Protocol tablet_unstable_v2 — Wayland protocol for graphics tablets

This description provides a high-level overview of the interplay between the interfaces defined this protocol. For details, see the protocol specification.

More than one tablet may exist, and device-specifics matter. Tablets are not represented by a single virtual device like wl_pointer. A client binds to the tablet manager object which is just a proxy object. From that, the client requests wp_tablet_manager.get_tablet_seat(wl_seat) and that returns the actual interface that has all the tablets. With this indirection, we can avoid merging wp_tablet into the actual Wayland protocol, a long-term benefit.

The wp_tablet_seat sends a "tablet added" event for each tablet connected. That event is followed by descriptive events about the hardware; currently that includes events for name, vid/pid and a wp_tablet.path event that describes a local path. This path can be used to uniquely identify a tablet or get more information through libwacom. Emulated or nested tablets can skip any of those, e.g. a virtual tablet may not have a vid/pid. The sequence of descriptive events is terminated by a wp_tablet.done event to signal that a client may now finalize any initialization for that tablet.

Events from tablets require a tool in proximity. Tools are also managed by the tablet seat; a "tool added" event is sent whenever a tool is new to the compositor. That event is followed by a number of descriptive events about the hardware; currently that includes capabilities, hardware id and serial number, and tool type. Similar to the tablet interface, a wp_tablet_tool.done event is sent to terminate that initial sequence.

Any event from a tool happens on the wp_tablet_tool interface. When the tool gets into proximity of the tablet, a proximity_in event is sent on the wp_tablet_tool interface, listing the tablet and the surface. That event is followed by a motion event with the coordinates. After that, it's the usual motion, axis, button, etc. events. The protocol's serialisation means events are grouped by wp_tablet_tool.frame events.

Two special events (that don't exist in X) are down and up. They signal "tip touching the surface". For tablets without real proximity detection, the sequence is: proximity_in, motion, down, frame.

When the tool leaves proximity, a proximity_out event is sent. If any button is still down, a button release event is sent before this proximity event. These button events are sent in the same frame as the proximity event to signal to the client that the buttons were held when the tool left proximity.

If the tool moves out of the surface but stays in proximity (i.e. between windows), compositor-specific grab policies apply. This usually means that the proximity-out is delayed until all buttons are released.

Moving a tool physically from one tablet to the other has no real effect on the protocol, since we already have the tool object from the "tool added" event. All the information is already there and the proximity events on both tablets are all a client needs to reconstruct what happened.

Some extra axes are normalized, i.e. the client knows the range as specified in the protocol (e.g. [0, 65535]), the granularity however is unknown. The current normalized axes are pressure, distance, and slider.

Other extra axes are in physical units as specified in the protocol. The current extra axes with physical units are tilt, rotation and wheel rotation.

Since tablets work independently of the pointer controlled by the mouse, the focus handling is independent too and controlled by proximity. The wp_tablet_tool.set_cursor request sets a tool-specific cursor. This cursor surface may be the same as the mouse cursor, and it may be the same across tools but it is possible to be more fine-grained. For example, a client may set different cursors for the pen and eraser.

Tools are generally independent of tablets and it is compositor-specific policy when a tool can be removed. Common approaches will likely include some form of removing a tool when all tablets the tool was used on are removed.

Warning! The protocol described in this file is experimental and backward incompatible changes may be made. Backward compatible changes may be added together with the corresponding interface version bump. Backward incompatible changes are done by bumping the version number in the protocol and interface names and resetting the interface version. Once the protocol is to be declared stable, the 'z' prefix and the version number in the protocol and interface names are removed and the interface version number is reset.

License 
    Copyright 2014 © Stephen "Lyude" Chandler Paul
    Copyright 2015-2016 © Red Hat, Inc.

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Interface zwp_tablet_manager_v2 — controller object for graphic tablet devices

An object that provides access to the graphics tablets available on this system. All tablets are associated with a seat, to get access to the actual tablets, use wp_tablet_manager.get_tablet_seat.

Request zwp_tablet_manager_v2.get_tablet_seat — get the tablet seat

Get the wp_tablet_seat object for the given seat. This object provides access to all graphics tablets in this seat.

Request zwp_tablet_manager_v2.destroy — release the memory for the tablet manager object

Destroy the wp_tablet_manager object. Objects created from this object are unaffected and should be destroyed separately.

