/*
* Copyright (c) 2008-2008 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 class
*
*/
#include <e32math.h>
#include "xngesture.h"
#include "xngesturedefs.h"
using namespace XnGestureHelper;
// ======== LOCAL FUNCTIONS ===================================================
/**
* Point array for which only x axis is relevant
*/
class TXAxisPointArray : public TXnPointArray
{
public:
TXAxisPointArray( const RArray< TXnPointEntry >& aPoints )
: TXnPointArray( aPoints )
{
}
// from TXnPointArray
TPoint operator[]( TInt aIndex ) const
{
return TPoint( Raw( aIndex ).iX, 0 );
}
};
/**
* Point array for which only y axis is relevant
*/
class TYAxisPointArray : public TXnPointArray
{
public:
TYAxisPointArray( const RArray< TXnPointEntry >& aPoints )
: TXnPointArray( aPoints )
{
}
// from TXnPointArray
TPoint operator[]( TInt aIndex ) const
{
return TPoint( 0, Raw( aIndex ).iY );
}
};
/** @return the current time */
TTime CurrentTime()
{
TTime time;
time.UniversalTime();
return time;
}
// ----------------------------------------------------------------------------
// destructor
// ----------------------------------------------------------------------------
//
CXnGesture::~CXnGesture()
{
iPoints.Close();
}
// ----------------------------------------------------------------------------
// Reset
// ----------------------------------------------------------------------------
//
void CXnGesture::Reset()
{
// store previous gesture data before resetting the state
if ( iPoints.Count() > 0 )
{
iPreviousGesture = TGestureRecord( Type(), iCompletionTime,
iPoints[iPoints.Count() - 1].iPos );
}
else
{
iPreviousGesture = TGestureRecord();
}
iPoints.Reset();
iHoldingState = ENotHolding;
iState = ENotComplete;
iHoldingPointIndex = 0;
}
// ----------------------------------------------------------------------------
// Reset
// ----------------------------------------------------------------------------
//
TBool CXnGesture::IsEmpty() const
{
return iPoints.Count() == 0;
}
// ----------------------------------------------------------------------------
// Add a point to the sequence of points that together make up the gesture
// ----------------------------------------------------------------------------
//
TInt CXnGesture::AddPoint( const TPoint& aPoint )
{
if ( !IsLatestPoint( aPoint ) )
{
return iPoints.Append( TXnPointEntry( aPoint, CurrentTime() ) );
}
return KErrNone;
}
/**
* @return ETrue if the point is within a specified distance of the other point
*/
inline TBool IsNear( const TPoint& aPointUnderTest, const TPoint& aPoint,
TInt aMargin )
{
TRect rect(
aPoint.iX - aMargin, aPoint.iY - aMargin,
aPoint.iX + aMargin, aPoint.iY + aMargin );
return rect.Contains( aPointUnderTest );
}
// ----------------------------------------------------------------------------
// IsNearHoldingPoint
// ----------------------------------------------------------------------------
//
TBool CXnGesture::IsNearHoldingPoint( const TPoint& aPoint ) const
{
return IsNear( aPoint, iPoints[iHoldingPointIndex].iPos,
KSamePointTolerance );
}
// ----------------------------------------------------------------------------
// IsLatestPoint
// ----------------------------------------------------------------------------
//
TBool CXnGesture::IsLatestPoint( const TPoint& aPoint ) const
{
if ( iPoints.Count() > 0 )
{
return aPoint == CurrentPos();
}
return EFalse;
}
// ----------------------------------------------------------------------------
// StartHolding
// ----------------------------------------------------------------------------
//
void CXnGesture::StartHolding()
{
iHoldingState = EHoldStarting;
