path: root/src/declarative/util/qmlstateoperations.cpp

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** This file is part of the QtDeclarative module of the Qt Toolkit.
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#include <private/qobject_p.h>
#include <qml.h>
#include <QtDeclarative/qmlcontext.h>
#include <QtDeclarative/qmlexpression.h>
#include "qmlstateoperations.h"
#include <QtCore/qdebug.h>
#include <QtDeclarative/qmlinfo.h>
#include <private/qfxanchors_p.h>
#include <private/qfxitem_p.h>
#include <QtGui/qgraphicsitem.h>
#include <QtCore/qmath.h>

QT_BEGIN_NAMESPACE

class QmlParentChangePrivate : public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QmlParentChange)
public:
    QmlParentChangePrivate() : target(0), parent(0), origParent(0), origStackBefore(0) {}

    QFxItem *target;
    QFxItem *parent;
    QGuard<QFxItem> origParent;
    QGuard<QFxItem> origStackBefore;

    void doChange(QFxItem *targetParent, QFxItem *stackBefore = 0);
};

void QmlParentChangePrivate::doChange(QFxItem *targetParent, QFxItem *stackBefore)
{
    if (targetParent && target && target->parentItem()) {
        //### for backwards direction, can we just restore original x, y, scale, rotation
        Q_Q(QmlParentChange);
        bool ok;
        const QTransform &transform = target->itemTransform(targetParent, &ok);
        if (transform.type() >= QTransform::TxShear || !ok) {
            qmlInfo(QObject::tr("Unable to preserve appearance under complex transform"), q);
        }

        qreal scale = 1;
        qreal rotation = 0;
        if (transform.type() != QTransform::TxRotate) {
            if (transform.m11() == transform.m22())
                scale = transform.m11();
            else {
                qmlInfo(QObject::tr("Unable to preserve appearance under non-uniform scale"), q);
                ok = false;
            }
        } else if (transform.type() == QTransform::TxRotate) {
            if (transform.m11() == transform.m22())
                scale = qSqrt(transform.m11()*transform.m11() + transform.m12()*transform.m12());
            else {
                qmlInfo(QObject::tr("Unable to preserve appearance under non-uniform scale"), q);
                ok = false;
            }

            if (scale != 0)
                rotation = atan2(transform.m12()/scale, transform.m11()/scale) * 180/M_PI;
            else {
                qmlInfo(QObject::tr("Unable to preserve appearance under scale of 0"), q);
                ok = false;
            }
        }

        qreal xt = transform.dx();
        qreal yt = transform.dy();
        if (target->transformOrigin() != QFxItem::TopLeft) {
            qreal tempxt = target->transformOriginPoint().x();
            qreal tempyt = target->transformOriginPoint().y();
            QTransform t;
            t.translate(-tempxt, -tempyt);
            t.rotate(rotation);
            t.scale(scale, scale);
            t.translate(tempxt, tempyt);
            QPointF offset = t.map(QPointF(0,0));
            xt += offset.x();
            yt += offset.y();
        }

        target->setParentItem(targetParent);
        if (ok) {
            //qDebug() << xt << yt << rotation << scale;
            target->setX(xt);
            target->setY(yt);
            target->setRotation(rotation);
            target->setScale(scale);
        }
    } else if (target) {
        target->setParentItem(targetParent);
    }

    //restore the original stack position.
    //### if stackBefore has also been reparented this won't work
    if (stackBefore)
        target->stackBefore(stackBefore);
}

/*!
    \preliminary
    \qmlclass ParentChange
    \brief The ParentChange element allows you to reparent an Item in a state change.

    ParentChange reparents an Item while preserving its visual appearance (position, rotation,
    and scale) on screen. You can then specify a transition to move/rotate/scale the Item to
    its final intended appearance.

