--- name: "wayland_server_touch_t" section: "3" platform: "linux" package: "waylandpp-dev" version: "1.0.0-6+b2" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/wayland_server_touch_t" --- # wayland\_server\_touch\_t(3) touchscreen input device ## NAME wayland::server::touch\_t - touchscreen input device ## SYNOPSIS `#include ` Inherits wayland::server::resource\_t. ### Public Member Functions std::function\< void()\> & **on\_release** ()\ release the touch object void **down** (uint32\_t serial, uint32\_t time, **surface\_t** const &surface, int32\_t id, double x, double y, bool post=true)\ touch down event and beginning of a touch sequence void **up** (uint32\_t serial, uint32\_t time, int32\_t id, bool post=true)\ end of a touch event sequence void **motion** (uint32\_t time, int32\_t id, double x, double y, bool post=true)\ update of touch point coordinates void **frame** (bool post=true)\ end of touch frame event void **cancel** (bool post=true)\ touch session cancelled void **shape** (int32\_t id, double major, double minor, bool post=true)\ update shape of touch point bool **can\_shape** () const\ Check whether the **shape** function is available with the currently bound version of the protocol. void **orientation** (int32\_t id, double orientation, bool post=true)\ update orientation of touch point bool **can\_orientation** () const\ Check whether the **orientation** function is available with the currently bound version of the protocol. bool **proxy\_has\_object** () const\ Check whether this wrapper actually wraps an object. void **post\_no\_memory** () const\ uint32\_t **get\_id** () const\ client\_t **get\_client** () const\ unsigned int **get\_version** () const\ std::string **get\_class** ()\ ### Static Public Attributes static constexpr std::uint32\_t **down\_since\_version** = 1\ Minimum protocol version required for the **down** function. static constexpr std::uint32\_t **up\_since\_version** = 1\ Minimum protocol version required for the **up** function. static constexpr std::uint32\_t **motion\_since\_version** = 1\ Minimum protocol version required for the **motion** function. static constexpr std::uint32\_t **frame\_since\_version** = 1\ Minimum protocol version required for the **frame** function. static constexpr std::uint32\_t **cancel\_since\_version** = 1\ Minimum protocol version required for the **cancel** function. static constexpr std::uint32\_t **shape\_since\_version** = 6\ Minimum protocol version required for the **shape** function. static constexpr std::uint32\_t **orientation\_since\_version** = 6\ Minimum protocol version required for the **orientation** function. ## Detailed Description 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. Definition at line **3491** of file **wayland-server-protocol.hpp**. ## Member Function Documentation ### bool touch\_t::can\_orientation () const Check whether the **orientation** function is available with the currently bound version of the protocol. Definition at line **2906** of file **wayland-server-protocol.cpp**. ### bool touch\_t::can\_shape () const Check whether the **shape** function is available with the currently bound version of the protocol. Definition at line **2896** of file **wayland-server-protocol.cpp**. ### void touch\_t::cancel (bool post = `true`) 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. Definition at line **2886** of file **wayland-server-protocol.cpp**. ### void touch\_t::down (uint32\_t serial, uint32\_t time, surface\_t const & surface, int32\_t id, double x, double y, bool post = `true`) touch down event and beginning of a touch sequence **Parameters** *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 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. Definition at line **2866** of file **wayland-server-protocol.cpp**. ### void touch\_t::frame (bool post = `true`) 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. Definition at line **2881** of file **wayland-server-protocol.cpp**. ### std::string wayland::server::resource\_t::get\_class ()` [inherited]` Retrieve the interface name (class) of a resource object. **Returns** Interface name of the resource object. ### client\_t wayland::server::resource\_t::get\_client () const` [inherited]` Get the associated client **Returns** the client that owns the resource. ### uint32\_t wayland::server::resource\_t::get\_id () const` [inherited]` Get the internal ID of the resource **Returns** the internal ID of the resource ### unsigned int wayland::server::resource\_t::get\_version () const` [inherited]` Get interface version **Returns** Interface version this resource has been constructed with. ### void touch\_t::motion (uint32\_t time, int32\_t id, double x, double y, bool post = `true`) update of touch point coordinates **Parameters** *time* timestamp with millisecond granularity \ *id* the unique ID of this touch point \ *x* surface-local x coordinate \ *y* surface-local y coordinate A touch point has changed coordinates. Definition at line **2876** of file **wayland-server-protocol.cpp**. ### std::function\< void()\> & touch\_t::on\_release () release the touch object Definition at line **2860** of file **wayland-server-protocol.cpp**. ### void touch\_t::orientation (int32\_t id, double orientation, bool post = `true`) update orientation of touch point **Parameters** *id* the unique ID of this touch point \ *orientation* angle between major axis and positive surface y-axis in degrees Sent when a touchpoint has changed its orientation. This event does not occur on its own. It is sent before a wl\_touch.frame event and carries the new shape information for any previously reported, or new touch points of that frame. Other events describing the touch point such as wl\_touch.down, wl\_touch.motion or wl\_touch.shape may be sent within the same wl\_touch.frame. A client should treat these events as a single logical touch point update. The order of wl\_touch.shape, wl\_touch.orientation and wl\_touch.motion is not guaranteed. A wl\_touch.down event is guaranteed to occur before the first wl\_touch.orientation event for this touch ID but both events may occur within the same wl\_touch.frame. The orientation describes the clockwise angle of a touchpoint's major axis to the positive surface y-axis and is normalized to the -180 to +180 degree range. The granularity of orientation depends on the touch device, some devices only support binary rotation values between 0 and 90 degrees. This event is only sent by the compositor if the touch device supports orientation reports. Definition at line **2901** of file **wayland-server-protocol.cpp**. ### void wayland::server::resource\_t::post\_no\_memory () const` [inherited]` Post 'not enough memory' error to the client If the compositor has not enough memory to fulfill a certail request of the client, this function can be called to notify the client of this circumstance. ### bool wayland::server::resource\_t::proxy\_has\_object () const` [inherited]` Check whether this wrapper actually wraps an object. **Returns** true if there is an underlying object, false if this wrapper is empty ### void touch\_t::shape (int32\_t id, double major, double minor, bool post = `true`) update shape of touch point **Parameters** *id* the unique ID of this touch point \ *major* length of the major axis in surface-local coordinates \ *minor* length of the minor axis in surface-local coordinates Sent when a touchpoint has changed its shape. This event does not occur on its own. It is sent before a wl\_touch.frame event and carries the new shape information for any previously reported, or new touch points of that frame. Other events describing the touch point such as wl\_touch.down, wl\_touch.motion or wl\_touch.orientation may be sent within the same wl\_touch.frame. A client should treat these events as a single logical touch point update. The order of wl\_touch.shape, wl\_touch.orientation and wl\_touch.motion is not guaranteed. A wl\_touch.down event is guaranteed to occur before the first wl\_touch.shape event for this touch ID but both events may occur within the same wl\_touch.frame. A touchpoint shape is approximated by an ellipse through the major and minor axis length. The major axis length describes the longer diameter of the ellipse, while the minor axis length describes the shorter diameter. Major and minor are orthogonal and both are specified in surface-local coordinates. The center of the ellipse is always at the touchpoint location as reported by wl\_touch.down or wl\_touch.move. This event is only sent by the compositor if the touch device supports shape reports. The client has to make reasonable assumptions about the shape if it did not receive this event. Definition at line **2891** of file **wayland-server-protocol.cpp**. ### void touch\_t::up (uint32\_t serial, uint32\_t time, int32\_t id, bool post = `true`) end of a touch event sequence **Parameters** *serial* serial number of the touch up event \ *time* timestamp with millisecond granularity \ *id* the unique ID of this touch point 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. Definition at line **2871** of file **wayland-server-protocol.cpp**. ## Member Data Documentation ### constexpr std::uint32\_t wayland::server::touch\_t::cancel\_since\_version = 1` [static]`, ` [constexpr]` Minimum protocol version required for the **cancel** function. Definition at line **3605** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::touch\_t::down\_since\_version = 1` [static]`, ` [constexpr]` Minimum protocol version required for the **down** function. Definition at line **3540** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::touch\_t::frame\_since\_version = 1` [static]`, ` [constexpr]` Minimum protocol version required for the **frame** function. Definition at line **3589** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::touch\_t::motion\_since\_version = 1` [static]`, ` [constexpr]` Minimum protocol version required for the **motion** function. Definition at line **3571** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::touch\_t::orientation\_since\_version = 6` [static]`, ` [constexpr]` Minimum protocol version required for the **orientation** function. Definition at line **3683** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::touch\_t::shape\_since\_version = 6` [static]`, ` [constexpr]` Minimum protocol version required for the **shape** function. Definition at line **3643** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::touch\_t::up\_since\_version = 1` [static]`, ` [constexpr]` Minimum protocol version required for the **up** function. Definition at line **3556** of file **wayland-server-protocol.hpp**. ## Author Generated automatically by Doxygen for Wayland++ from the source code.