[PATCH libinput] tablet: Add a left handed mode and tests

Peter Hutterer peter.hutterer at who-t.net
Mon Jan 19 19:33:59 PST 2015


On Mon, Jan 19, 2015 at 09:44:08PM -0500, Stephen Chandler Paul wrote:
> On the majority of Wacom tablets, the buttons are on the left side, opposite of
> the side where the palm is meant to rest. Because of this, it's impossible to
> use the tablet with your left hand (comfortably, anyway) unless you flip it
> over, in which case the coordinates need to be inverted for it to match up with
> the screen properly. This is where left handed mode comes in. When enabled, it
> reverses all the coordinates so that the tablet may be rotated, and the palm
> rest on the tablet moved over to the left side.
> 
> Signed-off-by: Stephen Chandler Paul <thatslyude at gmail.com>
> ---
>  src/evdev-tablet.c | 16 +++++++++-
>  test/tablet.c      | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 100 insertions(+), 1 deletion(-)
> 
> This probably should have been sent with the last patch instead of as a separate
> patch, oops!
> 
> diff --git a/src/evdev-tablet.c b/src/evdev-tablet.c
> index f80d642..10f8697 100644
> --- a/src/evdev-tablet.c
> +++ b/src/evdev-tablet.c
> @@ -86,6 +86,12 @@ tablet_mark_all_axes_changed(struct tablet_dispatch *tablet,
>  }
>  
>  static void
> +tablet_change_to_left_handed(struct evdev_device *device)
> +{
> +	device->left_handed.enabled = device->left_handed.want_enabled;
> +}
> +
> +static void
>  tablet_update_tool(struct tablet_dispatch *tablet,
>  		   struct evdev_device *device,
>  		   enum libinput_tool_type tool,
> @@ -142,7 +148,11 @@ tablet_check_notify_axes(struct tablet_dispatch *tablet,
>  		switch (a) {
>  		case LIBINPUT_TABLET_AXIS_X:
>  		case LIBINPUT_TABLET_AXIS_Y:
> -			tablet->axes[a] = absinfo->value;
> +			if (device->left_handed.enabled)
> +				tablet->axes[a] =
> +					absinfo->maximum - absinfo->value;

this won't work if you have a non-zero absinfo->minimum. The formula is 
   max - (value - min)
Please add a helper function for inverting an axis, not the last time
we'll get this wrong :)

> +			else
> +				tablet->axes[a] = absinfo->value;
>  			break;
>  		case LIBINPUT_TABLET_AXIS_DISTANCE:
>  		case LIBINPUT_TABLET_AXIS_PRESSURE:
> @@ -486,6 +496,8 @@ tablet_flush(struct tablet_dispatch *tablet,
>  					    tablet->axes);
>  		tablet_set_status(tablet, TABLET_TOOL_OUT_OF_PROXIMITY);
>  		tablet_unset_status(tablet, TABLET_TOOL_LEAVING_PROXIMITY);
> +
> +		tablet_change_to_left_handed(device);
>  	}
>  
>  	/* Update state */
> @@ -588,5 +600,7 @@ evdev_tablet_create(struct evdev_device *device)
>  		return NULL;
>  	}
>  
> +	evdev_init_left_handed(device, tablet_change_to_left_handed);
> +
>  	return &tablet->base;
>  }
> diff --git a/test/tablet.c b/test/tablet.c
> index 367c4db..cfc7cde 100644
> --- a/test/tablet.c
> +++ b/test/tablet.c
> @@ -239,6 +239,90 @@ START_TEST(motion)
>  }
>  END_TEST
>  
> +START_TEST(left_handed)
> +{
> +	struct litest_device *dev = litest_current_device();
> +	struct libinput *li = dev->libinput;
> +	struct libinput_event *event;
> +	struct libinput_event_tablet *tablet_event;
> +	double right_hand_x, right_hand_y;
> +	double left_hand_x, left_hand_y;
> +	struct axis_replacement axes[] = {
> +		{ ABS_DISTANCE, 10 },
> +		{ -1, -1 }
> +	};
> +
> +	ck_assert(libinput_device_config_left_handed_is_available(dev->libinput_device));
> +
> +	litest_drain_events(li);
> +
> +	/* Test that left-handed mode doesn't go into effect until the tool has
> +	 * left proximity of the tablet */
> +	litest_tablet_proximity_in(dev, 20, 20, axes);

fwiw, always use uneven coordinates for tests like these, otherwise you may
not spot an accidental bug in the form of x = y.

