Client: Add support for high-resolution scrolling

With wl_pointer version 8, the axis_discrete event is replaced with the
axis_value120 event.

The main difference between axis_discrete and axis_value120 is that the
latter carries scroll deltas that can be fractions of 120, e.g. 30, etc.

See also https://gitlab.freedesktop.org/wayland/wayland/-/merge_requests/72

Change-Id: I4f724ead7ba146dde6d8975fa4edfcfca761769d
Reviewed-by: David Edmundson <davidedmundson@kde.org>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

src/3rdparty/wayland/protocols/wayland.xml

@@ -187,7 +187,7 @@
     </event>
   </interface>
 
-  <interface name="wl_compositor" version="4">
+  <interface name="wl_compositor" version="5">
     <description summary="the compositor singleton">
       A compositor.  This object is a singleton global.  The
       compositor is in charge of combining the contents of multiple
@@ -258,6 +258,12 @@
 	for the pool from the file descriptor passed when the pool was
 	created, but using the new size.  This request can only be
 	used to make the pool bigger.
+
+        This request only changes the amount of bytes that are mmapped
+        by the server and does not touch the file corresponding to the
+        file descriptor passed at creation time. It is the client's
+        responsibility to ensure that the file is at least as big as
+        the new pool size.
       </description>
       <arg name="size" type="int" summary="new size of the pool, in bytes"/>
     </request>
@@ -271,8 +277,8 @@
       Clients can create wl_shm_pool objects using the create_pool
       request.
 
-      At connection setup time, the wl_shm object emits one or more
+      On binding the wl_shm object one or more format events
-      format events to inform clients about the valid pixel formats
+      are emitted to inform clients about the valid pixel formats
       that can be used for buffers.
     </description>
 
@@ -296,6 +302,9 @@
 	The drm format codes match the macros defined in drm_fourcc.h, except
 	argb8888 and xrgb8888. The formats actually supported by the compositor
 	will be reported by the format event.
+
+	For all wl_shm formats and unless specified in another protocol
+	extension, pre-multiplied alpha is used for pixel values.
       </description>
       <!-- Note to protocol writers: don't update this list manually, instead
 	   run the automated script that keeps it in sync with drm_fourcc.h. -->
@@ -403,6 +412,10 @@
       <entry name="nv15" value="0x3531564e" summary="2x2 subsampled Cr:Cb plane"/>
       <entry name="q410" value="0x30313451"/>
       <entry name="q401" value="0x31303451"/>
+      <entry name="xrgb16161616" value="0x38345258" summary="[63:0] x:R:G:B 16:16:16:16 little endian"/>
+      <entry name="xbgr16161616" value="0x38344258" summary="[63:0] x:B:G:R 16:16:16:16 little endian"/>
+      <entry name="argb16161616" value="0x38345241" summary="[63:0] A:R:G:B 16:16:16:16 little endian"/>
+      <entry name="abgr16161616" value="0x38344241" summary="[63:0] A:B:G:R 16:16:16:16 little endian"/>
     </enum>
 
     <request name="create_pool">
@@ -431,10 +444,15 @@
   <interface name="wl_buffer" version="1">
     <description summary="content for a wl_surface">
       A buffer provides the content for a wl_surface. Buffers are
-      created through factory interfaces such as wl_drm, wl_shm or
+      created through factory interfaces such as wl_shm, wp_linux_buffer_params
-      similar. It has a width and a height and can be attached to a
+      (from the linux-dmabuf protocol extension) or similar. It has a width and
-      wl_surface, but the mechanism by which a client provides and
+      a height and can be attached to a wl_surface, but the mechanism by which a
-      updates the contents is defined by the buffer factory interface.
+      client provides and updates the contents is defined by the buffer factory
+      interface.
+
+      If the buffer uses a format that has an alpha channel, the alpha channel
+      is assumed to be premultiplied in the color channels unless otherwise
+      specified.
     </description>
 
     <request name="destroy" type="destructor">
@@ -878,7 +896,7 @@
 	which will subsequently be used in either the
 	data_device.enter event (for drag-and-drop) or the
 	data_device.selection event (for selections).  Immediately
-	following the data_device_data_offer event, the new data_offer
+	following the data_device.data_offer event, the new data_offer
 	object will send out data_offer.offer events to describe the
 	mime types it offers.
       </description>
@@ -948,9 +966,10 @@
 	immediately before receiving keyboard focus and when a new
 	selection is set while the client has keyboard focus.  The
 	data_offer is valid until a new data_offer or NULL is received
-	or until the client loses keyboard focus.  The client must
+	or until the client loses keyboard focus.  Switching surface with
-	destroy the previous selection data_offer, if any, upon receiving
+	keyboard focus within the same client doesn't mean a new selection
-	this event.
+	will be sent.  The client must destroy the previous selection
+	data_offer, if any, upon receiving this event.
       </description>
       <arg name="id" type="object" interface="wl_data_offer" allow-null="true"
 	   summary="selection data_offer object"/>
@@ -1038,7 +1057,8 @@
       a basic surface.
 