Interface zwp_tablet_seat_v2 — controller object for graphic tablet devices of a seat

An object that provides access to the graphics tablets available on this seat. After binding to this interface, the compositor sends a set of wp_tablet_seat.tablet_added and wp_tablet_seat.tool_added events.

Request zwp_tablet_seat_v2.destroy — release the memory for the tablet seat object

Destroy the wp_tablet_seat object. Objects created from this object are unaffected and should be destroyed separately.

Event zwp_tablet_seat_v2.tablet_added — new device notification

This event is sent whenever a new tablet becomes available on this seat. This event only provides the object id of the tablet, any static information about the tablet (device name, vid/pid, etc.) is sent through the wp_tablet interface.

Event zwp_tablet_seat_v2.tool_added — a new tool has been used with a tablet

This event is sent whenever a tool that has not previously been used with a tablet comes into use. This event only provides the object id of the tool; any static information about the tool (capabilities, type, etc.) is sent through the wp_tablet_tool interface.

Event zwp_tablet_seat_v2.pad_added — new pad notification

This event is sent whenever a new pad is known to the system. Typically, pads are physically attached to tablets and a pad_added event is sent immediately after the wp_tablet_seat.tablet_added. However, some standalone pad devices logically attach to tablets at runtime, and the client must wait for wp_tablet_pad.enter to know the tablet a pad is attached to.

This event only provides the object id of the pad. All further features (buttons, strips, rings) are sent through the wp_tablet_pad interface.

Interface zwp_tablet_tool_v2 — a physical tablet tool

An object that represents a physical tool that has been, or is currently in use with a tablet in this seat. Each wp_tablet_tool object stays valid until the client destroys it; the compositor reuses the wp_tablet_tool object to indicate that the object's respective physical tool has come into proximity of a tablet again.

A wp_tablet_tool object's relation to a physical tool depends on the tablet's ability to report serial numbers. If the tablet supports this capability, then the object represents a specific physical tool and can be identified even when used on multiple tablets.

A tablet tool has a number of static characteristics, e.g. tool type, hardware_serial and capabilities. These capabilities are sent in an event sequence after the wp_tablet_seat.tool_added event before any actual events from this tool. This initial event sequence is terminated by a wp_tablet_tool.done event.

Tablet tool events are grouped by wp_tablet_tool.frame events. Any events received before a wp_tablet_tool.frame event should be considered part of the same hardware state change.

Request zwp_tablet_tool_v2.set_cursor — set the tablet tool's surface

Sets the surface of the cursor used for this tool on the given tablet. This request only takes effect if the tool is in proximity of one of the requesting client's surfaces or the surface parameter is the current pointer surface. If there was a previous surface set with this request it is replaced. If surface is NULL, the cursor image is hidden.

The parameters hotspot_x and hotspot_y define the position of the pointer surface relative to the pointer location. Its top-left corner is always at (x, y) - (hotspot_x, hotspot_y), where (x, y) are the coordinates of the pointer location, in surface-local coordinates.

On surface.attach requests to the pointer surface, hotspot_x and hotspot_y are decremented by the x and y parameters passed to the request. Attach must be confirmed by wl_surface.commit as usual.

The hotspot can also be updated by passing the currently set pointer surface to this request with new values for hotspot_x and hotspot_y.

The current and pending input regions of the wl_surface are cleared, and wl_surface.set_input_region is ignored until the wl_surface is no longer used as the cursor. When the use as a cursor ends, the current and pending input regions become undefined, and the wl_surface is unmapped.

This request gives the surface the role of a wp_tablet_tool cursor. A surface may only ever be used as the cursor surface for one wp_tablet_tool. If the surface already has another role or has previously been used as cursor surface for a different tool, a protocol error is raised.

  • serial uint: serial of the enter event
  • surface object<wl_surface>: None
  • hotspot_x int: surface-local x coordinate
  • hotspot_y int: surface-local y coordinate

Request zwp_tablet_tool_v2.destroy — destroy the tool object

This destroys the client's resource for this tool object.

Event zwp_tablet_tool_v2.type — tool type

The tool type is the high-level type of the tool and usually decides the interaction expected from this tool.

This event is sent in the initial burst of events before the wp_tablet_tool.done event.

