client: Wait to create QPointingDevice; give seat name to ctor

Wait until both the seat name and capabilities are known, to avoid
depending on the order of messages. On Weston, seat_name() is called
after seat_capabilities(), while it's the other way around on others.

Pass the seat name along in each place where the QPointingDevice ctor is
invoked.

This gets us closer to multi-seat support on Wayland: at least
qtdecl/examples/quick/pointerhandlers/singlePointHandlerProperties.qml
can see the seat name of the device provided with each QTouchEvent or
QTabletEvent. Followup to bb151390240c1f20a6464adbefa497f3559554dd and
e168e1fc80231c0e2751b4f6f2a736efadff92fa

Pick-to: 6.8
Task-number: QTBUG-72167
Task-number: QTBUG-115207
Change-Id: Ife25cfec0307893d949a2a50a9b49a8f560a60e0
Reviewed-by: David Edmundson <davidedmundson@kde.org>

src/plugins/platforms/wayland/qwaylandinputdevice.cpp

@@ -431,21 +431,35 @@ QWaylandInputDevice::~QWaylandInputDevice()
 void QWaylandInputDevice::seat_capabilities(uint32_t caps)
 {
     mCaps = caps;
+    maybeRegisterInputDevices();
+}
 
-    if (caps & WL_SEAT_CAPABILITY_KEYBOARD && !mKeyboard) {
+void QWaylandInputDevice::seat_name(const QString &name)
+{
+    mSeatName = name;
+    mSeatNameKnown = true;
+    maybeRegisterInputDevices();
+}
+
+void QWaylandInputDevice::maybeRegisterInputDevices()
+{
+    if (!mSeatNameKnown)
+        return; // too early
+
+    if (mCaps & WL_SEAT_CAPABILITY_KEYBOARD && !mKeyboard) {
         mKeyboard.reset(createKeyboard(this));
-    } else if (!(caps & WL_SEAT_CAPABILITY_KEYBOARD) && mKeyboard) {
+    } else if (!(mCaps & WL_SEAT_CAPABILITY_KEYBOARD) && mKeyboard) {
         mKeyboard.reset();
     }
 
-    if (caps & WL_SEAT_CAPABILITY_POINTER && !mPointer) {
+    if (mCaps & WL_SEAT_CAPABILITY_POINTER && !mPointer) {
         mPointer.reset(createPointer(this));
 
         auto *pointerGestures = mQDisplay->pointerGestures();
         if (pointerGestures) {
             // NOTE: The name of the device and its system ID are not exposed on Wayland.
             mTouchPadDevice = new QPointingDevice(
-                        QLatin1String("touchpad"), 0, QInputDevice::DeviceType::TouchPad,
+                    QLatin1StringView("touchpad"), 0, QInputDevice::DeviceType::TouchPad,
                     QPointingDevice::PointerType::Finger, QInputDevice::Capability::Position,
                     MaxTouchPoints, 0, mSeatName, QPointingDeviceUniqueId(), this);
             QWindowSystemInterface::registerInputDevice(mTouchPadDevice);
@@ -454,33 +468,28 @@ void QWaylandInputDevice::seat_capabilities(uint32_t caps)
             mPointerGestureSwipe.reset(pointerGestures->createPointerGestureSwipe(this));
             mPointerGestureSwipe->init(pointerGestures->get_swipe_gesture(mPointer->object()));
         }
-    } else if (!(caps & WL_SEAT_CAPABILITY_POINTER) && mPointer) {
+    } else if (!(mCaps & WL_SEAT_CAPABILITY_POINTER) && mPointer) {
         mPointer.reset();
         mPointerGesturePinch.reset();
         mPointerGestureSwipe.reset();
     }
 
-    if (caps & WL_SEAT_CAPABILITY_TOUCH && !mTouch) {
+    if (mCaps & WL_SEAT_CAPABILITY_TOUCH && !mTouch) {
         mTouch.reset(createTouch(this));
 
         if (!mTouchDevice) {
             // TODO number of touchpoints, actual name and ID
             mTouchDevice = new QPointingDevice(
-                        QLatin1String("some touchscreen"), 0, QInputDevice::DeviceType::TouchScreen,
+                    QLatin1StringView("touchscreen"), 0, QInputDevice::DeviceType::TouchScreen,
                     QPointingDevice::PointerType::Finger, QInputDevice::Capability::Position,
                     MaxTouchPoints, 0, mSeatName, QPointingDeviceUniqueId(), this);
             QWindowSystemInterface::registerInputDevice(mTouchDevice);
         }
-    } else if (!(caps & WL_SEAT_CAPABILITY_TOUCH) && mTouch) {
+    } else if (!(mCaps & WL_SEAT_CAPABILITY_TOUCH) && mTouch) {
         mTouch.reset();
     }
 }
 
-void QWaylandInputDevice::seat_name(const QString &name)
-{
-    mSeatName = name;
-}
-
 QWaylandInputDevice::Keyboard *QWaylandInputDevice::createKeyboard(QWaylandInputDevice *device)
 {
     return new Keyboard(device);

src/plugins/platforms/wayland/qwaylandinputdevice_p.h

@@ -148,6 +148,7 @@ protected:
     uint32_t mId = -1;
     uint32_t mCaps = 0;
     QString mSeatName;
+    bool mSeatNameKnown = false;
 
 #if QT_CONFIG(cursor)
     struct CursorState {
@@ -185,6 +186,7 @@ protected:
 
     void seat_capabilities(uint32_t caps) override;
     void seat_name(const QString &name) override;
+    void maybeRegisterInputDevices();
     void handleTouchPoint(int id, QEventPoint::State state, const QPointF &surfacePosition = QPoint());
 
     QPointingDevice *mTouchDevice = nullptr;

src/plugins/platforms/wayland/qwaylandtabletv2.cpp

@@ -95,7 +95,7 @@ void QWaylandTabletSeatV2::zwp_tablet_seat_v2_pad_added(zwp_tablet_pad_v2 *id)
 QWaylandTabletV2::QWaylandTabletV2(::zwp_tablet_v2 *tablet, const QString &seatName)
     : QPointingDevice(u"unknown"_s, -1, DeviceType::Stylus, PointerType::Pen,
                       Capability::Position | Capability::Hover,
-                      1, 1)
+                      1, 1, seatName)
     , QtWayland::zwp_tablet_v2(tablet)
 {
     qCDebug(lcQpaInputDevices) << "new tablet on seat" << seatName;
@@ -142,7 +142,7 @@ void QWaylandTabletV2::zwp_tablet_v2_removed()
 QWaylandTabletToolV2::QWaylandTabletToolV2(QWaylandTabletSeatV2 *tabletSeat, ::zwp_tablet_tool_v2 *tool)
     : QPointingDevice(u"tool"_s, -1, DeviceType::Stylus, PointerType::Pen,
                       Capability::Position | Capability::Hover,
-                      1, 1)
+                      1, 1, tabletSeat->seat()->seatname())
     , QtWayland::zwp_tablet_tool_v2(tool)
     , m_tabletSeat(tabletSeat)
 {