       Note! This protocol is deprecated and not intended for production use.
-      For desktop-style user interfaces, use xdg_shell.
+      For desktop-style user interfaces, use xdg_shell. Compositors and clients
+      should not implement this interface.
     </description>
 
     <enum name="error">
@@ -1332,7 +1352,7 @@
     </event>
   </interface>
 
-  <interface name="wl_surface" version="4">
+  <interface name="wl_surface" version="5">
     <description summary="an onscreen surface">
       A surface is a rectangular area that may be displayed on zero
       or more outputs, and shown any number of times at the compositor's
@@ -1384,6 +1404,7 @@
       <entry name="invalid_scale" value="0" summary="buffer scale value is invalid"/>
       <entry name="invalid_transform" value="1" summary="buffer transform value is invalid"/>
       <entry name="invalid_size" value="2" summary="buffer size is invalid"/>
+      <entry name="invalid_offset" value="3" summary="buffer offset is invalid"/>
     </enum>
 
     <request name="destroy" type="destructor">
@@ -1406,7 +1427,14 @@
 	buffer's upper left corner, relative to the current buffer's upper
 	left corner, in surface-local coordinates. In other words, the
 	x and y, combined with the new surface size define in which
-	directions the surface's size changes.
+	directions the surface's size changes. Setting anything other than 0
+	as x and y arguments is discouraged, and should instead be replaced
+	with using the separate wl_surface.offset request.
+
+	When the bound wl_surface version is 5 or higher, passing any
+	non-zero x or y is a protocol violation, and will result in an
+	'invalid_offset' error being raised. To achieve equivalent semantics,
+	use wl_surface.offset.
 
 	Surface contents are double-buffered state, see wl_surface.commit.
 
@@ -1434,9 +1462,12 @@
 	from the same backing storage or use wp_linux_buffer_release.
 
 	Destroying the wl_buffer after wl_buffer.release does not change
-	the surface contents. However, if the client destroys the
+	the surface contents. Destroying the wl_buffer before wl_buffer.release
-	wl_buffer before receiving the wl_buffer.release event, the surface
+	is allowed as long as the underlying buffer storage isn't re-used (this
-	contents become undefined immediately.
+	can happen e.g. on client process termination). However, if the client
+	destroys the wl_buffer before receiving the wl_buffer.release event and
+	mutates the underlying buffer storage, the surface contents become
+	undefined immediately.
 
 	If wl_surface.attach is sent with a NULL wl_buffer, the
 	following wl_surface.commit will remove the surface content.
@@ -1734,9 +1765,30 @@
       <arg name="width" type="int" summary="width of damage rectangle"/>
       <arg name="height" type="int" summary="height of damage rectangle"/>
     </request>
+
+    <!-- Version 5 additions -->
+
+    <request name="offset" since="5">
+      <description summary="set the surface contents offset">
+	The x and y arguments specify the location of the new pending
+	buffer's upper left corner, relative to the current buffer's upper
+	left corner, in surface-local coordinates. In other words, the
+	x and y, combined with the new surface size define in which
+	directions the surface's size changes.
+
+	Surface location offset is double-buffered state, see
+	wl_surface.commit.
+
+	This request is semantically equivalent to and the replaces the x and y
+	arguments in the wl_surface.attach request in wl_surface versions prior
+	to 5. See wl_surface.attach for details.
+      </description>
+      <arg name="x" type="int" summary="surface-local x coordinate"/>
+      <arg name="y" type="int" summary="surface-local y coordinate"/>
+    </request>
    </interface>
 
-  <interface name="wl_seat" version="7">
+  <interface name="wl_seat" version="8">
     <description summary="group of input devices">
       A seat is a group of keyboards, pointer and touch devices. This
       object is published as a global during start up, or when such a
@@ -1838,9 +1890,22 @@
 
