[PATCH v3 weston] Introduce wl_relative_pointer interface

Jonas Ådahl jadahl at gmail.com
Thu Jun 25 21:38:01 PDT 2015


A wl_relative_pointer object is an extension to the wl_pointer interface
only used for emitting relative pointer events. It will only emit events
when the parent pointer has focus.

To get a relative pointer object, use the get_relative_pointer request
of the global wl_relative_pointer_manager object. When stabilizing it
might make more sense to just add it to wl_seat instead of having a
single use global interface.

All interface names are currently prefixed with underscore in order to
avoid any future conflicts with stable protocol.

Signed-off-by: Jonas Ådahl <jadahl at gmail.com>
---

Changes since v2:

 * Updated copyright.
 * Updated the license text to corrected one.
 * Clarified that relative motion events are unaffected by clamping.
 * Clarified that pointer acceleration behaviour is device specific.
 * Clarified that the order of relative_motion and motion is not
   guaranteed.
 * Explained that button events etc are to be fetched from the
   corresponding wl_pointer object.
 * Clarified that relative motion events are in x/y coordinate space.
 * Added an 'unstable protocol' warning explaining compatibility etc.


 Makefile.am                   |   7 +-
 protocol/relative-pointer.xml | 127 ++++++++++++++++++++++++++++
 src/compositor.c              |   3 +
 src/compositor.h              |   5 ++
 src/input.c                   | 186 ++++++++++++++++++++++++++++++++++++++----
 5 files changed, 309 insertions(+), 19 deletions(-)
 create mode 100644 protocol/relative-pointer.xml

diff --git a/Makefile.am b/Makefile.am
index 0a30cb4..70c436f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -105,7 +105,9 @@ nodist_weston_SOURCES =					\
 	protocol/presentation_timing-protocol.c		\
 	protocol/presentation_timing-server-protocol.h	\
 	protocol/scaler-protocol.c			\
-	protocol/scaler-server-protocol.h
+	protocol/scaler-server-protocol.h		\
+	protocol/relative-pointer-protocol.c		\
+	protocol/relative-pointer-server-protocol.h
 
 BUILT_SOURCES += $(nodist_weston_SOURCES)
 
@@ -1183,7 +1185,8 @@ EXTRA_DIST +=					\
 	protocol/presentation_timing.xml	\
 	protocol/scaler.xml			\
 	protocol/ivi-application.xml		\
-	protocol/ivi-hmi-controller.xml
+	protocol/ivi-hmi-controller.xml		\
+	protocol/relative-pointer.xml
 
