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#include "private/qgesturemanager_p.h"
#include "private/qstandardgestures_p.h"
#include "private/qwidget_p.h"
#include "private/qgesture_p.h"
#include "private/qgraphicsitem_p.h"
#include "qgesture.h"
#include "qevent.h"
#include "qgraphicsitem.h"

#ifdef Q_WS_MAC
#include "qmacgesturerecognizer_mac_p.h"
#endif

#include "qdebug.h"

// #define GESTURE_DEBUG
#ifndef GESTURE_DEBUG
# define DEBUG if (0) qDebug
#else
# define DEBUG qDebug
#endif

QT_BEGIN_NAMESPACE

QGestureManager::QGestureManager(QObject *parent)
    : QObject(parent), state(NotGesture), lastCustomGestureId(0)
{
    qRegisterMetaType<Qt::GestureState>();

#if defined(Q_WS_MAC)
    registerGestureRecognizer(new QMacSwipeGestureRecognizer);
    registerGestureRecognizer(new QMacPinchGestureRecognizer);
  #if defined(QT_MAC_USE_COCOA)
    registerGestureRecognizer(new QMacPanGestureRecognizer);
  #endif
#else
    registerGestureRecognizer(new QPanGestureRecognizer);
#endif
}

QGestureManager::~QGestureManager()
{

}

Qt::GestureType QGestureManager::registerGestureRecognizer(QGestureRecognizer *recognizer)
{
    QGesture *dummy = recognizer->createGesture(0);
    if (!dummy) {
        qWarning("QGestureManager::registerGestureRecognizer: the recognizer doesn't provide gesture object");
        return Qt::GestureType(0);
    }
    Qt::GestureType type = dummy->gestureType();
    if (type == Qt::CustomGesture) {
        // generate a new custom gesture id
        ++lastCustomGestureId;
        type = Qt::GestureType(Qt::CustomGesture + lastCustomGestureId);
    }
    recognizers.insertMulti(type, recognizer);
    delete dummy;
    return type;
}

void QGestureManager::unregisterGestureRecognizer(Qt::GestureType)
{

}

QGesture* QGestureManager::getState(QObject *object, Qt::GestureType type)
{
    // if the widget is being deleted we should be carefull and not to
    // create a new state, as it will create QWeakPointer which doesnt work
    // from the destructor.
    if (object->isWidgetType()) {
        if (static_cast<QWidget *>(object)->d_func()->data.in_destructor)
            return 0;
    }

    QWeakPointer<QGesture> state = objectGestures.value(QGestureManager::ObjectGesture(object, type));
    if (!state) {
        QGestureRecognizer *recognizer = recognizers.value(type);
        if (recognizer) {
            state = recognizer->createGesture(object);
            if (!state)
                return 0;
            if (state.data()->gestureType() == Qt::CustomGesture) {
                // if the recognizer didn't fill in the gesture type, then this
                // is a custom gesture with autogenerated it and we fill it.
                state.data()->d_func()->gestureType = type;
            }
            objectGestures.insert(QGestureManager::ObjectGesture(object, type), state);
            gestureToRecognizer[state.data()] = recognizer;
        }
    }
    return state.data();
}

bool QGestureManager::filterEvent(QObject *receiver, QEvent *event)
{
    QSet<QGesture *> triggeredGestures;
    QSet<QGesture *> finishedGestures;
    QSet<QGesture *> newMaybeGestures;
    QSet<QGesture *> canceledGestures;
    QSet<QGesture *> notGestures;

