Add some meat to QGraphicsObject

Added a toGraphicsObject() method to QGraphicsItem to allow upcasting.
Expose some of QGraphicsItems setter/getter pairs as real properties
in QGraphicsObject, including NOTIFY signals.

Reviewed-by: Andreas

4 files changed, 166 insertions, 107 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index b83f9db..6d87c36 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -1260,6 +1260,28 @@ QGraphicsWidget *QGraphicsItem::window() const
 }
 
 /*!
+  \since 4.6
+
+  Return the graphics item cast to a QGraphicsObject, if the class is actually a
+  graphics object, 0 otherwise.
+*/
+QGraphicsObject *QGraphicsItem::toGraphicsObject()
+{
+    return d_ptr->isObject ? static_cast<QGraphicsObject *>(this) : 0;
+}
+
+/*!
+  \since 4.6
+
+  Return the graphics item cast to a QGraphicsObject, if the class is actually a
+  graphics object, 0 otherwise.
+*/
+const QGraphicsObject *QGraphicsItem::toGraphicsObject() const
+{
+    return d_ptr->isObject ? static_cast<const QGraphicsObject *>(this) : 0;
+}
+
+/*!
     Sets this item's parent item to \a parent. If this item already has a
     parent, it is first removed from the previous parent. If \a parent is 0,
     this item will become a top-level item.
@@ -1799,6 +1821,9 @@ void QGraphicsItemPrivate::setVisibleHelper(bool newVisible, bool explicitly, bo
 void QGraphicsItem::setVisible(bool visible)
 {
     d_ptr->setVisibleHelper(visible, /* explicit = */ true);
+
+    if (d_ptr->isObject)
+        emit static_cast<QGraphicsObject *>(this)->visibleChanged();
 }
 
 /*!
@@ -1920,6 +1945,9 @@ void QGraphicsItemPrivate::setEnabledHelper(bool newEnabled, bool explicitly, bo
 void QGraphicsItem::setEnabled(bool enabled)
 {
     d_ptr->setEnabledHelper(enabled, /* explicitly = */ true);
+
+    if (d_ptr->isObject)
+        emit static_cast<QGraphicsObject *>(this)->enabledChanged();
 }
 
 /*!
@@ -2082,6 +2110,8 @@ void QGraphicsItem::setOpacity(qreal opacity)
                                           /*maybeDirtyClipPath=*/false,
                                           /*force=*/false,
                                           /*ignoreOpacity=*/true);
+    if (d_ptr->isObject)
+        emit static_cast<QGraphicsObject *>(this)->opacityChanged();
 }
 
 /*!
@@ -2524,6 +2554,8 @@ void QGraphicsItemPrivate::setPosHelper(const QPointF &pos)
     this->pos = pos;
     dirtySceneTransform = 1;
     inSetPosHelper = 0;
+    if (isObject)
+        emit static_cast<QGraphicsObject *>(q)->positionChanged();
 }
 
 /*!
@@ -6324,6 +6356,108 @@ static void qt_graphicsItem_highlightSelected(
 }
 
 /*!
+    \class QGraphicsObject
+    \brief The QGraphicsObject class provides a base class for all graphics items that
+    require signals, slots and properties.
+    \since 4.6
+    \ingroup graphicsview-api
+
+    The class extends a QGraphicsItem with QObject's signal/slot and property mechanisms.
+    It maps many of QGraphicsItem's basic setters and getters to properties and adds notification
+    signals for many of them.
+*/
+
+/*!
+    Constructs a QGraphicsObject with \a parent.
+*/
+QGraphicsObject::QGraphicsObject(QGraphicsItem *parent)
+        : QGraphicsItem(parent)
+{
+    QGraphicsItem::d_ptr->isObject = true;
+}
+
+/*!
+  \internal
+*/
+QGraphicsObject::QGraphicsObject(QGraphicsItemPrivate &dd, QGraphicsItem *parent, QGraphicsScene *scene)
+    : QGraphicsItem(dd, parent, scene)
+{
+    QGraphicsItem::d_ptr->isObject = true;
+}
+
+/*!
+  \property QGraphicsObject::opacity
+  \brief the opacity of the item
+
+  \sa QGraphicsItem::setOpacity, QGraphicsItem::opacity
+*/
+
+/*!
+  \fn QGraphicsObject::opacityChanged()
+
+  This signal gets emitted whenever the opacity of the item changes
+
+  \sa opacity
+*/
+
+/*!
+  \property QGraphicsObject::pos
+  \brief the position of the item
+
+  Describes the items position.
+
+  \sa QGraphicsItem::setPos, QGraphicsItem::pos, positionChanged
+*/
+
+/*!
+  \fn QGraphicsObject::positionChanged()
+
+  This signal gets emitted whenever the position of the item changes
+
+  \sa pos
+*/
+
+/*!
+  \property QGraphicsObject::enabled
+  \brief whether the item is enabled or not
+
+  This property is declared in QGraphicsItem.
+
+  By default, this property is true.
+
+  \sa QGraphicsItem::isEnabled(), QGraphicsItem::setEnabled(), enabledChanged()
+*/
+
+/*!
+  \fn QGraphicsObject::enabledChanged()
+
+  This signal gets emitted whenever the item get's enabled or disabled.
+
+  \sa enabled
+*/
+
+/*!
+  \property QGraphicsObject::visible
+  \brief whether the item is visible or not
+
+  This property is declared in QGraphicsItem.
+
+  By default, this property is true.
+
+  \sa QGraphicsItem::isVisible(), QGraphicsItem::setVisible(), visibleChanged()
+*/
+
+/*!
+  \fn QGraphicsObject::visibleChanged()
+
+  This signal gets emitted whenever the visibility of the item changes
+
+  \sa visible
+*/
+
+
+
+/*!
     \class QAbstractGraphicsShapeItem
     \brief The QAbstractGraphicsShapeItem class provides a common base for
     all path items.
@@ -8148,17 +8282,6 @@ public:
 };
 