    ParentChange can only preserve visual appearance if no complex transforms are involved.
    More specifically, it will not work if the transform property has been set for any
    Items involved in the reparenting (defined as any Items in the common ancestor tree
    for the original and new parent).
*/

QML_DEFINE_TYPE(Qt,4,6,(QT_VERSION&0x00ff00)>>8,ParentChange,QmlParentChange)
QmlParentChange::QmlParentChange(QObject *parent)
    : QmlStateOperation(*(new QmlParentChangePrivate), parent)
{
}

QmlParentChange::~QmlParentChange()
{
}

/*!
    \qmlproperty Object ParentChange::target
    This property holds the item to be reparented
*/

QFxItem *QmlParentChange::object() const
{
    Q_D(const QmlParentChange);
    return d->target;
}

void QmlParentChange::setObject(QFxItem *target)
{
    Q_D(QmlParentChange);
    d->target = target;
}

/*!
    \qmlproperty Item ParentChange::parent
    This property holds the parent for the item in this state
*/

QFxItem *QmlParentChange::parent() const
{
    Q_D(const QmlParentChange);
    return d->parent;
}

void QmlParentChange::setParent(QFxItem *parent)
{
    Q_D(QmlParentChange);
    d->parent = parent;
}

QmlStateOperation::ActionList QmlParentChange::actions()
{
    Q_D(QmlParentChange);
    if (!d->target || !d->parent)
        return ActionList();

    Action a;
    a.event = this;

    return ActionList() << a;
}

class AccessibleFxItem : public QFxItem
{
    Q_OBJECT
    Q_DECLARE_PRIVATE_D(QGraphicsItem::d_ptr.data(), QFxItem)
public:
    int siblingIndex() {
        Q_D(QFxItem);
        return d->siblingIndex;
    }
};

void QmlParentChange::saveOriginals()
{
    Q_D(QmlParentChange);
    if (!d->target) {
        d->origParent = 0;
        d->origStackBefore = 0;
        return;
    }

    d->origParent = d->target->parentItem();

    if (!d->origParent) {
        d->origStackBefore = 0;
        return;
    }

    //try to determine the item's original stack position so we can restore it
    int siblingIndex = ((AccessibleFxItem*)d->target)->siblingIndex() + 1;
    QList<QGraphicsItem*> children = d->origParent->childItems();
    for (int i = 0; i < children.count(); ++i) {
        QFxItem *child = qobject_cast<QFxItem*>(children.at(i));
        if (!child)
            continue;
        if (((AccessibleFxItem*)child)->siblingIndex() == siblingIndex) {
            d->origStackBefore = child;
            break;
        }
    }
}

void QmlParentChange::execute()
{
    Q_D(QmlParentChange);
    d->doChange(d->parent);
}

bool QmlParentChange::isReversable()
{
    return true;
}

void QmlParentChange::reverse()
{
    Q_D(QmlParentChange);
    d->doChange(d->origParent, d->origStackBefore);
}

QString QmlParentChange::typeName() const
{
    return QLatin1String("ParentChange");
}

bool QmlParentChange::override(ActionEvent*other)
{
    Q_D(QmlParentChange);
    if (other->typeName() != QLatin1String("ParentChange"))
        return false;
    if (QmlParentChange *otherPC = static_cast<QmlParentChange*>(other))
        return (d->target == otherPC->object());
    return false;
}

class QmlStateChangeScriptPrivate : public QObjectPrivate
{
public:
    QmlStateChangeScriptPrivate() {}

    QmlScriptString script;
    QString name;
};

/*!
    \qmlclass StateChangeScript QmlStateChangeScript
    \brief The StateChangeScript element allows you to run a script in a state.
*/
QML_DEFINE_TYPE(Qt,4,6,(QT_VERSION&0x00ff00)>>8,StateChangeScript,QmlStateChangeScript)
QmlStateChangeScript::QmlStateChangeScript(QObject *parent)
: QmlStateOperation(*(new QmlStateChangeScriptPrivate), parent)
{
}

