5c4272b8e9
Currently, there's no means for the DnD origin to know whether the
destination is actually finished with the DnD transaction, short of
finalizing it after the first transfer finishes, or leaking it forever.
But this poses other interoperation problems, drag destinations might
be requesting several mimetypes at once, might be just poking to find
out the most suitable format, might want to defer the action to a popup,
might be poking contents early before the selection was dropped...
In addition, data_source.cancelled is suitable for the situations where
the DnD operation fails (not on a drop target, no matching mimetypes,
etc..), but seems undocumented for that use (and unused in weston's DnD).
In order to improve the situation, the drag source should be notified
of all stages of DnD. In addition to documenting the "cancelled" event
for DnD purposes, The following 2 events have been added:
- wl_data_source.dnd_drop_performed: Happens when the operation has been
physically finished (eg. the button is released), it could be the right
place to reset the pointer cursor back and undo any other state resulting
from the initial button press.
- wl_data_source.dnd_finished: Happens when the destination side destroys
the wl_data_offer, at this point the source can just forget all data
related to the DnD selection as well, plus optionally deleting the data
on move operations.
Changes since v6:
- Turned wl_data_offer.finish calls with 0/NULL state/mimetype an
error, made it explicit that it will only result in
wl_data_offer.dnd_finished being sent if successful.
Changes since v5:
- Further rewording of wl_data_offer.finish and wl_data_offer.accept.
Added error for untimely wl_data_offer.finish requests.
Changes since v4:
- Applied rewording suggestions from Jonas Ådahl. Added new
wl_data_offer.finish request to allow explicit finalization on the
destination side.
Changes since v3:
- Renamed dnd_performed to a more descriptive dnd_drop_performed,
documented backwards compatible behavior on wl_data_offer.accept and
wl_data_source.cancelled.
Changes since v2:
- Minor rewording.
Changes since v1:
- Renamed events to have a common "dnd" namespace. Made dnd_performed to
happen invariably, data_device.cancelled may still happen afterwards.
Signed-off-by: Carlos Garnacho <carlosg@gnome.org>
Reviewed-by: Michael Catanzaro <mcatanzaro@igalia.com>
Reviewed-by: Jonas Ådahl <jadahl@gmail.com>
Reviewed-by: Mike Blumenkrantz <zmike@samsung.com>
Reviewed-by: Bryce Harrington <bryce@osg.samsung.com>
|
||
|---|---|---|
| cursor | ||
| doc | ||
| m4 | ||
| protocol | ||
| spec | ||
| src | ||
| tests | ||
| .gitignore | ||
| autogen.sh | ||
| configure.ac | ||
| COPYING | ||
| Makefile.am | ||
| publish-doc | ||
| README | ||
| TODO | ||
| wayland-scanner.m4 | ||
| wayland-scanner.mk | ||
What is Wayland?
Wayland is a project to define a protocol for a compositor to talk to
its clients as well as a library implementation of the protocol. The
compositor can be a standalone display server running on Linux kernel
modesetting and evdev input devices, an X application, or a wayland
client itself. The clients can be traditional applications, X servers
(rootless or fullscreen) or other display servers.
The wayland protocol is essentially only about input handling and
buffer management. The compositor receives input events and forwards
them to the relevant client. The clients creates buffers and renders
into them and notifies the compositor when it needs to redraw. The
protocol also handles drag and drop, selections, window management and
other interactions that must go through the compositor. However, the
protocol does not handle rendering, which is one of the features that
makes wayland so simple. All clients are expected to handle rendering
themselves, typically through cairo or OpenGL.
The weston compositor is a reference implementation of a wayland
compositor and the weston repository also includes a few example
clients.
Building the wayland libraries is fairly simple, aside from libffi,
they don't have many dependencies:
$ git clone git://anongit.freedesktop.org/wayland/wayland
$ cd wayland
$ ./autogen.sh --prefix=PREFIX
$ make
$ make install
where PREFIX is where you want to install the libraries. See
http://wayland.freedesktop.org for more complete build instructions
for wayland, weston, xwayland and various toolkits.