QWheelEvent high-resolution delta support.

Support pixel-based deltas as well as sending
dx and dy values in the same event. Keep source and
behavior compatibility with Qt 4.

New API:
QPoint pixelDelta() const
QPoint angleDelta() const

Deprecate delta() and orientation().

Both pixel-based deltas and combined updates are
necessary for smooth trackpad-based scrolling on
OS X.

Qt 4 compatible behavior is achieved by sending an
extra wheel event in cases where the initial event
has a combined dx and dy update. This extra event
sends dx in delta() and orientation(), with pixelDelta()
and angleDelta() set to null.

Modify the Cocoa implementation to provide pixel
deltas. It is expected that not all platforms can
provide these. Angle deltas will always be available.

Change-Id: I20c10f0df338ddcd6a3f7a4d40949ed5ae3b4795
Reviewed-by: Morten Johan Sørvig <morten.sorvig@nokia.com>

1 files changed, 18 insertions, 6 deletions

diff --git a/src/gui/kernel/qevent.h b/src/gui/kernel/qevent.h
index 93dea41de9..ca93095a94 100644
--- a/src/gui/kernel/qevent.h
+++ b/src/gui/kernel/qevent.h
@@ -148,9 +148,21 @@ public:
     QWheelEvent(const QPointF &pos, const QPointF& globalPos, int delta,
                 Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers,
                 Qt::Orientation orient = Qt::Vertical);
+    QWheelEvent(const QPointF &pos, const QPointF& globalPos,
+                QPoint pixelDelta, QPoint angleDelta, int qt4Delta, Qt::Orientation qt4Orientation,
+                Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers);
+
     ~QWheelEvent();
 
-    inline int delta() const { return d; }
+
+    inline QPoint pixelDelta() const { return pixelD; }
+    inline QPoint angleDelta() const { return angleD; }
+
+#if QT_DEPRECATED_SINCE(5, 0)
+    inline QT_DEPRECATED int delta() const  { return qt4D; }
+    inline QT_DEPRECATED Qt::Orientation orientation() const { return qt4O; }
+#endif
+
 #ifndef QT_NO_INTEGER_EVENT_COORDINATES
     inline QPoint pos() const { return p.toPoint(); }
     inline QPoint globalPos()   const { return g.toPoint(); }
@@ -163,15 +175,15 @@ public:
     inline const QPointF &globalPosF()   const { return g; }
 
     inline Qt::MouseButtons buttons() const { return mouseState; }
-    Qt::Orientation orientation() const { return o; }
-
-
 protected:
     QPointF p;
     QPointF g;
-    int d;
+    QPoint pixelD;
+    QPoint angleD;
+    int qt4D;
+    Qt::Orientation qt4O;
     Qt::MouseButtons mouseState;
-    Qt::Orientation o;
+    int reserved;
 };
 #endif