org.freedesktop.wayland.client

Interface WlDataOfferEventsV3

All Superinterfaces:

WlDataOfferEvents, WlDataOfferEventsV2

public interface WlDataOfferEventsV3
extends WlDataOfferEventsV2

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.

Field Summary

Fields

Modifier and Type	Field and Description
static int	VERSION

Method Summary

Modifier and Type	Method and Description
void	action(WlDataOfferProxy emitter, int dndAction) notify the selected action
void	offer(WlDataOfferProxy emitter, String mimeType) advertise offered mime type
void	sourceActions(WlDataOfferProxy emitter, int sourceActions) notify the source-side available actions

Field Detail

VERSION

static final int VERSION

See Also:

Constant Field Values

Method Detail

offer

void offer(WlDataOfferProxy emitter,
           @Nonnull
           String mimeType)

advertise offered mime type

Sent immediately after creating the wl_data_offer object. One event per offered mime type.

Specified by:

offer in interface WlDataOfferEvents

Specified by:

offer in interface WlDataOfferEventsV2

Parameters:

emitter - The protocol object that emitted the event.

mimeType - offered mime type

sourceActions

void sourceActions(WlDataOfferProxy emitter,
                   int sourceActions)

notify the source-side available actions

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.

Parameters:

emitter - The protocol object that emitted the event.

sourceActions - actions offered by the data source

action

void action(WlDataOfferProxy emitter,
            int dndAction)

notify the selected action

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.

Parameters:

emitter - The protocol object that emitted the event.

dndAction - action selected by the compositor