Add QWheelEvent::source

This is analogous to 0a92295ca829a62125c9f122fd3daec991993855
which added QMouseEvent::source.

For now, we say that a wheel event is synthetic when it comes from
a trackpad or other device that provides scrolling by some means
other than an actual wheel.

Change-Id: I0452ca2080b551b18b9c2f6e42db925d14ae339e
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>

7 files changed, 78 insertions, 16 deletions

diff --git a/src/gui/kernel/qevent.cpp b/src/gui/kernel/qevent.cpp
index f845bf89c9..5bc70b9fb2 100644
--- a/src/gui/kernel/qevent.cpp
+++ b/src/gui/kernel/qevent.cpp
@@ -575,7 +575,8 @@ QHoverEvent::~QHoverEvent()
     wheel event delta: angleDelta() returns the delta in wheel
     degrees. This value is always provided. pixelDelta() returns
     the delta in screen pixels and is available on platforms that
-    have high-resolution trackpads, such as Mac OS X.
+    have high-resolution trackpads, such as Mac OS X. If that is the
+    case, source() will return Qt::MouseEventSynthesizedBySystem.
 
     The functions pos() and globalPos() return the mouse cursor's
     location at the time of the event.
@@ -600,6 +601,22 @@ QHoverEvent::~QHoverEvent()
 */
 
 /*!
+    \fn Qt::MouseEventSource QWheelEvent::source() const
+    \since 5.5
+
+    Returns information about the wheel event source.
+
+    The source can be used to distinguish between events that come from a mouse
+    with a physical wheel and events that are generated by some other means,
+    such as a flick gesture on a touchpad.
+
+    \note Many platforms provide no such information. On such platforms
+    \l Qt::MouseEventNotSynthesized is returned always.
+
+    \sa Qt::MouseEventSource
+*/
+
+/*!
     \fn Qt::Orientation QWheelEvent::orientation() const
     \obsolete
 
@@ -731,7 +748,44 @@ QWheelEvent::QWheelEvent(const QPointF &pos, const QPointF& globalPos,
             QPoint pixelDelta, QPoint angleDelta, int qt4Delta, Qt::Orientation qt4Orientation,
             Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers, Qt::ScrollPhase phase)
     : QInputEvent(Wheel, modifiers), p(pos), g(globalPos), pixelD(pixelDelta),
-      angleD(angleDelta), qt4D(qt4Delta), qt4O(qt4Orientation), mouseState(buttons), ph(phase)
+      angleD(angleDelta), qt4D(qt4Delta), qt4O(qt4Orientation), mouseState(buttons), ph(phase),
+      src(Qt::MouseEventNotSynthesized)
+{}
+
+/*!
+    Constructs a wheel event object.
+
+    The \a pos provides the location of the mouse cursor
+    within the window. The position in global coordinates is specified
+    by \a globalPos.
+
+    \a pixelDelta contains the scrolling distance in pixels on screen, while
+    \a angleDelta contains the wheel rotation distance. \a pixelDelta is
+    optional and can be null.
+
+    The mouse and keyboard states at the time of the event are specified by
+    \a buttons and \a modifiers.
+
+    For backwards compatibility, the event can also hold monodirectional wheel
+    event data: \a qt4Delta specifies the rotation, and \a qt4Orientation the
+    direction.
+
+    The scrolling phase of the event is specified by \a phase.
+
+    If the wheel event comes from a physical mouse wheel, \a source is set to
+    Qt::MouseEventNotSynthesized. If it comes from a gesture detected by the
+    operating system, or from a non-mouse hardware device, such that \a pixelDelta is
+    directly related to finger movement, \a source is set to Qt::MouseEventSynthesizedBySystem.
+    If it comes from Qt, source would be set to Qt::MouseEventSynthesizedByQt.
+
+    \sa posF(), globalPosF(), angleDelta(), pixelDelta(), phase()
+*/
+
+QWheelEvent::QWheelEvent(const QPointF &pos, const QPointF& globalPos,
+            QPoint pixelDelta, QPoint angleDelta, int qt4Delta, Qt::Orientation qt4Orientation,
+            Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers, Qt::ScrollPhase phase, Qt::MouseEventSource source)
+    : QInputEvent(Wheel, modifiers), p(pos), g(globalPos), pixelD(pixelDelta),
+      angleD(angleDelta), qt4D(qt4Delta), qt4O(qt4Orientation), mouseState(buttons), ph(phase), src(source)
 {}
 