 #
 # manual test modules in tests subdirectory
diff --git a/protocol/relative-pointer.xml b/protocol/relative-pointer.xml
new file mode 100644
index 0000000..185d33b
--- /dev/null
+++ b/protocol/relative-pointer.xml
@@ -0,0 +1,127 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<protocol name="relative_pointer">
+
+  <copyright>
+    Copyright © 2014      Jonas Ådahl
+    Copyright © 2015      Red Hat Inc.
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice (including the next
+    paragraph) shall be included in all copies or substantial portions of the
+    Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+  </copyright>
+
+  <interface name="_wl_relative_pointer_manager" version="1">
+    <description summary="get relative pointer objects">
+      A global interface used for getting the relative pointer object for a
+      given seat.
+
+      Warning! The protocol described in this file is experimental. Each version
+      of this protocol should be considered incompatible with any other version,
+      and a client binding to a version different to the one advertised will be
+      terminated. When the protocol is stabalized, backward compatibility is
+      guaranteed, the '_' prefix will be removed from the name and the version
+      will be reset to 1.
+    </description>
+
+    <request name="get_relative_pointer">
+      <description summary="get a relative pointer object">
+        Create a relative pointer interface given a wl_pointer object. See
+        the wl_relative_pointer interface for more details.
+      </description>
+
+      <arg name="id" type="new_id" interface="_wl_relative_pointer"/>
+      <arg name="pointer" type="object" interface="wl_pointer"/>
+    </request>
+  </interface>
+
+  <interface name="_wl_relative_pointer" version="1">
+    <description summary="relative pointer object">
+      A wl_relative_pointer object is an extension to the wl_pointer interface
+      used for emitting relative pointer events. It shares the same focus as
+      wl_pointer objects of the same seat and will only emit events when it
+      has focus.
+    </description>
+
+    <request name="release" type="destructor">
+      <description summary="release the relative pointer object"/>
+    </request>
+
+    <event name="relative_motion">
+      <description summary="relative pointer motion">
+        Relative x/y pointer motion in from the pointer of the seat associated
+        with this object.
+
+        A relative motion is in the same dimension as regular wl_pointer motion
+        events, except they do not represent an absolute position. For example,
+        moving a pointer from (x, y) to (x', y') would have the equivalent
+        relative motion (x' - x, y' - y). If a pointer motion caused the
+        absolute pointer position to be clipped by for example the edge of the
+        monitor, the relative motion is unaffected by the clipping and will
+        represent the unclipped motion.
+
+        This event also contains non-accelerated motion deltas. The
+        non-accelerated delta is, when applicable, the regular pointer motion
+        delta as it was before having applied motion acceleration
+        transformations. The compositor will have applied the same processing
+        (such as normalization) meaning the events will have roughly the same
+        magnitude as accelerated motion events.
+
+        Note that the non-accelerated delta does not represent 'raw' events as
+        they were read from some device. Pointer motion acceleration is device-
+        and configuration-specific and non-accelerated deltas and accelerated
+        deltas may have the same value on some devices.
+
+        Relative motions are not coupled to wl_pointer.motion events, and can
+        be sent in combination with such events, but also independently. There
+        may also be scenarious where wl_pointer.motion is sent, but there is no
+        relative motion. The order of an absolute and relative motion event
+        originating from the same physical motion is not guaranteed.
+
+        The motion vectors are encoded as double fixed point values.
+
+        A double fixed point value is a 64 bit data type encoded as two separate
+        signed 32 bit integers. The integral part of the value is stored in one
+        of the integers and the fractional part in the other.
+
+        If the client needs button events, it can receive them from a wl_pointer
+        object of the same seat that the wl_relative_pointer object is
+        associated with.
+      </description>
+
+      <arg name="time" type="uint"
+           summary="timestamp with millisecond granularity"/>
+      <arg name="dx_int" type="int"
+           summary="integral part of the x component of the motion vector"/>
+      <arg name="dx_frac" type="int"
+           summary="fractional part of the x component of the motion vector"/>
+      <arg name="dy_int" type="int"
+           summary="integral part of the y component of the motion vector"/>
+      <arg name="dy_frac" type="int"
+           summary="fractional part of the y component of the motion vector"/>
+      <arg name="dx_unaccel_int" type="int"
+           summary="integral part of the x component of the unaccelerated motion vector"/>
+      <arg name="dx_unaccel_frac" type="int"
+           summary="fractional part of the x component of the unaccelerated motion vector"/>
+      <arg name="dy_unaccel_int" type="int"
+           summary="integral part of the y component of the unaccelerated motion vector"/>
+      <arg name="dy_unaccel_frac" type="int"
+           summary="fractional part of the y component of the unaccelerated motion vector"/>
+    </event>
+  </interface>
+
+</protocol>
diff --git a/src/compositor.c b/src/compositor.c
index 5594d30..b462531 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -4560,6 +4560,9 @@ weston_compositor_init(struct weston_compositor *ec,
 	weston_plane_init(&ec->primary_plane, ec, 0, 0);
 	weston_compositor_stack_plane(ec, &ec->primary_plane, NULL);
 
