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, 5 insertions, 6 deletions

diff --git a/src/gui/kernel/qwindowsysteminterface_p.h b/src/gui/kernel/qwindowsysteminterface_p.h
index dd6f29b41f..128b9ae0bc 100644
--- a/src/gui/kernel/qwindowsysteminterface_p.h
+++ b/src/gui/kernel/qwindowsysteminterface_p.h
@@ -297,10 +297,10 @@ public:
 
     class TouchEvent : public InputEvent {
     public:
-        TouchEvent(QWindow *w, ulong time, QEvent::Type t, QTouchDevice *dev,
+        TouchEvent(QWindow *w, ulong time, QEvent::Type t, const QPointingDevice *dev,
                    const QList<QTouchEvent::TouchPoint> &p, Qt::KeyboardModifiers mods)
             :InputEvent(w, time, Touch, mods), device(dev), points(p), touchType(t) { }
-        QTouchDevice *device;
+        const QPointingDevice *device;
         QList<QTouchEvent::TouchPoint> points;
         QEvent::Type touchType;
     };
@@ -440,7 +440,7 @@ public:
 #ifndef QT_NO_GESTURES
     class GestureEvent : public InputEvent {
     public:
-        GestureEvent(QWindow *window, ulong time, Qt::NativeGestureType type, QTouchDevice *dev, QPointF pos, QPointF globalPos)
+        GestureEvent(QWindow *window, ulong time, Qt::NativeGestureType type, const QPointingDevice *dev, QPointF pos, QPointF globalPos)
             : InputEvent(window, time, Gesture, Qt::NoModifier), type(type), pos(pos), globalPos(globalPos),
               realValue(0), sequenceId(0), intValue(0), device(dev) { }
         Qt::NativeGestureType type;
@@ -451,7 +451,7 @@ public:
         // Windows
         ulong sequenceId;
         quint64 intValue;
-        QTouchDevice *device;
+        const QPointingDevice *device;
     };
 #endif
 
@@ -533,11 +533,10 @@ public:
 
     static QList<QTouchEvent::TouchPoint>
         fromNativeTouchPoints(const QList<QWindowSystemInterface::TouchPoint> &points,
-                              const QWindow *window, quint8 deviceId, QEvent::Type *type = nullptr);
+                              const QWindow *window, QEvent::Type *type = nullptr);
     static QList<QWindowSystemInterface::TouchPoint>
         toNativeTouchPoints(const QList<QTouchEvent::TouchPoint>& pointList,
                             const QWindow *window);
-    static void clearPointIdMap();
 
     static void installWindowSystemEventHandler(QWindowSystemEventHandler *handler);
     static void removeWindowSystemEventhandler(QWindowSystemEventHandler *handler);