Initialization and manipulation of input devices

Data Structures

struct  libinput_device
 A base handle for accessing libinput devices. More...
 
struct  libinput_device_group
 A base handle for accessing libinput device groups. More...
 
struct  libinput_tablet_tool
 An object representing a tool being used by a device with the LIBINPUT_DEVICE_CAP_TABLET_TOOL capability. More...
 

Enumerations

enum  libinput_device_capability {
  LIBINPUT_DEVICE_CAP_KEYBOARD, LIBINPUT_DEVICE_CAP_POINTER, LIBINPUT_DEVICE_CAP_TOUCH, LIBINPUT_DEVICE_CAP_TABLET_TOOL,
  LIBINPUT_DEVICE_CAP_TABLET_PAD, LIBINPUT_DEVICE_CAP_GESTURE, LIBINPUT_DEVICE_CAP_SWITCH
}
 Capabilities on a device. More...
 
enum  libinput_key_state { LIBINPUT_KEY_STATE_RELEASED, LIBINPUT_KEY_STATE_PRESSED }
 Logical state of a key. More...
 
enum  libinput_led { LIBINPUT_LED_NUM_LOCK, LIBINPUT_LED_CAPS_LOCK, LIBINPUT_LED_SCROLL_LOCK }
 Mask reflecting LEDs on a device. More...
 
enum  libinput_button_state { LIBINPUT_BUTTON_STATE_RELEASED, LIBINPUT_BUTTON_STATE_PRESSED }
 Logical state of a physical button. More...
 
enum  libinput_pointer_axis { LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL, LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL }
 Axes on a device with the capability LIBINPUT_DEVICE_CAP_POINTER that are not x or y coordinates. More...
 
enum  libinput_pointer_axis_source { LIBINPUT_POINTER_AXIS_SOURCE_WHEEL, LIBINPUT_POINTER_AXIS_SOURCE_FINGER, LIBINPUT_POINTER_AXIS_SOURCE_CONTINUOUS, LIBINPUT_POINTER_AXIS_SOURCE_WHEEL_TILT }
 The source for a libinput_pointer_axis event. More...
 
enum  libinput_tablet_tool_type {
  LIBINPUT_TABLET_TOOL_TYPE_PEN, LIBINPUT_TABLET_TOOL_TYPE_ERASER, LIBINPUT_TABLET_TOOL_TYPE_BRUSH, LIBINPUT_TABLET_TOOL_TYPE_PENCIL,
  LIBINPUT_TABLET_TOOL_TYPE_AIRBRUSH, LIBINPUT_TABLET_TOOL_TYPE_MOUSE, LIBINPUT_TABLET_TOOL_TYPE_LENS
}
 Available tool types for a device with the LIBINPUT_DEVICE_CAP_TABLET_TOOL capability. More...
 
enum  libinput_tablet_tool_proximity_state { LIBINPUT_TABLET_TOOL_PROXIMITY_STATE_OUT, LIBINPUT_TABLET_TOOL_PROXIMITY_STATE_IN }
 The state of proximity for a tool on a device. More...
 
enum  libinput_tablet_tool_tip_state { LIBINPUT_TABLET_TOOL_TIP_UP, LIBINPUT_TABLET_TOOL_TIP_DOWN }
 The tip contact state for a tool on a device. More...
 
enum  libinput_switch_state { LIBINPUT_SWITCH_STATE_OFF, LIBINPUT_SWITCH_STATE_ON }
 The state of a switch. More...
 
enum  libinput_switch { LIBINPUT_SWITCH_LID, LIBINPUT_SWITCH_TABLET_MODE }
 The type of a switch. More...
 

Functions

struct libinput_devicelibinput_device_ref (struct libinput_device *device)
 Increase the refcount of the input device. More...
 
struct libinput_devicelibinput_device_unref (struct libinput_device *device)
 Decrease the refcount of the input device. More...
 
void libinput_device_set_user_data (struct libinput_device *device, void *user_data)
 Set caller-specific data associated with this input device. More...
 
void * libinput_device_get_user_data (struct libinput_device *device)
 Get the caller-specific data associated with this input device, if any. More...
 
struct libinputlibinput_device_get_context (struct libinput_device *device)
 Get the libinput context from the device. More...
 
struct libinput_device_grouplibinput_device_get_device_group (struct libinput_device *device)
 Get the device group this device is assigned to. More...
 
const char * libinput_device_get_sysname (struct libinput_device *device)
 Get the system name of the device. More...
 
