[PATCH v2 libinput] Add libinput_event_pointer_get_axis_value_discrete() to count wheel clicks

Jonas Ådahl jadahl at gmail.com
Tue Jan 13 23:21:04 PST 2015


On Wed, Jan 14, 2015 at 01:30:36PM +1000, Peter Hutterer wrote:
> The recent normalization of wheel events means we get the angle in degrees but
> we don't know how this corresponds to clicks. The M325 has a 20 degree click
> angle, most other mice have 15 degrees. So an angle of 60 can be 3 or 4 click
> events.
> 
> Most clients care more about the click count than the angle on a mouse wheel.
> Provide that value when needed.
> 
> Adding a discrete value to the axis event leaves the possibility of defining
> discrete units for finger/continuous scroll sources in the future. Right now,
> these will always reuturn 0.
> 
> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>

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

> ---
> Changes to v1:
> - rename from get_click_count to get_axis_value_discrete
> 
>  src/evdev-mt-touchpad-edge-scroll.c |  9 ++++++---
>  src/evdev.c                         | 26 +++++++++++++++++---------
>  src/libinput-private.h              |  1 +
>  src/libinput.c                      | 11 ++++++++++-
>  src/libinput.h                      | 21 +++++++++++++++++++++
>  src/libinput.sym                    |  1 +
>  test/pointer.c                      |  7 ++++++-
>  7 files changed, 62 insertions(+), 14 deletions(-)
> 
> diff --git a/src/evdev-mt-touchpad-edge-scroll.c b/src/evdev-mt-touchpad-edge-scroll.c
> index a4dc093..8605034 100644
> --- a/src/evdev-mt-touchpad-edge-scroll.c
> +++ b/src/evdev-mt-touchpad-edge-scroll.c
> @@ -327,7 +327,8 @@ tp_edge_scroll_post_events(struct tp_dispatch *tp, uint64_t time)
>  					pointer_notify_axis(device, time,
>  						t->scroll.direction,
>  						LIBINPUT_POINTER_AXIS_SOURCE_FINGER,
> -						0.0);
> +						0.0,
> +						0);
>  					t->scroll.direction = -1;
>  				}
>  				continue;
> @@ -351,7 +352,8 @@ tp_edge_scroll_post_events(struct tp_dispatch *tp, uint64_t time)
>  
>  		pointer_notify_axis(device, time, axis,
>  				    LIBINPUT_POINTER_AXIS_SOURCE_FINGER,
> -				    *delta);
> +				    *delta,
> +				    0);
>  		t->scroll.direction = axis;
>  
>  		tp_edge_scroll_handle_event(tp, t, SCROLL_EVENT_POSTED);
> @@ -371,7 +373,8 @@ tp_edge_scroll_stop_events(struct tp_dispatch *tp, uint64_t time)
>  			pointer_notify_axis(device, time,
>  					    t->scroll.direction,
>  					    LIBINPUT_POINTER_AXIS_SOURCE_FINGER,
> -					    0.0);
> +					    0.0,
> +					    0);
>  			t->scroll.direction = -1;
>  		}
>  	}
> diff --git a/src/evdev.c b/src/evdev.c
> index d80594d..0e78381 100644
> --- a/src/evdev.c
> +++ b/src/evdev.c
> @@ -541,16 +541,20 @@ evdev_notify_axis(struct evdev_device *device,
>  		  uint64_t time,
>  		  enum libinput_pointer_axis axis,
>  		  enum libinput_pointer_axis_source source,
> -		  double value)
> +		  double value,
> +		  double discrete)
>  {
> -	if (device->scroll.natural_scrolling_enabled)
> +	if (device->scroll.natural_scrolling_enabled) {
>  		value *= -1;
> +		discrete *= -1;
> +	}
>  
>  	pointer_notify_axis(&device->base,
>  			    time,
>  			    axis,
>  			    source,
> -			    value);
> +			    value,
> +			    discrete);
>  }
>  
