itemChange() is now called when transformation properties change.

When changing transformation properties (i.e., setRotation(),
setScale(), setTransformOriginPoint()), itemChange() is now called to
allow notification and change of the values. The flag
ItemSendsGeometryChanges needs to be set to enable this.

Autotest included.

Task-number: QTBUG-8112
Reviewed-by: alexis

3 files changed, 209 insertions, 7 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index 948ff28..66b262c 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -381,7 +381,9 @@
 
     \value ItemSendsGeometryChanges The item enables itemChange()
     notifications for ItemPositionChange, ItemPositionHasChanged,
-    ItemMatrixChange, ItemTransformChange, and ItemTransformHasChanged. For
+    ItemMatrixChange, ItemTransformChange, ItemTransformHasChanged,
+    ItemRotationChange, ItemRotationHasChanged, ItemScaleChange, ItemScaleHasChanged,
+    ItemTransformOriginPointChange, and ItemTransformOriginPointHasChanged. For
     performance reasons, these notifications are disabled by default. You must
     enable this flag to receive notifications for position and transform
     changes. This flag was introduced in Qt 4.6.
@@ -475,6 +477,52 @@
     (same as transform()), and QGraphicsItem ignores the return value for this
     notification (i.e., a read-only notification).
 
+    \value ItemRotationChange The item's rotation property changes. This
+    notification is sent if the ItemSendsGeometryChanges flag is enabled, and
+    when the item's rotation property changes (i.e., as a result of calling
+    setRotation()). The value argument is the new rotation (i.e., a double);
+    to get the old rotation, call rotation(). Do not call setRotation() in
+    itemChange() as this notification is delivered; instead, you can return
+    the new rotation from itemChange().
+
+    \value ItemRotationHasChanged The item's rotation property has changed.
+    This notification is sent if the ItemSendsGeometryChanges flag is enabled,
+    and after the item's rotation property has changed. The value argument is
+    the new rotation (i.e., a double), and QGraphicsItem ignores the return
+    value for this notification (i.e., a read-only notification). Do not call
+    setRotation() in itemChange() as this notification is delivered.
+
+    \value ItemScaleChange The item's scale property changes. This notification
+    is sent if the ItemSendsGeometryChanges flag is enabled, and when the item's
+    scale property changes (i.e., as a result of calling setScale()). The value
+    argument is the new scale (i.e., a double); to get the old scale, call
+    scale(). Do not call setScale() in itemChange() as this notification is
+    delivered; instead, you can return the new scale from itemChange().
+
+    \value ItemScaleHasChanged The item's scale property has changed. This
+    notification is sent if the ItemSendsGeometryChanges flag is enabled, and
+    after the item's scale property has changed. The value argument is the new
+    scale (i.e., a double), and QGraphicsItem ignores the return value for this
+    notification (i.e., a read-only notification). Do not call setScale() in
+    itemChange() as this notification is delivered.
+
+    \value ItemTransformOriginPointChange The item's transform origin point
+    property changes. This notification is sent if the ItemSendsGeometryChanges
+    flag is enabled, and when the item's transform origin point property changes
+    (i.e., as a result of calling setTransformOriginPoint()). The value argument
+    is the new origin point (i.e., a QPointF); to get the old origin point, call
+    transformOriginPoint(). Do not call setTransformOriginPoint() in itemChange()
+    as this notification is delivered; instead, you can return the new transform
+    origin point from itemChange().
+
+    \value ItemTransformOriginPointHasChanged The item's transform origin point
+    property has changed. This notification is sent if the ItemSendsGeometryChanges
+    flag is enabled, and after the item's transform origin point property has
+    changed. The value argument is the new origin point (i.e., a QPointF), and
+    QGraphicsItem ignores the return value for this notification (i.e., a read-only
+    notification). Do not call setTransformOriginPoint() in itemChange() as this
+    notification is delivered.
+
     \value ItemSelectedChange The item's selected state changes. If the item is
     presently selected, it will become unselected, and vice verca. The value
     argument is the new selected state (i.e., true or false). Do not call
@@ -3722,12 +3770,28 @@ qreal QGraphicsItem::rotation() const
 void QGraphicsItem::setRotation(qreal angle)
 {
     prepareGeometryChange();
+    qreal newRotation = angle;
+
+    if (d_ptr->flags & ItemSendsGeometryChanges) {
+        // Notify the item that the rotation is changing.
+        const QVariant newRotationVariant(itemChange(ItemRotationChange, angle));
+        newRotation = newRotationVariant.toReal();
+    }
+
     if (!d_ptr->transformData)
         d_ptr->transformData = new QGraphicsItemPrivate::TransformData;
-    d_ptr->transformData->rotation = angle;
+
+    if (d_ptr->transformData->rotation == newRotation)
+        return;
+
+    d_ptr->transformData->rotation = newRotation;
     d_ptr->transformData->onlyTransform = false;
     d_ptr->dirtySceneTransform = 1;
 