 
-QGraphicsObject::QGraphicsObject(QGraphicsItem *parent)
-        : QGraphicsItem(parent)
-{
-}
-
-QGraphicsObject::QGraphicsObject(QGraphicsItemPrivate &dd, QGraphicsItem *parent, QGraphicsScene *scene)
-    : QGraphicsItem(dd, parent, scene)
-{
-}
-
-
 /*!
     Constructs a QGraphicsTextItem, using \a text as the default plain
     text. \a parent is passed to QGraphicsItem's constructor.
diff --git a/src/gui/graphicsview/qgraphicsitem.h b/src/gui/graphicsview/qgraphicsitem.h
index 69aab20..a5ccef2 100644
--- a/src/gui/graphicsview/qgraphicsitem.h
+++ b/src/gui/graphicsview/qgraphicsitem.h
@@ -63,6 +63,7 @@ class QBrush;
 class QCursor;
 class QFocusEvent;
 class QGraphicsItemGroup;
+class QGraphicsObject;
 class QGraphicsSceneContextMenuEvent;
 class QGraphicsSceneDragDropEvent;
 class QGraphicsSceneEvent;
@@ -159,6 +160,9 @@ public:
     bool isWidget() const;
     bool isWindow() const;
 
+    QGraphicsObject *toGraphicsObject();
+    const QGraphicsObject *toGraphicsObject() const;
+
     QGraphicsItemGroup *group() const;
     void setGroup(QGraphicsItemGroup *group);
 
@@ -484,6 +488,31 @@ inline QRectF QGraphicsItem::mapRectFromParent(qreal ax, qreal ay, qreal w, qrea
 inline QRectF QGraphicsItem::mapRectFromScene(qreal ax, qreal ay, qreal w, qreal h) const
 { return mapRectFromScene(QRectF(ax, ay, w, h)); }
 
+
+class Q_GUI_EXPORT QGraphicsObject : public QObject, public QGraphicsItem
+{
+    Q_OBJECT
+    Q_INTERFACES(QGraphicsItem)
+    Q_PROPERTY(qreal opacity READ opacity WRITE setOpacity NOTIFY opacityChanged)
+    Q_PROPERTY(QPointF pos READ pos WRITE setPos NOTIFY positionChanged)
+    Q_PROPERTY(bool enabled READ isEnabled WRITE setEnabled NOTIFY enabledChanged)
+    Q_PROPERTY(bool visible READ isVisible WRITE setVisible NOTIFY visibleChanged)
+public:
+    QGraphicsObject(QGraphicsItem *parent = 0);
+
+Q_SIGNALS:
+    void opacityChanged();
+    void visibleChanged();
+    void enabledChanged();
+    void positionChanged();
+
+protected:
+    QGraphicsObject(QGraphicsItemPrivate &dd, QGraphicsItem *parent, QGraphicsScene *scene);
+private:
+    friend class QGraphicsItem;
+};
+
+
 class QAbstractGraphicsShapeItemPrivate;
 class Q_GUI_EXPORT QAbstractGraphicsShapeItem : public QGraphicsItem
 {
@@ -832,20 +861,6 @@ private:
 inline void QGraphicsPixmapItem::setOffset(qreal ax, qreal ay)
 { setOffset(QPointF(ax, ay)); }
 