    QGraphicsObject *graphicsObject = qobject_cast<QGraphicsObject *>(receiver);
    if (receiver->isWidgetType() || graphicsObject) {
        QMap<QObject *, Qt::GestureType> contexts;
        if (receiver->isWidgetType()) {
            QWidget *w = static_cast<QWidget *>(receiver);
            if (!w->d_func()->gestureContext.isEmpty()) {
                typedef QMap<Qt::GestureType, Qt::GestureContext>::const_iterator ContextIterator;
                for(ContextIterator it = w->d_func()->gestureContext.begin(),
                    e = w->d_func()->gestureContext.end(); it != e; ++it) {
                    contexts.insertMulti(w, it.key());
                }
            }
            // find all gesture contexts for the widget tree
            w = w->parentWidget();
            while (w)
            {
                typedef QMap<Qt::GestureType, Qt::GestureContext>::const_iterator ContextIterator;
                for (ContextIterator it = w->d_func()->gestureContext.begin(),
                     e = w->d_func()->gestureContext.end(); it != e; ++it) {
                    if (it.value() == Qt::WidgetWithChildrenGesture)
                        contexts.insertMulti(w, it.key());
                }
                w = w->parentWidget();
            }
        } else {
            QGraphicsObject *item = graphicsObject;
            if (!item->QGraphicsItem::d_func()->gestureContext.isEmpty()) {
                typedef QMap<Qt::GestureType, Qt::GestureContext>::const_iterator ContextIterator;
                for(ContextIterator it = item->QGraphicsItem::d_func()->gestureContext.begin(),
                    e = item->QGraphicsItem::d_func()->gestureContext.end(); it != e; ++it) {
                    contexts.insertMulti(item, it.key());
                }
            }
            // find all gesture contexts for the widget tree
            item = item->parentObject();
            while (item)
            {
                typedef QMap<Qt::GestureType, Qt::GestureContext>::const_iterator ContextIterator;
                for (ContextIterator it = item->QGraphicsItem::d_func()->gestureContext.begin(),
                     e = item->QGraphicsItem::d_func()->gestureContext.end(); it != e; ++it) {
                    if (it.value() == Qt::WidgetWithChildrenGesture)
                        contexts.insertMulti(item, it.key());
                }
                item = item->parentObject();
            }
        }
        // filter the event through recognizers
        typedef QMap<QObject *, Qt::GestureType>::const_iterator ContextIterator;
        for (ContextIterator cit = contexts.begin(), ce = contexts.end(); cit != ce; ++cit) {
            Qt::GestureType gestureType = cit.value();
            QMap<Qt::GestureType, QGestureRecognizer *>::const_iterator
                    rit = recognizers.lowerBound(gestureType),
                    re = recognizers.upperBound(gestureType);
            for (; rit != re; ++rit) {
                QGestureRecognizer *recognizer = rit.value();
                QObject *target = cit.key();
                QGesture *state = getState(target, gestureType);
                if (!state)
                    continue;
                QGestureRecognizer::Result result = recognizer->filterEvent(state, target, event);
                QGestureRecognizer::Result type = result & QGestureRecognizer::ResultState_Mask;
                if (type == QGestureRecognizer::GestureTriggered) {
                    DEBUG() << "QGestureManager: gesture triggered: " << state;
                    triggeredGestures << state;
                } else if (type == QGestureRecognizer::GestureFinished) {
                    DEBUG() << "QGestureManager: gesture finished: " << state;
                    finishedGestures << state;
                } else if (type == QGestureRecognizer::MaybeGesture) {
                    DEBUG() << "QGestureManager: maybe gesture: " << state;
                    newMaybeGestures << state;
                } else if (type == QGestureRecognizer::NotGesture) {
                    DEBUG() << "QGestureManager: not gesture: " << state;
                    notGestures << state;
                } else if (type == QGestureRecognizer::Ignore) {
                    DEBUG() << "QGestureManager: gesture ignored the event: " << state;
                } else {
                    DEBUG() << "QGestureManager: hm, lets assume the recognizer ignored the event: " << state;
                }
                if (result & QGestureRecognizer::ConsumeEventHint) {
                    DEBUG() << "QGestureManager: we were asked to consume the event: " << state;
                    //TODO: consume events if asked
                }
            }
        }
    } else if (QGesture *state = qobject_cast<QGesture*>(receiver)) {
        if (QGestureRecognizer *recognizer = gestureToRecognizer.value(state)) {
            QGestureRecognizer::Result result = recognizer->filterEvent(state, state, event);
            QGestureRecognizer::Result type = result & QGestureRecognizer::ResultState_Mask;
            if (type == QGestureRecognizer::GestureTriggered) {
                DEBUG() << "QGestureManager: gesture triggered: " << state;
                triggeredGestures << state;
            } else if (type == QGestureRecognizer::GestureFinished) {
                DEBUG() << "QGestureManager: gesture finished: " << state;
                finishedGestures << state;
            } else if (type == QGestureRecognizer::MaybeGesture) {
                DEBUG() << "QGestureManager: maybe gesture: " << state;
                newMaybeGestures << state;
            } else if (type == QGestureRecognizer::NotGesture) {
                DEBUG() << "QGestureManager: not gesture: " << state;
                notGestures << state;
            } else if (type == QGestureRecognizer::Ignore) {
                DEBUG() << "QGestureManager: gesture ignored the event: " << state;
            } else {
                DEBUG() << "QGestureManager: hm, lets assume the recognizer ignored the event: " << state;
            }
        }
    } else {
        return false;
    }

    QSet<QGesture *> startedGestures = triggeredGestures - activeGestures;
    triggeredGestures &= activeGestures;

