--- name: "wayland_server_data_device_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_data_device_t" --- # wayland\_server\_data\_device\_t(3) data transfer device ## NAME wayland::server::data\_device\_t - data transfer device ## SYNOPSIS `#include ` Inherits wayland::server::resource\_t. ### Public Member Functions std::function\< void(**data\_source\_t**, **surface\_t**, **surface\_t**, uint32\_t)\> & **on\_start\_drag** ()\ start drag-and-drop operation std::function\< void(**data\_source\_t**, uint32\_t)\> & **on\_set\_selection** ()\ copy data to the selection std::function\< void()\> & **on\_release** ()\ destroy data device void **data\_offer** (bool post=true)\ introduce a new wl\_data\_offer void **enter** (uint32\_t serial, **surface\_t** const &surface, double x, double y, **data\_offer\_t** const &id, bool post=true)\ initiate drag-and-drop session void **leave** (bool post=true)\ end drag-and-drop session void **motion** (uint32\_t time, double x, double y, bool post=true)\ drag-and-drop session motion void **drop** (bool post=true)\ end drag-and-drop session successfully void **selection** (**data\_offer\_t** const &id, bool post=true)\ advertise new selection void **post\_role** (std::string const &msg)\ Post error: given wl\_surface has another role. 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 **data\_offer\_since\_version** = 1\ Minimum protocol version required for the **data\_offer** function. static constexpr std::uint32\_t **enter\_since\_version** = 1\ Minimum protocol version required for the **enter** function. static constexpr std::uint32\_t **leave\_since\_version** = 1\ Minimum protocol version required for the **leave** function. static constexpr std::uint32\_t **motion\_since\_version** = 1\ Minimum protocol version required for the **motion** function. static constexpr std::uint32\_t **drop\_since\_version** = 1\ Minimum protocol version required for the **drop** function. static constexpr std::uint32\_t **selection\_since\_version** = 1\ Minimum protocol version required for the **selection** function. ## Detailed Description data transfer device There is one wl\_data\_device per seat which can be obtained from the global wl\_data\_device\_manager singleton. A wl\_data\_device provides access to inter-client data transfer mechanisms such as copy-and-paste and drag-and-drop. Definition at line **1333** of file **wayland-server-protocol.hpp**. ## Member Function Documentation ### void data\_device\_t::data\_offer (bool post = `true`) introduce a new wl\_data\_offer **Returns** the new data\_offer object The data\_offer event introduces a new wl\_data\_offer object, which will subsequently be used in either the data\_device.enter event (for drag-and-drop) or the data\_device.selection event (for selections). Immediately following the data\_device.data\_offer event, the new data\_offer object will send out data\_offer.offer events to describe the mime types it offers. Definition at line **2096** of file **wayland-server-protocol.cpp**. ### void data\_device\_t::drop (bool post = `true`) end drag-and-drop session successfully The event is sent when a drag-and-drop operation is ended because the implicit grab is removed. The drag-and-drop destination is expected to honor the last action received through wl\_data\_offer.action, if the resulting action is 'copy' or 'move', the destination can still perform wl\_data\_offer.receive requests, and is expected to end all transfers with a wl\_data\_offer.finish request. If the resulting action is 'ask', the action will not be considered final. The drag-and-drop destination is expected to perform one last wl\_data\_offer.set\_actions request, or wl\_data\_offer.destroy in order to cancel the operation. Definition at line **2116** of file **wayland-server-protocol.cpp**. ### void data\_device\_t::enter (uint32\_t serial, surface\_t const & surface, double x, double y, data\_offer\_t const & id, bool post = `true`) initiate drag-and-drop session **Parameters** *serial* serial number of the enter event \ *surface* client surface entered \ *x* surface-local x coordinate \ *y* surface-local y coordinate \ *id* source data\_offer object This event is sent when an active drag-and-drop pointer enters a surface owned by the client. The position of the pointer at enter time is provided by the x and y arguments, in surface-local coordinates. Definition at line **2101** 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 data\_device\_t::leave (bool post = `true`) end drag-and-drop session This event is sent when the drag-and-drop pointer leaves the surface and the session ends. The client must destroy the wl\_data\_offer introduced at enter time at this point. Definition at line **2106** of file **wayland-server-protocol.cpp**. ### void data\_device\_t::motion (uint32\_t time, double x, double y, bool post = `true`) drag-and-drop session motion **Parameters** *time* timestamp with millisecond granularity \ *x* surface-local x coordinate \ *y* surface-local y coordinate This event is sent when the drag-and-drop pointer moves within the currently focused surface. The new position of the pointer is