// remove all points that were introduced after holding started
for ( TInt i = iPoints.Count() - 1; i > iHoldingPointIndex; i-- )
{
iPoints.Remove( i );
}
}
// ----------------------------------------------------------------------------
// SetHoldingPoint
// ----------------------------------------------------------------------------
//
void CXnGesture::SetHoldingPoint()
{
iHoldingPointIndex = iPoints.Count() - 1;
}
// ----------------------------------------------------------------------------
// ContinueHolding
// ----------------------------------------------------------------------------
//
void CXnGesture::ContinueHolding()
{
iHoldingState = EHolding;
}
// ----------------------------------------------------------------------------
// SetReleased
// ----------------------------------------------------------------------------
//
void CXnGesture::SetReleased()
{
// IsMovementStopped expects SetComplete to be called before SetRelea
__ASSERT_DEBUG( EComplete == iState, Panic( EGesturePanicIllegalLogic ) );
iState = EReleased;
}
/**
* @return elapsed time between aStartTime and aEndTime
*/
inline TTimeIntervalMicroSeconds32 Elapsed(
const TTime& aStartTime,
const TTime& aEndTime )
{
return aEndTime.MicroSecondsFrom( aStartTime ).Int64();
}
// ----------------------------------------------------------------------------
// SetComplete
// ----------------------------------------------------------------------------
//
void CXnGesture::SetComplete()
{
__ASSERT_DEBUG( iPoints.Count() > 0, Panic( EGesturePanicIllegalLogic ) );
iState = EComplete;
iCompletionTime = CurrentTime();
}
// ----------------------------------------------------------------------------
// SetComplete
// ----------------------------------------------------------------------------
//
void CXnGesture::SetCancelled()
{
iState = ECancelled;
}
// ----------------------------------------------------------------------------
// IsTap
// ----------------------------------------------------------------------------
//
TBool CXnGesture::IsTap() const
{
return CodeFromPoints( EAxisBoth ) == EGestureTap;
}
/**
* Translates a non-holding code into a holding code
* @param aCode original gesture code
* @return a gesture code with hold flag applied
*/
inline TXnGestureCode Hold( TXnGestureCode aCode )
{
if ( aCode != EGestureStart &&
aCode != EGestureDrag &&
aCode != EGestureReleased &&
aCode != EGestureUnknown )
{
return static_cast< TXnGestureCode >( aCode | EFlagHold );
}
return aCode;
}
// ----------------------------------------------------------------------------
// Code
// ----------------------------------------------------------------------------
//
TXnGestureCode CXnGesture::Code( TAxis aRelevantAxis ) const
{
switch ( iState )
{
case ENotComplete:
// "start" event if only first point received
// need to check that not holding, in case user pressed stylus
// down, and activated holding without moving the stylus
if ( iPoints.Count() == 1 && !IsHolding() )
{
return EGestureStart;
}
// "drag" event if holding not started or holding started earlier
else if ( iHoldingState != EHoldStarting )
{
return EGestureDrag;
}
// holding was just started
else
{
return Hold( CodeFromPoints( aRelevantAxis ) );
}
case EComplete:
{
TXnGestureCode code = CodeFromPoints( aRelevantAxis );
#ifdef _GESTURE_DOUBLE_TAP_SUPPORT
if ( EGestureTap == code && IsTapDoubleTap() )
{
code = EGestureDoubleTap;
}
#endif // _GESTURE_DOUBLE_TAP_SUPPORT
return code;
}
case EReleased:
return EGestureReleased;
case ECancelled: // fallthrough
default:
return EGestureUnknown;
}
}
// ----------------------------------------------------------------------------
// IsHolding