    // check if a running gesture switched back to maybe state
    QSet<QGesture *> activeToMaybeGestures = activeGestures & newMaybeGestures;

    // check if a running gesture switched back to not gesture state, i.e. were canceled
    QSet<QGesture *> activeToCancelGestures = activeGestures & notGestures;
    canceledGestures += activeToCancelGestures;

    // start timers for new gestures in maybe state
    foreach (QGesture *state, newMaybeGestures) {
        QBasicTimer &timer = maybeGestures[state];
        if (!timer.isActive())
            timer.start(3000, this);
    }
    // kill timers for gestures that were in maybe state
    QSet<QGesture *> notMaybeGestures = (startedGestures | triggeredGestures | finishedGestures | canceledGestures | notGestures);
    foreach(QGesture *gesture, notMaybeGestures) {
        QMap<QGesture *, QBasicTimer>::iterator it =
                maybeGestures.find(gesture);
        if (it != maybeGestures.end()) {
            it.value().stop();
            maybeGestures.erase(it);
        }
    }

    Q_ASSERT((startedGestures & finishedGestures).isEmpty());
    Q_ASSERT((startedGestures & newMaybeGestures).isEmpty());
    Q_ASSERT((startedGestures & canceledGestures).isEmpty());
    Q_ASSERT((finishedGestures & newMaybeGestures).isEmpty());
    Q_ASSERT((finishedGestures & canceledGestures).isEmpty());
    Q_ASSERT((canceledGestures & newMaybeGestures).isEmpty());

    QSet<QGesture *> notStarted = finishedGestures - activeGestures;
    if (!notStarted.isEmpty()) {
        // there are some gestures that claim to be finished, but never started.
        // probably those are "singleshot" gestures so we'll fake the started state.
        foreach (QGesture *gesture, notStarted)
            gesture->d_func()->state = Qt::GestureStarted;
        deliverEvents(notStarted, receiver);
    }

    activeGestures += startedGestures;
    // sanity check: all triggered gestures should already be in active gestures list
    Q_ASSERT((activeGestures & triggeredGestures).size() == triggeredGestures.size());
    activeGestures -= finishedGestures;
    activeGestures -= activeToMaybeGestures;
    activeGestures -= canceledGestures;

    // set the proper gesture state on each gesture
    foreach (QGesture *gesture, startedGestures)
        gesture->d_func()->state = Qt::GestureStarted;
    foreach (QGesture *gesture, triggeredGestures)
        gesture->d_func()->state = Qt::GestureUpdated;
    foreach (QGesture *gesture, finishedGestures)
        gesture->d_func()->state = Qt::GestureFinished;
    foreach (QGesture *gesture, canceledGestures)
        gesture->d_func()->state = Qt::GestureCanceled;
    foreach (QGesture *gesture, activeToMaybeGestures)
        gesture->d_func()->state = Qt::GestureFinished;

    if (!activeGestures.isEmpty() || !maybeGestures.isEmpty() ||
        !startedGestures.isEmpty() || !triggeredGestures.isEmpty() ||
        !finishedGestures.isEmpty() || !canceledGestures.isEmpty()) {
        DEBUG() << "QGestureManager::filterEvent:"
                << "\n\tactiveGestures:" << activeGestures
                << "\n\tmaybeGestures:" << maybeGestures.keys()
                << "\n\tstarted:" << startedGestures
                << "\n\ttriggered:" << triggeredGestures
                << "\n\tfinished:" << finishedGestures
                << "\n\tcanceled:" << canceledGestures;
    }

    deliverEvents(startedGestures+triggeredGestures+finishedGestures+canceledGestures, receiver);

    // reset gestures that ended
    QSet<QGesture *> endedGestures = finishedGestures + canceledGestures;
    foreach (QGesture *gesture, endedGestures) {
        if (QGestureRecognizer *recognizer = gestureToRecognizer.value(gesture, 0)) {
            recognizer->reset(gesture);
        }
        gestureTargets.remove(gesture);
    }
    return false;
}

void QGestureManager::deliverEvents(const QSet<QGesture*> &gestures, QObject *lastReceiver)
{
    if (gestures.isEmpty())
        return;