     <event name="name" since="2">
       <description summary="unique identifier for this seat">
-	In a multiseat configuration this can be used by the client to help
+	In a multi-seat configuration the seat name can be used by clients to
-	identify which physical devices the seat represents. Based on
+	help identify which physical devices the seat represents.
-	the seat configuration used by the compositor.
+
+	The seat name is a UTF-8 string with no convention defined for its
+	contents. Each name is unique among all wl_seat globals. The name is
+	only guaranteed to be unique for the current compositor instance.
+
+	The same seat names are used for all clients. Thus, the name can be
+	shared across processes to refer to a specific wl_seat global.
+
+	The name event is sent after binding to the seat global. This event is
+	only sent once per seat object, and the name does not change over the
+	lifetime of the wl_seat global.
+
+	Compositors may re-use the same seat name if the wl_seat global is
+	destroyed and re-created later.
       </description>
       <arg name="name" type="string" summary="seat identifier"/>
     </event>
@@ -1856,7 +1921,7 @@
 
   </interface>
 
-  <interface name="wl_pointer" version="7">
+  <interface name="wl_pointer" version="8">
     <description summary="pointer input device">
       The wl_pointer interface represents one or more input devices,
       such as mice, which control the pointer location and pointer_focus
@@ -1905,6 +1970,10 @@
 	wl_surface is no longer used as the cursor. When the use as a
 	cursor ends, the current and pending input regions become
 	undefined, and the wl_surface is unmapped.
+
+	The serial parameter must match the latest wl_pointer.enter
+	serial number sent to the client. Otherwise the request will be
+	ignored.
       </description>
       <arg name="serial" type="uint" summary="serial number of the enter event"/>
       <arg name="surface" type="object" interface="wl_surface" allow-null="true"
@@ -2152,6 +2221,9 @@
 	This event carries the axis value of the wl_pointer.axis event in
 	discrete steps (e.g. mouse wheel clicks).
 
+	This event is deprecated with wl_pointer version 8 - this event is not
+	sent to clients supporting version 8 or later.
+
 	This event does not occur on its own, it is coupled with a
 	wl_pointer.axis event that represents this axis value on a
 	continuous scale. The protocol guarantees that each axis_discrete
@@ -2159,7 +2231,8 @@
 	axis number within the same wl_pointer.frame. Note that the protocol
 	allows for other events to occur between the axis_discrete and
 	its coupled axis event, including other axis_discrete or axis
-	events.
+	events. A wl_pointer.frame must not contain more than one axis_discrete
+	event per axis type.
 
 	This event is optional; continuous scrolling devices
 	like two-finger scrolling on touchpads do not have discrete
@@ -2177,9 +2250,37 @@
       <arg name="axis" type="uint" enum="axis" summary="axis type"/>
       <arg name="discrete" type="int" summary="number of steps"/>
     </event>
+
+    <event name="axis_value120" since="8">
+      <description summary="axis high-resolution scroll event">
+	Discrete high-resolution scroll information.
+
+	This event carries high-resolution wheel scroll information,
+	with each multiple of 120 representing one logical scroll step
+	(a wheel detent). For example, an axis_value120 of 30 is one quarter of
+	a logical scroll step in the positive direction, a value120 of
+	-240 are two logical scroll steps in the negative direction within the
+	same hardware event.
+	Clients that rely on discrete scrolling should accumulate the
+	value120 to multiples of 120 before processing the event.
+
+	The value120 must not be zero.
+
+	This event replaces the wl_pointer.axis_discrete event in clients
+	supporting wl_pointer version 8 or later.
+
+	Where a wl_pointer.axis_source event occurs in the same
+	wl_pointer.frame, the axis source applies to this event.
+
+	The order of wl_pointer.axis_value120 and wl_pointer.axis_source is
+	not guaranteed.
+      </description>
+      <arg name="axis" type="uint" enum="axis" summary="axis type"/>
+      <arg name="value120" type="int" summary="scroll distance as fraction of 120"/>
+    </event>
   </interface>
 
-  <interface name="wl_keyboard" version="7">
+  <interface name="wl_keyboard" version="8">
     <description summary="keyboard input device">
       The wl_keyboard interface represents one or more keyboards
       associated with a seat.
@@ -2193,13 +2294,14 @@
       <entry name="no_keymap" value="0"
 	     summary="no keymap; client must understand how to interpret the raw keycode"/>
       <entry name="xkb_v1" value="1"
-	     summary="libxkbcommon compatible; to determine the xkb keycode, clients must add 8 to the key event keycode"/>
+	     summary="libxkbcommon compatible, null-terminated string; to determine the xkb keycode, clients must add 8 to the key event keycode"/>
     </enum>
 
     <event name="keymap">
       <description summary="keyboard mapping">
 	This event provides a file descriptor to the client which can be
-	memory-mapped to provide a keyboard mapping description.
+	memory-mapped in read-only mode to provide a keyboard mapping
+	description.
 
