[PATCH wayland-protocols] unstable: add xdg-primary-selection protocol
Jonas Ådahl
jadahl at gmail.com
Thu Aug 16 14:46:45 UTC 2018
On Thu, Aug 16, 2018 at 04:25:06PM +0200, Carlos Garnacho wrote:
> Hi!,
>
> Thanks Simon for moving this forward. FTR this looks good to me. Had
> some chat with Jonas on IRC about the suitability of xdg vs wp
> prefixes, but I personally think your choice is fine. Either way, this
> is
To elaborate what the discussion was about:
"xdg" shouldn't be seen as a "desktop" (device that sits on a desk)
thing, but a place to put protocols that aims to "bridge" different
environments, be they things running in devices placed on desks or in
hands.
For example, if someone plugs in a mouse to a smartphone or tablet, if
that person has the middle-click-paste function on the actual desktop
computer, I'd assume the same user would expect it also on the
not-a-desktop-computer device.
Personally I don't think clipboard really fall into this category of
desktop environment interoperability, and "primary selection" is not
really different from the regular clipboard and drag-n-drop
functionality here I think.
On the other hand, if we see clipboard as something that bridges
environments (e.g. if gtk wants to have interoperable clipboard, it
needs to use a bridging protocol), and with that in mind, primary
selection *do* fall into this category (so does regular clipboard, but
can't rename that so meh).
So, my personal opinion is that putting this inside a "xdg_" prefix is
not entirely suitable, given that this is clipboard type plumbing that
just happens to historically come from the traditional desktop Linux
usage.
Thoughts? If we ignore form factors (desktop vs hand held), where does
it fall, you think?
Jonas
>
> Acked-by: Carlos Garnacho <carlosg at gnome.org>
>
> On Sun, Jul 8, 2018 at 9:14 PM, Simon Ser <contact at emersion.fr> wrote:
> > This primary selection is similar in spirit to the eponimous
> > in X11, allowing a quick "select text + middle click" shortcut
> > to copying and pasting.
> >
> > It's otherwise very similar to its Yayland counterpart, and
> > explicitly made consistent with it.
> >
> > Signed-off-by: Simon Ser <contact at emersion.fr>
> > ---
> > This is a continuation of [1]. This protocol was pretty close to being accepted.
> >
> > I've chosen to put the xdg prefix because this primary selection is mostly relevant
> > to desktop compositors.
> >
> > I've added myself as maintainer, Carlos and Lyude let me know if you want to replace
> > me or be added to the list too.
> >
> > [1]: https://lists.freedesktop.org/archives/wayland-devel/2016-February/027101.html
> >
> > Makefile.am | 3 +-
> > unstable/xdg-primary-selection/README | 4 +
> > .../xdg-primary-selection-unstable-v1.xml | 225 ++++++++++++++++++
> > 3 files changed, 231 insertions(+), 1 deletion(-)
> > create mode 100644 unstable/xdg-primary-selection/README
> > create mode 100644 unstable/xdg-primary-selection/xdg-primary-selection-unstable-v1.xml
> >
> > diff --git a/Makefile.am b/Makefile.am
> > index 2b59d34..66a65af 100644
> > --- a/Makefile.am
> > +++ b/Makefile.am
> > @@ -19,7 +19,8 @@ unstable_protocols = \
> > unstable/keyboard-shortcuts-inhibit/keyboard-shortcuts-inhibit-unstable-v1.xml \
> > unstable/xdg-output/xdg-output-unstable-v1.xml \
> > unstable/input-timestamps/input-timestamps-unstable-v1.xml \
> > - unstable/xdg-decoration/xdg-decoration-unstable-v1.xml \
> > + unstable/xdg-decoration/xdg-decoration-unstable-v1.xml \
> > + unstable/xdg-primary-selection/xdg-primary-selection-unstable-v1.xml \
> > $(NULL)
> >
> > stable_protocols = \
> > diff --git a/unstable/xdg-primary-selection/README b/unstable/xdg-primary-selection/README
> > new file mode 100644
> > index 0000000..ae0a402
> > --- /dev/null
> > +++ b/unstable/xdg-primary-selection/README
> > @@ -0,0 +1,4 @@
> > +Primary selection protocol
> > +
> > +Maintainers:
> > +Simon Ser <contact at emersion.fr>
> > diff --git a/unstable/xdg-primary-selection/xdg-primary-selection-unstable-v1.xml b/unstable/xdg-primary-selection/xdg-primary-selection-unstable-v1.xml
> > new file mode 100644
> > index 0000000..eb97425
> > --- /dev/null
> > +++ b/unstable/xdg-primary-selection/xdg-primary-selection-unstable-v1.xml
> > @@ -0,0 +1,225 @@
> > +<?xml version="1.0" encoding="UTF-8"?>
> > +<protocol name="xdg_primary_selection_unstable_v1">
> > + <copyright>
> > + Copyright © 2015, 2016 Red Hat
> > +
> > + Permission is hereby granted, free of charge, to any person obtaining a
> > + copy of this software and associated documentation files (the "Software"),
> > + to deal in the Software without restriction, including without limitation
> > + the rights to use, copy, modify, merge, publish, distribute, sublicense,
> > + and/or sell copies of the Software, and to permit persons to whom the
> > + Software is furnished to do so, subject to the following conditions:
> > +
> > + The above copyright notice and this permission notice (including the next
> > + paragraph) shall be included in all copies or substantial portions of the
> > + Software.
> > +
> > + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> > + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> > + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> > + THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> > + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> > + FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> > + DEALINGS IN THE SOFTWARE.
