path: root/src/declarative/graphicsitems/qdeclarativegraphicsobjectcontainer.cpp

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#include "private/qdeclarativegraphicsobjectcontainer_p.h"

#include "private/qdeclarativeitem_p.h"

#include <QGraphicsObject>
#include <QGraphicsWidget>
#include <QGraphicsSceneResizeEvent>

QT_BEGIN_NAMESPACE

class QDeclarativeGraphicsObjectContainerPrivate : public QDeclarativeItemPrivate
{
    Q_DECLARE_PUBLIC(QDeclarativeGraphicsObjectContainer)

public:
    QDeclarativeGraphicsObjectContainerPrivate() : QDeclarativeItemPrivate(), graphicsObject(0), syncedResize(false)
    { }

    void _q_updateSize();

    void setFiltering(bool on)
    {
        Q_Q(QDeclarativeGraphicsObjectContainer);
        if (graphicsObject && graphicsObject->isWidget()) {
            if (!on) {
                graphicsObject->removeEventFilter(q);
                QObject::disconnect(q, SIGNAL(widthChanged()), q, SLOT(_q_updateSize()));
                QObject::disconnect(q, SIGNAL(heightChanged()), q, SLOT(_q_updateSize()));
            } else {
                graphicsObject->installEventFilter(q);
                QObject::connect(q, SIGNAL(widthChanged()), q, SLOT(_q_updateSize()));
                QObject::connect(q, SIGNAL(heightChanged()), q, SLOT(_q_updateSize()));
            }
        }
    }


    QGraphicsObject *graphicsObject;
    bool syncedResize;
};


/*!
    \qmlclass GraphicsObjectContainer QDeclarativeGraphicsObjectContainer
    \since 4.7
    \brief The GraphicsObjectContainer element allows you to add QGraphicsObjects into Fluid UI elements.

    While any QObject based class can be exposed to QML, QDeclarativeItem
    provides a lot of important functionality, including anchors and proper
    management of child items. GraphicsObjectContainer helps provide these
    functions to other QGraphicsObjects, so that they can be used unaltered in
    a QML scene. QGraphicsObjects, which are not QDeclarativeItems, and which are
    placed in a QML scene outside of a GraphicsObjectContainer, will not appear
    on screen at all.

    A GraphicsObjectContainer can have one element inside it, and it must be a
    QGraphicsObject or subclass which has been exposed to the QML engine.
    The graphics object inside the GraphicsObjectContainer can then be used
    like any other item in QML with the exception of not being reparentable
    and not having the standard properties of QML items (such as anchors).

    As the contained object is positioned relative to the container, anchors
    affecting the container item will affect the onscreen position of the
    contained item. If synchronizedResizing is set to true, then anchors
    affecting the container item's size will also affect the contained item's
    size.

    Example:
    \code
    import Qt 4.6
    import MyApp 2.1 as Widgets
    Rectangle{
        id: rect
        property alias widgetPropertyThree: widget.myThirdProperty;
        GraphicsObjectContainer{
            synchronizedResizing: true
            anchors.margins: 10
            anchors.fill: parent
            Widgets.MyWidget{
                myProperty: "A Value"
                myOtherProperty: rect.color
            }
        }
    }
    \endcode
*/

/*!
    \internal
    \class QDeclarativeGraphicsObjectContainer
    \brief The QDeclarativeGraphicsObjectContainer class allows you to add QGraphicsObjects into Fluid UI applications.
*/

QDeclarativeGraphicsObjectContainer::QDeclarativeGraphicsObjectContainer(QDeclarativeItem *parent)
: QDeclarativeItem(*new QDeclarativeGraphicsObjectContainerPrivate, parent)
{
}

QDeclarativeGraphicsObjectContainer::~QDeclarativeGraphicsObjectContainer()
{
}

QGraphicsObject *QDeclarativeGraphicsObjectContainer::graphicsObject() const
{
    Q_D(const QDeclarativeGraphicsObjectContainer);
    return d->graphicsObject;
}