 	From version 7 onwards, the fd must be mapped with MAP_PRIVATE by
 	the recipient, as MAP_SHARED may fail.
@@ -2305,7 +2407,7 @@
     </event>
   </interface>
 
-  <interface name="wl_touch" version="7">
+  <interface name="wl_touch" version="8">
     <description summary="touchscreen input device">
       The wl_touch interface represents a touchscreen
       associated with a seat.
@@ -2449,7 +2551,7 @@
     </event>
   </interface>
 
-  <interface name="wl_output" version="3">
+  <interface name="wl_output" version="4">
     <description summary="compositor output region">
       An output describes part of the compositor geometry.  The
       compositor works in the 'compositor coordinate system' and an
@@ -2505,12 +2607,15 @@
 	The physical size can be set to zero if it doesn't make sense for this
 	output (e.g. for projectors or virtual outputs).
 
+	The geometry event will be followed by a done event (starting from
+	version 2).
+
 	Note: wl_output only advertises partial information about the output
 	position and identification. Some compositors, for instance those not
 	implementing a desktop-style output layout or those exposing virtual
 	outputs, might fake this information. Instead of using x and y, clients
 	should use xdg_output.logical_position. Instead of using make and model,
-	clients should use xdg_output.name and xdg_output.description.
+	clients should use name and description.
       </description>
       <arg name="x" type="int"
 	   summary="x position within the global compositor space"/>
@@ -2566,6 +2671,9 @@
 	The vertical refresh rate can be set to zero if it doesn't make
 	sense for this output (e.g. for virtual outputs).
 
+	The mode event will be followed by a done event (starting from
+	version 2).
+
 	Clients should not use the refresh rate to schedule frames. Instead,
 	they should use the wl_surface.frame event or the presentation-time
 	protocol.
@@ -2612,6 +2720,8 @@
 	the scale of the output. That way the compositor can
 	avoid scaling the surface, and the client can supply
 	a higher detail image.
+
+	The scale event will be followed by a done event.
       </description>
       <arg name="factor" type="int" summary="scaling factor of output"/>
     </event>
@@ -2624,6 +2734,62 @@
 	use the output object anymore.
       </description>
     </request>
+
+    <!-- Version 4 additions -->
+
+    <event name="name" since="4">
+      <description summary="name of this output">
+	Many compositors will assign user-friendly names to their outputs, show
+	them to the user, allow the user to refer to an output, etc. The client
+	may wish to know this name as well to offer the user similar behaviors.
+
+	The name is a UTF-8 string with no convention defined for its contents.
+	Each name is unique among all wl_output globals. The name is only
+	guaranteed to be unique for the compositor instance.
+
+	The same output name is used for all clients for a given wl_output
+	global. Thus, the name can be shared across processes to refer to a
+	specific wl_output global.
+
+	The name is not guaranteed to be persistent across sessions, thus cannot
+	be used to reliably identify an output in e.g. configuration files.
+
+	Examples of names include 'HDMI-A-1', 'WL-1', 'X11-1', etc. However, do
+	not assume that the name is a reflection of an underlying DRM connector,
+	X11 connection, etc.
+
+	The name event is sent after binding the output object. This event is
+	only sent once per output object, and the name does not change over the
+	lifetime of the wl_output global.
+
+	Compositors may re-use the same output name if the wl_output global is
+	destroyed and re-created later. Compositors should avoid re-using the
+	same name if possible.
+
+	The name event will be followed by a done event.
+      </description>
+      <arg name="name" type="string" summary="output name"/>
+    </event>
+
+    <event name="description" since="4">
+      <description summary="human-readable description of this output">
+	Many compositors can produce human-readable descriptions of their
+	outputs. The client may wish to know this description as well, e.g. for
+	output selection purposes.
+
+	The description is a UTF-8 string with no convention defined for its
+	contents. The description is not guaranteed to be unique among all
+	wl_output globals. Examples might include 'Foocorp 11" Display' or
+	'Virtual X11 output via :1'.
+
+	The description event is sent after binding the output object and
+	whenever the description changes. The description is optional, and may
+	not be sent at all.
+
+	The description event will be followed by a done event.
+      </description>
+      <arg name="description" type="string" summary="output description"/>
+    </event>
   </interface>
 
