wayland_pointer_t - Man Page

pointer input device

Synopsis

#include <wayland-client-protocol.hpp>

Inherits wayland::proxy_t.

Public Types

enum wrapper_type { wrapper_type::standard, wrapper_type::display, wrapper_type::foreign, wrapper_type::proxy_wrapper }

Public Member Functions

void set_cursor (uint32_t serial, surface_t const &surface, int32_t hotspot_x, int32_t hotspot_y)
set the pointer surface
void release ()
release the pointer 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, surface_t, double, double)> & on_enter ()
enter event
std::function< void(uint32_t, surface_t)> & on_leave ()
leave event
std::function< void(uint32_t, double, double)> & on_motion ()
pointer motion event
std::function< void(uint32_t, uint32_t, uint32_t, pointer_button_state)> & on_button ()
pointer button event
std::function< void(uint32_t, pointer_axis, double)> & on_axis ()
axis event
std::function< void()> & on_frame ()
end of a pointer event sequence
std::function< void(pointer_axis_source)> & on_axis_source ()
axis source event
std::function< void(uint32_t, pointer_axis)> & on_axis_stop ()
axis stop event
std::function< void(pointer_axis, int32_t)> & on_axis_discrete ()
axis click event
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 set_cursor_since_version = 1
Minimum protocol version required for the set_cursor function.
static constexpr std::uint32_t release_since_version = 3
Minimum protocol version required for the release function.

Detailed Description

pointer input device

The wl_pointer interface represents one or more input devices, such as mice, which control the pointer location and pointer_focus of a seat.

The wl_pointer interface generates motion, enter and leave events for the surfaces that the pointer is located over, and button and axis events for button presses, button releases and scrolling.

Examples egl.cpp, and shm.cpp.

Definition at line 2597 of file wayland-client-protocol.hpp.

Member Enumeration Documentation

enum 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 115 of file wayland-client.hpp.

Member Function Documentation

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 is thrown

bool pointer_t::can_release () const

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

Definition at line 2871 of file wayland-client-protocol.cpp.

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

Get the interface name (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 the object associated with the proxy

Examples dump.cpp.

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

Get the protocol object version of a proxy object. 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 that no version information is available, so the caller must 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 at line 301 of file wayland-client.hpp.

std::function< void(uint32_t, pointer_axis, double)> & pointer_t::on_axis ()

axis event

Parameters

time timestamp with millisecond granularity
axis axis type
value length of vector in surface-local coordinate space

Scroll and other axis notifications.

For scroll events (vertical and horizontal scroll axes), the value parameter is the length of a vector along the specified axis in a coordinate space identical to those of motion events, representing a relative movement along the specified axis.

For devices that support movements non-parallel to axes multiple axis events will be emitted.

When applicable, for example for touch pads, the server can choose to emit scroll events where the motion vector is equivalent to a motion event vector.

When applicable, a client can transform its content relative to the scroll distance.

Definition at line 2896 of file wayland-client-protocol.cpp.

std::function< void(pointer_axis, int32_t)> & pointer_t::on_axis_discrete ()

axis click event

Parameters

axis axis type
discrete number of steps

Discrete step information for scroll and other axes.

This event carries the axis value of the wl_pointer.axis event in discrete steps (e.g. mouse wheel clicks).

This event does not occur on its own, it is coupled with a wl_pointer.axis event that represents this axis value on a continuous scale. The protocol guarantees that each axis_discrete event is always followed by exactly one axis event with the same axis number within the same wl_pointer.frame. Note that the protocol allows for other events to occur between the axis_discrete and its coupled axis event, including other axis_discrete or axis events.

This event is optional; continuous scrolling devices like two-finger scrolling on touchpads do not have discrete steps and do not generate this event.

The discrete value carries the directional information. e.g. a value of -2 is two steps towards the negative direction of this axis.

The axis number is identical to the axis number in the associated axis event.

The order of wl_pointer.axis_discrete and wl_pointer.axis_source is not guaranteed.

Definition at line 2916 of file wayland-client-protocol.cpp.

std::function< void(pointer_axis_source)> & pointer_t::on_axis_source ()

axis source event

Parameters

axis_source source of the axis event

Source information for scroll and other axes.

This event does not occur on its own. It is sent before a wl_pointer.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 wl_pointer.axis_source.finger, a wl_pointer.axis_stop event will be sent when the user lifts the finger off the device.

If the source is wl_pointer.axis_source.wheel, wl_pointer.axis_source.wheel_tilt or wl_pointer.axis_source.continuous, a wl_pointer.axis_stop event may or may not be sent. Whether a compositor sends an axis_stop event for these sources is hardware-specific and implementation-dependent; clients must not rely on receiving an axis_stop event for these scroll sources and should treat scroll sequences from these scroll sources as unterminated by default.

This event is optional. If the source is unknown for a particular axis event sequence, no event is sent. Only one wl_pointer.axis_source event is permitted per frame.

The order of wl_pointer.axis_discrete and wl_pointer.axis_source is not guaranteed.

Definition at line 2906 of file wayland-client-protocol.cpp.

std::function< void(uint32_t, pointer_axis)> & pointer_t::on_axis_stop ()

axis stop event

Parameters

time timestamp with millisecond granularity
axis the axis stopped with this event

Stop notification for scroll and other axes.

