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    41 

    42 #include "qdeclarativegesturearea_p.h"

    43 

    44 #include <qdeclarativeexpression.h>

    45 #include <qdeclarativecontext.h>

    46 #include <qdeclarativeinfo.h>

    47 

    48 #include <private/qdeclarativeproperty_p.h>

    49 #include <private/qdeclarativeitem_p.h>

    50 

    51 #include <QtCore/qdebug.h>

    52 #include <QtCore/qstringlist.h>

    53 

    54 #include <QtGui/qevent.h>

    55 

    56 #include <private/qobject_p.h>

    57 

    58 QT_BEGIN_NAMESPACE

    59 

    60 class QDeclarativeGestureAreaPrivate : public QDeclarativeItemPrivate

    61 {

    62     Q_DECLARE_PUBLIC(QDeclarativeGestureArea)

    63 public:

    64     QDeclarativeGestureAreaPrivate() : componentcomplete(false), gesture(0) {}

    65 

    66     typedef QMap<Qt::GestureType,QDeclarativeExpression*> Bindings;

    67     Bindings bindings;

    68 

    69     bool componentcomplete;

    70 

    71     QByteArray data;

    72 

    73     QGesture *gesture;

    74 

    75     bool gestureEvent(QGestureEvent *event);

    76 };

    77 

    78 /*!

    79     \qmlclass GestureArea QDeclarativeGestureArea

    80     \brief The GestureArea item enables simple gesture handling.

    81     \inherits Item

    82 

    83     A GestureArea is like a MouseArea, but it has signals for gesture events.

    84 

    85     \e {Elements in the Qt.labs module are not guaranteed to remain compatible

    86     in future versions.}

    87 

    88     \e {This element is only functional on devices with touch input.}

    89 

    90     \qml

    91     import Qt.labs.gestures 0.1

    92 

    93     GestureArea {

    94         anchors.fill: parent

    95         onPan: ... gesture.acceleration ...

    96         onPinch: ... gesture.rotationAngle ...

    97         onSwipe: ...

    98         onTapAndHold: ...

    99         onTap: ...

   100         onGesture: ...

   101     }

   102     \endqml

   103 

   104     Each signal has a \e gesture parameter that has the

   105     properties of the gesture.

   106 

   107     \table

   108     \header \o Signal \o Type \o Property \o Description

   109     \row \o onTap \o point \o position \o the position of the tap

   110     \row \o onTapAndHold \o point \o position \o the position of the tap

   111     \row \o onPan \o real \o acceleration \o the acceleration of the pan

   112     \row \o onPan \o point \o delta \o the offset from the previous input position to the current input

   113     \row \o onPan \o point \o offset \o the total offset from the first input position to the current input position

   114     \row \o onPan \o point \o lastOffset \o the previous value of offset

   115     \row \o onPinch \o point \o centerPoint \o the midpoint between the two input points

   116     \row \o onPinch \o point \o lastCenterPoint \o the previous value of centerPoint

   117     \row \o onPinch \o point \o startCenterPoint \o the first value of centerPoint

   118     \row \o onPinch \o real \o rotationAngle \o the angle covered by the gesture motion

   119     \row \o onPinch \o real \o lastRotationAngle \o the previous value of rotationAngle

   120     \row \o onPinch \o real \o totalRotationAngle \o the complete angle covered by the gesture

   121     \row \o onPinch \o real \o scaleFactor \o the change in distance between the two input points

   122     \row \o onPinch \o real \o lastScaleFactor \o the previous value of scaleFactor

   123     \row \o onPinch \o real \o totalScaleFactor \o the complete scale factor of the gesture

   124     \row \o onSwipe \o real \o swipeAngle \o the angle of the swipe

   125     \endtable

   126 

   127     Custom gestures, handled by onGesture, will have custom properties.

   128 

   129     GestureArea is an invisible item: it is never painted.

   130 

   131     \sa Gesture, MouseArea

   132 */

   133 

   134 /*!

   135     \internal

   136     \class QDeclarativeGestureArea

   137     \brief The QDeclarativeGestureArea class provides simple gesture handling.