   <interface name="wl_region" version="1">

src/plugins/platforms/wayland/qwaylandinputdevice.cpp

@@ -375,7 +375,7 @@ QWaylandInputDevice::Touch::~Touch()
 }
 
 QWaylandInputDevice::QWaylandInputDevice(QWaylandDisplay *display, int version, uint32_t id)
-    : QtWayland::wl_seat(display->wl_registry(), id, qMin(version, 7))
+    : QtWayland::wl_seat(display->wl_registry(), id, qMin(version, 8))
     , mQDisplay(display)
     , mDisplay(display->wl_display())
 {
@@ -982,14 +982,16 @@ void QWaylandInputDevice::Pointer::pointer_axis_discrete(uint32_t axis, int32_t
     if (!focusWindow())
         return;
 
+    const int32_t delta120 = value * 15 * 8;
+
     switch (axis) {
     case axis_vertical_scroll:
         qCDebug(lcQpaWaylandInput) << "wl_pointer.axis_discrete vertical:" << value;
-        mFrameData.discreteDelta.ry() += value;
+        mFrameData.delta120.ry() += delta120;
         break;
     case axis_horizontal_scroll:
         qCDebug(lcQpaWaylandInput) << "wl_pointer.axis_discrete horizontal:" << value;
-        mFrameData.discreteDelta.rx() += value;
+        mFrameData.delta120.rx() += delta120;
         break;
     default:
         //TODO: is this really needed?
@@ -998,6 +1000,26 @@ void QWaylandInputDevice::Pointer::pointer_axis_discrete(uint32_t axis, int32_t
     }
 }
 
+void QWaylandInputDevice::Pointer::pointer_axis_value120(uint32_t axis, int32_t value)
+{
+    if (!focusWindow())
+        return;
+
+    switch (axis) {
+    case axis_vertical_scroll:
+        qCDebug(lcQpaWaylandInput) << "wl_pointer.axis_value120 vertical:" << value;
+        mFrameData.delta120.ry() += value;
+        break;
+    case axis_horizontal_scroll:
+        qCDebug(lcQpaWaylandInput) << "wl_pointer.axis_value120 horizontal:" << value;
+        mFrameData.delta120.rx() += value;
+        break;
+    default:
+        qCWarning(lcQpaWaylandInput) << "wl_pointer.axis_value120: Unknown axis:" << axis;
+        return;
+    }
+}
+
 void QWaylandInputDevice::Pointer::setFrameEvent(QWaylandPointerEvent *event)
 {
     qCDebug(lcQpaWaylandInput) << "Setting frame event " << event->type;
@@ -1016,7 +1038,7 @@ void QWaylandInputDevice::Pointer::setFrameEvent(QWaylandPointerEvent *event)
 
 void QWaylandInputDevice::Pointer::FrameData::resetScrollData()
 {
-    discreteDelta = QPoint();
+    delta120 = QPoint();
     delta = QPointF();
     axisSource = axis_source_wheel;
 }
@@ -1060,15 +1082,16 @@ QPoint QWaylandInputDevice::Pointer::FrameData::pixelDeltaAndError(QPointF *accu
 
 QPoint QWaylandInputDevice::Pointer::FrameData::angleDelta() const
 {
-    if (discreteDelta.isNull()) {
+    if (delta120.isNull()) {
         // If we didn't get any discrete events, then we need to fall back to
         // the continuous information.
         return (delta * -12).toPoint(); //TODO: why multiply by 12?
     }
 
     // The angle delta is in eights of degrees, and our docs says most mice have
-    // 1 click = 15 degrees. It's also in the opposite direction of surface space.
+    // 1 click = 15 degrees, i.e. 120 is one click. It's also in the opposite
-    return -discreteDelta * 15 * 8;
+    // direction of surface space.
+    return -delta120;
 }
 
 Qt::MouseEventSource QWaylandInputDevice::Pointer::FrameData::wheelEventSource() const

src/plugins/platforms/wayland/qwaylandinputdevice_p.h

@@ -308,6 +308,7 @@ protected:
     void pointer_axis_stop(uint32_t time, uint32_t axis) override;
     void pointer_axis_discrete(uint32_t axis, int32_t value) override;
     void pointer_frame() override;
+    void pointer_axis_value120(uint32_t axis, int32_t value120) override;
 
 private slots:
     void handleFocusDestroyed() { invalidateFocus(); }
@@ -343,7 +344,7 @@ public:
         QWaylandPointerEvent *event = nullptr;
 