> +	libinput_dispatch(li);

use litest_wait_for_event_of_type() here, makes the flow a bit easier.

> +
> +	while ((event = libinput_get_event(li))) {
> +		if (libinput_event_get_type(event) == LIBINPUT_EVENT_TABLET_AXIS) {
> +			tablet_event = libinput_event_get_tablet_event(event);
> +
> +			right_hand_x = libinput_event_tablet_get_axis_value(
> +			    tablet_event, LIBINPUT_TABLET_AXIS_X);
> +			right_hand_y = libinput_event_tablet_get_axis_value(
> +			    tablet_event, LIBINPUT_TABLET_AXIS_Y);
> +		}
> +
> +		libinput_event_destroy(event);
> +	}
> +
> +	libinput_device_config_left_handed_set(dev->libinput_device, 1);
> +	litest_event(dev, EV_ABS, ABS_X, 10);
> +	litest_event(dev, EV_ABS, ABS_Y, 10);
> +	libinput_dispatch(li);
> +
> +	while ((event = libinput_get_event(li))) {
> +		if (libinput_event_get_type(event) == LIBINPUT_EVENT_TABLET_AXIS) {
> +			double x, y;
> +
> +			tablet_event = libinput_event_get_tablet_event(event);
> +
> +			x = libinput_event_tablet_get_axis_value(
> +			    tablet_event, LIBINPUT_TABLET_AXIS_X);
> +			y = libinput_event_tablet_get_axis_value(
> +			    tablet_event, LIBINPUT_TABLET_AXIS_Y);
> +
> +			litest_assert_double_lt(x, right_hand_x);
> +			litest_assert_double_lt(y, right_hand_y);
> +		}
> +
> +		libinput_event_destroy(event);
> +	}
> +
> +	/* In left handed mode, since the formula inverts the values of the
> +	 * coordinates, using the same coordinates as test values should always
> +	 * result in the left handed coordinates being larger then the right
> +	 * handed ones */

you have access to the libevdev device, I think it's best to get the min/max
and make sure that it's actually inverted for both axes.

> +	litest_tablet_proximity_out(dev);
> +	litest_tablet_proximity_in(dev, 20, 20, axes);
> +	libinput_dispatch(li);
> +
> +	while ((event = libinput_get_event(li))) {
> +		if (libinput_event_get_type(event) == LIBINPUT_EVENT_TABLET_AXIS) {

litest_wait_for_event_of_type as well here.

Cheers,
   Peter

> +			tablet_event = libinput_event_get_tablet_event(event);
> +
> +			left_hand_x = libinput_event_tablet_get_axis_value(
> +			    tablet_event, LIBINPUT_TABLET_AXIS_X);
> +			left_hand_y = libinput_event_tablet_get_axis_value(
> +			    tablet_event, LIBINPUT_TABLET_AXIS_Y);
> +
> +			litest_assert_double_gt(left_hand_x, right_hand_x);
> +			litest_assert_double_gt(left_hand_y, right_hand_y);
> +		}
> +
> +		libinput_event_destroy(event);
> +	}
> +}
> +END_TEST
> +
>  START_TEST(motion_event_state)
>  {
>  	struct litest_device *dev = litest_current_device();
> @@ -869,6 +953,7 @@ main(int argc, char **argv)
>  	litest_add("tablet:proximity", bad_distance_events, LITEST_TABLET | LITEST_DISTANCE, LITEST_ANY);
>  	litest_add("tablet:motion", motion, LITEST_TABLET, LITEST_ANY);
>  	litest_add("tablet:motion", motion_event_state, LITEST_TABLET, LITEST_ANY);
> +	litest_add("tablet:left_handed", left_handed, LITEST_TABLET, LITEST_ANY);
>  	litest_add("tablet:normalization", normalization, LITEST_TABLET, LITEST_ANY);
>  	litest_add("tablet:pad", pad_buttons_ignored, LITEST_TABLET, LITEST_ANY);
>  
> -- 
> 2.0.5
> 


More information about the wayland-devel mailing list