-class Q_GUI_EXPORT QGraphicsObject : public QObject, public QGraphicsItem
-{
-    Q_OBJECT
-    Q_INTERFACES(QGraphicsItem)
-    Q_PROPERTY(qreal opacity READ opacity WRITE setOpacity)
-    Q_PROPERTY(QPointF pos READ pos WRITE setPos)
-    Q_PROPERTY(bool enabled READ isEnabled WRITE setEnabled)
-    Q_PROPERTY(bool visible READ isVisible WRITE setVisible)
-public:
-    QGraphicsObject(QGraphicsItem *parent = 0);
-protected:
-    QGraphicsObject(QGraphicsItemPrivate &dd, QGraphicsItem *parent, QGraphicsScene *scene);
-};
-
 class QGraphicsTextItemPrivate;
 class QTextDocument;
 class QTextCursor;
diff --git a/src/gui/graphicsview/qgraphicsitem_p.h b/src/gui/graphicsview/qgraphicsitem_p.h
index 5626867..0e6658c 100644
--- a/src/gui/graphicsview/qgraphicsitem_p.h
+++ b/src/gui/graphicsview/qgraphicsitem_p.h
@@ -149,6 +149,7 @@ public:
         dirtySceneTransform(1),
         geometryChanged(0),
         inDestructor(0),
+        isObject(0),
         globalStackingOrder(-1),
         q_ptr(0)
     {
@@ -405,7 +406,8 @@ public:
     quint32 dirtySceneTransform  : 1;
     quint32 geometryChanged : 1;
     quint32 inDestructor : 1;
-    quint32 unused : 15; // feel free to use
+    quint32 isObject : 1;
+    quint32 unused : 14; // feel free to use
 
     // Optional stacking order
     int globalStackingOrder;
diff --git a/src/gui/graphicsview/qgraphicswidget.cpp b/src/gui/graphicsview/qgraphicswidget.cpp
index 84434db..419277d 100644
--- a/src/gui/graphicsview/qgraphicswidget.cpp
+++ b/src/gui/graphicsview/qgraphicswidget.cpp
@@ -170,87 +170,6 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
-    \property QGraphicsWidget::enabled
-    \brief whether the item is enabled or not
-
-    This property is declared in QGraphicsItem.
-
-    By default, this property is true.
-
-    \sa QGraphicsItem::isEnabled(), QGraphicsItem::setEnabled()
-*/
-
-/*!
-    \property QGraphicsWidget::visible
-    \brief whether the item is visible or not
-
-    This property is declared in QGraphicsItem.
-
-    By default, this property is true.
-
-    \sa QGraphicsItem::isVisible(), QGraphicsItem::setVisible(), show(),
-    hide()
-*/
-
-/*!
-    \property QGraphicsWidget::opacity
-    \brief the opacity of the widget
-*/    
-
-/*!
-    \property QGraphicsWidget::pos
-    \brief the position of the widget
-*/
-
-/*!
-    \property QGraphicsWidget::xRotation
-    \since 4.6
-    \brief the rotation angle in degrees around the X axis
-*/
-
-/*!
-    \property QGraphicsWidget::yRotation
-    \since 4.6
-    \brief the rotation angle in degrees around the Y axis
-*/
-
-/*!
-    \property QGraphicsWidget::zRotation
-    \since 4.6
-    \brief the rotation angle in degrees around the Z axis
-*/
-
-/*!
-    \property QGraphicsWidget::xScale
-    \since 4.6
-    \brief the scale factor on the X axis.
-*/
-
-/*!
-    \property QGraphicsWidget::yScale
-    \since 4.6
-    \brief the scale factor on the Y axis.
-*/
-
-/*!
-    \property QGraphicsWidget::horizontalShear
-    \since 4.6
-    \brief the horizontal shear.
-*/
-
-/*!
-    \property QGraphicsWidget::verticalShear
-    \since 4.6
-    \brief the vertical shear.
-*/
-
-/*!
-    \property QGraphicsWidget::transformOrigin
-    \since 4.6
-    \brief the transformation origin for the transformation properties.
-*/
-
-/*!
     Constructs a QGraphicsWidget instance. The optional \a parent argument is
     passed to QGraphicsItem's constructor. The optional \a wFlags argument
     specifies the widget's window flags (e.g., whether the widget should be a