         QPointF delta;
-        QPoint discreteDelta;
+        QPoint delta120;
         axis_source axisSource = axis_source_wheel;
 
         void resetScrollData();

tests/auto/wayland/CMakeLists.txt

@@ -17,6 +17,7 @@ if (NOT WEBOS)
     add_subdirectory(output)
     add_subdirectory(primaryselectionv1)
     add_subdirectory(seatv4)
+    add_subdirectory(seatv7)
     add_subdirectory(seat)
     add_subdirectory(surface)
     add_subdirectory(tabletv2)

tests/auto/wayland/seat/tst_seat.cpp

@@ -18,7 +18,7 @@ public:
             removeAll<Seat>();
 
             uint capabilities = MockCompositor::Seat::capability_pointer | MockCompositor::Seat::capability_touch;
-            int version = 7;
+            int version = 8;
             add<Seat>(capabilities, version);
         });
     }
@@ -40,8 +40,7 @@ private slots:
     void fingerScroll();
     void fingerScrollSlow();
     void continuousScroll();
-    void wheelDiscreteScroll_data();
+    void highResolutionScroll();
-    void wheelDiscreteScroll();
 
     // Touch tests
     void createsTouch();
@@ -56,13 +55,13 @@ private slots:
 void tst_seat::bindsToSeat()
 {
     QCOMPOSITOR_COMPARE(get<Seat>()->resourceMap().size(), 1);
-    QCOMPOSITOR_COMPARE(get<Seat>()->resourceMap().first()->version(), 7);
+    QCOMPOSITOR_COMPARE(get<Seat>()->resourceMap().first()->version(), 8);
 }
 
 void tst_seat::createsPointer()
 {
     QCOMPOSITOR_TRY_COMPARE(pointer()->resourceMap().size(), 1);
-    QCOMPOSITOR_TRY_COMPARE(pointer()->resourceMap().first()->version(), 7);
+    QCOMPOSITOR_TRY_COMPARE(pointer()->resourceMap().first()->version(), 8);
 }
 
 void tst_seat::setsCursorOnEnter()
@@ -320,28 +319,19 @@ void tst_seat::fingerScrollSlow()
     QCOMPARE(accumulated.y(), -1);
 }
 
-void tst_seat::wheelDiscreteScroll_data()
+void tst_seat::highResolutionScroll()
-{
-    QTest::addColumn<uint>("source");
-    QTest::newRow("wheel") << uint(Pointer::axis_source_wheel);
-    QTest::newRow("wheel tilt") << uint(Pointer::axis_source_wheel_tilt);
-}
-
-void tst_seat::wheelDiscreteScroll()
 {
     WheelWindow window;
     QCOMPOSITOR_TRY_VERIFY(xdgSurface() && xdgSurface()->m_committedConfigureSerial);
 
-    QFETCH(uint, source);
-
     exec([=] {
         auto *p = pointer();
         auto *c = client();
         p->sendEnter(xdgToplevel()->surface(), {32, 32});
         p->sendFrame(c);
-        p->sendAxisSource(c, Pointer::axis_source(source));
+        p->sendAxisSource(c, Pointer::axis_source_wheel);
-        p->sendAxisDiscrete(c, Pointer::axis_vertical_scroll, 1); // 1 click downwards
+        p->sendAxisValue120(c, Pointer::axis_vertical_scroll, 30); // quarter of a click
-        p->sendAxis(c, Pointer::axis_vertical_scroll, 1.0);
+        p->sendAxis(c, Pointer::axis_vertical_scroll, 3.75);
         p->sendFrame(c);
     });
 
