wayland: Provide basic tablet wheel event support

Adds basic support for the "wheel" event from the Wayland tablet protocol.
Ideally we would accumulate the angle and report a wheel event with an
appropriate value for "clicks". We can get away with a much cruder method
for the time being, however, since no Wacom tablet puck actually provides
a smooth scrollwheel. Checking whether the angle in CLUTTER_INPUT_AXIS_WHEEL
exceeds a nominally-small threshold is sufficient to determine that the
wheel has advanced by at least one physical click.

https://bugzilla.gnome.org/show_bug.cgi?id=783716
This commit is contained in:
Jason Gerecke 2017-06-12 15:25:10 -07:00 committed by Carlos Garnacho
parent 901490545c
commit 726296f022
2 changed files with 37 additions and 2 deletions

View File

@ -163,6 +163,9 @@ clutter_input_device_evdev_update_from_tool (ClutterInputDevice *device,
if (libinput_tablet_tool_has_slider (evdev_tool->tool))
_clutter_input_device_add_axis (device, CLUTTER_INPUT_AXIS_SLIDER, -1, 1, 0);
if (libinput_tablet_tool_has_wheel (evdev_tool->tool))
_clutter_input_device_add_axis (device, CLUTTER_INPUT_AXIS_WHEEL, -180, 180, 0);
g_object_thaw_notify (G_OBJECT (device));
}

View File

@ -800,6 +800,38 @@ broadcast_rotation (MetaWaylandTabletTool *tool,
}
}
static void
broadcast_wheel (MetaWaylandTabletTool *tool,
const ClutterEvent *event)
{
struct wl_resource *resource;
ClutterInputDevice *source;
gdouble angle;
gint32 clicks = 0;
source = clutter_event_get_source_device (event);
if (!clutter_input_device_get_axis_value (source, event->motion.axes,
CLUTTER_INPUT_AXIS_WHEEL,
&angle))
return;
/* FIXME: Perform proper angle-to-clicks accumulation elsewhere */
if (angle > 0.01)
clicks = 1;
else if (angle < -0.01)
clicks = -1;
else
return;
wl_resource_for_each (resource, &tool->focus_resource_list)
{
zwp_tablet_tool_v2_send_wheel (resource,
wl_fixed_from_double (angle),
clicks);
}
}
static void
broadcast_axes (MetaWaylandTabletTool *tool,
const ClutterEvent *event)
@ -823,8 +855,8 @@ broadcast_axes (MetaWaylandTabletTool *tool,
broadcast_rotation (tool, event);
if (capabilities & (1 << ZWP_TABLET_TOOL_V2_CAPABILITY_SLIDER))
broadcast_axis (tool, event, CLUTTER_INPUT_AXIS_SLIDER);
/* FIXME: Missing wp_tablet_tool.wheel */
if (capabilities & (1 << ZWP_TABLET_TOOL_V2_CAPABILITY_WHEEL))
broadcast_wheel (tool, event);
}
static void