>  static inline void
> @@ -577,7 +581,8 @@ evdev_process_relative(struct evdev_device *device,
>  			time,
>  			LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL,
>  			LIBINPUT_POINTER_AXIS_SOURCE_WHEEL,
> -			-1 * e->value * device->scroll.wheel_click_angle);
> +			-1 * e->value * device->scroll.wheel_click_angle,
> +			-1 * e->value);
>  		break;
>  	case REL_HWHEEL:
>  		evdev_flush_pending_event(device, time);
> @@ -586,7 +591,8 @@ evdev_process_relative(struct evdev_device *device,
>  			time,
>  			LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL,
>  			LIBINPUT_POINTER_AXIS_SOURCE_WHEEL,
> -			e->value * device->scroll.wheel_click_angle);
> +			e->value * device->scroll.wheel_click_angle,
> +			e->value);
>  		break;
>  	}
>  }
> @@ -1864,7 +1870,8 @@ evdev_post_scroll(struct evdev_device *device,
>  				  time,
>  				  LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL,
>  				  source,
> -				  dy);
> +				  dy,
> +				  0);
>  	}
>  
>  	if (dx != 0.0 &&
> @@ -1874,7 +1881,8 @@ evdev_post_scroll(struct evdev_device *device,
>  				  time,
>  				  LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL,
>  				  source,
> -				  dx);
> +				  dx,
> +				  0);
>  	}
>  }
>  
> @@ -1889,13 +1897,13 @@ evdev_stop_scroll(struct evdev_device *device,
>  				    time,
>  				    LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL,
>  				    source,
> -				    0);
> +				    0, 0);
>  	if (device->scroll.direction & (1 << LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL))
>  		pointer_notify_axis(&device->base,
>  				    time,
>  				    LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL,
>  				    source,
> -				    0);
> +				    0, 0);
>  
>  	device->scroll.buildup_horizontal = 0;
>  	device->scroll.buildup_vertical = 0;
> diff --git a/src/libinput-private.h b/src/libinput-private.h
> index 84a0d44..2b73286 100644
> --- a/src/libinput-private.h
> +++ b/src/libinput-private.h
> @@ -280,6 +280,7 @@ pointer_notify_axis(struct libinput_device *device,
>  		    uint64_t time,
>  		    enum libinput_pointer_axis axis,
>  		    enum libinput_pointer_axis_source source,
> +		    double click_count,
>  		    double value);
>  
>  void
> diff --git a/src/libinput.c b/src/libinput.c
> index 426c306..37df962 100644
> --- a/src/libinput.c
> +++ b/src/libinput.c
> @@ -67,6 +67,7 @@ struct libinput_event_pointer {
>  	enum libinput_pointer_axis axis;
>  	enum libinput_pointer_axis_source source;
>  	double value;
> +	double discrete;
>  };
>  
>  struct libinput_event_touch {
> @@ -391,6 +392,12 @@ libinput_event_pointer_get_axis_value(struct libinput_event_pointer *event)
>  	return event->value;
>  }
>  
> +LIBINPUT_EXPORT double
> +libinput_event_pointer_get_axis_value_discrete(struct libinput_event_pointer *event)
> +{
> +	return event->discrete;
> +}
> +
>  LIBINPUT_EXPORT enum libinput_pointer_axis_source
>  libinput_event_pointer_get_axis_source(struct libinput_event_pointer *event)
>  {
> @@ -994,7 +1001,8 @@ pointer_notify_axis(struct libinput_device *device,
>  		    uint64_t time,
>  		    enum libinput_pointer_axis axis,
>  		    enum libinput_pointer_axis_source source,
> -		    double value)
> +		    double value,
> +		    double discrete)
>  {