+	if (weston_input_init(ec) != 0)
+		return -1;
+
 	s = weston_config_get_section(ec->config, "keyboard", NULL, NULL);
 	weston_config_section_get_string(s, "keymap_rules",
 					 (char **) &xkb_names.rules, NULL);
diff --git a/src/compositor.h b/src/compositor.h
index 331b758..55cc88f 100644
--- a/src/compositor.h
+++ b/src/compositor.h
@@ -340,7 +340,9 @@ struct weston_pointer {
 	struct weston_seat *seat;
 
 	struct wl_list resource_list;
+	struct wl_list relative_resource_list;
 	struct wl_list focus_resource_list;
+	struct wl_list relative_focus_resource_list;
 	struct weston_view *focus;
 	uint32_t focus_serial;
 	struct wl_listener focus_view_listener;
@@ -1584,6 +1586,9 @@ weston_output_mode_switch_to_native(struct weston_output *output);
 int
 noop_renderer_init(struct weston_compositor *ec);
 
+int
+weston_input_init(struct weston_compositor *compositor);
+
 struct weston_compositor *
 backend_init(struct wl_display *display, int *argc, char *argv[],
 	     struct weston_config *config);
diff --git a/src/input.c b/src/input.c
index 9131287..b48a6c9 100644
--- a/src/input.c
+++ b/src/input.c
@@ -32,7 +32,9 @@
 #include <limits.h>
 
 #include "../shared/os-compatibility.h"
+#include "../shared/util.h"
 #include "compositor.h"
+#include "protocol/relative-pointer-server-protocol.h"
 
 static void
 empty_region(pixman_region32_t *region)
@@ -47,6 +49,49 @@ static void unbind_resource(struct wl_resource *resource)
 }
 
 WL_EXPORT void
+weston_pointer_motion_to_abs(struct weston_pointer *pointer,
+			     struct weston_pointer_motion_event *event,
+			     wl_fixed_t *x, wl_fixed_t *y)
+{
+	if (event->mask & WESTON_POINTER_MOTION_ABS) {
+		*x = wl_fixed_from_double(event->x);
+		*y = wl_fixed_from_double(event->y);
+	} else if (event->mask & WESTON_POINTER_MOTION_REL) {
+		*x = pointer->x + wl_fixed_from_double(event->dx);
+		*y = pointer->y + wl_fixed_from_double(event->dy);
+	} else {
+		assert(!"invalid motion event");
+		*x = *y = 0;
+	}
+}
+
+static int
+weston_pointer_motion_to_rel(struct weston_pointer *pointer,
+			     struct weston_pointer_motion_event *event,
+			     double *dx, double *dy,
+			     double *dx_unaccel, double *dy_unaccel)
+{
+	if (event->mask & WESTON_POINTER_MOTION_REL &&
+	    event->mask & WESTON_POINTER_MOTION_REL_NOACCEL) {
+		*dx = event->dx;
+		*dy = event->dy;
+		*dx_unaccel = event->dx_unaccel;
+		*dy_unaccel = event->dy_unaccel;
+		return 1;
+	} else if (event->mask & WESTON_POINTER_MOTION_REL) {
+		*dx_unaccel = *dx = event->dx;
+		*dy_unaccel = *dy = event->dy;
+		return 1;
+	} else if (event->mask & WESTON_POINTER_MOTION_REL_NOACCEL) {
+		*dx_unaccel = *dx = event->dx_unaccel;
+		*dy_unaccel = *dy = event->dy_unaccel;
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
+WL_EXPORT void
 weston_seat_repick(struct weston_seat *seat)
 {
 	const struct weston_pointer *pointer = seat->pointer;
@@ -162,6 +207,42 @@ default_grab_pointer_focus(struct weston_pointer_grab *grab)
 }
 