  • tool_type uint: the physical tool type

Event zwp_tablet_tool_v2.hardware_serial — unique hardware serial number of the tool

If the physical tool can be identified by a unique 64-bit serial number, this event notifies the client of this serial number.

If multiple tablets are available in the same seat and the tool is uniquely identifiable by the serial number, that tool may move between tablets.

Otherwise, if the tool has no serial number and this event is missing, the tool is tied to the tablet it first comes into proximity with. Even if the physical tool is used on multiple tablets, separate wp_tablet_tool objects will be created, one per tablet.

This event is sent in the initial burst of events before the wp_tablet_tool.done event.

  • hardware_serial_hi uint: the unique serial number of the tool, most significant bits
  • hardware_serial_lo uint: the unique serial number of the tool, least significant bits

Event zwp_tablet_tool_v2.hardware_id_wacom — hardware id notification in Wacom's format

This event notifies the client of a hardware id available on this tool.

The hardware id is a device-specific 64-bit id that provides extra information about the tool in use, beyond the wl_tool.type enumeration. The format of the id is specific to tablets made by Wacom Inc. For example, the hardware id of a Wacom Grip Pen (a stylus) is 0x802.

This event is sent in the initial burst of events before the wp_tablet_tool.done event.

  • hardware_id_hi uint: the hardware id, most significant bits
  • hardware_id_lo uint: the hardware id, least significant bits

Event zwp_tablet_tool_v2.capability — tool capability notification

This event notifies the client of any capabilities of this tool, beyond the main set of x/y axes and tip up/down detection.

One event is sent for each extra capability available on this tool.

This event is sent in the initial burst of events before the wp_tablet_tool.done event.

  • capability uint: the capability

Event zwp_tablet_tool_v2.done — tool description events sequence complete

This event signals the end of the initial burst of descriptive events. A client may consider the static description of the tool to be complete and finalize initialization of the tool.

Event zwp_tablet_tool_v2.removed — tool removed

This event is sent when the tool is removed from the system and will send no further events. Should the physical tool come back into proximity later, a new wp_tablet_tool object will be created.

It is compositor-dependent when a tool is removed. A compositor may remove a tool on proximity out, tablet removal or any other reason. A compositor may also keep a tool alive until shutdown.

If the tool is currently in proximity, a proximity_out event will be sent before the removed event. See wp_tablet_tool.proximity_out for the handling of any buttons logically down.

When this event is received, the client must wp_tablet_tool.destroy the object.

Event zwp_tablet_tool_v2.proximity_in — proximity in event

Notification that this tool is focused on a certain surface.

This event can be received when the tool has moved from one surface to another, or when the tool has come back into proximity above the surface.

If any button is logically down when the tool comes into proximity, the respective button event is sent after the proximity_in event but within the same frame as the proximity_in event.

  • serial uint: None
  • tablet object<zwp_tablet_v2>: The tablet the tool is in proximity of
  • surface object<wl_surface>: The current surface the tablet tool is over

Event zwp_tablet_tool_v2.proximity_out — proximity out event

Notification that this tool has either left proximity, or is no longer focused on a certain surface.

When the tablet tool leaves proximity of the tablet, button release events are sent for each button that was held down at the time of leaving proximity. These events are sent before the proximity_out event but within the same wp_tablet.frame.

If the tool stays within proximity of the tablet, but the focus changes from one surface to another, a button release event may not be sent until the button is actually released or the tool leaves the proximity of the tablet.

Event zwp_tablet_tool_v2.down — tablet tool is making contact

Sent whenever the tablet tool comes in contact with the surface of the tablet.

If the tool is already in contact with the tablet when entering the input region, the client owning said region will receive a wp_tablet.proximity_in event, followed by a wp_tablet.down event and a wp_tablet.frame event.

Note that this event describes logical contact, not physical contact. On some devices, a compositor may not consider a tool in logical contact until a minimum physical pressure threshold is exceeded.

  • serial uint: None

Event zwp_tablet_tool_v2.up — tablet tool is no longer making contact

Sent whenever the tablet tool stops making contact with the surface of the tablet, or when the tablet tool moves out of the input region and the compositor grab (if any) is dismissed.

If the tablet tool moves out of the input region while in contact with the surface of the tablet and the compositor does not have an ongoing grab on the surface, the client owning said region will receive a wp_tablet.up event, followed by a wp_tablet.proximity_out event and a wp_tablet.frame event. If the compositor has an ongoing grab on this device, this event sequence is sent whenever the grab is dismissed in the future.