>  	struct libinput_event_pointer *axis_event;
>  
> @@ -1007,6 +1015,7 @@ pointer_notify_axis(struct libinput_device *device,
>  		.axis = axis,
>  		.value = value,
>  		.source = source,
> +		.discrete = discrete,
>  	};
>  
>  	post_device_event(device, time,
> diff --git a/src/libinput.h b/src/libinput.h
> index f605e52..c6dd57e 100644
> --- a/src/libinput.h
> +++ b/src/libinput.h
> @@ -683,6 +683,8 @@ libinput_event_pointer_get_axis(struct libinput_event_pointer *event);
>   * @ref LIBINPUT_EVENT_POINTER_AXIS.
>   *
>   * @return the axis value of this event
> + *
> + * @see libinput_event_pointer_get_axis_value_discrete
>   */
>  double
>  libinput_event_pointer_get_axis_value(struct libinput_event_pointer *event);
> @@ -726,6 +728,25 @@ enum libinput_pointer_axis_source
>  libinput_event_pointer_get_axis_source(struct libinput_event_pointer *event);
>  
>  /**
> + * @ingroup pointer
> + *
> + * Return the axis value in discrete steps for a given axis event. How a
> + * value translates into a discrete step depends on the source.
> + *
> + * If the source is @ref LIBINPUT_POINTER_AXIS_SOURCE_WHEEL, the discrete
> + * value correspond to the number of physical mouse clicks.
> + *
> + * If the source is @ref LIBINPUT_POINTER_AXIS_SOURCE_CONTINUOUS or @ref
> + * LIBINPUT_POINTER_AXIS_SOURCE_FINGER, the discrete value is always 0.
> + *
> + * @return The discrete value for the given event.
> + *
> + * @see libinput_event_pointer_get_axis_value
> + */
> +double
> +libinput_event_pointer_get_axis_value_discrete(struct libinput_event_pointer *event);
> +
> +/**
>   * @ingroup event_pointer
>   *
>   * @return The generic libinput_event of this event
> diff --git a/src/libinput.sym b/src/libinput.sym
> index 826bfde..d9ebbc2 100644
> --- a/src/libinput.sym
> +++ b/src/libinput.sym
> @@ -73,6 +73,7 @@ global:
>  	libinput_event_pointer_get_axis;
>  	libinput_event_pointer_get_axis_source;
>  	libinput_event_pointer_get_axis_value;
> +	libinput_event_pointer_get_axis_value_discrete;
>  	libinput_event_pointer_get_base_event;
>  	libinput_event_pointer_get_button_state;
>  	libinput_event_pointer_get_button;
> diff --git a/test/pointer.c b/test/pointer.c
> index d12c9f6..2055c41 100644
> --- a/test/pointer.c
> +++ b/test/pointer.c
> @@ -353,9 +353,12 @@ test_wheel_event(struct litest_device *dev, int which, int amount)
>  	   up by a factor 15 */
>  	const int scroll_step = 15;
>  	int expected = amount * scroll_step;
> +	int discrete = amount;
>  
> -	if (libinput_device_config_scroll_get_natural_scroll_enabled(dev->libinput_device))
> +	if (libinput_device_config_scroll_get_natural_scroll_enabled(dev->libinput_device)) {
>  		expected *= -1;
> +		discrete *= -1;
> +	}
>  
>  	/* mouse scroll wheels are 'upside down' */
>  	if (which == REL_WHEEL)
> @@ -379,6 +382,8 @@ test_wheel_event(struct litest_device *dev, int which, int amount)
>  	ck_assert_int_eq(libinput_event_pointer_get_axis_value(ptrev), expected);
>  	ck_assert_int_eq(libinput_event_pointer_get_axis_source(ptrev),
>  			 LIBINPUT_POINTER_AXIS_SOURCE_WHEEL);
> +	ck_assert_int_eq(libinput_event_pointer_get_axis_value_discrete(ptrev),
> +			 discrete);
>  	libinput_event_destroy(event);
>  }
>  
> -- 
> 2.1.0
> 


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