const char * libinput_device_get_name (struct libinput_device *device)
 The descriptive device name as advertised by the kernel and/or the hardware itself. More...
 
unsigned int libinput_device_get_id_product (struct libinput_device *device)
 Get the product ID for this device. More...
 
unsigned int libinput_device_get_id_vendor (struct libinput_device *device)
 Get the vendor ID for this device. More...
 
const char * libinput_device_get_output_name (struct libinput_device *device)
 A device may be mapped to a single output, or all available outputs. More...
 
struct libinput_seatlibinput_device_get_seat (struct libinput_device *device)
 Get the seat associated with this input device, see Seats for details. More...
 
int libinput_device_set_seat_logical_name (struct libinput_device *device, const char *name)
 Change the logical seat associated with this device by removing the device and adding it to the new seat. More...
 
struct udev_device * libinput_device_get_udev_device (struct libinput_device *device)
 Return a udev handle to the device that is this libinput device, if any. More...
 
void libinput_device_led_update (struct libinput_device *device, enum libinput_led leds)
 Update the LEDs on the device, if any. More...
 
int libinput_device_has_capability (struct libinput_device *device, enum libinput_device_capability capability)
 Check if the given device has the specified capability. More...
 
int libinput_device_get_size (struct libinput_device *device, double *width, double *height)
 Get the physical size of a device in mm, where meaningful. More...
 
int libinput_device_pointer_has_button (struct libinput_device *device, uint32_t code)
 Check if a LIBINPUT_DEVICE_CAP_POINTER device has a button with the given code (see linux/input.h). More...
 
int libinput_device_keyboard_has_key (struct libinput_device *device, uint32_t code)
 Check if a LIBINPUT_DEVICE_CAP_KEYBOARD device has a key with the given code (see linux/input.h). More...
 
int libinput_device_touch_get_touch_count (struct libinput_device *device)
 Check how many touches a LIBINPUT_DEVICE_CAP_TOUCH device supports simultaneously. More...
 
int libinput_device_switch_has_switch (struct libinput_device *device, enum libinput_switch sw)
 Check if a LIBINPUT_DEVICE_CAP_SWITCH device has a switch of the given type. More...
 
int libinput_device_tablet_pad_get_num_buttons (struct libinput_device *device)
 Return the number of buttons on a device with the LIBINPUT_DEVICE_CAP_TABLET_PAD capability. More...
 
int libinput_device_tablet_pad_get_num_rings (struct libinput_device *device)
 Return the number of rings a device with the LIBINPUT_DEVICE_CAP_TABLET_PAD capability provides. More...
 
int libinput_device_tablet_pad_get_num_strips (struct libinput_device *device)
 Return the number of strips a device with the LIBINPUT_DEVICE_CAP_TABLET_PAD capability provides. More...
 
struct libinput_device_grouplibinput_device_group_ref (struct libinput_device_group *group)
 Increase the refcount of the device group. More...
 
struct libinput_device_grouplibinput_device_group_unref (struct libinput_device_group *group)
 Decrease the refcount of the device group. More...
 
void libinput_device_group_set_user_data (struct libinput_device_group *group, void *user_data)
 Set caller-specific data associated with this device group. More...
 
void * libinput_device_group_get_user_data (struct libinput_device_group *group)
 Get the caller-specific data associated with this input device group, if any. More...
 

Detailed Description

Enumeration Type Documentation

◆ libinput_button_state

Logical state of a physical button.

Note that the logical state may not represent the physical state of the button.

Enumerator
LIBINPUT_BUTTON_STATE_RELEASED 
LIBINPUT_BUTTON_STATE_PRESSED 

◆ libinput_device_capability

Capabilities on a device.

A device may have one or more capabilities at a time, capabilities remain static for the lifetime of the device.

Enumerator
LIBINPUT_DEVICE_CAP_KEYBOARD 
LIBINPUT_DEVICE_CAP_POINTER 
LIBINPUT_DEVICE_CAP_TOUCH 
LIBINPUT_DEVICE_CAP_TABLET_TOOL 
LIBINPUT_DEVICE_CAP_TABLET_PAD 
LIBINPUT_DEVICE_CAP_GESTURE 
LIBINPUT_DEVICE_CAP_SWITCH 

◆ libinput_key_state

Logical state of a key.

Note that the logical state may not represent the physical state of the key.