Note that this event describes logical contact, not physical contact. On some devices, a compositor may not consider a tool out of logical contact until physical pressure falls below a specific threshold.

Event zwp_tablet_tool_v2.motion — motion event

Sent whenever a tablet tool moves.

  • x fixed: surface-local x coordinate
  • y fixed: surface-local y coordinate

Event zwp_tablet_tool_v2.pressure — pressure change event

Sent whenever the pressure axis on a tool changes. The value of this event is normalized to a value between 0 and 65535.

Note that pressure may be nonzero even when a tool is not in logical contact. See the down and up events for more details.

  • pressure uint: The current pressure value

Event zwp_tablet_tool_v2.distance — distance change event

Sent whenever the distance axis on a tool changes. The value of this event is normalized to a value between 0 and 65535.

Note that distance may be nonzero even when a tool is not in logical contact. See the down and up events for more details.

  • distance uint: The current distance value

Event zwp_tablet_tool_v2.tilt — tilt change event

Sent whenever one or both of the tilt axes on a tool change. Each tilt value is in degrees, relative to the z-axis of the tablet. The angle is positive when the top of a tool tilts along the positive x or y axis.

  • tilt_x fixed: The current value of the X tilt axis
  • tilt_y fixed: The current value of the Y tilt axis

Event zwp_tablet_tool_v2.rotation — z-rotation change event

Sent whenever the z-rotation axis on the tool changes. The rotation value is in degrees clockwise from the tool's logical neutral position.

  • degrees fixed: The current rotation of the Z axis

Event zwp_tablet_tool_v2.slider — Slider position change event

Sent whenever the slider position on the tool changes. The value is normalized between -65535 and 65535, with 0 as the logical neutral position of the slider.

The slider is available on e.g. the Wacom Airbrush tool.

  • position int: The current position of slider

Event zwp_tablet_tool_v2.wheel — Wheel delta event

Sent whenever the wheel on the tool emits an event. This event contains two values for the same axis change. The degrees value is in the same orientation as the wl_pointer.vertical_scroll axis. The clicks value is in discrete logical clicks of the mouse wheel. This value may be zero if the movement of the wheel was less than one logical click.

Clients should choose either value and avoid mixing degrees and clicks. The compositor may accumulate values smaller than a logical click and emulate click events when a certain threshold is met. Thus, wl_tablet_tool.wheel events with non-zero clicks values may have different degrees values.

  • degrees fixed: The wheel delta in degrees
  • clicks int: The wheel delta in discrete clicks

Event zwp_tablet_tool_v2.button — button event

Sent whenever a button on the tool is pressed or released.

If a button is held down when the tool moves in or out of proximity, button events are generated by the compositor. See wp_tablet_tool.proximity_in and wp_tablet_tool.proximity_out for details.

  • serial uint: None
  • button uint: The button whose state has changed
  • state uint: Whether the button was pressed or released

Event zwp_tablet_tool_v2.frame — frame event

Marks the end of a series of axis and/or button updates from the tablet. The Wayland protocol requires axis updates to be sent sequentially, however all events within a frame should be considered one hardware event.

  • time uint: The time of the event with millisecond granularity

Enum zwp_tablet_tool_v2.type — a physical tool type

Describes the physical type of a tool. The physical type of a tool generally defines its base usage.

The mouse tool represents a mouse-shaped tool that is not a relative device but bound to the tablet's surface, providing absolute coordinates.

The lens tool is a mouse-shaped tool with an attached lens to provide precision focus.

  • pen: Pen
  • eraser: Eraser
  • brush: Brush
  • pencil: Pencil
  • airbrush: Airbrush
  • finger: Finger
  • mouse: Mouse
  • lens: Lens

Enum zwp_tablet_tool_v2.capability — capability flags for a tool

Describes extra capabilities on a tablet.

Any tool must provide x and y values, extra axes are device-specific.

  • tilt: Tilt axes
  • pressure: Pressure axis
  • distance: Distance axis
  • rotation: Z-rotation axis
  • slider: Slider axis
  • wheel: Wheel axis

Enum zwp_tablet_tool_v2.button_state — physical button state

Describes the physical state of a button that produced the button event.