+    // Send post-notification.
+    if (d_ptr->flags & ItemSendsGeometryChanges)
+        itemChange(ItemRotationHasChanged, newRotation);
+
     if (d_ptr->isObject)
         emit static_cast<QGraphicsObject *>(this)->rotationChanged();
 }
@@ -3770,12 +3834,28 @@ qreal QGraphicsItem::scale() const
 void QGraphicsItem::setScale(qreal factor)
 {
     prepareGeometryChange();
+    qreal newScale = factor;
+
+    if (d_ptr->flags & ItemSendsGeometryChanges) {
+        // Notify the item that the scale is changing.
+        const QVariant newScaleVariant(itemChange(ItemScaleChange, factor));
+        newScale = newScaleVariant.toReal();
+    }
+
     if (!d_ptr->transformData)
         d_ptr->transformData = new QGraphicsItemPrivate::TransformData;
-    d_ptr->transformData->scale = factor;
+
+    if (d_ptr->transformData->scale == newScale)
+        return;
+
+    d_ptr->transformData->scale = newScale;
     d_ptr->transformData->onlyTransform = false;
     d_ptr->dirtySceneTransform = 1;
 
+    // Send post-notification.
+    if (d_ptr->flags & ItemSendsGeometryChanges)
+        itemChange(ItemScaleHasChanged, newScale);
+
     if (d_ptr->isObject)
         emit static_cast<QGraphicsObject *>(this)->scaleChanged();
 }
@@ -3877,12 +3957,31 @@ QPointF QGraphicsItem::transformOriginPoint() const
 void QGraphicsItem::setTransformOriginPoint(const QPointF &origin)
 {
     prepareGeometryChange();
+    QPointF newOrigin = origin;
+
+    if (d_ptr->flags & ItemSendsGeometryChanges) {
+        // Notify the item that the origin point is changing.
+        const QVariant newOriginVariant(itemChange(ItemTransformOriginPointChange,
+                                                   qVariantFromValue<QPointF>(origin)));
+        newOrigin = newOriginVariant.toPointF();
+    }
+
     if (!d_ptr->transformData)
         d_ptr->transformData = new QGraphicsItemPrivate::TransformData;
-    d_ptr->transformData->xOrigin = origin.x();
-    d_ptr->transformData->yOrigin = origin.y();
+
+    if (d_ptr->transformData->xOrigin == newOrigin.x()
+        && d_ptr->transformData->yOrigin == newOrigin.y()) {
+        return;
+    }
+
+    d_ptr->transformData->xOrigin = newOrigin.x();
+    d_ptr->transformData->yOrigin = newOrigin.y();
     d_ptr->transformData->onlyTransform = false;
     d_ptr->dirtySceneTransform = 1;
+
+    // Send post-notification.
+    if (d_ptr->flags & ItemSendsGeometryChanges)
+        itemChange(ItemTransformOriginPointHasChanged, qVariantFromValue<QPointF>(newOrigin));
 }
 