Enumerator
LIBINPUT_KEY_STATE_RELEASED 
LIBINPUT_KEY_STATE_PRESSED 

◆ libinput_led

Mask reflecting LEDs on a device.

Enumerator
LIBINPUT_LED_NUM_LOCK 
LIBINPUT_LED_CAPS_LOCK 
LIBINPUT_LED_SCROLL_LOCK 

◆ libinput_pointer_axis

Axes on a device with the capability LIBINPUT_DEVICE_CAP_POINTER that are not x or y coordinates.

The two scroll axes LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL and LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL are engaged separately, depending on the device. libinput provides some scroll direction locking but it is up to the caller to determine which axis is needed and appropriate in the current interaction

Enumerator
LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL 
LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL 

◆ libinput_pointer_axis_source

The source for a libinput_pointer_axis event.

See libinput_event_pointer_get_axis_source() for details.

Enumerator
LIBINPUT_POINTER_AXIS_SOURCE_WHEEL 

The event is caused by the rotation of a wheel.

LIBINPUT_POINTER_AXIS_SOURCE_FINGER 

The event is caused by the movement of one or more fingers on a device.

LIBINPUT_POINTER_AXIS_SOURCE_CONTINUOUS 

The event is caused by the motion of some device.

LIBINPUT_POINTER_AXIS_SOURCE_WHEEL_TILT 

The event is caused by the tilting of a mouse wheel rather than its rotation.

This method is commonly used on mice without separate horizontal scroll wheels.

◆ libinput_switch

The type of a switch.

Enumerator
LIBINPUT_SWITCH_LID 

The laptop lid was closed when the switch state is LIBINPUT_SWITCH_STATE_ON, or was opened when it is LIBINPUT_SWITCH_STATE_OFF.

LIBINPUT_SWITCH_TABLET_MODE 

This switch indicates whether the device is in normal laptop mode or behaves like a tablet-like device where the primary interaction is usually a touch screen.

When in tablet mode, the keyboard and touchpad are usually inaccessible.

If the switch is in state LIBINPUT_SWITCH_STATE_OFF, the device is in laptop mode. If the switch is in state LIBINPUT_SWITCH_STATE_ON, the device is in tablet mode and the keyboard or touchpad may not be accessible.

It is up to the caller to identify which devices are inaccessible in tablet mode.

◆ libinput_switch_state

The state of a switch.

The default state of a switch is LIBINPUT_SWITCH_STATE_OFF and no event is sent to confirm a switch in the off position. If a switch is logically on during initialization, libinput sends an event of type LIBINPUT_EVENT_SWITCH_TOGGLE with a state LIBINPUT_SWITCH_STATE_ON.

Enumerator
LIBINPUT_SWITCH_STATE_OFF 
LIBINPUT_SWITCH_STATE_ON 

◆ libinput_tablet_tool_proximity_state

The state of proximity for a tool on a device.

The device must have the LIBINPUT_DEVICE_CAP_TABLET_TOOL capability.

The proximity of a tool is a binary state signalling whether the tool is within a detectable distance of the tablet device. A tool that is out of proximity cannot generate events.

On some hardware a tool goes out of proximity when it ceases to touch the surface. On other hardware, the tool is still detectable within a short distance (a few cm) off the surface.

Enumerator
LIBINPUT_TABLET_TOOL_PROXIMITY_STATE_OUT 
LIBINPUT_TABLET_TOOL_PROXIMITY_STATE_IN 

◆ libinput_tablet_tool_tip_state

The tip contact state for a tool on a device.

The device must have the LIBINPUT_DEVICE_CAP_TABLET_TOOL capability.

The tip contact state of a tool is a binary state signalling whether the tool is touching the surface of the tablet device.

Enumerator
LIBINPUT_TABLET_TOOL_TIP_UP 
LIBINPUT_TABLET_TOOL_TIP_DOWN 

◆ libinput_tablet_tool_type

Available tool types for a device with the LIBINPUT_DEVICE_CAP_TABLET_TOOL capability.

The tool type defines the default usage of the tool as advertised by the manufacturer. Multiple different physical tools may share the same tool type, e.g. a Wacom Classic Pen, Wacom Pro Pen and a Wacom Grip Pen are all of type LIBINPUT_TABLET_TOOL_TYPE_PEN. Use libinput_tablet_tool_get_tool_id() to get a specific model where applicable.

Note that on some device, the eraser tool is on the tail end of a pen device. On other devices, e.g. MS Surface 3, the eraser is the pen tip while a button is held down.