 static void
+weston_pointer_send_relative_motion(struct weston_pointer *pointer,
+				    uint32_t time,
+				    struct weston_pointer_motion_event *event)
+{
+	double dx, dy, dx_unaccel, dy_unaccel;
+	int32_t dx_int, dx_frac;
+	int32_t dy_int, dy_frac;
+	int32_t dx_unaccel_int, dx_unaccel_frac;
+	int32_t dy_unaccel_int, dy_unaccel_frac;
+	struct wl_list *resource_list;
+	struct wl_resource *resource;
+
+	if (weston_pointer_motion_to_rel(pointer, event,
+					 &dx, &dy,
+					 &dx_unaccel, &dy_unaccel)) {
+		resource_list = &pointer->relative_focus_resource_list;
+		wl_double_fixed_from_double(dx, &dx_int, &dx_frac);
+		wl_double_fixed_from_double(dy, &dy_int, &dy_frac);
+		wl_double_fixed_from_double(dx_unaccel,
+					    &dx_unaccel_int,
+					    &dx_unaccel_frac);
+		wl_double_fixed_from_double(dy_unaccel,
+					    &dy_unaccel_int,
+					    &dy_unaccel_frac);
+		wl_resource_for_each(resource, resource_list) {
+			_wl_relative_pointer_send_relative_motion(
+				resource, time,
+				dx_int, dx_frac,
+				dy_int, dy_frac,
+				dx_unaccel_int, dx_unaccel_frac,
+				dy_unaccel_int, dy_unaccel_frac);
+		}
+	}
+}
+
+static void
 default_grab_pointer_motion(struct weston_pointer_grab *grab, uint32_t time,
 			    struct weston_pointer_motion_event *event)
 {
@@ -187,6 +268,8 @@ default_grab_pointer_motion(struct weston_pointer_grab *grab, uint32_t time,
 					       pointer->sx, pointer->sy);
 		}
 	}
+
+	weston_pointer_send_relative_motion(pointer, time, event);
 }
 
 static void
@@ -503,7 +586,9 @@ weston_pointer_create(struct weston_seat *seat)
 		return NULL;
 
 	wl_list_init(&pointer->resource_list);
+	wl_list_init(&pointer->relative_resource_list);
 	wl_list_init(&pointer->focus_resource_list);
+	wl_list_init(&pointer->relative_focus_resource_list);
 	weston_pointer_set_default_grab(pointer,
 					seat->compositor->default_pointer_grab);
 	wl_list_init(&pointer->focus_resource_listener.link);
@@ -665,6 +750,7 @@ weston_pointer_set_focus(struct weston_pointer *pointer,
 	struct wl_display *display = pointer->seat->compositor->wl_display;
 	uint32_t serial;
 	struct wl_list *focus_resource_list;
+	struct wl_list *relative_focus_resource_list;
 	int refocus = 0;
 
 	if ((!pointer->focus && view) ||
@@ -674,6 +760,7 @@ weston_pointer_set_focus(struct weston_pointer *pointer,
 		refocus = 1;
 
 	focus_resource_list = &pointer->focus_resource_list;
+	relative_focus_resource_list = &pointer->relative_focus_resource_list;
 
 	if (!wl_list_empty(focus_resource_list) && refocus) {
 		serial = wl_display_next_serial(display);
@@ -683,6 +770,8 @@ weston_pointer_set_focus(struct weston_pointer *pointer,
 		}
 
 		move_resources(&pointer->resource_list, focus_resource_list);
+		move_resources(&pointer->relative_resource_list,
+			       relative_focus_resource_list);
 	}
 
 	if (find_resource_for_view(&pointer->resource_list, view) && refocus) {
@@ -700,6 +789,9 @@ weston_pointer_set_focus(struct weston_pointer *pointer,
 		move_resources_for_client(focus_resource_list,
 					  &pointer->resource_list,
 					  surface_client);
+		move_resources_for_client(relative_focus_resource_list,
+					  &pointer->relative_resource_list,
+					  surface_client);
 
 		wl_resource_for_each(resource, focus_resource_list) {
 			wl_pointer_send_enter(resource,
@@ -932,23 +1024,6 @@ weston_pointer_move_to(struct weston_pointer *pointer,
 }
 
