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Please review the following information to ** ensure the GNU General Public License version 3.0 requirements will be ** met: http://www.gnu.org/copyleft/gpl.html. ** ** ** $QT_END_LICENSE$ ** ****************************************************************************/ #include "private/qdeclarativeflipable_p.h" #include "private/qdeclarativeitem_p.h" #include "private/qdeclarativeguard_p.h" #include #include QT_BEGIN_NAMESPACE class QDeclarativeFlipablePrivate : public QDeclarativeItemPrivate { Q_DECLARE_PUBLIC(QDeclarativeFlipable) public: QDeclarativeFlipablePrivate() : current(QDeclarativeFlipable::Front), front(0), back(0) {} void updateSceneTransformFromParent(); void setBackTransform(); QDeclarativeFlipable::Side current; QDeclarativeGuard front; QDeclarativeGuard back; bool wantBackXFlipped; bool wantBackYFlipped; }; /*! \qmltype Flipable \instantiates QDeclarativeFlipable \since 4.7 \ingroup qml-basic-interaction-elements \brief The Flipable item provides a surface that can be flipped. \inherits Item Flipable is an item that can be visibly "flipped" between its front and back sides, like a card. It is used together with \l Rotation, \l State and \l Transition elements to produce a flipping effect. The \l front and \l back properties are used to hold the items that are shown respectively on the front and back sides of the flipable item. \section1 Example Usage The following example shows a Flipable item that flips whenever it is clicked, rotating about the y-axis. This flipable item has a \c flipped boolean property that is toggled whenever the MouseArea within the flipable is clicked. When \c flipped is true, the item changes to the "back" state; in this state, the \c angle of the \l Rotation item is changed to 180 degrees to produce the flipping effect. When \c flipped is false, the item reverts to the default state, in which the \c angle value is 0. \snippet doc/src/snippets/declarative/flipable/flipable.qml 0 \image flipable.gif The \l Transition creates the animation that changes the angle over four seconds. When the item changes between its "back" and default states, the NumberAnimation animates the angle between its old and new values. See \l {QML States} for details on state changes and the default state, and \l {QML Animation and Transitions} for more information on how animations work within transitions. \sa {declarative/ui-components/flipable}{Flipable example} */ QDeclarativeFlipable::QDeclarativeFlipable(QDeclarativeItem *parent) : QDeclarativeItem(*(new QDeclarativeFlipablePrivate), parent) { } QDeclarativeFlipable::~QDeclarativeFlipable() { } /*! \qmlproperty Item Flipable::front \qmlproperty Item Flipable::back The front and back sides of the flipable. */ QGraphicsObject *QDeclarativeFlipable::front() { Q_D(const QDeclarativeFlipable); return d->front; } void QDeclarativeFlipable::setFront(QGraphicsObject *front) { Q_D(QDeclarativeFlipable); if (d->front) { qmlInfo(this) << tr("front is a write-once property"); return; } d->front = front; d->front->setParentItem(this); if (Back == d->current) d->front->setOpacity(0.); emit frontChanged(); } QGraphicsObject *QDeclarativeFlipable::back() { Q_D(const QDeclarativeFlipable); return d->back; } void QDeclarativeFlipable::setBack(QGraphicsObject *back) { Q_D(QDeclarativeFlipable); if (d->back) { qmlInfo(this) << tr("back is a write-once property"); return; } d->back = back; d->back->setParentItem(this); if (Front == d->current) d->back->setOpacity(0.); connect(back, SIGNAL(widthChanged()), this, SLOT(retransformBack())); connect(back, SIGNAL(heightChanged()), this, SLOT(retransformBack())); emit backChanged(); } void QDeclarativeFlipable::retransformBack() { Q_D(QDeclarativeFlipable); if (d->current == QDeclarativeFlipable::Back && d->back) d->setBackTransform(); } /*! \qmlproperty enumeration Flipable::side The side of the Flipable currently visible. Possible values are \c Flipable.Front and \c Flipable.Back. */ QDeclarativeFlipable::Side QDeclarativeFlipable::side() const { Q_D(const QDeclarativeFlipable); if (d->dirtySceneTransform) const_cast(d)->ensureSceneTransform(); return d->current; } // determination on the currently visible side of the flipable // has to be done on the complete scene transform to give // correct results. void QDeclarativeFlipablePrivate::updateSceneTransformFromParent() { Q_Q(QDeclarativeFlipable); QDeclarativeItemPrivate::updateSceneTransformFromParent(); QPointF p1(0, 0); QPointF p2(1, 0); QPointF p3(1, 1); QPointF scenep1 = sceneTransform.map(p1); QPointF scenep2 = sceneTransform.map(p2); QPointF scenep3 = sceneTransform.map(p3); p1 = q->mapToParent(p1); p2 = q->mapToParent(p2); p3 = q->mapToParent(p3); qreal cross = (scenep1.x() - scenep2.x()) * (scenep3.y() - scenep2.y()) - (scenep1.y() - scenep2.y()) * (scenep3.x() - scenep2.x()); wantBackYFlipped = p1.x() >= p2.x(); wantBackXFlipped = p2.y() >= p3.y(); QDeclarativeFlipable::Side newSide; if (cross > 0) { newSide = QDeclarativeFlipable::Back; } else { newSide = QDeclarativeFlipable::Front; } if (newSide != current) { current = newSide; if (current == QDeclarativeFlipable::Back && back) setBackTransform(); if (front) front->setOpacity((current==QDeclarativeFlipable::Front)?qreal(1.):qreal(0.)); if (back) back->setOpacity((current==QDeclarativeFlipable::Back)?qreal(1.):qreal(0.)); emit q->sideChanged(); } } /* Depends on the width/height of the back item, and so needs reevaulating if those change. */ void QDeclarativeFlipablePrivate::setBackTransform() { QTransform mat; QGraphicsItemPrivate *dBack = QGraphicsItemPrivate::get(back); mat.translate(dBack->width()/2,dBack->height()/2); if (dBack->width() && wantBackYFlipped) mat.rotate(180, Qt::YAxis); if (dBack->height() && wantBackXFlipped) mat.rotate(180, Qt::XAxis); mat.translate(-dBack->width()/2,-dBack->height()/2); back->setTransform(mat); } QT_END_NAMESPACE