Note
The libinput_tablet_tool_type can only describe the default physical type of the device. For devices with adjustable physical properties the tool type remains the same, i.e. putting a Wacom stroke nib into a classic pen leaves the tool type as LIBINPUT_TABLET_TOOL_TYPE_PEN.
Enumerator
LIBINPUT_TABLET_TOOL_TYPE_PEN 

A generic pen.

LIBINPUT_TABLET_TOOL_TYPE_ERASER 

Eraser.

LIBINPUT_TABLET_TOOL_TYPE_BRUSH 

A paintbrush-like tool.

LIBINPUT_TABLET_TOOL_TYPE_PENCIL 

Physical drawing tool, e.g.

Wacom Inking Pen

LIBINPUT_TABLET_TOOL_TYPE_AIRBRUSH 

An airbrush-like tool.

LIBINPUT_TABLET_TOOL_TYPE_MOUSE 

A mouse bound to the tablet.

LIBINPUT_TABLET_TOOL_TYPE_LENS 

A mouse tool with a lens.

Function Documentation

◆ libinput_device_get_context()

struct libinput* libinput_device_get_context ( struct libinput_device device)

Get the libinput context from the device.

Parameters
deviceA previously obtained device
Returns
The libinput context for this device.

◆ libinput_device_get_device_group()

struct libinput_device_group* libinput_device_get_device_group ( struct libinput_device device)

Get the device group this device is assigned to.

Some physical devices like graphics tablets are represented by multiple kernel devices and thus by multiple struct libinput_device.

libinput assigns these devices to the same libinput_device_group allowing the caller to identify such devices and adjust configuration settings accordingly. For example, setting a tablet to left-handed often means turning it upside down. A touch device on the same tablet would need to be turned upside down too to work correctly.

All devices are part of a device group though for most devices the group will be a singleton. A device is assigned to a device group on LIBINPUT_EVENT_DEVICE_ADDED and removed from that group on LIBINPUT_EVENT_DEVICE_REMOVED. It is up to the caller to track how many devices are in each device group.

dot_inline_dotgraph_10.png

Device groups do not get re-used once the last device in the group was removed, i.e. unplugging and re-plugging a physical device with grouped devices will return a different device group after every unplug.

The returned device group is not refcounted and may become invalid after the next call to libinput. Use libinput_device_group_ref() and libinput_device_group_unref() to continue using the handle outside of the immediate scope.

Device groups are assigned based on the LIBINPUT_DEVICE_GROUP udev property, see Static device configuration via udev.

Returns
The device group this device belongs to

◆ libinput_device_get_id_product()

unsigned int libinput_device_get_id_product ( struct libinput_device device)

Get the product ID for this device.

Parameters
deviceA previously obtained device
Returns
The product ID of this device

◆ libinput_device_get_id_vendor()

unsigned int libinput_device_get_id_vendor ( struct libinput_device device)

Get the vendor ID for this device.

Parameters
deviceA previously obtained device
Returns
The vendor ID of this device

◆ libinput_device_get_name()

const char* libinput_device_get_name ( struct libinput_device device)

The descriptive device name as advertised by the kernel and/or the hardware itself.

To get the sysname for this device, use libinput_device_get_sysname().

The lifetime of the returned string is tied to the struct libinput_device. The string may be the empty string but is never NULL.

Parameters
deviceA previously obtained device
Returns
The device name

◆ libinput_device_get_output_name()

const char* libinput_device_get_output_name ( struct libinput_device device)

A device may be mapped to a single output, or all available outputs.

If a device is mapped to a single output only, a relative device may not move beyond the boundaries of this output. An absolute device has its input coordinates mapped to the extents of this output.

Note
Use of this function is discouraged. Its return value is not precisely defined and may not be understood by the caller or may be insufficient to map the device. Instead, the system configuration could set a udev property the caller understands and interprets correctly. The caller could then obtain device with libinput_device_get_udev_device() and query it for this property. For more complex cases, the caller must implement monitor-to-device association heuristics.
Returns
The name of the output this device is mapped to, or NULL if no output is set

◆ libinput_device_get_seat()

struct libinput_seat* libinput_device_get_seat ( struct libinput_device device)

Get the seat associated with this input device, see Seats for details.

A seat can be uniquely identified by the physical and logical seat name. There will ever be only one seat instance with a given physical and logical seat name pair at any given time, but if no external reference is kept, it may be destroyed if no device belonging to it is left.

