--- name: "wayland_server_data_source_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_source_t" --- # wayland\_server\_data\_source\_t(3) offer to transfer data ## NAME wayland::server::data\_source\_t - offer to transfer data ## SYNOPSIS `#include ` Inherits wayland::server::resource\_t. ### Public Member Functions std::function\< void(std::string)\> & **on\_offer** ()\ add an offered mime type std::function\< void()\> & **on\_destroy** ()\ destroy the data source std::function\< void(**data\_device\_manager\_dnd\_action**)\> & **on\_set\_actions** ()\ set the available drag-and-drop actions void **target** (std::string const &mime\_type, bool post=true)\ a target accepts an offered mime type void **send** (std::string const &mime\_type, int fd, bool post=true)\ send the data void **cancelled** (bool post=true)\ selection was cancelled void **dnd\_drop\_performed** (bool post=true)\ the drag-and-drop operation physically finished bool **can\_dnd\_drop\_performed** () const\ Check whether the **dnd\_drop\_performed** function is available with the currently bound version of the protocol. void **dnd\_finished** (bool post=true)\ the drag-and-drop operation concluded bool **can\_dnd\_finished** () const\ Check whether the **dnd\_finished** function is available with the currently bound version of the protocol. void **action** (**data\_device\_manager\_dnd\_action** const &dnd\_action, bool post=true)\ notify the selected action bool **can\_action** () const\ Check whether the **action** function is available with the currently bound version of the protocol. void **post\_invalid\_action\_mask** (std::string const &msg)\ Post error: action mask contains invalid values. void **post\_invalid\_source** (std::string const &msg)\ Post error: source doesn't accept this request. 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 **target\_since\_version** = 1\ Minimum protocol version required for the **target** function. static constexpr std::uint32\_t **send\_since\_version** = 1\ Minimum protocol version required for the **send** function. static constexpr std::uint32\_t **cancelled\_since\_version** = 1\ Minimum protocol version required for the **cancelled** function. static constexpr std::uint32\_t **dnd\_drop\_performed\_since\_version** = 3\ Minimum protocol version required for the **dnd\_drop\_performed** function. static constexpr std::uint32\_t **dnd\_finished\_since\_version** = 3\ Minimum protocol version required for the **dnd\_finished** function. static constexpr std::uint32\_t **action\_since\_version** = 3\ Minimum protocol version required for the **action** function. ## Detailed Description offer to transfer data The wl\_data\_source object is the source side of a wl\_data\_offer. It is created by the source client in a data transfer and provides a way to describe the offered data and a way to respond to requests to transfer the data. Definition at line **1089** of file **wayland-server-protocol.hpp**. ## Member Function Documentation ### void data\_source\_t::action (data\_device\_manager\_dnd\_action const & dnd\_action, bool post = `true`) notify the selected action **Parameters** *dnd\_action* action selected by the compositor This event indicates the action selected by the compositor after matching the source/destination side actions. Only one action (or none) will be offered here. This event can be emitted multiple times during the drag-and-drop operation, mainly in response to destination side changes through wl\_data\_offer.set\_actions, and as the data device enters/leaves surfaces. It is only possible to receive this event after wl\_data\_source.dnd\_drop\_performed if the drag-and-drop operation ended in an 'ask' action, in which case the final wl\_data\_source.action event will happen immediately before wl\_data\_source.dnd\_finished. Compositors may also change the selected action on the fly, mainly in response to keyboard modifier changes during the drag-and-drop operation. The most recent action received is always the valid one. The chosen action may change alongside negotiation (e.g. an 'ask' action can turn into a 'move' operation), so the effects of the final action must always be applied in wl\_data\_offer.dnd\_finished. Clients can trigger cursor surface changes from this point, so they reflect the current action. Definition at line **2020** of file **wayland-server-protocol.cpp**. ### bool data\_source\_t::can\_action () const Check whether the **action** function is available with the currently bound version of the protocol. Definition at line **2025** of file **wayland-server-protocol.cpp**. ### bool data\_source\_t::can\_dnd\_drop\_performed () const Check whether the **dnd\_drop\_performed** function is available with the currently bound version of the protocol. Definition at line **2005** of file **wayland-server-protocol.cpp**. ### bool data\_source\_t::can\_dnd\_finished () const Check whether the **dnd\_finished** function is available with the currently bound version of the protocol. Definition at line **2015** of file **wayland-server-protocol.cpp**. ### void data\_source\_t::cancelled (bool post = `true`) selection was cancelled This data source is no longer valid. There are several reasons why this could happen: - • The data source has been replaced by another data source. - • The drag-and-drop operation was performed, but the drop destination did not accept any of the mime types offered through wl\_data\_source.target. - • The drag-and-drop operation was performed, but the drop destination did not select any of the actions present in the mask offered through wl\_data\_source.action. - • The