   138 

   139 */

   140 QDeclarativeGestureArea::QDeclarativeGestureArea(QDeclarativeItem *parent) :

   141     QDeclarativeItem(*(new QDeclarativeGestureAreaPrivate), parent)

   142 {

   143     setAcceptedMouseButtons(Qt::LeftButton);

   144     setAcceptTouchEvents(true);

   145 }

   146 

   147 QDeclarativeGestureArea::~QDeclarativeGestureArea()

   148 {

   149 }

   150 

   151 QByteArray

   152 QDeclarativeGestureAreaParser::compile(const QList<QDeclarativeCustomParserProperty> &props)

   153 {

   154     QByteArray rv;

   155     QDataStream ds(&rv, QIODevice::WriteOnly);

   156 

   157     for(int ii = 0; ii < props.count(); ++ii)

   158     {

   159         QString propName = QString::fromUtf8(props.at(ii).name());

   160         Qt::GestureType type;

   161 

   162         if (propName == QLatin1String("onTap")) {

   163             type = Qt::TapGesture;

   164         } else if (propName == QLatin1String("onTapAndHold")) {

   165             type = Qt::TapAndHoldGesture;

   166         } else if (propName == QLatin1String("onPan")) {

   167             type = Qt::PanGesture;

   168         } else if (propName == QLatin1String("onPinch")) {

   169             type = Qt::PinchGesture;

   170         } else if (propName == QLatin1String("onSwipe")) {

   171             type = Qt::SwipeGesture;

   172         } else if (propName == QLatin1String("onGesture")) {

   173             type = Qt::CustomGesture;

   174         } else {

   175             error(props.at(ii), QDeclarativeGestureArea::tr("Cannot assign to non-existent property \"%1\"").arg(propName));

   176             return QByteArray();

   177         }

   178 

   179         QList<QVariant> values = props.at(ii).assignedValues();

   180 

   181         for (int i = 0; i < values.count(); ++i) {

   182             const QVariant &value = values.at(i);

   183 

   184             if (value.userType() == qMetaTypeId<QDeclarativeCustomParserNode>()) {

   185                 error(props.at(ii), QDeclarativeGestureArea::tr("GestureArea: nested objects not allowed"));

   186                 return QByteArray();

   187             } else if (value.userType() == qMetaTypeId<QDeclarativeCustomParserProperty>()) {

   188                 error(props.at(ii), QDeclarativeGestureArea::tr("GestureArea: syntax error"));

   189                 return QByteArray();

   190             } else {

   191                 QDeclarativeParser::Variant v = qvariant_cast<QDeclarativeParser::Variant>(value);

   192                 if (v.isScript()) {

   193                     ds << propName;

   194                     ds << int(type);

   195                     ds << v.asScript();

   196                 } else {

   197                     error(props.at(ii), QDeclarativeGestureArea::tr("GestureArea: script expected"));

   198                     return QByteArray();

   199                 }

   200             }

   201         }

   202     }

   203 

   204     return rv;

   205 }

   206 

   207 void QDeclarativeGestureAreaParser::setCustomData(QObject *object,

   208                                             const QByteArray &data)

   209 {

   210     QDeclarativeGestureArea *ga = static_cast<QDeclarativeGestureArea*>(object);

   211     ga->d_func()->data = data;

   212 }

   213 

   214 

   215 void QDeclarativeGestureArea::connectSignals()

   216 {

   217     Q_D(QDeclarativeGestureArea);

   218     if (!d->componentcomplete)

   219         return;

   220 

   221     QDataStream ds(d->data);

   222     while (!ds.atEnd()) {

   223         QString propName;

   224         ds >> propName;

   225         int gesturetype;

   226         ds >> gesturetype;

   227         QString script;

   228         ds >> script;

   229         QDeclarativeExpression *exp = new QDeclarativeExpression(qmlContext(this), 0, script);

   230         d->bindings.insert(Qt::GestureType(gesturetype),exp);

   231         grabGesture(Qt::GestureType(gesturetype));

   232     }

   233 }

   234 

   235 void QDeclarativeGestureArea::componentComplete()

   236 {

   237     QDeclarativeItem::componentComplete();

   238     Q_D(QDeclarativeGestureArea);

   239     d->componentcomplete=true;

   240     connectSignals();

   241 }

   242 

   243 QGesture *QDeclarativeGestureArea::gesture() const

   244 {

   245     Q_D(const QDeclarativeGestureArea);

   246     return d->gesture;

   247 }

   248 

   249 bool QDeclarativeGestureArea::sceneEvent(QEvent *event)

   250 {

   251     Q_D(QDeclarativeGestureArea);

   252     if (event->type() == QEvent::Gesture)

   253         return d->gestureEvent(static_cast<QGestureEvent*>(event));

   254     return QDeclarativeItem::sceneEvent(event);

   255 }

   256 

   257 bool QDeclarativeGestureAreaPrivate::gestureEvent(QGestureEvent *event)

   258 {

   259     bool accept = true;

   260     for (Bindings::Iterator it = bindings.begin(); it != bindings.end(); ++it) {

   261         if ((gesture = event->gesture(it.key()))) {

   262             it.value()->evaluate();

   263             event->setAccepted(true); // XXX only if value returns true?

   264         }

   265     }

   266     return accept;

   267 }

   268 

   269 QT_END_NAMESPACE