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Diffstat (limited to 'src/declarative/graphicsitems/qdeclarativeflipable.cpp')
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diff --git a/src/declarative/graphicsitems/qdeclarativeflipable.cpp b/src/declarative/graphicsitems/qdeclarativeflipable.cpp new file mode 100644 index 0000000000..d23374b512 --- /dev/null +++ b/src/declarative/graphicsitems/qdeclarativeflipable.cpp @@ -0,0 +1,254 @@ +/**************************************************************************** +** +** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtDeclarative module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "private/qdeclarativeflipable_p.h" + +#include "private/qdeclarativeitem_p.h" +#include "private/qdeclarativeguard_p.h" + +#include <qdeclarativeinfo.h> + +#include <QtGui/qgraphicstransform.h> + +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<QGraphicsObject> front; + QDeclarativeGuard<QGraphicsObject> back; + + bool wantBackXFlipped; + bool wantBackYFlipped; +}; + +/*! + \qmlclass Flipable 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<QDeclarativeFlipablePrivate *>(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)?1.:0.); + if (back) + back->setOpacity((current==QDeclarativeFlipable::Back)?1.: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 |