/*!
    \qmlproperty QGraphicsObject GraphicsObjectContainer::graphicsObject
    The QGraphicsObject associated with this element.
*/
void QDeclarativeGraphicsObjectContainer::setGraphicsObject(QGraphicsObject *object)
{
    Q_D(QDeclarativeGraphicsObjectContainer);
    if (object == d->graphicsObject)
        return;

    //### remove previously set item?

    d->setFiltering(false);

    d->graphicsObject = object;

    if (d->graphicsObject) {
        d->graphicsObject->setParentItem(this);

        if (d->syncedResize && d->graphicsObject->isWidget()) {
            QGraphicsWidget *gw = static_cast<QGraphicsWidget*>(d->graphicsObject);
            QSizeF gwSize = gw->size(); //### should we use sizeHint?
            QSizeF newSize = gwSize;
            if (heightValid())
                newSize.setHeight(height());
            if (widthValid())
                newSize.setWidth(width());
            if (gwSize != newSize)
                gw->resize(newSize);

            gwSize = gw->size();
            setImplicitWidth(gwSize.width());
            setImplicitHeight(gwSize.height());

            d->setFiltering(true);
        }
    }
}

QVariant QDeclarativeGraphicsObjectContainer::itemChange(GraphicsItemChange change, const QVariant &value)
{
    Q_D(QDeclarativeGraphicsObjectContainer);
    if (change == ItemSceneHasChanged) {
        QGraphicsObject *o = d->graphicsObject;
        d->graphicsObject = 0;
        setGraphicsObject(o);
    }
    return QDeclarativeItem::itemChange(change, value);
}

bool QDeclarativeGraphicsObjectContainer::eventFilter(QObject *watched, QEvent *e)
{
    Q_D(QDeclarativeGraphicsObjectContainer);
    if (watched == d->graphicsObject && e->type() == QEvent::GraphicsSceneResize) {
        if (d->graphicsObject && d->graphicsObject->isWidget() && d->syncedResize) {
           QSizeF newSize = static_cast<QGraphicsWidget*>(d->graphicsObject)->size();
           setImplicitWidth(newSize.width());
           setImplicitHeight(newSize.height());
       }
    }
    return QDeclarativeItem::eventFilter(watched, e);
}

/*!
    \qmlproperty bool GraphicsObjectContainer::synchronizedResizing

    This property determines whether or not the container and graphics object will synchronize their
    sizes.

    \note This property only applies when wrapping a QGraphicsWidget.

    If synchronizedResizing is enabled, the container and widget will
    synchronize their sizes as follows.
    \list
    \o If a size has been set on the container, the widget will be resized to the container.
    Any changes in the container's size will be reflected in the widget.

    \o \e Otherwise, the container will initially be sized to the preferred size of the widget.
    Any changes to the container's size will be reflected in the widget, and any changes to the
    widget's size will be reflected in the container.
    \endlist
*/
bool QDeclarativeGraphicsObjectContainer::synchronizedResizing() const
{
    Q_D(const QDeclarativeGraphicsObjectContainer);
    return d->syncedResize;
}

void QDeclarativeGraphicsObjectContainer::setSynchronizedResizing(bool on)
{
    Q_D(QDeclarativeGraphicsObjectContainer);
    if (on == d->syncedResize)
        return;

    d->syncedResize = on;
    d->setFiltering(on);
}

void QDeclarativeGraphicsObjectContainerPrivate::_q_updateSize()
{
    if (!graphicsObject || !graphicsObject->isWidget() || !syncedResize)
        return;

    QGraphicsWidget *gw = static_cast<QGraphicsWidget*>(graphicsObject);
    const QSizeF newSize(width(), height());
    gw->resize(newSize);

    //### will respecting the widgets min/max ever get us in trouble? (all other items always
    //    size to exactly what you tell them)
    /*QSizeF constrainedSize = newSize.expandedTo(gw->minimumSize()).boundedTo(gw->maximumSize());
    gw->resize(constrainedSize);
    if (constrainedSize != newSize) {
        setImplicitWidth(constrainedSize.width());
        setImplicitHeight(constrainedSize.height());
    }*/
}

#include <moc_qdeclarativegraphicsobjectcontainer_p.cpp>

QT_END_NAMESPACE