  • released: button is not pressed
  • pressed: button is pressed

Enum zwp_tablet_tool_v2.error

Interface zwp_tablet_v2 — graphics tablet device

The wp_tablet interface represents one graphics tablet device. The tablet interface itself does not generate events; all events are generated by wp_tablet_tool objects when in proximity above a tablet.

A tablet has a number of static characteristics, e.g. device name and pid/vid. These capabilities are sent in an event sequence after the wp_tablet_seat.tablet_added event. This initial event sequence is terminated by a wp_tablet.done event.

Request zwp_tablet_v2.destroy — destroy the tablet object

This destroys the client's resource for this tablet object.

Event zwp_tablet_v2.name — tablet device name

This event is sent in the initial burst of events before the wp_tablet.done event.

  • name string: the device name

Event zwp_tablet_v2.id — tablet device USB vendor/product id

This event is sent in the initial burst of events before the wp_tablet.done event.

  • vid uint: USB vendor id
  • pid uint: USB product id

Event zwp_tablet_v2.path — path to the device

A system-specific device path that indicates which device is behind this wp_tablet. This information may be used to gather additional information about the device, e.g. through libwacom.

A device may have more than one device path. If so, multiple wp_tablet.path events are sent. A device may be emulated and not have a device path, and in that case this event will not be sent.

The format of the path is unspecified, it may be a device node, a sysfs path, or some other identifier. It is up to the client to identify the string provided.

This event is sent in the initial burst of events before the wp_tablet.done event.

  • path string: path to local device

Event zwp_tablet_v2.done — tablet description events sequence complete

This event is sent immediately to signal the end of the initial burst of descriptive events. A client may consider the static description of the tablet to be complete and finalize initialization of the tablet.

Event zwp_tablet_v2.removed — tablet removed event

Sent when the tablet has been removed from the system. When a tablet is removed, some tools may be removed.

When this event is received, the client must wp_tablet.destroy the object.

Interface zwp_tablet_pad_ring_v2 — pad ring

A circular interaction area, such as the touch ring on the Wacom Intuos Pro series tablets.

Events on a ring are logically grouped by the wl_tablet_pad_ring.frame event.

Request zwp_tablet_pad_ring_v2.set_feedback — set compositor feedback

Request that the compositor use the provided feedback string associated with this ring. This request should be issued immediately after a wp_tablet_pad_group.mode_switch event from the corresponding group is received, or whenever the ring is mapped to a different action. See wp_tablet_pad_group.mode_switch for more details.

Clients are encouraged to provide context-aware descriptions for the actions associated with the ring; compositors may use this information to offer visual feedback about the button layout (eg. on-screen displays).

The provided string 'description' is a UTF-8 encoded string to be associated with this ring, and is considered user-visible; general internationalization rules apply.

The serial argument will be that of the last wp_tablet_pad_group.mode_switch event received for the group of this ring. Requests providing other serials than the most recent one will be ignored.

  • description string: ring description
  • serial uint: serial of the mode switch event

Request zwp_tablet_pad_ring_v2.destroy — destroy the ring object

This destroys the client's resource for this ring object.

Event zwp_tablet_pad_ring_v2.source — ring event source

Source information for ring events.

This event does not occur on its own. It is sent before a wp_tablet_pad_ring.frame event and carries the source information for all events within that frame.

The source specifies how this event was generated. If the source is wp_tablet_pad_ring.source.finger, a wp_tablet_pad_ring.stop event will be sent when the user lifts the finger off the device.

This event is optional. If the source is unknown for an interaction, no event is sent.

  • source uint: the event source

Event zwp_tablet_pad_ring_v2.angle — angle changed

Sent whenever the angle on a ring changes.

The angle is provided in degrees clockwise from the logical north of the ring in the pad's current rotation.

  • degrees fixed: the current angle in degrees

Event zwp_tablet_pad_ring_v2.stop — interaction stopped

Stop notification for ring events.

For some wp_tablet_pad_ring.source types, a wp_tablet_pad_ring.stop event is sent to notify a client that the interaction with the ring has terminated. This enables the client to implement kinetic scrolling. See the wp_tablet_pad_ring.source documentation for information on when this event may be generated.

Any wp_tablet_pad_ring.angle events with the same source after this event should be considered as the start of a new interaction.

