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, 3 insertions, 0 deletions

diff --git a/src/gui/kernel/qwindowsysteminterface_qpa.h b/src/gui/kernel/qwindowsysteminterface_qpa.h
index 78152a1178..836fb40bd7 100644
--- a/src/gui/kernel/qwindowsysteminterface_qpa.h
+++ b/src/gui/kernel/qwindowsysteminterface_qpa.h
@@ -80,7 +80,10 @@ public:
                                        quint32 nativeModifiers,
                                        const QString& text = QString(), bool autorep = false,
                                        ushort count = 1);
+    static void handleWheelEvent(QWindow *w, const QPointF & local, const QPointF & global, QPoint pixelDelta, QPoint angleDelta, Qt::KeyboardModifiers mods = Qt::NoModifier);
+    static void handleWheelEvent(QWindow *w, ulong timestamp, const QPointF & local, const QPointF & global, QPoint pixelDelta, QPoint angleDelta, Qt::KeyboardModifiers mods = Qt::NoModifier);
 
+    // Wheel event compatibility functions. Will be removed: do not use.
     static void handleWheelEvent(QWindow *w, const QPointF & local, const QPointF & global, int d, Qt::Orientation o, Qt::KeyboardModifiers mods = Qt::NoModifier);
     static void handleWheelEvent(QWindow *w, ulong timestamp, const QPointF & local, const QPointF & global, int d, Qt::Orientation o, Qt::KeyboardModifiers mods = Qt::NoModifier);