provided by the x and y arguments, in surface-local coordinates. Definition at line **2111** of file **wayland-server-protocol.cpp**. ### std::function\< void()\> & data\_device\_t::on\_release () destroy data device This request destroys the data device. Definition at line **2090** of file **wayland-server-protocol.cpp**. ### std::function\< void(data\_source\_t, uint32\_t)\> & data\_device\_t::on\_set\_selection () copy data to the selection **Parameters** *source* data source for the selection \ *serial* serial number of the event that triggered this request This request asks the compositor to set the selection to the data from the source on behalf of the client. To unset the selection, set the source to NULL. Definition at line **2084** of file **wayland-server-protocol.cpp**. ### std::function\< void(data\_source\_t, surface\_t, surface\_t, uint32\_t)\> & data\_device\_t::on\_start\_drag () start drag-and-drop operation **Parameters** *source* data source for the eventual transfer \ *origin* surface where the drag originates \ *icon* drag-and-drop icon surface \ *serial* serial number of the implicit grab on the origin This request asks the compositor to start a drag-and-drop operation on behalf of the client. The source argument is the data source that provides the data for the eventual data transfer. If source is NULL, enter, leave and motion events are sent only to the client that initiated the drag and the client is expected to handle the data passing internally. If source is destroyed, the drag-and-drop session will be cancelled. The origin surface is the surface where the drag originates and the client must have an active implicit grab that matches the serial. The icon surface is an optional (can be NULL) surface that provides an icon to be moved around with the cursor. Initially, the top-left corner of the icon surface is placed at the cursor hotspot, but subsequent wl\_surface.attach request can move the relative position. Attach requests must be confirmed with wl\_surface.commit as usual. The icon surface is given the role of a drag-and-drop icon. If the icon surface already has another role, it raises a protocol error. The current and pending input regions of the icon wl\_surface are cleared, and wl\_surface.set\_input\_region is ignored until the wl\_surface is no longer used as the icon surface. When the use as an icon ends, the current and pending input regions become undefined, and the wl\_surface is unmapped. Definition at line **2078** 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. ### void data\_device\_t::post\_role (std::string const & msg) Post error: given wl\_surface has another role. Definition at line **2126** of file **wayland-server-protocol.cpp**. ### 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 data\_device\_t::selection (data\_offer\_t const & id, bool post = `true`) advertise new selection **Parameters** *id* selection data\_offer object The selection event is sent out to notify the client of a new wl\_data\_offer for the selection for this device. The data\_device.data\_offer and the data\_offer.offer events are sent out immediately before this event to introduce the data offer object. The selection event is sent to a client immediately before receiving keyboard focus and when a new selection is set while the client has keyboard focus. The data\_offer is valid until a new data\_offer or NULL is received or until the client loses keyboard focus. Switching surface with keyboard focus within the same client doesn't mean a new selection will be sent. The client must destroy the previous selection data\_offer, if any, upon receiving this event. Definition at line **2121** of file **wayland-server-protocol.cpp**. ## Member Data Documentation ### constexpr std::uint32\_t wayland::server::data\_device\_t::data\_offer\_since\_version = 1` [static]`, ` [constexpr]` Minimum protocol version required for the **data\_offer** function. Definition at line **1434** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::data\_device\_t::drop\_since\_version = 1` [static]`, ` [constexpr]` Minimum protocol version required for the **drop** function. Definition at line **1506** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::data\_device\_t::enter\_since\_version = 1` [static]`, ` [constexpr]` Minimum protocol version required for the **enter** function. Definition at line **1453** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::data\_device\_t::leave\_since\_version = 1` [static]`, ` [constexpr]` Minimum protocol version required for the **leave** function. Definition at line **1466** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::data\_device\_t::motion\_since\_version = 1` [static]`, ` [constexpr]` Minimum protocol version required for the **motion** function. Definition at line **1483** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::data\_device\_t::selection\_since\_version = 1` [static]`, ` [constexpr]` Minimum protocol version required for the **selection** function. Definition at line **1529** of file **wayland-server-protocol.hpp**. ## Author Generated automatically by Doxygen for Wayland++ from the source code.