 /*!
@@ -11072,6 +11171,24 @@ QDebug operator<<(QDebug debug, QGraphicsItem::GraphicsItemChange change)
     case QGraphicsItem::ItemScenePositionHasChanged:
         str = "ItemScenePositionHasChanged";
         break;
+    case QGraphicsItem::ItemRotationChange:
+        str = "ItemRotationChange";
+        break;
+    case QGraphicsItem::ItemRotationHasChanged:
+        str = "ItemRotationHasChanged";
+        break;
+    case QGraphicsItem::ItemScaleChange:
+        str = "ItemScaleChange";
+        break;
+    case QGraphicsItem::ItemScaleHasChanged:
+        str = "ItemScaleHasChanged";
+        break;
+    case QGraphicsItem::ItemTransformOriginPointChange:
+        str = "ItemTransformOriginPointChange";
+        break;
+    case QGraphicsItem::ItemTransformOriginPointHasChanged:
+        str = "ItemTransformOriginPointHasChanged";
+        break;
     }
     debug << str;
     return debug;
diff --git a/src/gui/graphicsview/qgraphicsitem.h b/src/gui/graphicsview/qgraphicsitem.h
index 56f94a2..117113f 100644
--- a/src/gui/graphicsview/qgraphicsitem.h
+++ b/src/gui/graphicsview/qgraphicsitem.h
@@ -139,7 +139,13 @@ public:
         ItemZValueHasChanged,
         ItemOpacityChange,
         ItemOpacityHasChanged,
-        ItemScenePositionHasChanged
+        ItemScenePositionHasChanged,
+        ItemRotationChange,
+        ItemRotationHasChanged,
+        ItemScaleChange,
+        ItemScaleHasChanged,
+        ItemTransformOriginPointChange,
+        ItemTransformOriginPointHasChanged
     };
 
     enum CacheMode {
diff --git a/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp b/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
index 92a7f2e..b408ba2 100644
--- a/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
+++ b/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
@@ -4316,6 +4316,21 @@ protected:
             break;
         case QGraphicsItem::ItemScenePositionHasChanged:
             break;
+        case QGraphicsItem::ItemRotationChange:
+            oldValues << rotation();
+            break;
+        case QGraphicsItem::ItemRotationHasChanged:
+            break;
+        case QGraphicsItem::ItemScaleChange:
+            oldValues << scale();
+            break;
+        case QGraphicsItem::ItemScaleHasChanged:
+            break;
+        case QGraphicsItem::ItemTransformOriginPointChange:
+            oldValues << transformOriginPoint();
+            break;
+        case QGraphicsItem::ItemTransformOriginPointHasChanged:
+            break;
         }
         return itemChangeReturnValue.isValid() ? itemChangeReturnValue : value;
     }
@@ -4412,6 +4427,48 @@ void tst_QGraphicsItem::itemChange()
         QCOMPARE(tester.zValue(), qreal(2.0));
     }
     {
+        // ItemRotationChange / ItemRotationHasChanged
+        tester.itemChangeReturnValue = qreal(15.0);
+        tester.setRotation(10.0);
+        ++changeCount; // notification sent too
+        ++changeCount;
+        QCOMPARE(tester.changes.size(), changeCount);
+        QCOMPARE(tester.changes.at(tester.changes.size() - 2), QGraphicsItem::ItemRotationChange);
+        QCOMPARE(tester.changes.at(tester.changes.size() - 1), QGraphicsItem::ItemRotationHasChanged);
+        QCOMPARE(tester.values.at(tester.changes.size() - 2), QVariant(qreal(10.0)));
+        QCOMPARE(tester.values.at(tester.changes.size() - 1), QVariant(qreal(15.0)));
+        QCOMPARE(tester.oldValues.last(), QVariant(qreal(0.0)));
+        QCOMPARE(tester.rotation(), qreal(15.0));
+    }
+    {
+        // ItemScaleChange / ItemScaleHasChanged
+        tester.itemChangeReturnValue = qreal(2.0);
+        tester.setScale(1.5);
+        ++changeCount; // notification sent too
+        ++changeCount;
+        QCOMPARE(tester.changes.size(), changeCount);
+        QCOMPARE(tester.changes.at(tester.changes.size() - 2), QGraphicsItem::ItemScaleChange);
+        QCOMPARE(tester.changes.at(tester.changes.size() - 1), QGraphicsItem::ItemScaleHasChanged);
+        QCOMPARE(tester.values.at(tester.changes.size() - 2), QVariant(qreal(1.5)));
+        QCOMPARE(tester.values.at(tester.changes.size() - 1), QVariant(qreal(2.0)));
+        QCOMPARE(tester.oldValues.last(), QVariant(qreal(1.0)));
+        QCOMPARE(tester.scale(), qreal(2.0));
+    }
+    {
+        // ItemTransformOriginPointChange / ItemTransformOriginPointHasChanged
+        tester.itemChangeReturnValue = QPointF(2.0, 2.0);
+        tester.setTransformOriginPoint(1.0, 1.0);
+        ++changeCount; // notification sent too
+        ++changeCount;
+        QCOMPARE(tester.changes.size(), changeCount);
+        QCOMPARE(tester.changes.at(tester.changes.size() - 2), QGraphicsItem::ItemTransformOriginPointChange);
+        QCOMPARE(tester.changes.at(tester.changes.size() - 1), QGraphicsItem::ItemTransformOriginPointHasChanged);
+        QCOMPARE(tester.values.at(tester.changes.size() - 2), QVariant(QPointF(1.0, 1.0)));
+        QCOMPARE(tester.values.at(tester.changes.size() - 1), QVariant(QPointF(2.0, 2.0)));
+        QCOMPARE(tester.oldValues.last(), QVariant(QPointF(0.0, 0.0)));
+        QCOMPARE(tester.transformOriginPoint(), QPointF(2.0, 2.0));
+    }
+    {
         // ItemFlagsChange
         tester.itemChangeReturnValue = QGraphicsItem::ItemIsSelectable;
         tester.setFlag(QGraphicsItem::ItemIsSelectable, false);
@@ -7385,10 +7442,19 @@ void tst_QGraphicsItem::itemSendsGeometryChanges()
     QTransform x = QTransform().rotate(45);
     QPointF pos(10, 10);
     qreal o(0.5);
+    qreal r(10.0);
+    qreal s(1.5);
+    QPointF origin(1.0, 1.0);
     item.setTransform(x);
     item.setPos(pos);
+    item.setRotation(r);
+    item.setScale(s);
+    item.setTransformOriginPoint(origin);
     QCOMPARE(item.transform(), x);
     QCOMPARE(item.pos(), pos);
+    QCOMPARE(item.rotation(), r);
+    QCOMPARE(item.scale(), s);
+    QCOMPARE(item.transformOriginPoint(), origin);
     QCOMPARE(item.changes.size(), 0);
 