QmlStateChangeScript::~QmlStateChangeScript()
{
}

/*!
    \qmlproperty script StateChangeScript::script
    This property holds the script to run when the state is current.
*/
QmlScriptString QmlStateChangeScript::script() const
{
    Q_D(const QmlStateChangeScript);
    return d->script;
}

void QmlStateChangeScript::setScript(const QmlScriptString &s)
{
    Q_D(QmlStateChangeScript);
    d->script = s;
}

QString QmlStateChangeScript::name() const
{
    Q_D(const QmlStateChangeScript);
    return d->name;
}

void QmlStateChangeScript::setName(const QString &n)
{
    Q_D(QmlStateChangeScript);
    d->name = n;
}

void QmlStateChangeScript::execute()
{
    Q_D(QmlStateChangeScript);
    const QString &script = d->script.script();
    if (!script.isEmpty()) {
        QmlExpression expr(d->script.context(), script, d->script.scopeObject());
        expr.setTrackChange(false);
        expr.value();
    }
}

QmlStateChangeScript::ActionList QmlStateChangeScript::actions()
{
    ActionList rv;
    Action a;
    a.event = this;
    rv << a;
    return rv;
}

/*!
    \qmlclass AnchorChanges
    \brief The AnchorChanges element allows you to change the anchors of an item in a state.

    \snippet examples/declarative/anchors/anchor-changes.qml 0

    For more information on anchors see \l {anchor-layout}{Anchor Layouts}.
*/

QML_DEFINE_TYPE(Qt,4,6,(QT_VERSION&0x00ff00)>>8,AnchorChanges,QmlAnchorChanges)

class QmlAnchorChangesPrivate : public QObjectPrivate
{
public:
    QmlAnchorChangesPrivate() : target(0) {}

    QString name;
    QFxItem *target;
    QString resetString;
    QStringList resetList;
    QFxAnchorLine left;
    QFxAnchorLine right;
    QFxAnchorLine horizontalCenter;
    QFxAnchorLine top;
    QFxAnchorLine bottom;
    QFxAnchorLine verticalCenter;
    QFxAnchorLine baseline;

    QFxAnchorLine origLeft;
    QFxAnchorLine origRight;
    QFxAnchorLine origHCenter;
    QFxAnchorLine origTop;
    QFxAnchorLine origBottom;
    QFxAnchorLine origVCenter;
    QFxAnchorLine origBaseline;
    qreal origX;
    qreal origY;
    qreal origWidth;
    qreal origHeight;
};

/*!
    \qmlproperty Object AnchorChanges::target
    This property holds the object that the anchors to change belong to
*/

QmlAnchorChanges::QmlAnchorChanges(QObject *parent)
 : QmlStateOperation(*(new QmlAnchorChangesPrivate), parent)
{
}

QmlAnchorChanges::~QmlAnchorChanges()
{
}

QmlAnchorChanges::ActionList QmlAnchorChanges::actions()
{
    Action a;
    a.event = this;
    return ActionList() << a;
}

QFxItem *QmlAnchorChanges::object() const
{
    Q_D(const QmlAnchorChanges);
    return d->target;
}

void QmlAnchorChanges::setObject(QFxItem *target)
{
    Q_D(QmlAnchorChanges);
    d->target = target;
}

QString QmlAnchorChanges::reset() const
{
    Q_D(const QmlAnchorChanges);
    return d->resetString;
}

void QmlAnchorChanges::setReset(const QString &reset)
{
    Q_D(QmlAnchorChanges);
    d->resetString = reset;
    d->resetList = d->resetString.split(QLatin1Char(','));
}

/*!
    \qmlproperty AnchorLine AnchorChanges::left
    \qmlproperty AnchorLine AnchorChanges::right
    \qmlproperty AnchorLine AnchorChanges::horizontalCenter
    \qmlproperty AnchorLine AnchorChanges::top
    \qmlproperty AnchorLine AnchorChanges::bottom
    \qmlproperty AnchorLine AnchorChanges::verticalCenter
    \qmlproperty AnchorLine AnchorChanges::baseline