    // group gestures by widgets
    typedef QMap<QObject *, QList<QGesture *> > GesturesPerReceiver;
    GesturesPerReceiver groupedGestures;
    // for conflicted gestures the key is always the innermost widget (i.e. the child)
    GesturesPerReceiver conflictedGestures;
    QMultiHash<QObject *, QGesture *> objectGestures;

    foreach (QGesture *gesture, gestures) {
        QObject *target = gestureTargets.value(gesture, 0);
        if (!target) {
            Q_ASSERT(gesture->state() == Qt::GestureStarted);
            if (gesture->hasHotSpot()) {
                // guess the target using the hotspot of the gesture
                QPoint pt = gesture->hotSpot().toPoint();
                if (!pt.isNull()) {
                    if (QWidget *w = qApp->topLevelAt(pt))
                        target = w->childAt(w->mapFromGlobal(pt));
                }
            }
            if (!target) {
                target = gesture->targetObject();
                if (!target)
                    target = lastReceiver;
            }
        }
        if (target) {
            gestureTargets.insert(gesture, target);
            if (target->isWidgetType())
                objectGestures.insert(target, gesture);
            groupedGestures[target].append(gesture);
        } else {
            qWarning() << "QGestureManager::deliverEvent: could not find the target for gesture"
                    << gesture->gestureType();
        }
    }

    typedef QMultiHash<QObject *, QGesture *>::const_iterator ObjectGesturesIterator;
    for (ObjectGesturesIterator it = objectGestures.begin(), e = objectGestures.end(); it != e; ++it) {
        QObject *object1 = it.key();
        QWidget *widget1 = qobject_cast<QWidget *>(object1);
        QGraphicsObject *item1 = qobject_cast<QGraphicsObject *>(object1);
        QGesture *gesture1 = it.value();
        ObjectGesturesIterator cit = it;
        for (++cit; cit != e; ++cit) {
            QObject *object2 = cit.key();
            QWidget *widget2 = qobject_cast<QWidget *>(object2);
            QGraphicsObject *item2 = qobject_cast<QGraphicsObject *>(object2);
            QGesture *gesture2 = cit.value();
            // TODO: ugly, rewrite this.
            if ((widget1 && widget2 && widget2->isAncestorOf(widget1)) ||
                (item1 && item2 && item2->isAncestorOf(item1))) {
                groupedGestures[object2].removeOne(gesture2);
                groupedGestures[object1].removeOne(gesture1);
                conflictedGestures[object1].append(gesture1);
            } else if ((widget1 && widget2 && widget1->isAncestorOf(widget2)) ||
                       (item1 && item2 && item1->isAncestorOf(item2))) {
                groupedGestures[object2].removeOne(gesture2);
                groupedGestures[object1].removeOne(gesture1);
                conflictedGestures[object2].append(gesture2);
            }
        }
    }

    DEBUG() << "deliverEvents: conflicted =" << conflictedGestures.values()
            << " grouped =" << groupedGestures.values();

    // if there are conflicting gestures, send the GestureOverride event
    for (GesturesPerReceiver::const_iterator it = conflictedGestures.begin(),
        e = conflictedGestures.end(); it != e; ++it) {
        DEBUG() << "QGestureManager::deliverEvents: sending GestureOverride to"
                << it.key()
                << " gestures:" << it.value();
        QGestureEvent event(it.value());
        event.t = QEvent::GestureOverride;
        event.ignore();
        QApplication::sendEvent(it.key(), &event);
        if (!event.isAccepted()) {
            // nobody accepted the GestureOverride, put it back to deliver to
            // the closest context (i.e. to the inner-most widget).
            DEBUG() <<" override was not accepted";
            groupedGestures[it.key()].append(it.value());
        }
    }

    for (GesturesPerReceiver::const_iterator it = groupedGestures.begin(),
        e = groupedGestures.end(); it != e; ++it) {
        if (!it.value().isEmpty()) {
            DEBUG() << "QGestureManager::deliverEvents: sending to" << it.key()
                    << " gestures:" << it.value();
            QGestureEvent event(it.value());
            QApplication::sendEvent(it.key(), &event);
        }
    }
}

void QGestureManager::timerEvent(QTimerEvent *event)
{
    QMap<QGesture*, QBasicTimer>::iterator it = maybeGestures.begin(),
                                            e = maybeGestures.end();
    for (; it != e; ) {
        QBasicTimer &timer = it.value();
        Q_ASSERT(timer.isActive());
        if (timer.timerId() == event->timerId()) {
            timer.stop();
            QGesture *gesture = it.key();
            it = maybeGestures.erase(it);
            DEBUG() << "QGestureManager::timerEvent: gesture stopped due to timeout:" << gesture;
            QGestureRecognizer *recognizer = gestureToRecognizer.value(gesture, 0);
            if (recognizer)
                recognizer->reset(gesture);
        } else {
            ++it;
        }
    }
}

QT_END_NAMESPACE

#include "moc_qgesturemanager_p.cpp"