Event zwp_tablet_pad_ring_v2.frame — end of a ring event sequence

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

All wp_tablet_pad_ring events before a wp_tablet_pad_ring.frame event belong logically together. For example, on termination of a finger interaction on a ring the compositor will send a wp_tablet_pad_ring.source event, a wp_tablet_pad_ring.stop event and a wp_tablet_pad_ring.frame event.

A wp_tablet_pad_ring.frame event is sent for every logical event group, even if the group only contains a single wp_tablet_pad_ring event. Specifically, a client may get a sequence: angle, frame, angle, frame, etc.

  • time uint: timestamp with millisecond granularity

Enum zwp_tablet_pad_ring_v2.source — ring axis source

Describes the source types for ring events. This indicates to the client how a ring event was physically generated; a client may adjust the user interface accordingly. For example, events from a "finger" source may trigger kinetic scrolling.

  • finger: finger

Interface zwp_tablet_pad_strip_v2 — pad strip

A linear interaction area, such as the strips found in Wacom Cintiq models.

Events on a strip are logically grouped by the wl_tablet_pad_strip.frame event.

Request zwp_tablet_pad_strip_v2.set_feedback — set compositor feedback

Requests the compositor to use the provided feedback string associated with this strip. This request should be issued immediately after a wp_tablet_pad_group.mode_switch event from the corresponding group is received, or whenever the strip is mapped to a different action. See wp_tablet_pad_group.mode_switch for more details.

Clients are encouraged to provide context-aware descriptions for the actions associated with the strip, and compositors may use this information to offer visual feedback about the button layout (eg. on-screen displays).

The provided string 'description' is a UTF-8 encoded string to be associated with this ring, and is considered user-visible; general internationalization rules apply.

The serial argument will be that of the last wp_tablet_pad_group.mode_switch event received for the group of this strip. Requests providing other serials than the most recent one will be ignored.

  • description string: strip description
  • serial uint: serial of the mode switch event

Request zwp_tablet_pad_strip_v2.destroy — destroy the strip object

This destroys the client's resource for this strip object.

Event zwp_tablet_pad_strip_v2.source — strip event source

Source information for strip events.

This event does not occur on its own. It is sent before a wp_tablet_pad_strip.frame event and carries the source information for all events within that frame.

The source specifies how this event was generated. If the source is wp_tablet_pad_strip.source.finger, a wp_tablet_pad_strip.stop event will be sent when the user lifts their finger off the device.

This event is optional. If the source is unknown for an interaction, no event is sent.

  • source uint: the event source

Event zwp_tablet_pad_strip_v2.position — position changed

Sent whenever the position on a strip changes.

The position is normalized to a range of [0, 65535], the 0-value represents the top-most and/or left-most position of the strip in the pad's current rotation.

  • position uint: the current position

Event zwp_tablet_pad_strip_v2.stop — interaction stopped

Stop notification for strip events.

For some wp_tablet_pad_strip.source types, a wp_tablet_pad_strip.stop event is sent to notify a client that the interaction with the strip has terminated. This enables the client to implement kinetic scrolling. See the wp_tablet_pad_strip.source documentation for information on when this event may be generated.

Any wp_tablet_pad_strip.position events with the same source after this event should be considered as the start of a new interaction.

Event zwp_tablet_pad_strip_v2.frame — end of a strip event sequence

Indicates the end of a set of events that represent one logical hardware strip event. A client is expected to accumulate the data in all events within the frame before proceeding.

All wp_tablet_pad_strip events before a wp_tablet_pad_strip.frame event belong logically together. For example, on termination of a finger interaction on a strip the compositor will send a wp_tablet_pad_strip.source event, a wp_tablet_pad_strip.stop event and a wp_tablet_pad_strip.frame event.

A wp_tablet_pad_strip.frame event is sent for every logical event group, even if the group only contains a single wp_tablet_pad_strip event. Specifically, a client may get a sequence: position, frame, position, frame, etc.

  • time uint: timestamp with millisecond granularity

Enum zwp_tablet_pad_strip_v2.source — strip axis source

Describes the source types for strip events. This indicates to the client how a strip event was physically generated; a client may adjust the user interface accordingly. For example, events from a "finger" source may trigger kinetic scrolling.

