webengine/webkitutils/rt_gesturehelper/src/gesture.cpp
changeset 42 d39add9822e2
parent 38 6297cdf66332
child 46 ea4b2e4f7cac
child 47 9377e2ba0634
child 65 5bfc169077b2
--- a/webengine/webkitutils/rt_gesturehelper/src/gesture.cpp	Mon Jan 18 21:20:18 2010 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,726 +0,0 @@
-/*
-* 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 the License "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 "gesture.h"
-
-#include <e32math.h>
-#include <coemain.h>
-
-#include "gesturedefs.h"
-#include "utils.h"
-
-using namespace RT_GestureHelper;
-
-/** 
- * Point array for which only x axis is relevant
- */
-class TXAxisPointArray : public TPointArray
-    {
-public:
-    TXAxisPointArray( const RArray< TPointEntry >& aPoints )
-            : TPointArray( aPoints ) {}
-        
-    // from TPointArray
-    TPoint operator[]( TInt aIndex ) const 
-        {
-        return TPoint( Raw( aIndex ).iX, 0 );
-        }
-    };
-
-/** 
- * Point array for which only y axis is relevant
- */
-class TYAxisPointArray : public TPointArray
-    {
-public:
-    TYAxisPointArray( const RArray< TPointEntry >& aPoints )
-            : TPointArray( aPoints ) {}
-    
-    // from TPointArray
-    TPoint operator[]( TInt aIndex ) const 
-        {
-        return TPoint( 0, Raw( aIndex ).iY );
-        }
-    };
-
-namespace 
-    {
-    /** @return the current time */
-    TTime CurrentTime()
-        {
-        TTime time;
-        time.HomeTime();
-        return time;
-        }
-
-    /**
-     * @param aRelevantAxis See @ref MGestureEvent::Code
-     * @return gesture code by analysing the sequence of points
-     */
-    TGestureCode CodeFromPoints( const RArray< TPointEntry >& aPoints, 
-                                 TAxis aRelevantAxis ) 
-        {
-        // 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( aPoints );
-        TYAxisPointArray filterX( aPoints );
-        TPointArray filterNone( aPoints );
-        TPointArray& filter = 
-            aRelevantAxis == EAxisHorizontal ? static_cast< TPointArray& >( filterY ) : 
-            aRelevantAxis == EAxisVertical   ? static_cast< TPointArray& >( 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 TGestureRecogniser().GestureCode( filter );
-        }
-    } // unnamed namespace
-
-// ----------------------------------------------------------------------------
-// destructor
-// ----------------------------------------------------------------------------
-//
-CGesture::~CGesture()
-    {
-    iPoints.Close();
-    }
-
-// ----------------------------------------------------------------------------
-// AsStartEventL
-// ----------------------------------------------------------------------------
-//
-CGesture* CGesture::AsStartEventLC() const
-    {
-    __ASSERT_DEBUG( 0 < iPoints.Count(), Panic( EGesturePanicIllegalLogic ) );
-    CGesture* gesture = new ( ELeave ) CGesture;
-    CleanupStack::PushL( gesture );
-    User::LeaveIfError( gesture->AddPoint( iPoints[0].iPos, CCoeEnv::Static()->LastEvent().Time()));
-    return gesture;
-    }
-
-// ----------------------------------------------------------------------------
-// Reset
-// ----------------------------------------------------------------------------
-//
-void CGesture::Reset()
-    {
-    iPoints.Reset();
-    iHoldingState = ENotHolding;
-    iState = ENotComplete;
-    iHoldingPointIndex = 0;
-    iIsDoubleTap = EFalse;
-    iIsLongTap = EFalse;
-    }
-    
-// ----------------------------------------------------------------------------
-// Reset
-// ----------------------------------------------------------------------------
-//
-TBool CGesture::IsEmpty() const
-    {
-    return iPoints.Count() == 0;
-    }
-
-// ----------------------------------------------------------------------------
-// Add a point to the sequence of points that together make up the gesture
-// ----------------------------------------------------------------------------
-//
-TInt CGesture::AddPoint( const TPoint& aPoint, const TTime& aEventTime )
-    {
-    if ( !IsLatestPoint( aPoint ) )
-        {
-        return iPoints.Append( TPointEntry( aPoint, aEventTime ) );
-        }
-    return KErrNone;
-    }
-
-// ----------------------------------------------------------------------------
-// SetVisual
-// ----------------------------------------------------------------------------
-//
-
-
-// ----------------------------------------------------------------------------
-// IsNearHoldingPoint