drag-and-drop operation was performed but didn't happen over a surface. - • The compositor cancelled the drag-and-drop operation (e.g. compositor dependent timeouts to avoid stale drag-and-drop transfers). The client should clean up and destroy this data source. For objects of version 2 or older, wl\_data\_source.cancelled will only be emitted if the data source was replaced by another data source. Definition at line **1995** of file **wayland-server-protocol.cpp**. ### void data\_source\_t::dnd\_drop\_performed (bool post = `true`) the drag-and-drop operation physically finished The user performed the drop action. This event does not indicate acceptance, wl\_data\_source.cancelled may still be emitted afterwards if the drop destination does not accept any mime type. However, this event might however not be received if the compositor cancelled the drag-and-drop operation before this event could happen. Note that the data\_source may still be used in the future and should not be destroyed here. Definition at line **2000** of file **wayland-server-protocol.cpp**. ### void data\_source\_t::dnd\_finished (bool post = `true`) the drag-and-drop operation concluded The drop destination finished interoperating with this data source, so the client is now free to destroy this data source and free all associated data. If the action used to perform the operation was 'move', the source can now delete the transferred data. Definition at line **2010** 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. ### std::function\< void()\> & data\_source\_t::on\_destroy () destroy the data source Destroy the data source. Definition at line **1973** of file **wayland-server-protocol.cpp**. ### std::function\< void(std::string)\> & data\_source\_t::on\_offer () add an offered mime type **Parameters** *mime\_type* mime type offered by the data source This request adds a mime type to the set of mime types advertised to targets. Can be called several times to offer multiple types. Definition at line **1967** of file **wayland-server-protocol.cpp**. ### std::function\< void(data\_device\_manager\_dnd\_action)\> & data\_source\_t::on\_set\_actions () set the available drag-and-drop actions **Parameters** *dnd\_actions* actions supported by the data source Sets the actions that the source side client supports for this operation. This request may trigger wl\_data\_source.action and wl\_data\_offer.action events if the compositor needs to change the selected action. The dnd\_actions argument must contain only values expressed in the wl\_data\_device\_manager.dnd\_actions enum, otherwise it will result in a protocol error. This request must be made once only, and can only be made on sources used in drag-and-drop, so it must be performed before wl\_data\_device.start\_drag. Attempting to use the source other than for drag-and-drop will raise a protocol error. Definition at line **1979** of file **wayland-server-protocol.cpp**. ### void data\_source\_t::post\_invalid\_action\_mask (std::string const & msg) Post error: action mask contains invalid values. Definition at line **2030** of file **wayland-server-protocol.cpp**. ### void data\_source\_t::post\_invalid\_source (std::string const & msg) Post error: source doesn't accept this request. Definition at line **2035** 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 data\_source\_t::send (std::string const & mime\_type, int fd, bool post = `true`) send the data **Parameters** *mime\_type* mime type for the data \ *fd* file descriptor for the data Request for data from the client. Send the data as the specified mime type over the passed file descriptor, then close it. Definition at line **1990** of file **wayland-server-protocol.cpp**. ### void data\_source\_t::target (std::string const & mime\_type, bool post = `true`) a target accepts an offered mime type **Parameters** *mime\_type* mime type accepted by the target Sent when a target accepts pointer\_focus or motion events. If a target does not accept any of the offered types, type is NULL. Used for feedback during drag-and-drop. Definition at line **1985** of file **wayland-server-protocol.cpp**. ## Member Data Documentation ### constexpr std::uint32\_t wayland::server::data\_source\_t::action\_since\_version = 3` [static]`, ` [constexpr]` Minimum protocol version required for the **action** function. Definition at line **1293** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::data\_source\_t::cancelled\_since\_version = 1` [static]`, ` [constexpr]` Minimum protocol version required for the **cancelled** function. Definition at line **1212** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::data\_source\_t::dnd\_drop\_performed\_since\_version = 3` [static]`, ` [constexpr]` Minimum protocol version required for the **dnd\_drop\_performed** function. Definition at line **1231** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::data\_source\_t::dnd\_finished\_since\_version = 3` [static]`, ` [constexpr]` Minimum protocol version required for the **dnd\_finished** function. Definition at line **1252** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::data\_source\_t::send\_since\_version = 1` [static]`, ` [constexpr]` Minimum protocol version required for the **send** function. Definition at line **1182** of file **wayland-server-protocol.hpp**. ### constexpr std::uint32\_t wayland::server::data\_source\_t::target\_since\_version = 1` [static]`, ` [constexpr]` Minimum protocol version required for the **target** function. Definition at line **1167** of file **wayland-server-protocol.hpp**. ## Author Generated automatically by Doxygen for Wayland++ from the source code.