Add a children private property needed for QML to support QGraphicsObject

Commit adds a private property that QML can use to add children for a given
item. This is a custom list that calls a callback which actually reparent
the item instead of just appending in the list (otherwise it will mess up
the state of QGraphicsView). This is needed because childItems() is pretty
useless you get a list but if you append something on it then it adds
that into a copy. Also the children property is the default property
a concept used by QML.

Width and Height private properties has been added in order to support
better the integration with QGraphicsWidget in QML. The actual implementation
is in the private class of QGI and QGraphicsWidget reimplements it to return
the geometry. (In 4.7 QDeclarativeItem reimplements it too).

This change should be harmless everything is private.

Task-number:QT-2757
Reviewed-by:andreas

1 files changed, 103 insertions, 0 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index e10c03a..f110a5c 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -5224,6 +5224,8 @@ void QGraphicsItemPrivate::addChild(QGraphicsItem *child)
     needSortChildren = 1; // ### maybe 0
     child->d_ptr->siblingIndex = children.size();
     children.append(child);
+    if (isObject)
+        emit static_cast<QGraphicsObject *>(q_ptr)->childrenChanged();
 }
 
 /*!
@@ -5246,6 +5248,8 @@ void QGraphicsItemPrivate::removeChild(QGraphicsItem *child)
     // the child is not guaranteed to be at the index after the list is sorted.
     // (see ensureSortedChildren()).
     child->d_ptr->siblingIndex = -1;
+    if (isObject)
+        emit static_cast<QGraphicsObject *>(q_ptr)->childrenChanged();
 }
 
 /*!
@@ -7453,6 +7457,88 @@ void QGraphicsObject::ungrabGesture(Qt::GestureType gesture)
     }
 }
 
+void QGraphicsItemPrivate::append(QDeclarativeListProperty<QGraphicsObject> *list, QGraphicsObject *item)
+{
+    QGraphicsItemPrivate::get(item)->setParentItemHelper(static_cast<QGraphicsObject *>(list->object), /*newParentVariant=*/0, /*thisPointerVariant=*/0);
+}
+
+/*!
+    Returns a list of this item's children.
+
+    The items are sorted by stacking order. This takes into account both the
+    items' insertion order and their Z-values.
+
+*/
+QDeclarativeListProperty<QGraphicsObject> QGraphicsItemPrivate::childrenList()
+{
+    Q_Q(QGraphicsItem);
+    if (isObject) {
+        QGraphicsObject *that = static_cast<QGraphicsObject *>(q);
+        return QDeclarativeListProperty<QGraphicsObject>(that, &children, QGraphicsItemPrivate::append);
+    } else {
+        //QGraphicsItem is not supported for this property
+        return QDeclarativeListProperty<QGraphicsObject>();
+    }
+}
+
+/*!
+  \internal
+  Returns the width of the item
+  Reimplemented by QGraphicsWidget
+*/
+qreal QGraphicsItemPrivate::width() const
+{
+    return 0;
+}
+
+/*!
+  \internal
+  Set the width of the item
+  Reimplemented by QGraphicsWidget
+*/
+void QGraphicsItemPrivate::setWidth(qreal w)
+{
+    Q_UNUSED(w);
+}
+
+/*!
+  \internal
+  Reset the width of the item
+  Reimplemented by QGraphicsWidget
+*/
+void QGraphicsItemPrivate::resetWidth()
+{
+}
+
+/*!
+  \internal
+  Returns the height of the item
+  Reimplemented by QGraphicsWidget
+*/
+qreal QGraphicsItemPrivate::height() const
+{
+    return 0;
+}
+
+/*!
+  \internal
+  Set the height of the item
+  Reimplemented by QGraphicsWidget
+*/
+void QGraphicsItemPrivate::setHeight(qreal h)
+{
+    Q_UNUSED(h);
+}
+
+/*!
+  \internal
+  Reset the height of the item
+  Reimplemented by QGraphicsWidget
+*/
+void QGraphicsItemPrivate::resetHeight()
+{
+}
+
 /*!
   \property QGraphicsObject::parent
   \brief the parent of the item
@@ -7639,6 +7725,23 @@ void QGraphicsObject::ungrabGesture(Qt::GestureType gesture)
   \sa scale, rotation, QGraphicsItem::transformOriginPoint()
 */
 
+/*!
+    \fn void QGraphicsObject::widthChanged()
+    \internal
+*/
+
+/*!
+    \fn void QGraphicsObject::heightChanged()
+    \internal
+*/
+
+/*!
+
+  \fn QGraphicsObject::childrenChanged()
+
+  This signal gets emitted whenever the children list changes
+  \internal
+*/
 
 /*!
     \class QAbstractGraphicsShapeItem