     item.setOpacity(o);
@@ -7402,6 +7468,13 @@ void tst_QGraphicsItem::itemSendsGeometryChanges()
     QCOMPARE(item.transform(), QTransform());
     QCOMPARE(item.pos(), QPointF());
     QCOMPARE(item.opacity(), o);
+    item.setRotation(0.0);
+    item.setScale(1.0);
+    item.setTransformOriginPoint(0.0, 0.0);
+    QCOMPARE(item.changes.size(), 14); // rotation + scale + origin
+    QCOMPARE(item.rotation(), qreal(0.0));
+    QCOMPARE(item.scale(), qreal(1.0));
+    QCOMPARE(item.transformOriginPoint(), QPointF(0.0, 0.0));
 
     QCOMPARE(item.changes, QList<QGraphicsItem::GraphicsItemChange>()
              << QGraphicsItem::ItemOpacityChange
@@ -7411,7 +7484,13 @@ void tst_QGraphicsItem::itemSendsGeometryChanges()
              << QGraphicsItem::ItemTransformChange
              << QGraphicsItem::ItemTransformHasChanged
              << QGraphicsItem::ItemPositionChange
-             << QGraphicsItem::ItemPositionHasChanged);
+             << QGraphicsItem::ItemPositionHasChanged
+             << QGraphicsItem::ItemRotationChange
+             << QGraphicsItem::ItemRotationHasChanged
+             << QGraphicsItem::ItemScaleChange
+             << QGraphicsItem::ItemScaleHasChanged
+             << QGraphicsItem::ItemTransformOriginPointChange
+             << QGraphicsItem::ItemTransformOriginPointHasChanged);
 }
 
 // Make sure we update moved items correctly.