wayland::touch_t(3)

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💖 wayland::touch_t(3) — Wayland++ manual, bestie edition 💖

Okay so this is wayland::touch_t(3), straight out of the Wayland++ manual, and it's literally all about a touchscreen input device. We're keeping every single detail because that's the whole vibe. 💅

🌸 NAME 🌸

wayland::touch_t — touchscreen input device. That's the name, that's the assignment, iconic.

✨ SYNOPSIS ✨

#include <wayland-client-protocol.hpp>

Inherits wayland::proxy_t. Cute inheritance moment, no cap. 🫶

🎀 Public Types 🎀

  • enum class wrapper_type { standard, display, foreign, proxy_wrapper } — the wrapper type enum, inherited from wayland::proxy_t.

🦋 Public Member Functions 🦋

  • void release () — release the touch object. bye-bye touch object 👋
  • bool can_release () const — Check whether the release function is available with the currently bound version of the protocol.
  • std::function< void(uint32_t, uint32_t, surface_t, int32_t, double, double)> & on_down () — touch down event and beginning of a touch sequence.
  • std::function< void(uint32_t, uint32_t, int32_t)> & on_up () — end of a touch event sequence.
  • std::function< void(uint32_t, int32_t, double, double)> & on_motion () — update of touch point coordinates.
  • std::function< void()> & on_frame () — end of touch frame event.
  • std::function< void()> & on_cancel () — touch session cancelled.
  • std::function< void(int32_t, double, double)> & on_shape () — update shape of touch point.
  • std::function< void(int32_t, double)> & on_orientation () — update orientation of touch point.
  • uint32_t get_id () const — Get the id of a proxy object.
  • std::string get_class () const — Get the interface name (class) of a proxy object.
  • uint32_t get_version () const — Get the protocol object version of a proxy object.
  • wrapper_type get_wrapper_type () const — Get the type of a proxy object.
  • void set_queue (event_queue_t queue) — Assign a proxy to an event queue.
  • wl_proxy * c_ptr () const — Get a pointer to the underlying C struct.
  • bool proxy_has_object () const — Check whether this wrapper actually wraps an object.
  • operator bool () const — Check whether this wrapper actually wraps an object.
  • bool operator== (const proxy_t &right) const — Check whether two wrappers refer to the same object.
  • bool operator!= (const proxy_t &right) const — Check whether two wrappers refer to different objects.
  • void proxy_release () — Release the wrapped object (if any), making this an empty wrapper.

💜 Static Public Attributes 💜

  • static constexpr std::uint32_t release_since_version = 3 — Minimum protocol version required for the release function.

🔥 Detailed Description 🔥

touchscreen input device — yes, that's the whole main character energy of this class.

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 3298 of file wayland-client-protocol.hpp.

👑 Member Enumeration Documentation 👑

🌈 enum class wayland::proxy_t::wrapper_type [strong], [inherited] 🌈

Underlying wl_proxy type and properties of a proxy_t that affect construction, destruction, and event handling.

💀 Enumerator 💀

  • standard — C pointer is a standard type compatible with wl_proxy*. Events are dispatched and it is destructed when the proxy_t is destructed. User data is set.
  • display — C pointer is a wl_display*. No events are dispatched, wl_display_disconnect is called when the proxy_t is destructed. User data is set.
  • foreign — C pointer is a standard type compatible with wl_proxy*, but another library owns it and it should not be touched in a way that could affect the operation of the other library. No events are dispatched, wl_proxy_destroy is not called when the proxy_t is destructed, user data is not touched. Consequently, there is no reference counting for the proxy_t. Lifetime of such wrappers should preferably be short to minimize the chance that the owning library decides to destroy the wl_proxy.
  • proxy_wrapper — C pointer is a wl_proxy* that was constructed with wl_proxy_create_wrapper. No events are dispatched, wl_proxy_wrapper_destroy is called when the proxy_t is destroyed. Reference counting is active. A reference to the proxy_t creating this proxy wrapper is held to extend its lifetime until after the proxy wrapper is destroyed.

Definition at line 117 of file wayland-client.hpp.

💅 Member Function Documentation 💅

Okay bestie, this is the full function roster — including the inherited proxy_t goodies mixed in. We're doing all of them, no skipping. 💖

✨ wl_proxy * wayland::proxy_t::c_ptr () const [inherited] ✨

Get a pointer to the underlying C struct.