// ----------------------------------------------------------------------------
//
TBool CXnGesture::IsHolding() const
{
return iHoldingState >= EHoldStarting;
}
// ----------------------------------------------------------------------------
// StartPos
// ----------------------------------------------------------------------------
//
TPoint CXnGesture::StartPos() const
{
// at least one point will be in the array during callback (pointer down pos)
return iPoints[0].iPos;
}
// ----------------------------------------------------------------------------
// CurrentPos
// ----------------------------------------------------------------------------
//
TPoint CXnGesture::CurrentPos() const
{
// at least on point will be in the array during callback (pointer down pos)
return iPoints[iPoints.Count() - 1].iPos;
}
// ----------------------------------------------------------------------------
// IsMovementStopped
// ----------------------------------------------------------------------------
//
inline TBool CXnGesture::IsMovementStopped() const
{
// iCompletionTime is only only valid if client has called SetComplete
if ( iState >= EComplete )
{
return Elapsed( NthLastEntry( 1 ).iTime, iCompletionTime )
.Int() > KSpeedStopTime;
}
return EFalse;
}
namespace
{
const TInt KFloatingPointAccuracy = 0.000001;
/** @return percentage (0.0-1.0) how far aPos is from aEdge1 towards aEdge2 */
inline TReal32 Proportion( TReal32 aPos, TReal32 aEdge1, TReal32 aEdge2 )
{
if ( Abs( aEdge2 - aEdge1 ) > KFloatingPointAccuracy )
{
return ( aPos - aEdge1 ) / ( aEdge2 - aEdge1 );
}
return 0; // avoid division by zero
}
/** Edges (pixels) at which speed should be -100% or 100% */
NONSHARABLE_STRUCT( TEdges )
{
TReal32 iMin;
TReal32 iMax;
};
/**
* scale which allows different (coordinate -> percentage) mapping
* between -100% to 0% and 0 and 100%
*/
NONSHARABLE_STRUCT( TScale )
{
TScale( TInt aZero, const TEdges& aEdges )
: iMin( aEdges.iMin ), iZero( aZero ), iMax( aEdges.iMax )
{
}
/** @return aPos as a percentage between -100% and 100% in aScale */
TReal32 Percent( TReal32 aPos ) const;
/// coordinate where speed is -100%
TReal32 iMin;
/// coordinate where speed is 0%
TReal32 iZero;
/// coordinate where speed is 100%
TReal32 iMax;
};
/** @convert aPos into a percentage between -100% and 100% in aScale */
TReal32 TScale::Percent( TReal32 aPos ) const
{
TReal32 percent;
if ( aPos < iZero )
{
// return negative percentages on the lower side of zero point
percent = -1 * Proportion( aPos, iZero, iMin );
}
else
{
percent = Proportion( aPos, iZero, iMax );
}
// constrain between -100% and 100%
return Min( Max( percent, -1.0F ), 1.0F );
}
/** Scale in x and y dimensions */
NONSHARABLE_STRUCT( TScale2D )
{
TRealPoint Percent( const TPoint& aPos ) const
{
return TRealPoint(
iX.Percent( aPos.iX ),
iY.Percent( aPos.iY ) );
}
TScale iX;
TScale iY;
};
enum TDirection { ESmaller, ELarger };
/** @return the direction of pos compared to the previous pos */
inline TDirection Direction( TInt aPos, TInt aPreviousPos )
{
return aPos < aPreviousPos ? ESmaller : ELarger;
}
/** Direction in x and y dimensions */
NONSHARABLE_STRUCT( TDirection2D )
{
TDirection iX;
TDirection iY;
};
/** Return the direction (up/down) of signal at aIndex */
inline TDirection2D Direction(
TInt aIndex,
const RArray< TXnPointEntry >& aPoints )
{
const TPoint& pos = aPoints[aIndex].iPos;
const TPoint& prevPos = aPoints[aIndex - 1].iPos;
TDirection2D dir = {
Direction( pos.iX, prevPos.iX ),
Direction( pos.iY, prevPos.iY ) };
return dir;
}
/**
* @return a position in the aLow and aHigh, so that it aProportion of
* of length is above the pos