 #endif // QT_NO_WHEELEVENT
diff --git a/src/gui/kernel/qevent.h b/src/gui/kernel/qevent.h
index 0b6d96a590..35a8884865 100644
--- a/src/gui/kernel/qevent.h
+++ b/src/gui/kernel/qevent.h
@@ -176,7 +176,9 @@ public:
     QWheelEvent(const QPointF &pos, const QPointF& globalPos,
                 QPoint pixelDelta, QPoint angleDelta, int qt4Delta, Qt::Orientation qt4Orientation,
                 Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers, Qt::ScrollPhase phase);
-
+    QWheelEvent(const QPointF &pos, const QPointF &globalPos, QPoint pixelDelta, QPoint angleDelta,
+                int qt4Delta, Qt::Orientation qt4Orientation, Qt::MouseButtons buttons,
+                Qt::KeyboardModifiers modifiers, Qt::ScrollPhase phase, Qt::MouseEventSource source);
     ~QWheelEvent();
 
 
@@ -201,6 +203,8 @@ public:
 
     inline Qt::ScrollPhase phase() const { return Qt::ScrollPhase(ph); }
 
+    Qt::MouseEventSource source() const { return Qt::MouseEventSource(src); }
+
 protected:
     QPointF p;
     QPointF g;
@@ -210,7 +214,8 @@ protected:
     Qt::Orientation qt4O;
     Qt::MouseButtons mouseState;
     uint ph : 2;
-    int reserved : 30;
+    uint src: 2;
+    int reserved : 28;
 };
 #endif
 
diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index 9ddb9e15ee..a2953259ff 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -1833,7 +1833,7 @@ void QGuiApplicationPrivate::processWheelEvent(QWindowSystemInterfacePrivate::Wh
         return;
     }
 
-     QWheelEvent ev(localPoint, globalPoint, e->pixelDelta, e->angleDelta, e->qt4Delta, e->qt4Orientation, buttons, e->modifiers, e->phase);
+     QWheelEvent ev(localPoint, globalPoint, e->pixelDelta, e->angleDelta, e->qt4Delta, e->qt4Orientation, buttons, e->modifiers, e->phase, e->source);
      ev.setTimestamp(e->timestamp);
      QGuiApplication::sendSpontaneousEvent(window, &ev);
 #endif /* ifndef QT_NO_WHEELEVENT */
diff --git a/src/gui/kernel/qguiapplication_p.h b/src/gui/kernel/qguiapplication_p.h
index 165cd18580..8b444e1d34 100644
--- a/src/gui/kernel/qguiapplication_p.h
+++ b/src/gui/kernel/qguiapplication_p.h
@@ -270,6 +270,8 @@ public:
     static Qt::MouseEventFlags mouseEventFlags(const QMouseEvent *event);
     static void setMouseEventFlags(QMouseEvent *event, Qt::MouseEventFlags flags);
 
+    static Qt::MouseEventSource wheelEventSource(const QWheelEvent *event);
+
     const QDrawHelperGammaTables *gammaTables();
 
     // hook reimplemented in QApplication to apply the QStyle function on the QIcon
diff --git a/src/gui/kernel/qwindowsysteminterface.cpp b/src/gui/kernel/qwindowsysteminterface.cpp
index a564f507d8..6f41d85965 100644
--- a/src/gui/kernel/qwindowsysteminterface.cpp
+++ b/src/gui/kernel/qwindowsysteminterface.cpp
@@ -339,13 +339,13 @@ void QWindowSystemInterface::handleWheelEvent(QWindow *tlw, ulong timestamp, con
     handleWheelEvent(tlw, timestamp, local, global, QPoint(), point, mods);
 }
 
