[PATCH libinput 02/10] Add an interface to enable/disable tapping

[Jonas Ådahl]

On Tue, Jun 03, 2014 at 03:34:55PM +1000, Peter Hutterer wrote:
> Provide an interface to enable/disable tapping, with a default mapping of
> 1/2/3 fingers mapping to L/R/M button events, respectively.
> 
> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> ---
>  src/libinput-private.h | 13 +++++++++
>  src/libinput.c         | 33 +++++++++++++++++++++++
>  src/libinput.h         | 73 +++++++++++++++++++++++++++++++++++++++++++++++++-
>  3 files changed, 118 insertions(+), 1 deletion(-)
> 
> diff --git a/src/libinput-private.h b/src/libinput-private.h
> index 61cdc79..020167e 100644
> --- a/src/libinput-private.h
> +++ b/src/libinput-private.h
> @@ -69,12 +69,25 @@ struct libinput_seat {
>  	uint32_t button_count[KEY_CNT];
>  };
>  
> +struct libinput_device_config_tap {
> +	int (*count)(struct libinput_device *device);
> +	enum libinput_config_status (*enable)(struct libinput_device *device,
> +					      int enable);
> +	int (*is_enabled)(struct libinput_device *device);
> +	void (*reset)(struct libinput_device *device);
> +};
> +
> +struct libinput_device_config {
> +	struct libinput_device_config_tap *tap;
> +};
> +
>  struct libinput_device {
>  	struct libinput_seat *seat;
>  	struct list link;
>  	void *user_data;
>  	int terminated;
>  	int refcount;
> +	struct libinput_device_config config;
>  };
>  
>  typedef void (*libinput_source_dispatch_t)(void *data);
> diff --git a/src/libinput.c b/src/libinput.c
> index 6b7e8b8..6a713bb 100644
> --- a/src/libinput.c
> +++ b/src/libinput.c
> @@ -1182,3 +1182,36 @@ libinput_event_touch_get_base_event(struct libinput_event_touch *event)
>  {
>  	return &event->base;
>  }
> +
> +LIBINPUT_EXPORT int
> +libinput_device_config_tap_get_finger_count(struct libinput_device *device)
> +{
> +	return device->config.tap ? device->config.tap->count(device) : 0;
> +}
> +
> +LIBINPUT_EXPORT enum libinput_config_status
> +libinput_device_config_tap_enable(struct libinput_device *device,
> +				  int enable)
> +{
> +	if (enable &&
> +	    libinput_device_config_tap_get_finger_count(device) == 0)
> +		return LIBINPUT_CONFIG_STATUS_UNSUPPORTED;

Shouldn't this be returned also if !enable? It would be a bit confusing
if disabling is allowed, but enabling is not.

Also, in what circumstances will config.tap be set, but finger count
returning 0? What type of devices would have tapping configuration
enabled with no tapping possible?

> +
> +	return device->config.tap->enable(device, enable);
> +}
> +
> +LIBINPUT_EXPORT int
> +libinput_device_config_tap_is_enabled(struct libinput_device *device)
> +{
> +	if (libinput_device_config_tap_get_finger_count(device) == 0)
> +		return 0;
> +
> +	return device->config.tap->is_enabled(device);
> +}
> +
> +LIBINPUT_EXPORT void
> +libinput_device_config_tap_reset(struct libinput_device *device)
> +{
> +	if (device->config.tap)
> +		device->config.tap->reset(device);
> +}
> diff --git a/src/libinput.h b/src/libinput.h
> index c9ec71a..0c84547 100644
> --- a/src/libinput.h
> +++ b/src/libinput.h
> @@ -1362,8 +1362,79 @@ enum libinput_config_status {
>  const char *
>  libinput_config_status_to_str(enum libinput_config_status status);
>  
> +/**
> + * @ingroup config
> + *
> + * Check if the device supports tap-to-click. See
> + * libinput_device_config_tap_set() for more information.

Should it be libinput_device_config_tap_enable() here instead?

> + *
> + * @param device The device to configure
> + * @return The number of fingers that can generate a tap event, or 0 if the
> + * device does not support tapping.
> + *
> + * @see libinput_device_config_tap_enable
> + * @see libinput_device_config_tap_is_enabled
> + * @see libinput_device_config_tap_reset
> + */
> +int
> +libinput_device_config_tap_get_finger_count(struct libinput_device *device);

I wonder where doing things like this, and
libinput_device_config_scroll_get_methods() will lead us. It'd mean we
expose some device information via the config API, and some via direct
device getters, which might not be the best thing for consistency.

Would it be better to keep device info getters, even though they are only
directly relevant to the configuration API, outside of the coniguration
API, so that it'll be the same for all device specific information
retrieval? There could potentially also be some device information that
are relevant to multiple config options, and in those cases, where would
they be retrieved from?


Jonas

> +
> +/**
> + * @ingroup config
> + *
> + * Enable tap-to-click on this device, with a default mapping of 1, 2, 3
> + * finger tap mapping to left, right, middle click, respectively.
> + * Tapping is limited by the number of simultaneous touches
> + * supported by the device, see
> + * libinput_device_config_tap_get_finger_count().
> + *
> + * @param device The device to configure
> + * @param enable Non-zero to enable, zero to disable
> + *
> + * @return A config status code. Disabling tapping on a device that does not
> + * support tapping always succeeds.
> + *
> + * @see libinput_device_config_tap_get_finger_count
> + * @see libinput_device_config_tap_is_enabled
> + * @see libinput_device_config_tap_reset
> + */
> +enum libinput_config_status
> +libinput_device_config_tap_enable(struct libinput_device *device,
> +				  int enable);
> +
> +/**
> + * @ingroup config
> + *
> + * Check if tap-to-click is enabled on this device. If the device does not
> + * support tapping, this function always returns 0.
> + *
> + * @param device The device to configure
> + *
> + * @return 1 if enabled, 0 otherwise.
> + *
> + * @see libinput_device_config_tap_get_finger_count
> + * @see libinput_device_config_tap_enable
> + * @see libinput_device_config_tap_reset
> + */
> +int
> +libinput_device_config_tap_is_enabled(struct libinput_device *device);
> +
> +/**
> + * @ingroup config
> + *
> + * Reset tapping to the default configuration for this device. If the device
> + * does not support tapping, this function does nothing.
> + *
> + * @param device The device to configure
> + *
> + * @see libinput_device_config_tap_get_finger_count
> + * @see libinput_device_config_tap_enable
> + * @see libinput_device_config_tap_is_enabled
> + */
> +void
> +libinput_device_config_tap_reset(struct libinput_device *device);
> +
>  #ifdef __cplusplus
>  }
>  #endif
> -
>  #endif /* LIBINPUT_H */
> -- 
> 1.9.0
> 
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