                iCurrentPointer = pointerNumber == 0 ? 1 : 0;

                }

            if(iPointerCount == 0)

                {

                iPointerCount = 1;

                iCurrentPointer = pointerNumber;

                // single touch gesture start

                iGesture->SetSingleTouchActive();

                HandleSinglePointerEventL( aEvent, aVisual );

                }

            else if(iPointerCount == 1)

                {              

                iPointerCount = 2;

                iCurrentPointer = -1;

                // add the last point of the single touch event

                // to first array of gesture

                iGesture->ResetToLastPoint(pointerNumber != 0,ETrue);

                iGesture->SetMultiTouchActive();

                // multi touch gesture start

                HandleMultiplePointerEventL( aEvent, pointerNumber );

                }

            else

                {

                }

            break;

        case TPointerEvent::EDrag:

            if(iPointerCount == 1)

                {

                HandleSinglePointerEventL( aEvent, aVisual );

                }

            else if(iPointerCount == 2)

                {

                HandleMultiplePointerEventL( aEvent, pointerNumber );

                }

            else

                {

                // nothing to be done

                }

            break;

        case TPointerEvent::EButton1Up:

            if(iPointerCount == 2)

                { 

                // multi touch gesture complete

                HandleMultiplePointerEventL( aEvent, pointerNumber );

                // should the pointer count decrese first n then

                // handling of event or otherwise

                iPointerCount = 1;    

                iCurrentPointer = pointerNumber == 0 ? 1 : 0;

                iGesture->ResetToLastPoint(ETrue,pointerNumber != 0);

                iGesture->SetSingleTouchActive();

                }

            else if( iPointerCount == 1 )

                {

                iPointerCount = 0;

                iCurrentPointer = -1;

                // single touch gesture complete

                HandleSinglePointerEventL( aEvent, aVisual ); 

                }

            else

                {

                // nothing to be done

                }

            break;

        default:

            break;

        }

    return ETrue; // consume

    }

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

// Handle a pointer event

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

//

TBool CGestureHelperImpl::HandleSinglePointerEventL( const TPointerEvent& aEvent,

        CAlfVisual* aVisual )

    {  

    switch ( aEvent.iType )

        {

        case TPointerEvent::EButton1Down:

            // If no up event was received during previous gesture, cancel 

            // previous event and reset state

            if ( !IsIdle() )

                {

                // ambiguous what is the right thing when "cancel" event leaves

                // and "start" does not. Leaving for cancel *after* "start" could 

                // be unexpected to client, as client would have handled start 

                // event successfully. Assume that leaving upon cancellation 

                // can be ignored.

                TRAP_IGNORE( EmitCancelEventL() );

                Reset();  

                }

            // as long as down event of a double tap comes within the double 

            // tap timeout, it does not matter how long the user keeps the finger

            // pressed for the gesture to be a double tap. Therefore, cancel

            // the timeout, as it is no longer relevant. (Of course, this call

            // will only do something if the timer is actually running, which

            // is only if received a tap event very recently.)

            iDoubleTapTimer->Cancel();

            // adding the first point implicitly makes the state "not idle"

            AddPointL( aEvent );

            iGesture->SetVisual( aVisual );

            // if pointer capturer leaves, the remaining pointer events will

            // not be captured if stylus is dragged outside the capturing visual

            // an error note will be shown, so the potential problem is irrelevant,

            // assuming client does not (incorrectly) block the leave from reaching 

            // the framework

            iPointerCapturer->StartL();

            // Delay emitting a down event _until_ it is known that this beginning 

            // gesture is _not_ the second tap of a double tap event.

            // iPreviousTapGesture is only non-null if very recently received 

            // a tap event and double tap is enabled. 

            if ( !iPreviousTapGesture )

                {

                EmitEventL( *iGesture );

                }

            // else delay emitting an event, as it might be a double tap 

            // (allow the second tap of a double tap to be anywhere, so don't check

            // for start pos here)

            break;

        case TPointerEvent::EDrag:

            // While stylus down, the same event is received repeatedly

            // even if stylus does not move. Filter out by checking if point 

            // is the same as the latest point

            if ( !iGesture->IsLatestPoint( Position( aEvent ) ) )

                {

                AddPointL( aEvent );

                // as long as the starting gesture is seen as a tap, do not emit any

                // drag events

                if ( !iGesture->IsTap() )

                    {

                    // if there is a previous tap gesture, getting drag events means that

                    // the previous gesture is not a double tap. So emit the previous gesture.

                    if ( iPreviousTapGesture )

                        {

                        // this is a second gesture after a tap (double tap is enabled)

                        EmitFirstTapEventL();

                        // emit down event for the current gesture (since its down was delayed, until

                        // it was to be known if the event is a tap. That is known now.)

                        EmitStartEventL( *iGesture );

                        }

                    // restart holding timer every time the current stylus pos changes

                    StartHoldingTimer( aEvent );

                    // emit the drag event to client

                    EmitEventL( *iGesture );

                    }

                // else: do not emit drag events until it is known that the gesture is not a tap

                // (or the second tap of double tap)

                }

            break;

        case TPointerEvent::EButton1Up:

            // reset in case the down event for next gesture is not received for a reason 

            // in client, and instead drag or up events are received. 

            // reset via cleanup stack to ensure Reset is run even if

            // observer leaves

            CleanupStack::PushL( TCleanupItem( &ResetHelper, this ) );

            // if adding of the point fails, notify client with a 

            // cancelled event. It would be wrong to send another

            // gesture code when the up point is not known

            if ( KErrNone == AddPoint( aEvent ) )

                {

                // if the gesture is a tap, the gesture is either the first tap of a _potential_

                // double tap, or the second tap of a double tap

                if ( iDoubleTapTimer->IsEnabled() && iGesture->IsTap() )

                    {

                    __ASSERT_DEBUG( !iGesture->IsHolding(), Panic( EGesturePanicIllegalLogic ) );

                    if ( !iPreviousTapGesture )

                        {

                        // First tap. Delay emitting its code evemt and released events until it is known

                        // whether the tap is a double tap

                        iPreviousTapGesture = iGesture;

                        iGesture = NewGesture();

                        iDoubleTapTimer->Start(); 

                        }

                    else

                        {

                        // This is a second tap of a double tap. Do not emit anything for the second

                        // tap. Only down event has been emitted for the first tap. Emit the code 

                        // event (double tap) and released for the first tap.

                        iPreviousTapGesture->SetDoubleTap();

                        EmitFirstTapEventL();

                        }

                    }

                else 

                    {

                    // modified iGesture to be "released"

                    CompleteAndEmitSingleTouchL( *iGesture );

                    }

                }

            else

                { // adding a point failed

                EmitCancelEventL();

                }

            // reset state

            CleanupStack::PopAndDestroy( this ); 

            break;

        default:

            break;

        }

    return ETrue; // consume

    }

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

// Handle multiple pointer events

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

//

TBool CGestureHelperImpl::HandleMultiplePointerEventL( const TPointerEvent& aEvent,

       const TInt aPointerNumber )

    { 

    switch ( aEvent.iType )

        {

        case TPointerEvent::EButton1Down:

            // adding the first point implicitly makes the state "not idle"

            AddMultiTouchPointsL( aEvent, aPointerNumber);