-void QWindowSystemInterface::handleWheelEvent(QWindow *w, const QPointF & local, const QPointF & global, QPoint pixelDelta, QPoint angleDelta, Qt::KeyboardModifiers mods, Qt::ScrollPhase phase)
+void QWindowSystemInterface::handleWheelEvent(QWindow *w, const QPointF & local, const QPointF & global, QPoint pixelDelta, QPoint angleDelta, Qt::KeyboardModifiers mods, Qt::ScrollPhase phase, Qt::MouseEventSource source)
 {
     unsigned long time = QWindowSystemInterfacePrivate::eventTime.elapsed();
-    handleWheelEvent(w, time, local, global, pixelDelta, angleDelta, mods, phase);
+    handleWheelEvent(w, time, local, global, pixelDelta, angleDelta, mods, phase, source);
 }
 
-void QWindowSystemInterface::handleWheelEvent(QWindow *tlw, ulong timestamp, const QPointF & local, const QPointF & global, QPoint pixelDelta, QPoint angleDelta, Qt::KeyboardModifiers mods, Qt::ScrollPhase phase)
+void QWindowSystemInterface::handleWheelEvent(QWindow *tlw, ulong timestamp, const QPointF & local, const QPointF & global, QPoint pixelDelta, QPoint angleDelta, Qt::KeyboardModifiers mods, Qt::ScrollPhase phase, Qt::MouseEventSource source)
 {
     // Qt 4 sends two separate wheel events for horizontal and vertical
     // deltas. For Qt 5 we want to send the deltas in one event, but at the
@@ -363,14 +363,14 @@ void QWindowSystemInterface::handleWheelEvent(QWindow *tlw, ulong timestamp, con
 
     // Simple case: vertical deltas only:
     if (angleDelta.y() != 0 && angleDelta.x() == 0) {
-        e = new QWindowSystemInterfacePrivate::WheelEvent(tlw, timestamp, local, global, pixelDelta, angleDelta, angleDelta.y(), Qt::Vertical, mods, phase);
+        e = new QWindowSystemInterfacePrivate::WheelEvent(tlw, timestamp, local, global, pixelDelta, angleDelta, angleDelta.y(), Qt::Vertical, mods, phase, source);
         QWindowSystemInterfacePrivate::handleWindowSystemEvent(e);
         return;
     }
 
     // Simple case: horizontal deltas only:
     if (angleDelta.y() == 0 && angleDelta.x() != 0) {
-        e = new QWindowSystemInterfacePrivate::WheelEvent(tlw, timestamp, local, global, pixelDelta, angleDelta, angleDelta.x(), Qt::Horizontal, mods, phase);
+        e = new QWindowSystemInterfacePrivate::WheelEvent(tlw, timestamp, local, global, pixelDelta, angleDelta, angleDelta.x(), Qt::Horizontal, mods, phase, source);
         QWindowSystemInterfacePrivate::handleWindowSystemEvent(e);
         return;
     }
@@ -378,12 +378,12 @@ void QWindowSystemInterface::handleWheelEvent(QWindow *tlw, ulong timestamp, con
     // Both horizontal and vertical deltas: Send two wheel events.
     // The first event contains the Qt 5 pixel and angle delta as points,
     // and in addition the Qt 4 compatibility vertical angle delta.
-    e = new QWindowSystemInterfacePrivate::WheelEvent(tlw, timestamp, local, global, pixelDelta, angleDelta, angleDelta.y(), Qt::Vertical, mods, phase);
+    e = new QWindowSystemInterfacePrivate::WheelEvent(tlw, timestamp, local, global, pixelDelta, angleDelta, angleDelta.y(), Qt::Vertical, mods, phase, source);
     QWindowSystemInterfacePrivate::handleWindowSystemEvent(e);
 