The returned seat is not refcounted and may become invalid after the next call to libinput. Use libinput_seat_ref() and libinput_seat_unref() to continue using the handle outside of the immediate scope.

Parameters
deviceA previously obtained device
Returns
The seat this input device belongs to

◆ libinput_device_get_size()

int libinput_device_get_size ( struct libinput_device device,
double *  width,
double *  height 
)

Get the physical size of a device in mm, where meaningful.

This function only succeeds on devices with the required data, i.e. tablets, touchpads and touchscreens.

If this function returns nonzero, width and height are unmodified.

Parameters
deviceThe device
widthSet to the width of the device
heightSet to the height of the device
Returns
0 on success, or nonzero otherwise

◆ libinput_device_get_sysname()

const char* libinput_device_get_sysname ( struct libinput_device device)

Get the system name of the device.

To get the descriptive device name, use libinput_device_get_name().

Parameters
deviceA previously obtained device
Returns
System name of the device

◆ libinput_device_get_udev_device()

struct udev_device* libinput_device_get_udev_device ( struct libinput_device device)

Return a udev handle to the device that is this libinput device, if any.

The returned handle has a refcount of at least 1, the caller must call udev_device_unref() once to release the associated resources. See the libudev documentation for details.

Some devices may not have a udev device, or the udev device may be unobtainable. This function returns NULL if no udev device was available.

Calling this function multiple times for the same device may not return the same udev handle each time.

Parameters
deviceA previously obtained device
Returns
A udev handle to the device with a refcount of >= 1 or NULL.
Return values
NULLThis device is not represented by a udev device

◆ libinput_device_get_user_data()

void* libinput_device_get_user_data ( struct libinput_device device)

Get the caller-specific data associated with this input device, if any.

Parameters
deviceA previously obtained device
Returns
Caller-specific data pointer or NULL if none was set
See also
libinput_device_set_user_data

◆ libinput_device_group_get_user_data()

void* libinput_device_group_get_user_data ( struct libinput_device_group group)

Get the caller-specific data associated with this input device group, if any.

Parameters
groupA previously obtained group
Returns
Caller-specific data pointer or NULL if none was set
See also
libinput_device_group_set_user_data

◆ libinput_device_group_ref()

struct libinput_device_group* libinput_device_group_ref ( struct libinput_device_group group)

Increase the refcount of the device group.

A device group will be freed whenever the refcount reaches 0. This may happen during libinput_dispatch() if all devices of this group were removed from the system. A caller must ensure to reference the device group correctly to avoid dangling pointers.

Parameters
groupA previously obtained device group
Returns
The passed device group

◆ libinput_device_group_set_user_data()

void libinput_device_group_set_user_data ( struct libinput_device_group group,
void *  user_data 
)

Set caller-specific data associated with this device group.

libinput does not manage, look at, or modify this data. The caller must ensure the data is valid.

Parameters
groupA previously obtained device group
user_dataCaller-specific data pointer
See also
libinput_device_group_get_user_data

◆ libinput_device_group_unref()

struct libinput_device_group* libinput_device_group_unref ( struct libinput_device_group group)

Decrease the refcount of the device group.

A device group will be freed whenever the refcount reaches 0. This may happen during libinput_dispatch() if all devices of this group were removed from the system. A caller must ensure to reference the device group correctly to avoid dangling pointers.

Parameters
groupA previously obtained device group
Returns
NULL if the device group was destroyed, otherwise the passed device group

◆ libinput_device_has_capability()

int libinput_device_has_capability ( struct libinput_device device,
enum libinput_device_capability  capability 
)

Check if the given device has the specified capability.

Returns
Non-zero if the given device has the capability or zero otherwise

◆ libinput_device_keyboard_has_key()

int libinput_device_keyboard_has_key ( struct libinput_device device,
uint32_t  code 
)

Check if a LIBINPUT_DEVICE_CAP_KEYBOARD device has a key with the given code (see linux/input.h).

Parameters
deviceA current input device
codeKey code to check for, e.g. KEY_ESC
Returns
1 if the device supports this key code, 0 if it does not, -1 on error.

◆ libinput_device_led_update()

void libinput_device_led_update ( struct libinput_device device,
enum libinput_led  leds 
)

Update the LEDs on the device, if any.

If the device does not have LEDs, or does not have one or more of the LEDs given in the mask, this function does nothing.

Parameters
deviceA previously obtained device
ledsA mask of the LEDs to set, or unset.