For some wl_pointer.axis_source types, a wl_pointer.axis_stop event is sent to notify a client that the axis sequence has terminated. This enables the client to implement kinetic scrolling. See the wl_pointer.axis_source documentation for information on when this event may be generated.

Any wl_pointer.axis events with the same axis_source after this event should be considered as the start of a new axis motion.

The timestamp is to be interpreted identical to the timestamp in the wl_pointer.axis event. The timestamp value may be the same as a preceding wl_pointer.axis event.

Definition at line 2911 of file wayland-client-protocol.cpp.

std::function< void(uint32_t, uint32_t, uint32_t, pointer_button_state)> & pointer_t::on_button ()

pointer button event

Parameters

serial serial number of the button event
time timestamp with millisecond granularity
button button that produced the event
state physical state of the button

Mouse button click and release notifications.

The location of the click is given by the last motion or enter event. The time argument is a timestamp with millisecond granularity, with an undefined base.

The button is a button code as defined in the Linux kernel's linux/input-event-codes.h header file, e.g. BTN_LEFT.

Any 16-bit button code value is reserved for future additions to the kernel's event code list. All other button codes above 0xFFFF are currently undefined but may be used in future versions of this protocol.

Examples egl.cpp, and shm.cpp.

Definition at line 2891 of file wayland-client-protocol.cpp.

std::function< void(uint32_t, surface_t, double, double)> & pointer_t::on_enter ()

enter event

Parameters

serial serial number of the enter event
surface surface entered by the pointer
surface_x surface-local x coordinate
surface_y surface-local y coordinate

Notification that this seat's pointer is focused on a certain surface.

When a seat's focus enters a surface, the pointer image is undefined and a client should respond to this event by setting an appropriate pointer image with the set_cursor request.

Examples egl.cpp, and shm.cpp.

Definition at line 2876 of file wayland-client-protocol.cpp.

std::function< void()> & pointer_t::on_frame ()

end of a pointer event sequence 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.

All wl_pointer events before a wl_pointer.frame event belong logically together. For example, in a diagonal scroll motion the compositor will send an optional wl_pointer.axis_source event, two wl_pointer.axis events (horizontal and vertical) and finally a wl_pointer.frame event. The client may use this information to calculate a diagonal vector for scrolling.

When multiple wl_pointer.axis events occur within the same frame, the motion vector is the combined motion of all events. When a wl_pointer.axis and a wl_pointer.axis_stop event occur within the same frame, this indicates that axis movement in one axis has stopped but continues in the other axis. When multiple wl_pointer.axis_stop events occur within the same frame, this indicates that these axes stopped in the same instance.

A wl_pointer.frame event is sent for every logical event group, even if the group only contains a single wl_pointer event. Specifically, a client may get a sequence: motion, frame, button, frame, axis, frame, axis_stop, frame.

The wl_pointer.enter and wl_pointer.leave events are logical events generated by the compositor and not the hardware. These events are also grouped by a wl_pointer.frame. When a pointer moves from one surface to another, a compositor should group the wl_pointer.leave event within the same wl_pointer.frame. However, a client must not rely on wl_pointer.leave and wl_pointer.enter being in the same wl_pointer.frame. Compositor-specific policies may require the wl_pointer.leave and wl_pointer.enter event being split across multiple wl_pointer.frame groups.

Definition at line 2901 of file wayland-client-protocol.cpp.

std::function< void(uint32_t, surface_t)> & pointer_t::on_leave ()

leave event

Parameters

serial serial number of the leave event
surface surface left by the pointer

Notification that this seat's pointer is no longer focused on a certain surface.

The leave notification is sent before the enter notification for the new focus.

Definition at line 2881 of file wayland-client-protocol.cpp.

std::function< void(uint32_t, double, double)> & pointer_t::on_motion ()

pointer motion event

Parameters

time timestamp with millisecond granularity
surface_x surface-local x coordinate
surface_y surface-local y coordinate

Notification of pointer location change. The arguments surface_x and surface_y are the location relative to the focused surface.

Definition at line 2886 of file 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. Note that display_t instances cannot be released this way. Attempts to do so are ignored.

Examples foreign_display.cpp.

void pointer_t::release ()

release the pointer object Using this request a client can tell the server that it is not going to use the pointer object anymore.

This request destroys the pointer proxy object, so clients must not call wl_pointer_destroy() after using this request.

Definition at line 2867 of file wayland-client-protocol.cpp.

void pointer_t::set_cursor (uint32_t serial, surface_t const & surface, int32_t hotspot_x, int32_t hotspot_y)

set the pointer surface

Parameters

serial serial number of the enter event
surface pointer surface
hotspot_x surface-local x coordinate
hotspot_y surface-local y coordinate

Set the pointer surface, i.e., the surface that contains the pointer image (cursor). This request gives the surface the role of a cursor. If the surface already has another role, it raises a protocol error.

The cursor actually changes only if the pointer focus for this device is 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 pointer 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.

Examples egl.cpp, and shm.cpp.

Definition at line 2862 of file 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

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

Minimum protocol version required for the release function.

Definition at line 2686 of file wayland-client-protocol.hpp.

constexpr std::uint32_t wayland::pointer_t::set_cursor_since_version = 1 [static], [constexpr]

Minimum protocol version required for the set_cursor function.

Definition at line 2671 of file wayland-client-protocol.hpp.

Author

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Info

Wed Aug 5 2020 Version 0.2.8 Wayland++