 WL_EXPORT void
-weston_pointer_motion_to_abs(struct weston_pointer *pointer,
-			     struct weston_pointer_motion_event *event,
-			     wl_fixed_t *x, wl_fixed_t *y)
-{
-	if (event->mask & WESTON_POINTER_MOTION_ABS) {
-		*x = wl_fixed_from_double(event->x);
-		*y = wl_fixed_from_double(event->y);
-	} else if (event->mask & WESTON_POINTER_MOTION_REL) {
-		*x = pointer->x + wl_fixed_from_double(event->dx);
-		*y = pointer->y + wl_fixed_from_double(event->dy);
-	} else {
-		assert(!"invalid motion event");
-		*x = *y = 0;
-	}
-}
-
-WL_EXPORT void
 weston_pointer_move(struct weston_pointer *pointer,
 		    struct weston_pointer_motion_event *event)
 {
@@ -2008,6 +2083,72 @@ bind_seat(struct wl_client *client, void *data, uint32_t version, uint32_t id)
 		wl_seat_send_name(resource, seat->seat_name);
 }
 
+static void
+relative_pointer_release(struct wl_client *client,
+			 struct wl_resource *resource)
+{
+	wl_resource_destroy(resource);
+}
+
+static const struct _wl_relative_pointer_interface relative_pointer_interface = {
+	relative_pointer_release
+};
+
+static void
+relative_pointer_manager_get_relative_pointer(struct wl_client *client,
+					      struct wl_resource *resource,
+					      uint32_t id,
+					      struct wl_resource *pointer_resource)
+{
+	struct weston_pointer *pointer =
+		wl_resource_get_user_data(pointer_resource);
+	struct wl_resource *cr;
+	struct weston_view *focus;
+
+	cr = wl_resource_create(client, &_wl_relative_pointer_interface,
+				wl_resource_get_version(resource), id);
+	if (cr == NULL) {
+		wl_client_post_no_memory(client);
+		return;
+	}
+
+	/* May be moved to focused list later by either
+	 * weston_pointer_set_focus or directly if this client is already
+	 * focused */
+	wl_list_insert(&pointer->relative_resource_list,
+		       wl_resource_get_link(cr));
+	wl_resource_set_implementation(cr, &relative_pointer_interface,
+				       pointer,
+				       unbind_resource);
+
+	focus = pointer->focus;
+	if (focus && focus->surface->resource &&
+	    wl_resource_get_client(focus->surface->resource) == client) {
+		wl_list_remove(wl_resource_get_link(cr));
+		wl_list_insert(&pointer->relative_focus_resource_list,
+			       wl_resource_get_link(cr));
+	}
+}
+
+static const struct _wl_relative_pointer_manager_interface relative_pointer_manager = {
+	relative_pointer_manager_get_relative_pointer,
+};
+
+static void
+bind_relative_pointer_manager(struct wl_client *client, void *data,
+			      uint32_t version, uint32_t id)
+{
+	struct weston_compositor *compositor = data;
+	struct wl_resource *resource;
+
+	resource = wl_resource_create(client,
+				      &_wl_relative_pointer_manager_interface,
+				      1, id);
+	wl_resource_set_implementation(resource, &relative_pointer_manager,
+				       compositor,
+				       NULL);
+}
+
 #ifdef ENABLE_XKBCOMMON
 int
 weston_compositor_xkb_init(struct weston_compositor *ec,
@@ -2429,3 +2570,14 @@ weston_seat_release(struct weston_seat *seat)
 
 	wl_signal_emit(&seat->destroy_signal, seat);
 }
+
+int
+weston_input_init(struct weston_compositor *compositor)
+{
+	if (!wl_global_create(compositor->wl_display,
+			      &_wl_relative_pointer_manager_interface, 1,
+			      compositor, bind_relative_pointer_manager))
+		return -1;
+
+	return 0;
+}
-- 
2.1.4



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