◆ libinput_device_pointer_has_button()

int libinput_device_pointer_has_button ( struct libinput_device device,
uint32_t  code 
)

Check if a LIBINPUT_DEVICE_CAP_POINTER device has a button with the given code (see linux/input.h).

Parameters
deviceA current input device
codeButton code to check for, e.g. BTN_LEFT
Returns
1 if the device supports this button code, 0 if it does not, -1 on error.

◆ libinput_device_ref()

struct libinput_device* libinput_device_ref ( struct libinput_device device)

Increase the refcount of the input device.

An input device will be freed whenever the refcount reaches 0. This may happen during libinput_dispatch() if the device was removed from the system. A caller must ensure to reference the device correctly to avoid dangling pointers.

Parameters
deviceA previously obtained device
Returns
The passed device

◆ libinput_device_set_seat_logical_name()

int libinput_device_set_seat_logical_name ( struct libinput_device device,
const char *  name 
)

Change the logical seat associated with this device by removing the device and adding it to the new seat.

This command is identical to physically unplugging the device, then re-plugging it as a member of the new seat. libinput will generate a LIBINPUT_EVENT_DEVICE_REMOVED event and this libinput_device is considered removed from the context; it will not generate further events and will be freed when the refcount reaches zero. A LIBINPUT_EVENT_DEVICE_ADDED event is generated with a new libinput_device handle. It is the caller's responsibility to update references to the new device accordingly.

If the logical seat name already exists in the device's physical seat, the device is added to this seat. Otherwise, a new seat is created.

Note
This change applies to this device until removal or libinput_suspend(), whichever happens earlier.
Parameters
deviceA previously obtained device
nameThe new logical seat name
Returns
0 on success, non-zero on error

◆ libinput_device_set_user_data()

void libinput_device_set_user_data ( struct libinput_device device,
void *  user_data 
)

Set caller-specific data associated with this input device.

libinput does not manage, look at, or modify this data. The caller must ensure the data is valid.

Parameters
deviceA previously obtained device
user_dataCaller-specific data pointer
See also
libinput_device_get_user_data

◆ libinput_device_switch_has_switch()

int libinput_device_switch_has_switch ( struct libinput_device device,
enum libinput_switch  sw 
)

Check if a LIBINPUT_DEVICE_CAP_SWITCH device has a switch of the given type.

Parameters
deviceA current input device
swSwitch to check for
Returns
1 if the device supports this switch, 0 if it does not, -1 on error.

◆ libinput_device_tablet_pad_get_num_buttons()

int libinput_device_tablet_pad_get_num_buttons ( struct libinput_device device)

Return the number of buttons on a device with the LIBINPUT_DEVICE_CAP_TABLET_PAD capability.

Buttons on a pad device are numbered sequentially, see Tablet pad button numbers for details.

Parameters
deviceA current input device
Returns
The number of buttons supported by the device.

◆ libinput_device_tablet_pad_get_num_rings()

int libinput_device_tablet_pad_get_num_rings ( struct libinput_device device)

Return the number of rings a device with the LIBINPUT_DEVICE_CAP_TABLET_PAD capability provides.

Parameters
deviceA current input device
Returns
The number of rings or 0 if the device has no rings.
See also
libinput_event_tablet_pad_get_ring_number

◆ libinput_device_tablet_pad_get_num_strips()

int libinput_device_tablet_pad_get_num_strips ( struct libinput_device device)

Return the number of strips a device with the LIBINPUT_DEVICE_CAP_TABLET_PAD capability provides.

Parameters
deviceA current input device
Returns
The number of strips or 0 if the device has no strips.
See also
libinput_event_tablet_pad_get_strip_number

◆ libinput_device_touch_get_touch_count()

int libinput_device_touch_get_touch_count ( struct libinput_device device)

Check how many touches a LIBINPUT_DEVICE_CAP_TOUCH device supports simultaneously.

Parameters
deviceA current input device
Returns
The number of simultaneous touches or 0 if unknown, -1 on error.

◆ libinput_device_unref()

struct libinput_device* libinput_device_unref ( struct libinput_device device)

Decrease the refcount of the input device.

An input device will be freed whenever the refcount reaches 0. This may happen during libinput_dispatch if the device was removed from the system. A caller must ensure to reference the device correctly to avoid dangling pointers.

Parameters
deviceA previously obtained device
Returns
NULL if the device was destroyed, otherwise the passed device