    These properties change the respective anchors of the item.
*/

QFxAnchorLine QmlAnchorChanges::left() const
{
    Q_D(const QmlAnchorChanges);
    return d->left;
}

void QmlAnchorChanges::setLeft(const QFxAnchorLine &edge)
{
    Q_D(QmlAnchorChanges);
    d->left = edge;
}

QFxAnchorLine QmlAnchorChanges::right() const
{
    Q_D(const QmlAnchorChanges);
    return d->right;
}

void QmlAnchorChanges::setRight(const QFxAnchorLine &edge)
{
    Q_D(QmlAnchorChanges);
    d->right = edge;
}

QFxAnchorLine QmlAnchorChanges::horizontalCenter() const
{
    Q_D(const QmlAnchorChanges);
    return d->horizontalCenter;
}

void QmlAnchorChanges::setHorizontalCenter(const QFxAnchorLine &edge)
{
    Q_D(QmlAnchorChanges);
    d->horizontalCenter = edge;
}

QFxAnchorLine QmlAnchorChanges::top() const
{
    Q_D(const QmlAnchorChanges);
    return d->top;
}

void QmlAnchorChanges::setTop(const QFxAnchorLine &edge)
{
    Q_D(QmlAnchorChanges);
    d->top = edge;
}

QFxAnchorLine QmlAnchorChanges::bottom() const
{
    Q_D(const QmlAnchorChanges);
    return d->bottom;
}

void QmlAnchorChanges::setBottom(const QFxAnchorLine &edge)
{
    Q_D(QmlAnchorChanges);
    d->bottom = edge;
}

QFxAnchorLine QmlAnchorChanges::verticalCenter() const
{
    Q_D(const QmlAnchorChanges);
    return d->verticalCenter;
}

void QmlAnchorChanges::setVerticalCenter(const QFxAnchorLine &edge)
{
    Q_D(QmlAnchorChanges);
    d->verticalCenter = edge;
}

QFxAnchorLine QmlAnchorChanges::baseline() const
{
    Q_D(const QmlAnchorChanges);
    return d->baseline;
}

void QmlAnchorChanges::setBaseline(const QFxAnchorLine &edge)
{
    Q_D(QmlAnchorChanges);
    d->baseline = edge;
}

void QmlAnchorChanges::execute()
{
    Q_D(QmlAnchorChanges);
    if (!d->target)
        return;

    //set any anchors that have been specified
    if (d->left.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->setLeft(d->left);
    if (d->right.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->setRight(d->right);
    if (d->horizontalCenter.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->setHorizontalCenter(d->horizontalCenter);
    if (d->top.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->setTop(d->top);
    if (d->bottom.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->setBottom(d->bottom);
    if (d->verticalCenter.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->setVerticalCenter(d->verticalCenter);
    if (d->baseline.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->setBaseline(d->baseline);
}

bool QmlAnchorChanges::isReversable()
{
    return true;
}

void QmlAnchorChanges::reverse()
{
    Q_D(QmlAnchorChanges);
    if (!d->target)
        return;

    //restore previous anchors
    if (d->origLeft.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->setLeft(d->origLeft);
    if (d->origRight.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->setRight(d->origRight);
    if (d->origHCenter.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->setHorizontalCenter(d->origHCenter);
    if (d->origTop.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->setTop(d->origTop);
    if (d->origBottom.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->setBottom(d->origBottom);
    if (d->origVCenter.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->setVerticalCenter(d->origVCenter);
    if (d->origBaseline.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->setBaseline(d->origBaseline);
}

QString QmlAnchorChanges::typeName() const
{
    return QLatin1String("AnchorChanges");
}

QList<Action> QmlAnchorChanges::extraActions()
{
    Q_D(QmlAnchorChanges);
    QList<Action> extra;