@@ -350,10 +340,26 @@ void tst_seat::wheelDiscreteScroll()
         auto e = window.m_events.takeFirst();
         QCOMPARE(e.phase, Qt::NoScrollPhase);
         QVERIFY(qAbs(e.angleDelta.x()) <= qAbs(e.angleDelta.y())); // Vertical scroll
-        // According to the docs the angle delta is in eights of a degree and most mice have
+        QCOMPARE(e.angleDelta, QPoint(0, -30));
-        // 1 click = 15 degrees. The angle delta should therefore be:
+        // Click scrolls are not continuous and should not have a pixel delta
-        // 15 degrees / (1/8 eights per degrees) = 120 eights of degrees.
+        QCOMPARE(e.pixelDelta, QPoint(0, 0));
-        QCOMPARE(e.angleDelta, QPoint(0, -120));
+    }
+
+    exec([=] {
+        auto *p = pointer();
+        auto *c = client();
+        p->sendAxisSource(c, Pointer::axis_source_wheel);
+        p->sendAxisValue120(c, Pointer::axis_vertical_scroll, 90); // complete the click
+        p->sendAxis(c, Pointer::axis_vertical_scroll, 11.25);
+        p->sendFrame(c);
+    });
+
+    QTRY_VERIFY(!window.m_events.empty());
+    {
+        auto e = window.m_events.takeFirst();
+        QCOMPARE(e.phase, Qt::NoScrollPhase);
+        QVERIFY(qAbs(e.angleDelta.x()) <= qAbs(e.angleDelta.y())); // Vertical scroll
+        QCOMPARE(e.angleDelta, QPoint(0, -90));
         // Click scrolls are not continuous and should not have a pixel delta
         QCOMPARE(e.pixelDelta, QPoint(0, 0));
     }
@@ -388,7 +394,7 @@ void tst_seat::continuousScroll()
 void tst_seat::createsTouch()
 {
     QCOMPOSITOR_TRY_COMPARE(touch()->resourceMap().size(), 1);
-    QCOMPOSITOR_TRY_COMPARE(touch()->resourceMap().first()->version(), 7);
+    QCOMPOSITOR_TRY_COMPARE(touch()->resourceMap().first()->version(), 8);
 }
 
 class TouchWindow : public QRasterWindow {

tests/auto/wayland/seatv7/CMakeLists.txt

@@ -0,0 +1,13 @@
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+#####################################################################
+## tst_seatv7 Test:
+#####################################################################
+
+qt_internal_add_test(tst_seatv7
+    SOURCES
+        tst_seatv7.cpp
+    LIBRARIES
+        SharedClientTest
+)