*/
TReal32 ProportionalLength( TReal32 aLow, TReal32 aHigh, TReal32 aProportion )
{
return ( aHigh - aLow ) * aProportion / ( 1 + aProportion );
}
/**
* @return aVariableEdge scaled to new position, when the other edge changes
* from aOldEdge to aNewEdge, so that aOrigin maintains the *same
* relative position* between aVariableEdge and the other edge
*/
inline TReal32 ScaledEdge(
TReal32 aOrigin,
TReal32 aVariableEdge,
TReal32 aOldEdge,
TReal aNewEdge )
{
TReal32 proportion = Proportion( aOrigin, aVariableEdge, aOldEdge );
return ( proportion * aNewEdge - aOrigin ) / ( proportion - 1 );
}
TScale Rescale(
TReal32 aPos,
TDirection aDir,
TDirection aPrevDir,
const TScale& aPrevScale,
const TEdges& aEdges )
{
TScale scale( aPrevScale );
if ( aPrevDir != aDir )
{
// the code duplication is accepted here, since it is difficult
// to factor out while maintaining the understandability of this
// anyway complex algorithm
if ( aDir == ESmaller )
{
scale.iMin = aEdges.iMin;
if ( aPrevScale.iZero < aPos )
{
TReal32 proportionAboveZero = Proportion(
aPos, aPrevScale.iZero, aPrevScale.iMax );
scale.iZero = aPos - ProportionalLength(
aEdges.iMin, aPos, proportionAboveZero );
}
else
{
// adjust zero pos so that proportion between aPos, Min,
// and Zero pos stay the same (Min will move to 0,
// aPos stays the same)
scale.iZero = ScaledEdge( aPos, aPrevScale.iZero,
aPrevScale.iMin, aEdges.iMin );
}
// adjust the upper edge to take into account the movement of
// zero pos
scale.iMax = ScaledEdge( aPos, aPrevScale.iMax,
aPrevScale.iZero, scale.iZero );
}
else // ELarger
{
scale.iMax = aEdges.iMax;
if ( aPos < aPrevScale.iZero )
{
TReal32 proportionBelowZero = Proportion(
aPos, aPrevScale.iZero, aPrevScale.iMin );
scale.iZero = aPos + ProportionalLength(
aPos, aEdges.iMax, proportionBelowZero );
}
else
{
// adjust zero pos so that proportion between aPos, Max, and
// Zero pos stay the same (Max will move edge, aPos stays
// the same)
scale.iZero = ScaledEdge( aPos, aPrevScale.iZero,
aPrevScale.iMax, aEdges.iMax );
}
// adjust the lower edge to take into account the movement of
// zero pos
scale.iMin = ScaledEdge( aPos, aPrevScale.iMin,
aPrevScale.iZero, scale.iZero );
}
}
return scale;
}
/** Edges in x and y dimensions */
NONSHARABLE_STRUCT( TEdges2D )
{
TEdges iX;
TEdges iY;
};
/**
* @param aEdges edges of the area in which gesture points are accepted
* @return the scale of latest point in the list of points
*/
TScale2D Scale( const RArray< TXnPointEntry >& aPoints, const TEdges2D& aEdges )
{
TScale2D scale = { TScale( aPoints[0].iPos.iX, aEdges.iX ),
TScale( aPoints[0].iPos.iY, aEdges.iY ) };
TInt count = aPoints.Count();
if ( count > 1 )
{
// iterate the whole point list to arrive to the current scale
TDirection2D dir( Direction( 1, aPoints ) );
for ( TInt i = 1; i < count; i++ )
{
// get direction at i
TDirection2D newDir( Direction( i, aPoints ) );
// get new scale at i
scale.iX = Rescale(
aPoints[i - 1].iPos.iX,
newDir.iX,
dir.iX,
scale.iX,
aEdges.iX );
scale.iY = Rescale(
aPoints[i - 1].iPos.iY,
newDir.iY,
dir.iY,
scale.iY,
aEdges.iY );
dir = newDir;
}
}
return scale;
}
} // unnamed namespace
TRealPoint CXnGesture::SpeedPercent( const TRect& aEdges ) const
{
// x and y coordinates are easier to handle separately, extract from TRect:
// ((iMinX, iMinY), (iMaxX, iMaxY)) -> ((iMinX, iMaxX), (iMinY, iMaxY))
TEdges2D edges = {
{ aEdges.iTl.iX, aEdges.iBr.iX },
{ aEdges.iTl.iY, aEdges.iBr.iY } };
// work out the current scale (coordinate -> percentage mapping) from
// the history of points (i.e., points of current gesture). Then
// calculate the percentage of the current position.
