Provided by: waylandpp-dev_1.0.0-3_amd64 
NAME
wayland::data_offer_t - offer to transfer data
SYNOPSIS
#include <wayland-client-protocol.hpp>
Inherits wayland::proxy_t.
Public Types
enum class wrapper_type { standard, display, foreign, proxy_wrapper }
Public Member Functions
void accept (uint32_t serial, std::string const &mime_type)
accept one of the offered mime types
void receive (std::string const &mime_type, int fd)
request that the data is transferred
void finish ()
the offer will no longer be used
bool can_finish () const
Check whether the finish function is available with the currently bound version of the
protocol.
void set_actions (data_device_manager_dnd_action const &dnd_actions,
data_device_manager_dnd_action const &preferred_action)
set the available/preferred drag-and-drop actions
bool can_set_actions () const
Check whether the set_actions function is available with the currently bound version
of the protocol.
std::function< void(std::string)> & on_offer ()
advertise offered mime type
std::function< void(data_device_manager_dnd_action)> & on_source_actions ()
notify the source-side available actions
std::function< void(data_device_manager_dnd_action)> & on_action ()
notify the selected action
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 accept_since_version = 1
Minimum protocol version required for the accept function.
static constexpr std::uint32_t receive_since_version = 1
Minimum protocol version required for the receive function.
static constexpr std::uint32_t finish_since_version = 3
Minimum protocol version required for the finish function.
static constexpr std::uint32_t set_actions_since_version = 3
Minimum protocol version required for the set_actions function.
Detailed Description
offer to transfer data
A wl_data_offer represents a piece of data offered for transfer by another client (the
source client). It is used by the copy-and-paste and drag-and-drop mechanisms. The offer
describes the different mime types that the data can be converted to and provides the
mechanism for transferring the data directly from the source client.
Definition at line 759 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
void data_offer_t::accept (uint32_t serial, std::string const & mime_type)
accept one of the offered mime types
Parameters
serial serial number of the accept request
mime_type mime type accepted by the client
Indicate that the client can accept the given mime type, or NULL for not accepted.
For objects of version 2 or older, this request is used by the client to give feedback
whether the client can receive the given mime type, or NULL if none is accepted; the
feedback does not determine whether the drag-and-drop operation succeeds or not.
For objects of version 3 or newer, this request determines the final result of the drag-
and-drop operation. If the end result is that no mime types were accepted, the drag-and-
drop operation will be cancelled and the corresponding drag source will receive
wl_data_source.cancelled. Clients may still use this event in conjunction with
wl_data_source.action for feedback.
Definition at line 2028 of file wayland-client-protocol.cpp.
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 data_offer_t::can_finish () const
Check whether the finish function is available with the currently bound version of the
protocol.
Definition at line 2045 of file wayland-client-protocol.cpp.
bool data_offer_t::can_set_actions () const
Check whether the set_actions function is available with the currently bound version of
the protocol.
Definition at line 2056 of file wayland-client-protocol.cpp.
void data_offer_t::finish ()
the offer will no longer be used Notifies the compositor that the drag destination
successfully finished the drag-and-drop operation.
Upon receiving this request, the compositor will emit wl_data_source.dnd_finished on the
drag source client.
It is a client error to perform other requests than wl_data_offer.destroy after this one.
It is also an error to perform this request after a NULL mime type has been set in
wl_data_offer.accept or no action was received through wl_data_offer.action.
If wl_data_offer.finish request is received for a non drag and drop operation, the
invalid_finish protocol error is raised.
Definition at line 2040 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
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(data_device_manager_dnd_action)> & data_offer_t::on_action ()
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 in response to
destination side action changes through wl_data_offer.set_actions.
This event will no longer be emitted after wl_data_device.drop happened on the drag-and-
drop destination, the client must honor the last action received, or the last preferred
one set through wl_data_offer.set_actions when handling an 'ask' action.
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. Prior to receiving
wl_data_device.drop, the chosen action may change (e.g. due to keyboard modifiers being
pressed). At the time of receiving wl_data_device.drop the drag-and-drop destination must
honor the last action received.
Action changes may still happen after wl_data_device.drop, especially on 'ask' actions,
where the drag-and-drop destination may choose another action afterwards. Action changes
happening at this stage are always the result of inter-client negotiation, the compositor
shall no longer be able to induce a different action.