     // The second event contains null pixel and angle points and the
     // Qt 4 compatibility horizontal angle delta.
-    e = new QWindowSystemInterfacePrivate::WheelEvent(tlw, timestamp, local, global, QPoint(), QPoint(), angleDelta.x(), Qt::Horizontal, mods, phase);
+    e = new QWindowSystemInterfacePrivate::WheelEvent(tlw, timestamp, local, global, QPoint(), QPoint(), angleDelta.x(), Qt::Horizontal, mods, phase, source);
     QWindowSystemInterfacePrivate::handleWindowSystemEvent(e);
 }
 
diff --git a/src/gui/kernel/qwindowsysteminterface.h b/src/gui/kernel/qwindowsysteminterface.h
index 7bb3938fe6..4d3bc43f1c 100644
--- a/src/gui/kernel/qwindowsysteminterface.h
+++ b/src/gui/kernel/qwindowsysteminterface.h
@@ -106,8 +106,8 @@ public:
                                        quint32 nativeModifiers,
                                        const QString& text = QString(), bool autorep = false,
                                        ushort count = 1, bool tryShortcutOverride = true);
-    static void handleWheelEvent(QWindow *w, const QPointF & local, const QPointF & global, QPoint pixelDelta, QPoint angleDelta, Qt::KeyboardModifiers mods = Qt::NoModifier, Qt::ScrollPhase phase = Qt::ScrollUpdate);
-    static void handleWheelEvent(QWindow *w, ulong timestamp, const QPointF & local, const QPointF & global, QPoint pixelDelta, QPoint angleDelta, Qt::KeyboardModifiers mods = Qt::NoModifier, Qt::ScrollPhase phase = Qt::ScrollUpdate);
+    static void handleWheelEvent(QWindow *w, const QPointF & local, const QPointF & global, QPoint pixelDelta, QPoint angleDelta, Qt::KeyboardModifiers mods = Qt::NoModifier, Qt::ScrollPhase phase = Qt::ScrollUpdate, Qt::MouseEventSource source = Qt::MouseEventNotSynthesized);
+    static void handleWheelEvent(QWindow *w, ulong timestamp, const QPointF & local, const QPointF & global, QPoint pixelDelta, QPoint angleDelta, Qt::KeyboardModifiers mods = Qt::NoModifier, Qt::ScrollPhase phase = Qt::ScrollUpdate, Qt::MouseEventSource source = Qt::MouseEventNotSynthesized);
 
     // 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);
diff --git a/src/gui/kernel/qwindowsysteminterface_p.h b/src/gui/kernel/qwindowsysteminterface_p.h
index 57411d8101..782d3e9400 100644
--- a/src/gui/kernel/qwindowsysteminterface_p.h
+++ b/src/gui/kernel/qwindowsysteminterface_p.h
@@ -232,8 +232,8 @@ public:
     class WheelEvent : public InputEvent {
     public:
         WheelEvent(QWindow *w, ulong time, const QPointF & local, const QPointF & global, QPoint pixelD, QPoint angleD, int qt4D, Qt::Orientation qt4O,
-                   Qt::KeyboardModifiers mods, Qt::ScrollPhase phase = Qt::ScrollUpdate)
-            : InputEvent(w, time, Wheel, mods), pixelDelta(pixelD), angleDelta(angleD), qt4Delta(qt4D), qt4Orientation(qt4O), localPos(local), globalPos(global), phase(phase) { }
+                   Qt::KeyboardModifiers mods, Qt::ScrollPhase phase = Qt::ScrollUpdate, Qt::MouseEventSource src = Qt::MouseEventNotSynthesized)
+            : InputEvent(w, time, Wheel, mods), pixelDelta(pixelD), angleDelta(angleD), qt4Delta(qt4D), qt4Orientation(qt4O), localPos(local), globalPos(global), phase(phase), source(src) { }
         QPoint pixelDelta;
         QPoint angleDelta;
         int qt4Delta;
@@ -241,6 +241,7 @@ public:
         QPointF localPos;
         QPointF globalPos;
         Qt::ScrollPhase phase;
+        Qt::MouseEventSource source;
     };
 
     class KeyEvent : public InputEvent {