Introduce QInputDevice hierarchy; replace QTouchDevice

We have seen during the Qt 5 series that QMouseEvent::source() does
not provide enough information: if it is synthesized, it could have
come from any device for which mouse events are synthesized, not only
from a touchscreen. By providing in every QInputEvent as complete
information about the actual source device as possible, we will enable
very fine-tuned behavior in the object that handles each event.

Further, we would like to support multiple keyboards, pointing devices,
and named groups of devices that are known as "seats" in Wayland.

In Qt 5, QPA plugins registered each touchscreen as it was discovered.
Now we extend this pattern to all input devices.  This new requirement
can be implemented gradually; for now, if a QTWSI input event is
received wtihout a device pointer, a default "core" device will be
created on-the-fly, and a warning emitted.

In Qt 5, QTouchEvent::TouchPoint::id() was forced to be unique even when
multiple devices were in use simultaneously. Now that each event
identifies the device it came from, this hack is no longer needed.

A stub of the new QPointerEvent is added; it will be developed further
in subsequent patches.

[ChangeLog][QtGui][QInputEvent] Every QInputEvent now carries a pointer
to an instance of QInputDevice, or the subclass QPointingDevice in case
of mouse, touch and tablet events. Each platform plugin is expected to
create the device instances, register them, and provide valid pointers
with all input events. If this is not done, warnings are emitted and
default devices are created as necessary. When the device has accurate
information, it provides the opportunity to fine-tune behavior depending
on device type and capabilities: for example if a QMouseEvent is
synthesized from a touchscreen, the recipient can see which touchscreen
it came from. Each device also has a seatName to distinguish users on
multi-user windowing systems. Touchpoint IDs are no longer unique on
their own, but the combination of ID and device is.

Fixes: QTBUG-46412
Fixes: QTBUG-72167
Task-number: QTBUG-69433
Task-number: QTBUG-52430
Change-Id: I933fb2b86182efa722037b7a33e404c5daf5292a
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

1 files changed, 9 insertions, 11 deletions

diff --git a/src/gui/kernel/qwindowsysteminterface.h b/src/gui/kernel/qwindowsysteminterface.h
index 1ea9fbaa1c..905498a62b 100644
--- a/src/gui/kernel/qwindowsysteminterface.h
+++ b/src/gui/kernel/qwindowsysteminterface.h
@@ -64,7 +64,7 @@
 QT_BEGIN_NAMESPACE
 
 class QMimeData;
-class QTouchDevice;
+class QPointingDevice;
 class QPlatformDragQtResponse;
 class QPlatformDropQtResponse;
 
@@ -148,20 +148,18 @@ public:
         QVector<QPointF> rawPositions; // in screen coordinates
     };
 
-    static void registerTouchDevice(const QTouchDevice *device);
-    static void unregisterTouchDevice(const QTouchDevice *device);
-    static bool isTouchDeviceRegistered(const QTouchDevice *device);
+    static void registerInputDevice(const QInputDevice *device);
 
     template<typename Delivery = QWindowSystemInterface::DefaultDelivery>
-    static bool handleTouchEvent(QWindow *window, QTouchDevice *device,
+    static bool handleTouchEvent(QWindow *window, const QPointingDevice *device,
                                  const QList<struct TouchPoint> &points, Qt::KeyboardModifiers mods = Qt::NoModifier);
     template<typename Delivery = QWindowSystemInterface::DefaultDelivery>
-    static bool handleTouchEvent(QWindow *window, ulong timestamp, QTouchDevice *device,
+    static bool handleTouchEvent(QWindow *window, ulong timestamp, const QPointingDevice *device,
                                  const QList<struct TouchPoint> &points, Qt::KeyboardModifiers mods = Qt::NoModifier);
     template<typename Delivery = QWindowSystemInterface::DefaultDelivery>
-    static bool handleTouchCancelEvent(QWindow *window, QTouchDevice *device, Qt::KeyboardModifiers mods = Qt::NoModifier);
+    static bool handleTouchCancelEvent(QWindow *window, const QPointingDevice *device, Qt::KeyboardModifiers mods = Qt::NoModifier);
     template<typename Delivery = QWindowSystemInterface::DefaultDelivery>
-    static bool handleTouchCancelEvent(QWindow *window, ulong timestamp, QTouchDevice *device, Qt::KeyboardModifiers mods = Qt::NoModifier);
+    static bool handleTouchCancelEvent(QWindow *window, ulong timestamp, const QPointingDevice *device, Qt::KeyboardModifiers mods = Qt::NoModifier);
 
     // rect is relative to parent
     template<typename Delivery = QWindowSystemInterface::DefaultDelivery>
@@ -241,11 +239,11 @@ public:
     static void handleTabletLeaveProximityEvent(int device, int pointerType, qint64 uid);
 
 #ifndef QT_NO_GESTURES
-    static bool handleGestureEvent(QWindow *window, QTouchDevice *device,  ulong timestamp, Qt::NativeGestureType type,
+    static bool handleGestureEvent(QWindow *window, const QPointingDevice *device,  ulong timestamp, Qt::NativeGestureType type,
                                    QPointF &local, QPointF &global);
-    static bool handleGestureEventWithRealValue(QWindow *window, QTouchDevice *device,  ulong timestamp, Qt::NativeGestureType type,
+    static bool handleGestureEventWithRealValue(QWindow *window, const QPointingDevice *device,  ulong timestamp, Qt::NativeGestureType type,
                                                 qreal value, QPointF &local, QPointF &global);
-    static bool handleGestureEventWithSequenceIdAndValue(QWindow *window, QTouchDevice *device, ulong timestamp,Qt::NativeGestureType type,
+    static bool handleGestureEventWithSequenceIdAndValue(QWindow *window, const QPointingDevice *device, ulong timestamp,Qt::NativeGestureType type,
                                                          ulong sequenceId, quint64 value, QPointF &local, QPointF &global);
 #endif // QT_NO_GESTURES