Upon 'ask' actions, it is expected that the drag-and-drop destination may potentially
choose a different action and/or mime type, based on wl_data_offer.source_actions and
finally chosen by the user (e.g. popping up a menu with the available options). The final
wl_data_offer.set_actions and wl_data_offer.accept requests must happen before the call to
wl_data_offer.finish.
Definition at line 2072 of file wayland-client-protocol.cpp.
std::function< void(std::string)> & data_offer_t::on_offer ()
advertise offered mime type
Parameters
mime_type offered mime type
Sent immediately after creating the wl_data_offer object. One event per offered mime type.
Definition at line 2062 of file wayland-client-protocol.cpp.
std::function< void(data_device_manager_dnd_action)> & data_offer_t::on_source_actions ()
notify the source-side available actions
Parameters
source_actions actions offered by the data source
This event indicates the actions offered by the data source. It will be sent right after
wl_data_device.enter, or anytime the source side changes its offered actions through
wl_data_source.set_actions.
Definition at line 2067 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.
void data_offer_t::receive (std::string const & mime_type, int fd)
request that the data is transferred
Parameters
mime_type mime type desired by receiver
fd file descriptor for data transfer
To transfer the offered data, the client issues this request and indicates the mime type
it wants to receive. The transfer happens through the passed file descriptor (typically
created with the pipe system call). The source client writes the data in the mime type
representation requested and then closes the file descriptor.
The receiving client reads from the read end of the pipe until EOF and then closes its
end, at which point the transfer is complete.
This request may happen multiple times for different mime types, both before and after
wl_data_device.drop. Drag-and-drop destination clients may preemptively fetch data or
examine it more closely to determine acceptance.
Definition at line 2034 of file wayland-client-protocol.cpp.
void data_offer_t::set_actions (data_device_manager_dnd_action const & dnd_actions,
data_device_manager_dnd_action const & preferred_action)
set the available/preferred drag-and-drop actions
Parameters
dnd_actions actions supported by the destination client
preferred_action action preferred by the destination client
Sets the actions that the destination side client supports for this operation. This
request may trigger the emission of wl_data_source.action and wl_data_offer.action events
if the compositor needs to change the selected action.
This request can be called multiple times throughout the drag-and-drop operation,
typically in response to wl_data_device.enter or wl_data_device.motion events.
This request determines the final result of the drag-and-drop operation. If the end result
is that no action is accepted, the drag source will receive wl_data_source.cancelled.
The dnd_actions argument must contain only values expressed in the
wl_data_device_manager.dnd_actions enum, and the preferred_action argument must only
contain one of those values set, otherwise it will result in a protocol error.
While managing an 'ask' action, the destination drag-and-drop client may perform further
wl_data_offer.receive requests, and is expected to perform one last
wl_data_offer.set_actions request with a preferred action other than 'ask' (and optionally
wl_data_offer.accept) before requesting wl_data_offer.finish, in order to convey the
action selected by the user. If the preferred action is not in the
wl_data_offer.source_actions mask, an error will be raised.
If the 'ask' action is dismissed (e.g. user cancellation), the client is expected to
perform wl_data_offer.destroy right away.
This request can only be made on drag-and-drop offers, a protocol error will be raised
otherwise.
Definition at line 2051 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().
Member Data Documentation
constexpr std::uint32_t wayland::data_offer_t::accept_since_version = 1 [static], [constexpr]
Minimum protocol version required for the accept function.
Definition at line 808 of file wayland-client-protocol.hpp.
constexpr std::uint32_t wayland::data_offer_t::finish_since_version = 3 [static], [constexpr]
Minimum protocol version required for the finish function.
Definition at line 859 of file wayland-client-protocol.hpp.
constexpr std::uint32_t wayland::data_offer_t::receive_since_version = 1 [static],
[constexpr]
Minimum protocol version required for the receive function.
Definition at line 835 of file wayland-client-protocol.hpp.
constexpr std::uint32_t wayland::data_offer_t::set_actions_since_version = 3 [static],
[constexpr]
Minimum protocol version required for the set_actions function.
Definition at line 907 of file wayland-client-protocol.hpp.
Author
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