-// ----------------------------------------------------------------------------
-//
-TBool CGesture::IsNearHoldingPoint( const TPoint& aPoint ) const
-    {
-    return ToleranceRect( iPoints[ iHoldingPointIndex ].iPos ).Contains( aPoint );
-    }
-
-// ----------------------------------------------------------------------------
-// IsLatestPoint
-// ----------------------------------------------------------------------------
-//
-TBool CGesture::IsLatestPoint( const TPoint& aPoint ) const
-    {
-    if ( iPoints.Count() > 0 )
-        {
-        return aPoint == CurrentPos();
-        }
-    return EFalse;
-    }
-
-// ----------------------------------------------------------------------------
-// StartHolding
-// ----------------------------------------------------------------------------
-//
-void CGesture::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 CGesture::SetHoldingPoint()
-    {
-    iHoldingPointIndex = iPoints.Count() - 1;
-    }
-
-// ----------------------------------------------------------------------------
-// ContinueHolding
-// ----------------------------------------------------------------------------
-//
-void CGesture::ContinueHolding()
-    {
-    iHoldingState = EHolding;
-    }
-
-// ----------------------------------------------------------------------------
-// SetReleased
-// ----------------------------------------------------------------------------
-//
-void CGesture::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 CGesture::SetComplete()
-    {
-    __ASSERT_DEBUG( iPoints.Count() > 0, Panic( EGesturePanicIllegalLogic ) );
-    iState = EComplete;
-    iCompletionTime = CurrentTime();
-    }
-
-// ----------------------------------------------------------------------------
-// SetComplete
-// ----------------------------------------------------------------------------
-//
-void CGesture::SetCancelled()
-    {
-    iState = ECancelled;
-    }
-
-void CGesture::SetDoubleTap() 
-    { 
-    iIsDoubleTap = ETrue; 
-    }
-
-void CGesture::SetLongTap(TBool aLongTap) 
-    { 
-    iIsLongTap = aLongTap; 
-    }
-
-// ----------------------------------------------------------------------------
-// IsTap
-// ----------------------------------------------------------------------------
-//
-TBool CGesture::IsTap() const
-    {
-    return CodeFromPoints( iPoints, 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 TGestureCode Hold( TGestureCode aCode )
-    {
-    if ( aCode != EGestureStart && 
-         aCode != EGestureDrag && 
-         aCode != EGestureReleased && 
-         aCode != EGestureUnknown )
-        {
-        return static_cast< TGestureCode >( aCode | EFlagHold );
-        }
-    return aCode;
-    }
-    
-// ----------------------------------------------------------------------------
-// Code
-// ----------------------------------------------------------------------------
-//
-TGestureCode CGesture::Code( TAxis aRelevantAxis ) /* const */
-    {
-    TGestureCode code;
-    
-    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() )
-                {
-                code = EGestureStart;
-                }
-            // "drag" event if holding not started or holding started earlier
-            else if ( iHoldingState != EHoldStarting )
-                {
-                code = EGestureDrag; 
-                }
-            // holding was just started
-            else 
-                {
-                code = Hold( CodeFromPoints( iPoints, aRelevantAxis ) );
-                }
-            iPrevGestureCode = code;
-            break;
-            }
-        case EComplete:
-            {
-            if ( iIsDoubleTap )
-                {
-                code = EGestureDoubleTap;
-                }
-            else if ( iIsLongTap )
-                {
-                code = EGestureLongTap;
-                }
-            
-            else if (iPrevGestureCode == EGestureDrag)
-                {
-                //code = IsFlick() ? EGestureFlick : EGestureDrop;
-                if (IsFlick()) 
-                    {
-                    code = EGestureFlick ;
-                    }
-                  else
-                    {
-                    // Check if it is a swipe.  In this case a swipe is a gesture where 
-                    // - the direction is close to the axes (up, down, left, right)
-                    // - speed is slower than flick 
-                    code = CodeFromPoints( iPoints, aRelevantAxis );
-                    if (code == EGestureUnknown)    
