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, 4 deletions

diff --git a/src/plugins/platforms/xcb/qxcbconnection.h b/src/plugins/platforms/xcb/qxcbconnection.h
index 8a4b577d2e..e6feabf79e 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.h
+++ b/src/plugins/platforms/xcb/qxcbconnection.h
@@ -44,6 +44,7 @@
 #include <xcb/randr.h>
 
 #include <QtCore/QTimer>
+#include <QtGui/qpointingdevice.h>
 #include <QtGui/private/qtguiglobal_p.h>
 #include "qxcbexport.h"
 #include <QHash>
@@ -263,10 +264,11 @@ private:
     inline bool timeGreaterThan(xcb_timestamp_t a, xcb_timestamp_t b) const
     { return static_cast<int32_t>(a - b) > 0 || b == XCB_CURRENT_TIME; }
 
-    void xi2SetupDevice(void *info, bool removeExisting = true);
+    void xi2SetupSlavePointerDevice(void *info, bool removeExisting = true, QPointingDevice *master = nullptr);
     void xi2SetupDevices();
+    // TODO get rid of this: store a smaller struct in QPointingDevicePrivate::extra
     struct TouchDeviceData {
-        QTouchDevice *qtTouchDevice = nullptr;
+        QPointingDevice *qtTouchDevice = nullptr;
         QHash<int, QWindowSystemInterface::TouchPoint> touchPoints;
         QHash<int, QPointF> pointPressedPosition; // in screen coordinates where each point was pressed
         struct ValuatorClassInfo {
@@ -290,10 +292,12 @@ private:
     void xi2HandleDeviceChangedEvent(void *event);
     void xi2ProcessTouch(void *xiDevEvent, QXcbWindow *platformWindow);
 #if QT_CONFIG(tabletevent)
+    // TODO get rid of this: store a smaller struct in QPointingDevicePrivate::extra
     struct TabletData {
         int deviceId = 0;
-        QTabletEvent::PointerType pointerType = QTabletEvent::UnknownPointer;
-        QTabletEvent::TabletDevice tool = QTabletEvent::Stylus;
+        QString name;
+        QPointingDevice::PointerType pointerType = QPointingDevice::PointerType::Unknown;
+        QInputDevice::DeviceType tool = QInputDevice::DeviceType::Stylus;
         Qt::MouseButtons buttons;
         qint64 serialId = 0;
         bool inProximity = false;
@@ -312,6 +316,7 @@ private:
     QVector<TabletData> m_tabletData;
     TabletData *tabletDataForDevice(int id);
 #endif // QT_CONFIG(tabletevent)
+    // TODO get rid of this: store a smaller struct in QPointingDevicePrivate::extra
     struct ScrollingDevice {
         int deviceId = 0;
         int verticalIndex = 0;