[PATCH libinput 8/9] Add libinput_device_set_seat_logical_name() to change seats at runtime

[Hans de Goede]

Hi,

On 11/24/2014 01:46 AM, Peter Hutterer wrote:
> The seat of a device is currently immutable, but a device may (in a
> multi-pointer case) move between different logical seats. Moving it between
> seats is akin to removing it and re-plugging it, so let's do exactly that.
>
> The physical seat name stays immutable.
>
> Pro:
> - device handling after changing a seat remains identical as handling any
>    other device.
> Con:
> - tracking a device across seat changes is difficult
> - this is not an atomic operation, if re-adding the device fails it stays
>    removed from the original seat and is now dead
>
> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>

Looks good:

Reviewed-by: Hans de Goede <hdegoede at redhat.com>

Regards,

Hans

> ---
>   src/libinput-private.h |  2 ++
>   src/libinput.c         | 13 +++++++++++++
>   src/libinput.h         | 26 ++++++++++++++++++++++++++
>   src/path.c             | 20 ++++++++++++++++++++
>   src/udev-seat.c        | 19 +++++++++++++++++++
>   5 files changed, 80 insertions(+)
>
> diff --git a/src/libinput-private.h b/src/libinput-private.h
> index 8c75d1f..07db7fd 100644
> --- a/src/libinput-private.h
> +++ b/src/libinput-private.h
> @@ -36,6 +36,8 @@ struct libinput_interface_backend {
>   	int (*resume)(struct libinput *libinput);
>   	void (*suspend)(struct libinput *libinput);
>   	void (*destroy)(struct libinput *libinput);
> +	int (*device_change_seat)(struct libinput_device *device,
> +				  const char *seat_name);
>   };
>
>   struct libinput {
> diff --git a/src/libinput.c b/src/libinput.c
> index 3f5370f..7b94320 100644
> --- a/src/libinput.c
> +++ b/src/libinput.c
> @@ -1213,6 +1213,19 @@ libinput_device_get_seat(struct libinput_device *device)
>   	return device->seat;
>   }
>
> +LIBINPUT_EXPORT int
> +libinput_device_set_seat_logical_name(struct libinput_device *device,
> +				      const char *name)
> +{
> +	struct libinput *libinput = device->seat->libinput;
> +
> +	if (name == NULL)
> +		return -1;
> +
> +	return libinput->interface_backend->device_change_seat(device,
> +							       name);
> +}
> +
>   LIBINPUT_EXPORT void
>   libinput_device_led_update(struct libinput_device *device,
>   			   enum libinput_led leds)
> diff --git a/src/libinput.h b/src/libinput.h
> index 092b0e7..9c9a313 100644
> --- a/src/libinput.h
> +++ b/src/libinput.h
> @@ -1373,6 +1373,32 @@ libinput_device_get_seat(struct libinput_device *device);
>   /**
>    * @ingroup device
>    *
> + * Change the logical seat associated with this device by removing the
> + * device and adding it to the new seat.
> + *
> + * This command is identical to physically unplugging the device, then
> + * re-plugging it as member of the new seat,
> + * @ref LIBINPUT_EVENT_DEVICE_REMOVED and @ref LIBINPUT_EVENT_DEVICE_ADDED
> + * events are sent accordingly. Those events mark the end of the lifetime
> + * of this device and the start of a new device.
> + *
> + * If the logical seat name already exists in the device's physical seat,
> + * the device is added to this seat. Otherwise, a new seat is created.
> + *
> + * @note This change applies to this device until removal or @ref
> + * libinput_suspend(), whichever happens earlier.
> + *
> + * @param device A previously obtained device
> + * @param name The new logical seat name
> + * @return 0 on success, non-zero on error
> + */
> +int
> +libinput_device_set_seat_logical_name(struct libinput_device *device,
> +				      const char *name);
> +
> +/**
> + * @ingroup device
> + *
>    * Update the LEDs on the device, if any. If the device does not have
>    * LEDs, or does not have one or more of the LEDs given in the mask, this
>    * function does nothing.
> diff --git a/src/path.c b/src/path.c
> index fef1d46..57f4cc6 100644
> --- a/src/path.c
> +++ b/src/path.c
> @@ -235,10 +235,30 @@ path_create_device(struct libinput *libinput,
>   	return device;
>   }
>
> +static int
> +path_device_change_seat(struct libinput_device *device,
> +			const char *seat_name)
> +{
> +	struct libinput *libinput = device->seat->libinput;
> +	struct evdev_device *evdev_device = (struct evdev_device *)device;
> +	struct udev_device *udev_device = NULL;
> +	int rc = -1;
> +
> +	udev_device = evdev_device->udev_device;
> +	udev_device_ref(udev_device);
> +	libinput_path_remove_device(device);
> +
> +	if (path_create_device(libinput, udev_device, seat_name) != NULL)
> +		rc = 0;
> +	udev_device_unref(udev_device);
> +	return rc;
> +}
> +
>   static const struct libinput_interface_backend interface_backend = {
>   	.resume = path_input_enable,
>   	.suspend = path_input_disable,
>   	.destroy = path_input_destroy,
> +	.device_change_seat = path_device_change_seat,
>   };
>
>   LIBINPUT_EXPORT struct libinput *
> diff --git a/src/udev-seat.c b/src/udev-seat.c
> index c69d175..f7a3df3 100644
> --- a/src/udev-seat.c
> +++ b/src/udev-seat.c
> @@ -332,10 +332,29 @@ udev_seat_get_named(struct udev_input *input, const char *seat_name)
>   	return NULL;
>   }
>
> +static int
> +udev_device_change_seat(struct libinput_device *device,
> +			const char *seat_name)
> +{
> +	struct libinput *libinput = device->seat->libinput;
> +	struct udev_input *input = (struct udev_input *)libinput;
> +	struct evdev_device *evdev_device = (struct evdev_device *)device;
> +	struct udev_device *udev_device = evdev_device->udev_device;
> +	int rc;
> +
> +	udev_device_ref(udev_device);
> +	device_removed(udev_device, input);
> +	rc = device_added(udev_device, input, seat_name);
> +	udev_device_unref(udev_device);
> +
> +	return rc;
> +}
> +
>   static const struct libinput_interface_backend interface_backend = {
>   	.resume = udev_input_enable,
>   	.suspend = udev_input_disable,
>   	.destroy = udev_input_destroy,
> +	.device_change_seat = udev_device_change_seat,
>   };
>
>   LIBINPUT_EXPORT struct libinput *
>