-                      {
-                      code = EGestureDrop ; // It was not a swipe, so then it is the drop gesture 
-                      }
-                    }
-                }
-            else
-                {
-                code = CodeFromPoints( iPoints, aRelevantAxis );
-                }
-            iPrevGestureCode = code;
-            break;
-            }
-            
-        case EReleased:
-            {
-            code = EGestureReleased;
-            break;
-            }
-            
-        case ECancelled: // fallthrough
-        default: 
-            code = EGestureUnknown;
-        }
-    return code;
-    }
-
-
-TBool CGesture::IsFlick() const
-    {
-    bool flick = EFalse;
-    TRealPoint speed = Speed();
-    TReal32 xSpeed = speed.iX;
-    TReal32 ySpeed = speed.iY;
-            
-    flick = (Abs(xSpeed) > KFlickSpeed || 
-             Abs(ySpeed) > KFlickSpeed);
-        
-    return flick;
-    }
-
-// ----------------------------------------------------------------------------
-// IsHolding
-// ----------------------------------------------------------------------------
-//
-TBool CGesture::IsHolding() const
-    {
-    return iHoldingState >= EHoldStarting;
-    }
-
-// ----------------------------------------------------------------------------
-// StartPos
-// ----------------------------------------------------------------------------
-//
-TPoint CGesture::StartPos() const
-    {
-    // at least one point will be in the array during callback (pointer down pos)
-    return iPoints[ 0 ].iPos;
-    }
-
-// ----------------------------------------------------------------------------
-// CurrentPos
-// ----------------------------------------------------------------------------
-//
-TPoint CGesture::CurrentPos() const
-    {
-    // at least on point will be in the array during callback (pointer down pos)
-    return iPoints.Count() > 0 ? iPoints[ iPoints.Count() - 1 ].iPos : TPoint(-1, -1);
-    }
-
-// ----------------------------------------------------------------------------
-// IsMovementStopped
-// ----------------------------------------------------------------------------
-//
-inline TBool CGesture::IsMovementStopped() const
-    {
-    // iCompletionTime is only only valid if client has called SetComplete 
-    if ( iState >= EComplete )
-        {
-        TInt el = Elapsed( NthLastEntry( 1 ).iTime, iCompletionTime ).Int(); 
-        return el > 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< TPointEntry >& 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< TPointEntry >& 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 CGesture::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 CGesture::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 CGesture::Distance() const
-    {
-    return CurrentPos() - StartPos();
-    }
-
-// ----------------------------------------------------------------------------
-// Visual
-// ----------------------------------------------------------------------------
-//
-
-// ----------------------------------------------------------------------------
-// TimeFromPreviousPoint
-// ----------------------------------------------------------------------------
-//
-inline TTimeIntervalMicroSeconds32 CGesture::TimeFromPreviousPoint() const
-    {
-    const TInt KLatestEntryOffset = 1;
-    return Elapsed( PreviousEntry().iTime, NthLastEntry( KLatestEntryOffset ).iTime );
-    }
-
-// ----------------------------------------------------------------------------
-// return nth point from the end of the points array
-// ----------------------------------------------------------------------------
-//
-inline const TPointEntry& CGesture::NthLastEntry( TInt aOffset ) const
-    {
-    return iPoints[ Max( iPoints.Count() - aOffset, 0 ) ];
-    }
-
-// ----------------------------------------------------------------------------
-// PreviousEntry
-// ----------------------------------------------------------------------------
-//
-inline const TPointEntry& CGesture::PreviousEntry() const
-    {
-    return NthLastEntry( KPreviousPointOffset );
-    }
-
-// ----------------------------------------------------------------------------
-// PreviousPos
-// ----------------------------------------------------------------------------
-//
-inline TPoint CGesture::PreviousPos() const
-    {
-    return PreviousEntry().iPos;
-    }
-
-inline TTime CGesture::TimeOfLastEntry() const
-    {
-    return NthLastEntry( 1 ).iTime;
-    }