  • finger: finger

Interface zwp_tablet_pad_group_v2 — a set of buttons, rings and strips

A pad group describes a distinct (sub)set of buttons, rings and strips present in the tablet. The criteria of this grouping is usually positional, eg. if a tablet has buttons on the left and right side, 2 groups will be presented. The physical arrangement of groups is undisclosed and may change on the fly.

Pad groups will announce their features during pad initialization. Between the corresponding wp_tablet_pad.group event and wp_tablet_pad_group.done, the pad group will announce the buttons, rings and strips contained in it, plus the number of supported modes.

Modes are a mechanism to allow multiple groups of actions for every element in the pad group. The number of groups and available modes in each is persistent across device plugs. The current mode is user-switchable, it will be announced through the wp_tablet_pad_group.mode_switch event both whenever it is switched, and after wp_tablet_pad.enter.

The current mode logically applies to all elements in the pad group, although it is at clients' discretion whether to actually perform different actions, and/or issue the respective .set_feedback requests to notify the compositor. See the wp_tablet_pad_group.mode_switch event for more details.

Request zwp_tablet_pad_group_v2.destroy — destroy the pad object

Destroy the wp_tablet_pad_group object. Objects created from this object are unaffected and should be destroyed separately.

Event zwp_tablet_pad_group_v2.buttons — buttons announced

Sent on wp_tablet_pad_group initialization to announce the available buttons in the group. Button indices start at 0, a button may only be in one group at a time.

This event is first sent in the initial burst of events before the wp_tablet_pad_group.done event.

Some buttons are reserved by the compositor. These buttons may not be assigned to any wp_tablet_pad_group. Compositors may broadcast this event in the case of changes to the mapping of these reserved buttons. If the compositor happens to reserve all buttons in a group, this event will be sent with an empty array.

  • buttons array: buttons in this group

Event zwp_tablet_pad_group_v2.ring — ring announced

Sent on wp_tablet_pad_group initialization to announce available rings. One event is sent for each ring available on this pad group.

This event is sent in the initial burst of events before the wp_tablet_pad_group.done event.

Event zwp_tablet_pad_group_v2.strip — strip announced

Sent on wp_tablet_pad initialization to announce available strips. One event is sent for each strip available on this pad group.

This event is sent in the initial burst of events before the wp_tablet_pad_group.done event.

Event zwp_tablet_pad_group_v2.modes — mode-switch ability announced

Sent on wp_tablet_pad_group initialization to announce that the pad group may switch between modes. A client may use a mode to store a specific configuration for buttons, rings and strips and use the wl_tablet_pad_group.mode_switch event to toggle between these configurations. Mode indices start at 0.

Switching modes is compositor-dependent. See the wp_tablet_pad_group.mode_switch event for more details.

This event is sent in the initial burst of events before the wp_tablet_pad_group.done event. This event is only sent when more than more than one mode is available.

  • modes uint: the number of modes

Event zwp_tablet_pad_group_v2.done — tablet group description events sequence complete

This event is sent immediately to signal the end of the initial burst of descriptive events. A client may consider the static description of the tablet to be complete and finalize initialization of the tablet group.

Event zwp_tablet_pad_group_v2.mode_switch — mode switch event

Notification that the mode was switched.

A mode applies to all buttons, rings and strips in a group simultaneously, but a client is not required to assign different actions for each mode. For example, a client may have mode-specific button mappings but map the ring to vertical scrolling in all modes. Mode indices start at 0.

Switching modes is compositor-dependent. The compositor may provide visual cues to the client about the mode, e.g. by toggling LEDs on the tablet device. Mode-switching may be software-controlled or controlled by one or more physical buttons. For example, on a Wacom Intuos Pro, the button inside the ring may be assigned to switch between modes.

The compositor will also send this event after wp_tablet_pad.enter on each group in order to notify of the current mode. Groups that only feature one mode will use mode=0 when emitting this event.

If a button action in the new mode differs from the action in the previous mode, the client should immediately issue a wp_tablet_pad.set_feedback request for each changed button.

If a ring or strip action in the new mode differs from the action in the previous mode, the client should immediately issue a wp_tablet_ring.set_feedback or wp_tablet_strip.set_feedback request for each changed ring or strip.

  • time uint: the time of the event with millisecond granularity
  • serial uint: None
  • mode uint: the new mode of the pad

Interface zwp_tablet_pad_v2 — a set of buttons, rings and strips

A pad device is a set of buttons, rings and strips usually physically present on the tablet device itself. Some exceptions exist where the pad device is physically detached, e.g. the Wacom ExpressKey Remote.

