meegim/ima/minversemousearea.cpp

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#include "minversemousearea.h"

#include <QGraphicsScene>
#include <QGraphicsSceneMouseEvent>


// Threshold in QDeclarativeFlickable is 20
static const int FlickThresholdSquare = 400;

MInverseMouseArea::MInverseMouseArea(QDeclarativeItem *parent)
    : QDeclarativeItem(parent),
      m_pressed(false),
      m_enabled(true)
{

}

MInverseMouseArea::~MInverseMouseArea()
{
    if (scene())
        scene()->removeEventFilter(this);
}

bool MInverseMouseArea::isEnabled() const
{
    return m_enabled;
}

void MInverseMouseArea::setEnabled(bool enabled)
{
    if (m_enabled != enabled) {
        if (!enabled)
            m_pressed = false;

        m_enabled = enabled;
        emit enabledChanged();
    }
}

QVariant MInverseMouseArea::itemChange(GraphicsItemChange change, const QVariant &value)
{
    switch (change) {
    case QGraphicsItem::ItemSceneChange: {
        QGraphicsScene *oldScene = scene();

        if (oldScene)
            oldScene->removeEventFilter(this);

        m_pressed = false;

        if (value.canConvert<QGraphicsScene *>()) {
            QGraphicsScene *newScene = value.value<QGraphicsScene *>();

            if (newScene)
                newScene->installEventFilter(this);
        }
        break;
    }
    case QGraphicsItem::ItemVisibleHasChanged: {
        if (!isVisible())
            m_pressed = false;
        break;
    }
    default:
        break;
    }

    return QDeclarativeItem::itemChange(change, value);
}

bool MInverseMouseArea::isClickedOnSoftwareInputPanel(QGraphicsSceneMouseEvent *event) const
{
    QGraphicsItem * item = scene()->itemAt(event->scenePos());
    while(item != NULL) {
        QDeclarativeItem * declItem = dynamic_cast<QDeclarativeItem *>(item);
        if(declItem != NULL && declItem->objectName() == "softwareInputPanel")
            return true;

        item = item->parentItem();
    }

    return false;
}

bool MInverseMouseArea::eventFilter(QObject *obj, QEvent *ev)
{
    Q_UNUSED(obj);

    if (!m_enabled || !isVisible())
        return false;    
    switch (ev->type()) {
    case QEvent::GraphicsSceneMousePress: {
        QGraphicsSceneMouseEvent *me = static_cast<QGraphicsSceneMouseEvent *>(ev);
        QPointF mappedPos = mapToRootItem(me->scenePos());

        m_pressed = !contains(mapFromScene(me->scenePos())) && !isClickedOnSoftwareInputPanel(me);
        if (m_pressed)
            emit pressedOutside(mappedPos.x(), mappedPos.y());
        break;
    }
    case QEvent::GraphicsSceneMouseMove: {
        if (m_pressed) {
            QGraphicsSceneMouseEvent *me = static_cast<QGraphicsSceneMouseEvent *>(ev);
            const QPointF &dist = me->scenePos() - me->buttonDownScenePos(Qt::LeftButton);

            if (dist.x() * dist.x() + dist.y() * dist.y() > FlickThresholdSquare)
                m_pressed = false;
        }
        break;
    }
    case QEvent::GraphicsSceneMouseRelease: {
        QGraphicsSceneMouseEvent *me = static_cast<QGraphicsSceneMouseEvent *>(ev);
        QPointF mappedPos = mapToRootItem(me->scenePos());

        if (m_pressed) {
            m_pressed = false;
            emit clickedOutside(mappedPos.x(), mappedPos.y());
        }
        break;
    }
    default:
        break;
    }

    return false;
}

QPointF MInverseMouseArea::mapToRootItem(QPointF pos) {
    QPointF mappedPos = pos;
    QDeclarativeItem *rootItem = parentItem();

    while (rootItem->parentItem()) {
        if (rootItem->objectName() == "windowContent") {
            break;
        }
        rootItem = rootItem->parentItem();
    }

    if (rootItem) {
        mappedPos = rootItem->mapFromScene(pos);
    }

    return mappedPos;
}