tests/auto/wayland/seatv7/tst_seatv7.cpp

@@ -0,0 +1,130 @@
+// Copyright (C) 2018 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#include "mockcompositor.h"
+#include <QtOpenGL/QOpenGLWindow>
+#include <QtGui/QRasterWindow>
+#include <QtGui/QEventPoint>
+
+using namespace MockCompositor;
+
+class SeatCompositor : public DefaultCompositor {
+public:
+    explicit SeatCompositor()
+    {
+        exec([this] {
+            m_config.autoConfigure = true;
+
+            removeAll<Seat>();
+
+            uint capabilities = MockCompositor::Seat::capability_pointer | MockCompositor::Seat::capability_touch;
+            int version = 7;
+            add<Seat>(capabilities, version);
+        });
+    }
+};
+
+class tst_seatv7 : public QObject, private SeatCompositor
+{
+    Q_OBJECT
+private slots:
+    void cleanup() { QTRY_VERIFY2(isClean(), qPrintable(dirtyMessage())); }
+    void bindsToSeat();
+
+    // Pointer tests
+    void wheelDiscreteScroll_data();
+    void wheelDiscreteScroll();
+};
+
+void tst_seatv7::bindsToSeat()
+{
+    QCOMPOSITOR_COMPARE(get<Seat>()->resourceMap().size(), 1);
+    QCOMPOSITOR_COMPARE(get<Seat>()->resourceMap().first()->version(), 7);
+}
+
+class WheelWindow : QRasterWindow {
+public:
+    WheelWindow()
+    {
+        resize(64, 64);
+        show();
+    }
+    void wheelEvent(QWheelEvent *event) override
+    {
+        QRasterWindow::wheelEvent(event);
+//        qDebug() << event << "angleDelta" << event->angleDelta() << "pixelDelta" << event->pixelDelta();
+
+        if (event->phase() != Qt::ScrollUpdate && event->phase() != Qt::NoScrollPhase) {
+            // Shouldn't have deltas in the these phases
+            QCOMPARE(event->angleDelta(), QPoint(0, 0));
+            QCOMPARE(event->pixelDelta(), QPoint(0, 0));
+        }
+
+        // The axis vector of the event is already in surface space, so there is now way to tell
+        // whether it is inverted or not.
+        QCOMPARE(event->inverted(), false);
+
+        // We didn't press any buttons
+        QCOMPARE(event->buttons(), Qt::NoButton);
+
+        m_events.append(Event{event});
+    }
+    struct Event // Because I didn't find a convenient way to copy it entirely
+    {
+        explicit Event() = default;
+        explicit Event(const QWheelEvent *event)
+            : phase(event->phase())
+            , pixelDelta(event->pixelDelta())
+            , angleDelta(event->angleDelta())
+            , source(event->source())
+        {
+        }
+        Qt::ScrollPhase phase{};
+        QPoint pixelDelta;
+        QPoint angleDelta; // eights of a degree, positive is upwards, left
+        Qt::MouseEventSource source{};
+    };
+    QList<Event> m_events;
+};
+
+void tst_seatv7::wheelDiscreteScroll_data()
+{
+    QTest::addColumn<uint>("source");
+    QTest::newRow("wheel") << uint(Pointer::axis_source_wheel);
+    QTest::newRow("wheel tilt") << uint(Pointer::axis_source_wheel_tilt);
+}
+
+void tst_seatv7::wheelDiscreteScroll()
+{
+    WheelWindow window;
+    QCOMPOSITOR_TRY_VERIFY(xdgSurface() && xdgSurface()->m_committedConfigureSerial);
+
+    QFETCH(uint, source);
+
+    exec([=] {
+        auto *p = pointer();
+        auto *c = client();
+        p->sendEnter(xdgToplevel()->surface(), {32, 32});
+        p->sendFrame(c);
+        p->sendAxisSource(c, Pointer::axis_source(source));
+        p->sendAxisDiscrete(c, Pointer::axis_vertical_scroll, 1); // 1 click downwards
+        p->sendAxis(c, Pointer::axis_vertical_scroll, 1.0);
+        p->sendFrame(c);
+    });
+
+    QTRY_VERIFY(!window.m_events.empty());
+    {
+        auto e = window.m_events.takeFirst();
+        QCOMPARE(e.phase, Qt::NoScrollPhase);
+        QVERIFY(qAbs(e.angleDelta.x()) <= qAbs(e.angleDelta.y())); // Vertical scroll
+        // According to the docs the angle delta is in eights of a degree and most mice have
+        // 1 click = 15 degrees. The angle delta should therefore be:
+        // 15 degrees / (1/8 eights per degrees) = 120 eights of degrees.
+        QCOMPARE(e.angleDelta, QPoint(0, -120));
+        // Click scrolls are not continuous and should not have a pixel delta
+        QCOMPARE(e.pixelDelta, QPoint(0, 0));
+    }
+}
+
+QCOMPOSITOR_TEST_MAIN(tst_seatv7)
+#include "tst_seatv7.moc"

tests/auto/wayland/shared/coreprotocol.cpp

@@ -423,6 +423,13 @@ void Pointer::sendFrame(wl_client *client)
         send_frame(r->handle);
 }
 
+void Pointer::sendAxisValue120(wl_client *client, QtWaylandServer::wl_pointer::axis axis, int value120)
+{
+    const auto pointerResources = resourceMap().values(client);
+    for (auto *r : pointerResources)
+        send_axis_value120(r->handle, axis, value120);
+}
+
 void Pointer::pointer_set_cursor(Resource *resource, uint32_t serial, wl_resource *surface, int32_t hotspot_x, int32_t hotspot_y)
 {
     Q_UNUSED(resource);

tests/auto/wayland/shared/coreprotocol.h

@@ -296,7 +296,7 @@ class Seat : public Global, public QtWaylandServer::wl_seat
 {
     Q_OBJECT
 public:
-    explicit Seat(CoreCompositor *compositor, uint capabilities = Seat::capability_pointer | Seat::capability_keyboard | Seat::capability_touch, int version = 7);
+    explicit Seat(CoreCompositor *compositor, uint capabilities = Seat::capability_pointer | Seat::capability_keyboard | Seat::capability_touch, int version = 8);
     ~Seat() override;
     void send_capabilities(Resource *resource, uint capabilities) = delete; // Use wrapper instead
     void send_capabilities(uint capabilities) = delete; // Use wrapper instead
@@ -346,6 +346,7 @@ public:
     void sendAxisSource(wl_client *client, axis_source source);
     void sendAxisStop(wl_client *client, axis axis);
     void sendFrame(wl_client *client);
+    void sendAxisValue120(wl_client *client, axis axis, int value120);
 
     Seat *m_seat = nullptr;
     QList<uint> m_enterSerials;