libweston/libinput-device: Enable/Set pointer capabilities only on pointer movement

Some panels advertise both pointer/touch capabilities but without having
real capability of driving a cursor (they're basically touch panels) and
use USB as a communication tunnel to transfer/send out input events.

As we can't really tell if they're fake or not, only advertise to
clients pointer capabilities if we detect movement on the cursor/pointer.

We handle it at lower level as that allows to handle the case where
removal of a real pointer should also remove the cursor from being
displayed on the screen.

Signed-off-by: Marius Vlad <marius.vlad@collabora.com>

libweston/libinput-device.c

@@ -60,6 +60,21 @@ evdev_led_update(struct evdev_device *device, enum weston_led weston_leds)
 	libinput_device_led_update(device->device, leds);
 }
 
+static void
+ensure_pointer_capability(struct libinput_device *libinput_device)
+{
+	struct evdev_device *device = libinput_device_get_user_data(libinput_device);
+	struct weston_seat *seat = device->seat;
+
+	if (!libinput_device_has_capability(libinput_device, LIBINPUT_DEVICE_CAP_POINTER))
+		return;
+
+	if (!(device->seat_caps & EVDEV_SEAT_POINTER)) {
+		weston_seat_init_pointer(seat);
+		device->seat_caps |= EVDEV_SEAT_POINTER;
+	}
+}
+
 static void
 handle_keyboard_key(struct libinput_device *libinput_device,
 		    struct libinput_event_keyboard *keyboard_event)
@@ -97,6 +112,8 @@ handle_pointer_motion(struct libinput_device *libinput_device,
 	struct timespec time;
 	double dx_unaccel, dy_unaccel;
 
+	ensure_pointer_capability(libinput_device);
+
 	timespec_from_usec(&time,
 			   libinput_event_pointer_get_time_usec(pointer_event));
 	dx_unaccel = libinput_event_pointer_get_dx_unaccelerated(pointer_event);
@@ -129,6 +146,8 @@ handle_pointer_motion_absolute(
 	double x, y;
 	uint32_t width, height;
 
+	ensure_pointer_capability(libinput_device);
+
 	if (!output)
 		return false;
 
@@ -160,6 +179,8 @@ handle_pointer_button(struct libinput_device *libinput_device,
 		libinput_event_pointer_get_seat_button_count(pointer_event);
 	struct timespec time;
 
+	ensure_pointer_capability(libinput_device);
+
 	/* Ignore button events that are not seat wide state changes. */
 	if ((button_state == LIBINPUT_BUTTON_STATE_PRESSED &&
 	     seat_button_count != 1) ||
@@ -239,6 +260,8 @@ handle_pointer_axis(struct libinput_device *libinput_device,
 	bool has_vert, has_horiz;
 	struct timespec time;
 
+	ensure_pointer_capability(libinput_device);
+
 	has_vert = libinput_event_pointer_has_axis(pointer_event,
 				   LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL);
 	has_horiz = libinput_event_pointer_has_axis(pointer_event,
@@ -708,11 +731,7 @@ evdev_device_create(struct libinput_device *libinput_device,
 		weston_seat_init_keyboard(seat, NULL);
 		device->seat_caps |= EVDEV_SEAT_KEYBOARD;
 	}
-	if (libinput_device_has_capability(libinput_device,
-					   LIBINPUT_DEVICE_CAP_POINTER)) {
-		weston_seat_init_pointer(seat);
-		device->seat_caps |= EVDEV_SEAT_POINTER;
-	}
+
 	if (libinput_device_has_capability(libinput_device,
 					   LIBINPUT_DEVICE_CAP_TOUCH)) {
 		weston_seat_init_touch(seat);