Pad devices have no axes that control the cursor and are generally auxiliary devices to the tool devices used on the tablet surface.

A pad device has a number of static characteristics, e.g. the number of rings. These capabilities are sent in an event sequence after the wp_tablet_seat.pad_added event before any actual events from this pad. This initial event sequence is terminated by a wp_tablet_pad.done event.

All pad features (buttons, rings and strips) are logically divided into groups and all pads have at least one group. The available groups are notified through the wp_tablet_pad.group event; the compositor will emit one event per group before emitting wp_tablet_pad.done.

Groups may have multiple modes. Modes allow clients to map multiple actions to a single pad feature. Only one mode can be active per group, although different groups may have different active modes.

Request zwp_tablet_pad_v2.set_feedback — set compositor feedback

Requests the compositor to use the provided feedback string associated with this button. This request should be issued immediately after a wp_tablet_pad_group.mode_switch event from the corresponding group is received, or whenever a button is mapped to a different action. See wp_tablet_pad_group.mode_switch for more details.

Clients are encouraged to provide context-aware descriptions for the actions associated with each button, and compositors may use this information to offer visual feedback on the button layout (e.g. on-screen displays).

Button indices start at 0. Setting the feedback string on a button that is reserved by the compositor (i.e. not belonging to any wp_tablet_pad_group) does not generate an error but the compositor is free to ignore the request.

The provided string 'description' is a UTF-8 encoded string to be associated with this ring, and is considered user-visible; general internationalization rules apply.

The serial argument will be that of the last wp_tablet_pad_group.mode_switch event received for the group of this button. Requests providing other serials than the most recent one will be ignored.

  • button uint: button index
  • description string: button description
  • serial uint: serial of the mode switch event

Request zwp_tablet_pad_v2.destroy — destroy the pad object

Destroy the wp_tablet_pad object. Objects created from this object are unaffected and should be destroyed separately.

Event zwp_tablet_pad_v2.group — group announced

Sent on wp_tablet_pad initialization to announce available groups. One event is sent for each pad group available.

This event is sent in the initial burst of events before the wp_tablet_pad.done event. At least one group will be announced.

Event zwp_tablet_pad_v2.path — path to the device

A system-specific device path that indicates which device is behind this wp_tablet_pad. This information may be used to gather additional information about the device, e.g. through libwacom.

The format of the path is unspecified, it may be a device node, a sysfs path, or some other identifier. It is up to the client to identify the string provided.

This event is sent in the initial burst of events before the wp_tablet_pad.done event.

  • path string: path to local device

Event zwp_tablet_pad_v2.buttons — buttons announced

Sent on wp_tablet_pad initialization to announce the available buttons.

This event is sent in the initial burst of events before the wp_tablet_pad.done event. This event is only sent when at least one button is available.

  • buttons uint: the number of buttons

Event zwp_tablet_pad_v2.done — pad description event sequence complete

This event signals the end of the initial burst of descriptive events. A client may consider the static description of the pad to be complete and finalize initialization of the pad.

Event zwp_tablet_pad_v2.button — physical button state

Sent whenever the physical state of a button changes.

  • time uint: the time of the event with millisecond granularity
  • button uint: the index of the button that changed state
  • state uint: None

Event zwp_tablet_pad_v2.enter — enter event

Notification that this pad is focused on the specified surface.

  • serial uint: serial number of the enter event
  • tablet object<zwp_tablet_v2>: the tablet the pad is attached to
  • surface object<wl_surface>: surface the pad is focused on

Event zwp_tablet_pad_v2.leave — leave event

Notification that this pad is no longer focused on the specified surface.

  • serial uint: serial number of the leave event
  • surface object<wl_surface>: surface the pad is no longer focused on

Event zwp_tablet_pad_v2.removed — pad removed event

Sent when the pad has been removed from the system. When a tablet is removed its pad(s) will be removed too.

When this event is received, the client must destroy all rings, strips and groups that were offered by this pad, and issue wp_tablet_pad.destroy the pad itself.

Enum zwp_tablet_pad_v2.button_state — physical button state

Describes the physical state of a button that caused the button event.

  • released: the button is not pressed
  • pressed: the button is pressed