    //### try to be smarter about which ones we add.
    //    or short-circuit later on if they haven't actually changed.
    //    we shouldn't set explicit width if there wasn't one before.
    if (d->target) {
        Action a;
        a.fromValue = d->origX;
        a.property = QmlMetaProperty(d->target, QLatin1String("x"));
        extra << a;

        a.fromValue = d->origY;
        a.property = QmlMetaProperty(d->target, QLatin1String("y"));
        extra << a;

        a.fromValue = d->origWidth;
        a.property = QmlMetaProperty(d->target, QLatin1String("width"));
        extra << a;

        a.fromValue = d->origHeight;
        a.property = QmlMetaProperty(d->target, QLatin1String("height"));
        extra << a;
    }

    return extra;
}

bool QmlAnchorChanges::changesBindings()
{
    return true;
}

void QmlAnchorChanges::saveOriginals()
{
    Q_D(QmlAnchorChanges);
    d->origLeft = d->target->anchors()->left();
    d->origRight = d->target->anchors()->right();
    d->origHCenter = d->target->anchors()->horizontalCenter();
    d->origTop = d->target->anchors()->top();
    d->origBottom = d->target->anchors()->bottom();
    d->origVCenter = d->target->anchors()->verticalCenter();
    d->origBaseline = d->target->anchors()->baseline();
}

void QmlAnchorChanges::clearForwardBindings()
{
    Q_D(QmlAnchorChanges);
    d->origX = d->target->x();
    d->origY = d->target->y();
    d->origWidth = d->target->width();
    d->origHeight = d->target->height();

    //reset any anchors that have been specified
    if (d->resetList.contains(QLatin1String("left")))
        d->target->anchors()->resetLeft();
    if (d->resetList.contains(QLatin1String("right")))
        d->target->anchors()->resetRight();
    if (d->resetList.contains(QLatin1String("horizontalCenter")))
        d->target->anchors()->resetHorizontalCenter();
    if (d->resetList.contains(QLatin1String("top")))
        d->target->anchors()->resetTop();
    if (d->resetList.contains(QLatin1String("bottom")))
        d->target->anchors()->resetBottom();
    if (d->resetList.contains(QLatin1String("verticalCenter")))
        d->target->anchors()->resetVerticalCenter();
    if (d->resetList.contains(QLatin1String("baseline")))
        d->target->anchors()->resetBaseline();

    //reset any anchors that we'll be setting in the state
    if (d->left.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetLeft();
    if (d->right.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetRight();
    if (d->horizontalCenter.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetHorizontalCenter();
    if (d->top.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetTop();
    if (d->bottom.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetBottom();
    if (d->verticalCenter.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetVerticalCenter();
    if (d->baseline.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetBaseline();
}

void QmlAnchorChanges::clearReverseBindings()
{
    Q_D(QmlAnchorChanges);
    d->origX = d->target->x();
    d->origY = d->target->y();
    d->origWidth = d->target->width();
    d->origHeight = d->target->height();

    //reset any anchors that were set in the state
    if (d->left.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetLeft();
    if (d->right.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetRight();
    if (d->horizontalCenter.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetHorizontalCenter();
    if (d->top.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetTop();
    if (d->bottom.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetBottom();
    if (d->verticalCenter.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetVerticalCenter();
    if (d->baseline.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetBaseline();

    //reset any anchors that were set in the original state
    if (d->origLeft.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetLeft();
    if (d->origRight.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetRight();
    if (d->origHCenter.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetHorizontalCenter();
    if (d->origTop.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetTop();
    if (d->origBottom.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetBottom();
    if (d->origVCenter.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetVerticalCenter();
    if (d->origBaseline.anchorLine != QFxAnchorLine::Invalid)
        d->target->anchors()->resetBaseline();
}

bool QmlAnchorChanges::override(ActionEvent*other)
{
    if (other->typeName() != QLatin1String("AnchorChanges"))
        return false;
    if (static_cast<ActionEvent*>(this) == other)
        return true;
    //### can we do any other meaningful comparison? Do we need to attempt to merge the two
    //    somehow if they have the same target and some of the same anchors?
    return false;
}

QT_END_NAMESPACE

#include "qmlstateoperations.moc"
#include "moc_qmlstateoperations.cpp"