Package org.freedesktop.wayland.client

Interface WlTouchEventsV4

All Superinterfaces:

WlTouchEvents, WlTouchEventsV2, WlTouchEventsV3

All Known Subinterfaces:

WlTouchEventsV5, WlTouchEventsV6, WlTouchEventsV7, WlTouchEventsV8, WlTouchEventsV9

public interface WlTouchEventsV4
extends WlTouchEventsV3

touchscreen input device

The wl_touch interface represents a touchscreen associated with a seat.

Touch interactions can consist of one or more contacts. For each contact, a series of events is generated, starting with a down event, followed by zero or more motion events, and ending with an up event. Events relating to the same contact point can be identified by the ID of the sequence.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	VERSION

Method Summary

Modifier and Type	Method	Description
void	cancel(WlTouchProxy emitter)	touch session cancelled
void	down(WlTouchProxy emitter, int serial, int time, WlSurfaceProxy surface, int id, Fixed x, Fixed y)	touch down event and beginning of a touch sequence
void	frame(WlTouchProxy emitter)	end of touch frame event
void	motion(WlTouchProxy emitter, int time, int id, Fixed x, Fixed y)	update of touch point coordinates
void	up(WlTouchProxy emitter, int serial, int time, int id)	end of a touch event sequence

Field Details

VERSION

static final int VERSION

See Also:

• Constant Field Values

Method Details

down

void down(WlTouchProxy emitter,
 int serial,
 int time,
 @Nonnull
 WlSurfaceProxy surface,
 int id,
 @Nonnull
 Fixed x,
 @Nonnull
 Fixed y)

touch down event and beginning of a touch sequence

A new touch point has appeared on the surface. This touch point is assigned a unique ID. Future events from this touch point reference this ID. The ID ceases to be valid after a touch up event and may be reused in the future.

Specified by:

down in interface WlTouchEvents

Specified by:

down in interface WlTouchEventsV2

Specified by:

down in interface WlTouchEventsV3

Parameters:

emitter - The protocol object that emitted the event.

serial - serial number of the touch down event

time - timestamp with millisecond granularity

surface - surface touched

id - the unique ID of this touch point

x - surface-local x coordinate

y - surface-local y coordinate

up

void up(WlTouchProxy emitter,
 int serial,
 int time,
 int id)

end of a touch event sequence

The touch point has disappeared. No further events will be sent for this touch point and the touch point's ID is released and may be reused in a future touch down event.

Specified by:

up in interface WlTouchEvents

Specified by:

up in interface WlTouchEventsV2

Specified by:

up in interface WlTouchEventsV3

Parameters:

emitter - The protocol object that emitted the event.

serial - serial number of the touch up event

time - timestamp with millisecond granularity

id - the unique ID of this touch point

motion

void motion(WlTouchProxy emitter,
 int time,
 int id,
 @Nonnull
 Fixed x,
 @Nonnull
 Fixed y)

update of touch point coordinates

A touch point has changed coordinates.

Specified by:

motion in interface WlTouchEvents

Specified by:

motion in interface WlTouchEventsV2

Specified by:

motion in interface WlTouchEventsV3

Parameters:

emitter - The protocol object that emitted the event.

time - timestamp with millisecond granularity

id - the unique ID of this touch point

x - surface-local x coordinate

y - surface-local y coordinate

frame

void frame(WlTouchProxy emitter)

end of touch frame event

Indicates the end of a set of events that logically belong together. A client is expected to accumulate the data in all events within the frame before proceeding.

A wl_touch.frame terminates at least one event but otherwise no guarantee is provided about the set of events within a frame. A client must assume that any state not updated in a frame is unchanged from the previously known state.

Specified by:

frame in interface WlTouchEvents

Specified by:

frame in interface WlTouchEventsV2

Specified by:

frame in interface WlTouchEventsV3

Parameters:

emitter - The protocol object that emitted the event.

cancel

void cancel(WlTouchProxy emitter)

touch session cancelled

Sent if the compositor decides the touch stream is a global gesture. No further events are sent to the clients from that particular gesture. Touch cancellation applies to all touch points currently active on this client's surface. The client is responsible for finalizing the touch points, future touch points on this surface may reuse the touch point ID.

No frame event is required after the cancel event.

Specified by:

cancel in interface WlTouchEvents

Specified by:

cancel in interface WlTouchEventsV2

Specified by:

cancel in interface WlTouchEventsV3

Parameters:

emitter - The protocol object that emitted the event.