--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/webengine/webkitutils/rt_gesturehelper/src/gesturerecogniser.cpp Mon Mar 30 12:54:55 2009 +0300
@@ -0,0 +1,224 @@
+/*
+* 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 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 helper implementation
+*
+*/
+
+
+#include "gesturerecogniser.h"
+
+#include <e32math.h>
+
+#include "gesturedefs.h"
+#include "rt_gestureobserver.h"
+#include "pointarray.h"
+#include "utils.h"
+
+using namespace RT_GestureHelper;
+
+/**
+ * Vector class (math)
+ */
+NONSHARABLE_CLASS( TVector )
+ {
+public:
+ /**
+ * Constructor
+ * @param aFrom starting point of the vector
+ * @param aTo ending point of the vector
+ */
+ TVector( const TPoint& aFrom, const TPoint& aTo )
+ : iX( aTo.iX - aFrom.iX ),
+ iY( aTo.iY - aFrom.iY )
+ {
+ }
+
+ /** @return angle of the vector */
+ TReal Angle() const
+ {
+ TReal angle = 0;
+ TReal length = Length();
+ if ( length != 0 )
+ {
+ Math::ACos( angle, iX / Length() );
+ if ( iY < 0 )
+ {
+ angle = 2 * KPi - angle;
+ }
+ }
+ return Degrees( angle );
+ }
+
+ /** @return length of the vector */
+ TReal Length() const
+ {
+ TReal length = 0;
+ Math::Sqrt( length, iX * iX + iY * iY );
+ return length;
+ }
+
+private:
+ /** @return radians in degrees */
+ inline TReal Degrees( TReal aRadians ) const
+ {
+ return aRadians * 180 / KPi;
+ }
+
+public:
+ /// x coordinate that represent the vector
+ TReal iX;
+ /// y coordinate that represent the vector
+ TReal iY;
+ };
+
+inline TPoint LastPoint( const TPointArray& aPoints )
+ {
+ __ASSERT_DEBUG( aPoints.Count() > 0, Panic( EGesturePanicIllegalLogic ) );
+ return aPoints[ aPoints.Count() - 1 ] ;
+ }
+
+/**
+ * @return Length of the gesture in points
+ */
+inline TReal GestureLength( const TPointArray& aPoints )
+ {
+ return TVector( aPoints[0], LastPoint( aPoints ) ).Length();
+ }
+
+/**
+ * @return ETrue if aAngleUnderTest is almost aAngle
+ * Closeness of the angles is controlled by KAngleTolerance
+ */
+static TBool IsNear( TReal aAngleUnderTest, TReal aAngle )
+ {
+ return aAngle - KAngleTolerance <= aAngleUnderTest &&
+ aAngleUnderTest <= aAngle + KAngleTolerance;
+ }
+
+/**
+ * @return the angle as a direction flags of TGesture
+ */
+inline TGestureCode Direction( TReal aAngle )
+ {
+ TGestureCode direction = EGestureUnknown;
+
+ if ( IsNear( aAngle, 90.0 ) )
+ {
+ direction = EGestureSwipeDown;
+ }
+ else if ( IsNear( aAngle, 180.0 ) )
+ {
+ direction = EGestureSwipeLeft;
+ }
+ else if ( IsNear( aAngle, 270.0 ) )
+ {
+ direction = EGestureSwipeUp;
+ }
+ else if ( 360.0 - KAngleTolerance <= aAngle || aAngle <= KAngleTolerance )
+ {
+ direction = EGestureSwipeRight;
+ }
+ else // for lint warning
+ {
+ // unknown angle
+ }
+
+ return direction;
+ }
+
+/** @return direction between points */
+inline TGestureCode Direction( const TPoint& aFromPoint, const TPoint& aToPoint )
+ {
+ return Direction( TVector( aFromPoint, aToPoint ).Angle() );
+ }
+
+/** @return overall direction between points */
+static TGestureCode GeneralDirection( const TPointArray& aPoints )
+ {
+ // If the start and end points are too close to each other, direction
+ // is undefined
+ if ( ToleranceRect( aPoints[0] ).Contains( LastPoint( aPoints ) ) )
+ {
+ return EGestureUnknown;
+ }
+ return Direction( aPoints[0], LastPoint( aPoints ) );
+ }
+
+// function type to get a point in the point array
+typedef TPoint (TPointArray::*PointByIndexFunc)( TInt aIndex ) const;
+
+/// @return latest point outside tolerance area or KErrNotFound if not point outside it
+TInt LatestCertainPointIndex( const TPointArray& aPoints, PointByIndexFunc aPointByIndex )
+ {
+ __ASSERT_DEBUG( aPoints.Count() > 0, Panic( EGesturePanicIllegalLogic ) );
+
+ int i = aPoints.Count();
+ TRect toleranceRect = ToleranceRect( (aPoints.*aPointByIndex)( aPoints.Count() - 1 ) );
+ // Find out the first point from the end of the array
+ // that is not contained in the tolerance rect.
+ while( 0 <= --i )
+ {
+ // if the point does not belong inside tolerance rect, it is the first point
+ // outside the rect
+ if( !toleranceRect.Contains( (aPoints.*aPointByIndex)(i) ) )
+ {
+ break;
+ }
+ }
+ return i;
+ }
+
+/** @return last direction of dragging */
+inline TGestureCode LastDirection( const TPointArray& aPoints )
+ {
+ TInt latestPointIndex = LatestCertainPointIndex( aPoints, TPointArray::operator[] );
+ if ( KErrNotFound != latestPointIndex )
+ {
+ return Direction( aPoints[latestPointIndex], LastPoint( aPoints ) );
+ }
+ // no points were outside the rect, and hence the direction is unknown
+ return EGestureUnknown;
+ }
+
+/**
+ * @return ETrue if points for a tap event
+ */
+inline TBool IsTap( const TPointArray& aPoints )
+ {
+ return KErrNotFound == LatestCertainPointIndex( aPoints, TPointArray::Raw );
+ }
+
+// ----------------------------------------------------------------------------
+// Return gesture code of a gesture formed by a sequence of points
+// ----------------------------------------------------------------------------
+//
+TGestureCode TGestureRecogniser::GestureCode( const TPointArray& aPoints ) const
+ {
+ __ASSERT_DEBUG( aPoints.Count() > 0, Panic( EGesturePanicIllegalLogic ) );
+
+ // tap needs to be treated separately, because recognising that needs to consider
+ // raw points (and not points in which x or y axis has been filtered out)
+ if ( IsTap( aPoints ) )
+ {
+ return EGestureTap;
+ }
+
+ TGestureCode direction = GeneralDirection( aPoints );
+ // if last direction is opposite of the general one, user has cancelled a swipe
+ if ( direction != LastDirection( aPoints ) )
+ {
+ direction = EGestureUnknown;
+ }
+ return direction;
+ }