return Scale( iPoints, edges ).Percent( CurrentPos() );
}
// ----------------------------------------------------------------------------
// Speed
// ----------------------------------------------------------------------------
//
TRealPoint CXnGesture::Speed() const
{
const TReal32 KMicroSecondsInSecond = 1000000;
// Speed is only evaluated at the end of the swipe
// if user stops at the end of the swipe before lifting stylus,
// speed is zero. If time is zero, return 0 speed (infinite does
// not make sense either). Will need to consider also earlier points
// and their times or start time, if this zero-speed behavior is a problem
TRealPoint speed;
TReal32 time = static_cast< TReal32 >( TimeFromPreviousPoint().Int() )
/ KMicroSecondsInSecond;
if ( !IsMovementStopped() && time > 0 )
{
TPoint distance = CurrentPos() - PreviousPos();
speed.iX = static_cast< TReal32 >( distance.iX ) / time;
speed.iY = static_cast< TReal32 >( distance.iY ) / time;
}
return speed;
}
// ----------------------------------------------------------------------------
// Distance
// ----------------------------------------------------------------------------
//
TPoint CXnGesture::Distance() const
{
return CurrentPos() - StartPos();
}
// ----------------------------------------------------------------------------
// TimeFromPreviousPoint
// ----------------------------------------------------------------------------
//
inline TTimeIntervalMicroSeconds32 CXnGesture::TimeFromPreviousPoint() const
{
const TInt KLatestEntryOffset = 1;
return Elapsed( PreviousEntry().iTime, NthLastEntry( KLatestEntryOffset ).iTime );
}
// ----------------------------------------------------------------------------
// CodeFromPoints
// ----------------------------------------------------------------------------
//
TXnGestureCode CXnGesture::CodeFromPoints( TAxis aRelevantAxis ) const
{
// select the correct filter based on aRelevantAxis
// these filter_ objects are array decorators that will eliminate either
// x, y or neither coordinate of each point
TXAxisPointArray filterY( iPoints );
TYAxisPointArray filterX( iPoints );
TXnPointArray filterNone( iPoints );
TXnPointArray& filter =
aRelevantAxis == EAxisHorizontal ? static_cast< TXnPointArray& >( filterY ) :
aRelevantAxis == EAxisVertical ? static_cast< TXnPointArray& >( filterX ) :
/* otherwise EAxisBoth */ filterNone;
// currently the gesture recogniser does not have any state, so it is fast
// to instantiate. The call is not static however, to allow the recogniser
// to be replaced by a more complicated implementation that has state.
// then it may make sense to make the recogniser a member variable.
return TXnGestureRecogniser().GestureCode( filter );
}
// ----------------------------------------------------------------------------
// return nth point from the end of the points array
// ----------------------------------------------------------------------------
//
inline const TXnPointEntry& CXnGesture::NthLastEntry( TInt aOffset ) const
{
return iPoints[Max( iPoints.Count() - aOffset, 0 )];
}
// ----------------------------------------------------------------------------
// PreviousEntry
// ----------------------------------------------------------------------------
//
inline const TXnPointEntry& CXnGesture::PreviousEntry() const
{
return NthLastEntry( KPreviousPointOffset );
}
// ----------------------------------------------------------------------------
// PreviousPos
// ----------------------------------------------------------------------------
//
inline TPoint CXnGesture::PreviousPos() const
{
return PreviousEntry().iPos;
}
// ----------------------------------------------------------------------------
// SetComplete
// ----------------------------------------------------------------------------
//
TBool CXnGesture::IsTapDoubleTap() const
{
return iPreviousGesture.iType == TGestureRecord::ETypeTap &&
Elapsed( iPreviousGesture.iCompletionTime, iCompletionTime ).Int() <=
KMaxDoubleTapDuration &&
IsNear( iPreviousGesture.iPos, iPoints[iPoints.Count() - 1].iPos,
KSamePointTolerance );
}
// ----------------------------------------------------------------------------
// Type
// ----------------------------------------------------------------------------
//
CXnGesture::TGestureRecord::TType CXnGesture::Type() const
{
if ( CodeFromPoints( EAxisBoth ) == EGestureTap && !IsHolding() )
{
if ( IsTapDoubleTap() )
{
return CXnGesture::TGestureRecord::ETypeDoubleTap;
}
else
{
return CXnGesture::TGestureRecord::ETypeTap;
}
}
else
{
return CXnGesture::TGestureRecord::ETypeOther;
}
}
// ----------------------------------------------------------------------------
// TGestureRecord constructor
// ----------------------------------------------------------------------------
//
CXnGesture::TGestureRecord::TGestureRecord()
{
iType = ETypeOther;
}
// ----------------------------------------------------------------------------
// TGestureRecord constructor
// ----------------------------------------------------------------------------
//
CXnGesture::TGestureRecord::TGestureRecord(
CXnGesture::TGestureRecord::TType aType,
TTime aCompletionTime,
TPoint aPos )
: iType( aType ), iCompletionTime( aCompletionTime ), iPos( aPos )
{
}