Implement new transformation handling for graphics items.

The idea of having separate rotationX/Y/Z, shearX/Y, etc.
methods in QGraphicsItem turned out to be not giving us
the flexibility we need and wanted.

The new code now implements a different scheme, where we
keep simple rotate (around z-axis), scale and
transformOriginPoint methods, but remove the other ones.

Instead we now have an additional list of QGraphicsTransform
object. QGraphicsTransform is an abstract class that inherits
QObject. Several specializations are provided and can be
used to transform (and through property bindings animate)
the item.

Reviewed-By: Andreas

1 files changed, 16 insertions, 23 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem_p.h b/src/gui/graphicsview/qgraphicsitem_p.h
index c208b99..b8d98c1 100644
--- a/src/gui/graphicsview/qgraphicsitem_p.h
+++ b/src/gui/graphicsview/qgraphicsitem_p.h
@@ -57,6 +57,8 @@
 #include "qset.h"
 #include "qpixmapcache.h"
 #include "qgraphicsview_p.h"
+#include "qgraphicstransform.h"
+#include "qgraphicstransform_p.h"
 
 #include <QtCore/qpoint.h>
 
@@ -192,7 +194,7 @@ public:
 
     void combineTransformToParent(QTransform *x, const QTransform *viewTransform = 0) const;
     void combineTransformFromParent(QTransform *x, const QTransform *viewTransform = 0) const;
-    void updateSceneTransformFromParent();
+    virtual void updateSceneTransformFromParent();
 
     // ### Qt 5: Remove. Workaround for reimplementation added after Qt 4.4.
     virtual QVariant inputMethodQueryHelper(Qt::InputMethodQuery query) const;
@@ -200,6 +202,7 @@ public:
 
     void setPosHelper(const QPointF &pos);
     void setTransformHelper(const QTransform &transform);
+    void appendGraphicsTransform(QGraphicsTransform *t);
     void setVisibleHelper(bool newVisible, bool explicitly, bool update = true);
     void setEnabledHelper(bool newEnabled, bool explicitly, bool update = true);
     bool discardUpdateRequest(bool ignoreClipping = false, bool ignoreVisibleBit = false,
@@ -467,45 +470,35 @@ public:
 
 struct QGraphicsItemPrivate::TransformData {
     QTransform transform;
-    qreal xScale;
-    qreal yScale;
-    qreal xRotation;
-    qreal yRotation;
-    qreal zRotation;
-    qreal horizontalShear;
-    qreal verticalShear;
+    qreal scale;
+    qreal rotation;
     qreal xOrigin;
     qreal yOrigin;
+    QList<QGraphicsTransform *> graphicsTransforms;
     bool onlyTransform;
 
     TransformData() :
-        xScale(1.0), yScale(1.0), xRotation(0.0), yRotation(0.0), zRotation(0.0),
-        horizontalShear(0.0), verticalShear(0.0), xOrigin(0.0), yOrigin(0.0),
+        scale(1.0), rotation(0.0),
+        xOrigin(0.0), yOrigin(0.0),
         onlyTransform(true)
     {}
 
     QTransform computedFullTransform(QTransform *postmultiplyTransform = 0) const
     {
         if (onlyTransform) {
-            if (!postmultiplyTransform)
-                return transform;
-            if (postmultiplyTransform->isIdentity())
+            if (!postmultiplyTransform || postmultiplyTransform->isIdentity())
                 return transform;
             if (transform.isIdentity())
                 return *postmultiplyTransform;
-            QTransform x(transform);
-            x *= *postmultiplyTransform;
-            return x;
+            return transform * *postmultiplyTransform;
         }
 
         QTransform x(transform);
-        if (xOrigin != 0 || yOrigin != 0)
-            x *= QTransform::fromTranslate(xOrigin, yOrigin);
-        x.rotate(xRotation, Qt::XAxis);
-        x.rotate(yRotation, Qt::YAxis);
-        x.rotate(zRotation, Qt::ZAxis);
-        x.shear(horizontalShear, verticalShear);
-        x.scale(xScale, yScale);
+        for (int i = 0; i < graphicsTransforms.size(); ++i)
+            graphicsTransforms.at(i)->applyTo(&x);
+        x.translate(xOrigin, yOrigin);
+        x.rotate(rotation, Qt::ZAxis);
+        x.scale(scale, scale);
         x.translate(-xOrigin, -yOrigin);
         if (postmultiplyTransform)
             x *= *postmultiplyTransform;