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Diffstat (limited to 'src/declarative/items/qsgflipable.cpp')
| -rw-r--r-- | src/declarative/items/qsgflipable.cpp | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/src/declarative/items/qsgflipable.cpp b/src/declarative/items/qsgflipable.cpp new file mode 100644 index 0000000000..a856d6360b --- /dev/null +++ b/src/declarative/items/qsgflipable.cpp @@ -0,0 +1,255 @@ +// Commit: caee66da925949cf7aef2ff8e1a86c38dd6e6efd +/**************************************************************************** +** +** 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 "qsgflipable_p.h" +#include "qsgitem_p.h" + +#include <private/qdeclarativeguard_p.h> + +#include <QtDeclarative/qdeclarativeinfo.h> + +QT_BEGIN_NAMESPACE + +// XXX todo - i think this needs work and a bit of a re-think + +class QSGLocalTransform : public QSGTransform +{ + Q_OBJECT +public: + QSGLocalTransform(QObject *parent) : QSGTransform(parent) {} + + void setTransform(const QTransform &t) { + transform = t; + update(); + } + virtual void applyTo(QMatrix4x4 *matrix) const { + *matrix *= transform; + } +private: + QTransform transform; +}; + +class QSGFlipablePrivate : public QSGItemPrivate +{ + Q_DECLARE_PUBLIC(QSGFlipable) +public: + QSGFlipablePrivate() : current(QSGFlipable::Front), front(0), back(0), sideDirty(false) {} + + virtual void transformChanged(); + void updateSide(); + void setBackTransform(); + + QSGFlipable::Side current; + QDeclarativeGuard<QSGLocalTransform> backTransform; + QDeclarativeGuard<QSGItem> front; + QDeclarativeGuard<QSGItem> back; + + bool sideDirty; + bool wantBackXFlipped; + bool wantBackYFlipped; +}; + +QSGFlipable::QSGFlipable(QSGItem *parent) +: QSGItem(*(new QSGFlipablePrivate), parent) +{ +} + +QSGFlipable::~QSGFlipable() +{ +} + +QSGItem *QSGFlipable::front() +{ + Q_D(const QSGFlipable); + return d->front; +} + +void QSGFlipable::setFront(QSGItem *front) +{ + Q_D(QSGFlipable); + 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(); +} + +QSGItem *QSGFlipable::back() +{ + Q_D(const QSGFlipable); + return d->back; +} + +void QSGFlipable::setBack(QSGItem *back) +{ + Q_D(QSGFlipable); + if (d->back) { + qmlInfo(this) << tr("back is a write-once property"); + return; + } + if (back == 0) + return; + d->back = back; + d->back->setParentItem(this); + + d->backTransform = new QSGLocalTransform(d->back); + d->backTransform->prependToItem(d->back); + + 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 QSGFlipable::retransformBack() +{ + Q_D(QSGFlipable); + if (d->current == QSGFlipable::Back && d->back) + d->setBackTransform(); +} + +QSGFlipable::Side QSGFlipable::side() const +{ + Q_D(const QSGFlipable); + + const_cast<QSGFlipablePrivate *>(d)->updateSide(); + return d->current; +} + +void QSGFlipablePrivate::transformChanged() +{ + Q_Q(QSGFlipable); + + if (!sideDirty) { + sideDirty = true; + q->polish(); + } + + QSGItemPrivate::transformChanged(); +} + +void QSGFlipable::updatePolish() +{ + Q_D(QSGFlipable); + d->updateSide(); +} + +// determination on the currently visible side of the flipable +// has to be done on the complete scene transform to give +// correct results. +void QSGFlipablePrivate::updateSide() +{ + Q_Q(QSGFlipable); + + if (!sideDirty) + return; + + sideDirty = false; + + QTransform sceneTransform; + itemToParentTransform(sceneTransform); + + 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); +#if 0 + p1 = q->mapToParent(p1); + p2 = q->mapToParent(p2); + p3 = q->mapToParent(p3); +#endif + + qreal cross = (scenep1.x() - scenep2.x()) * (scenep3.y() - scenep2.y()) - + (scenep1.y() - scenep2.y()) * (scenep3.x() - scenep2.x()); + + wantBackYFlipped = scenep1.x() >= scenep2.x(); + wantBackXFlipped = scenep2.y() >= scenep3.y(); + + QSGFlipable::Side newSide; + if (cross > 0) { + newSide = QSGFlipable::Back; + } else { + newSide = QSGFlipable::Front; + } + + if (newSide != current) { + current = newSide; + if (current == QSGFlipable::Back && back) + setBackTransform(); + if (front) + front->setOpacity((current==QSGFlipable::Front)?1.:0.); + if (back) + back->setOpacity((current==QSGFlipable::Back)?1.:0.); + emit q->sideChanged(); + } +} + +/* Depends on the width/height of the back item, and so needs reevaulating + if those change. +*/ +void QSGFlipablePrivate::setBackTransform() +{ + QTransform mat; + mat.translate(back->width()/2,back->height()/2); + if (back->width() && wantBackYFlipped) + mat.rotate(180, Qt::YAxis); + if (back->height() && wantBackXFlipped) + mat.rotate(180, Qt::XAxis); + mat.translate(-back->width()/2,-back->height()/2); + + if (backTransform) + backTransform->setTransform(mat); +} + +QT_END_NAMESPACE + +#include "qsgflipable.moc" |