Returns: the underlying wl_proxy wrapped by this proxy_t if it exists — otherwise an exception gets thrown. She does not do “maybe.” 😭

✨ bool touch_t::can_release () const ✨

Check whether the release function is available with the currently bound version of the protocol.

Definition lives at line 3243 of wayland-client-protocol.cpp.

✨ std::string wayland::proxy_t::get_class () const [inherited] ✨

Get the interface name — aka the class — of a proxy object.

Returns: the interface name of the object associated with the proxy.

✨ uint32_t wayland::proxy_t::get_id () const [inherited] ✨

Get the id of a proxy object.

Returns: the id of the object associated with the proxy.

✨ uint32_t wayland::proxy_t::get_version () const [inherited] ✨

Gets the protocol object version of a proxy object, or 0 if the proxy was created with unversioned API.

A returned value of 0 means no version information is available, so the caller has to make safe assumptions about the object's real version.

display_t will always return version 0.

Returns: the protocol object version of the proxy, or 0.

✨ wrapper_type wayland::proxy_t::get_wrapper_type () const [inline], [inherited] ✨

Get the type of a proxy object.

Definition lives at line 303 of wayland-client.hpp.

✨ std::function< void()> & touch_t::on_cancel () ✨

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, and future touch points on this surface may reuse the touch point ID.

Definition lives at line 3269 of wayland-client-protocol.cpp.

✨ std::function< void(uint32_t, uint32_t, surface_t, int32_t, double, double)> & touch_t::on_down () ✨

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 lives at line 3249 of wayland-client-protocol.cpp.

✨ std::function< void()> & touch_t::on_frame () ✨

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 lives at line 3264 of wayland-client-protocol.cpp.

✨ std::function< void(uint32_t, int32_t, double, double)> & touch_t::on_motion () ✨

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 lives at line 3259 of wayland-client-protocol.cpp.

✨ std::function< void(int32_t, double)> & touch_t::on_orientation () ✨

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 lives at line 3279 of wayland-client-protocol.cpp.

✨ std::function< void(int32_t, double, double)> & touch_t::on_shape () ✨

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 lives at line 3274 of wayland-client-protocol.cpp.

✨ std::function< void(uint32_t, uint32_t, int32_t)> & touch_t::on_up () ✨

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 lives at line 3254 of wayland-client-protocol.cpp.

✨ wayland::proxy_t::operator bool () const [inherited] ✨

Check whether this wrapper actually wraps an object.

Returns: true if there is an underlying object, false if this wrapper is empty.

✨ bool wayland::proxy_t::operator!= (const proxy_t & right) const [inherited] ✨

Check whether two wrappers refer to different objects.

✨ bool wayland::proxy_t::operator== (const proxy_t & right) const [inherited] ✨

Check whether two wrappers refer to the same object.

✨ bool wayland::proxy_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 wayland::proxy_t::proxy_release () [inherited] ✨

Release the wrapped object (if any), making this an empty wrapper.

Heads up, bestie: display_t instances cannot be released this way. Attempts to do so are ignored. 💀

Examples: foreign_display.cpp.

✨ void touch_t::release () ✨

Release the touch object.

Definition lives at line 3238 of wayland-client-protocol.cpp.

✨ void wayland::proxy_t::set_queue (event_queue_t queue) [inherited] ✨

Assign a proxy to an event queue.

Parameters:

  • queue — the event queue that will handle this proxy

Assign proxy to event queue. Events coming from proxy will be queued in queue instead of the display's main queue.

See also: display_t::dispatch_queue().

Examples: proxy_wrapper.cpp.

🎀 Member Data Documentation 🎀

✨ std::uint32_t wayland::touch_t::release_since_version = 3 [static], [constexpr] ✨

Minimum protocol version required for the release function.

Definition lives at line 3334 of wayland-client-protocol.hpp.

🌸 Author 🌸

Generated automatically by Doxygen for Wayland++ from the source code.

That's the whole page, bestie — version 1.0.1, dated Fri Mar 27 2026 13:15:00, and filed under wayland::touch_t(3). You ate this manual page up, no cap. 💅✨🫶

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