> > + </copyright>
> > +
> > + <description summary="Primary selection protocol">
> > + This protocol provides the ability to have a primary selection device to
> > + match that of the X server. This primary selection is a shortcut to the
> > + common clipboard selection, where text just needs to be selected in order
> > + to allow copying it elsewhere. The de facto way to perform this action
> > + is the middle mouse button, although it is not limited to this one.
> > +
> > + Clients wishing to honor primary selection should create a primary
> > + selection source and set it as the selection through
> > + xdg_primary_selection_device.set_selection whenever the text selection
> > + changes. In order to minimize calls in pointer-driven text selection,
> > + it should happen only once after the operation finished. Similarly,
> > + a NULL source should be set when text is unselected.
> > +
> > + xdg_primary_selection_offer objects are first announced through the
> > + xdg_primary_selection_device.data_offer event. Immediately after this event,
> > + the primary data offer will emit xdg_primary_selection_offer.offer events
> > + to let know of the mime types being offered.
> > +
> > + When the primary selection changes, the client with the keyboard focus
> > + will receive xdg_primary_selection_device.selection events. Only the client
> > + with the keyboard focus will receive such events with a non-NULL
> > + xdg_primary_selection_offer. Across keyboard focus changes, previously
> > + focused clients will receive xdg_primary_selection_device.events with a
> > + NULL xdg_primary_selection_offer.
> > +
> > + In order to request the primary selection data, the client must pass
> > + a recent serial pertaining to the press event that is triggering the
> > + operation, if the compositor deems the serial valid and recent, the
> > + xdg_primary_selection_source.send event will happen in the other end
> > + to let the transfer begin. The client owning the primary selection
> > + should write the requested data, and close the file descriptor
> > + immediately.
> > +
> > + If the primary selection owner client disappeared during the transfer,
> > + the client reading the data will receive a
> > + xdg_primary_selection_device.selection event with a NULL
> > + xdg_primary_selection_offer, the client should take this as a hint
> > + to finish the reads related to the no longer existing offer.
> > +
> > + The primary selection owner should be checking for errors during
> > + writes, merely cancelling the ongoing transfer if any happened.
> > + </description>
> > +
> > + <interface name="zxdg_primary_selection_device_manager_v1" version="1">
> > + <description summary="X primary selection emulation">
> > + The primary selection device manager is a singleton global object that
> > + provides access to the primary selection. It allows to create
> > + xdg_primary_selection_source objects, as well as retrieving the per-seat
> > + xdg_primary_selection_device objects.
> > + </description>
> > +
> > + <request name="create_source">
> > + <description summary="create a new primary selection source">
> > + Create a new primary selection source.
> > + </description>
> > + <arg name="id" type="new_id" interface="zxdg_primary_selection_source_v1"/>
> > + </request>
> > +
> > + <request name="get_device">
> > + <description summary="create a new primary selection device">
> > + Create a new data device for a given seat.
> > + </description>
> > + <arg name="id" type="new_id" interface="zxdg_primary_selection_device_v1"/>
> > + <arg name="seat" type="object" interface="wl_seat"/>
> > + </request>
> > +
> > + <request name="destroy" type="destructor">
> > + <description summary="destroy the primary selection device manager">
> > + Destroy the primary selection device manager.
> > + </description>
> > + </request>
> > + </interface>
> > +
> > + <interface name="zxdg_primary_selection_device_v1" version="1">
> > + <request name="set_selection">
> > + <description summary="set the primary selection">
> > + Replaces the current selection. The previous owner of the primary selection
> > + will receive a xdg_primary_selection_source.cancelled event.
> > +
> > + To unset the selection, set the source to NULL.
> > + </description>
> > + <arg name="source" type="object" interface="zxdg_primary_selection_source_v1" allow-null="true"/>
> > + <arg name="serial" type="uint" summary="serial of the event that triggered this request"/>
> > + </request>
> > +
> > + <event name="data_offer">
> > + <description summary="introduce a new xdg_primary_selection_offer">
> > + Introduces a new xdg_primary_selection_offer object that may be used
> > + to receive the current primary selection. Immediately following this
> > + event, the new xdg_primary_selection_offer object will send
> > + xdg_primary_selection_offer.offer events to describe the offered mime
> > + types.
> > + </description>
> > + <arg name="offer" type="new_id" interface="zxdg_primary_selection_offer_v1"/>
> > + </event>
> > +
> > + <event name="selection">
> > + <description summary="advertise a new primary selection">
> > + The xdg_primary_selection_device.selection event is sent to notify the
> > + client of a new primary selection. This event is sent after the
> > + xdg_primary_selection.data_offer event introducing this object, and after
> > + the offer has announced its mimetypes through
> > + xdg_primary_selection_offer.offer.
> > +
> > + The data_offer is valid until a new offer or NULL is received
> > + or until the client loses keyboard focus. The client must destroy the
> > + previous selection data_offer, if any, upon receiving this event.
> > + </description>
> > + <arg name="id" type="object" interface="zxdg_primary_selection_offer_v1" allow-null="true"/>
> > + </event>
> > +
> > + <request name="destroy" type="destructor">
> > + <description summary="destroy the primary selection device">
> > + Destroy the primary selection device.
> > + </description>
> > + </request>
> > + </interface>
> > +
> > + <interface name="zxdg_primary_selection_offer_v1" version="1">
> > + <description summary="offer to transfer primary selection contents">
> > + A xdg_primary_selection_offer represents an offer to transfer the contents
> > + of the primary selection clipboard to the client. Similar to
> > + wl_data_offer, the offer also describes the mime types that the source
> > + will transferthat the
> > + data can be converted to and provides the mechanisms for transferring the
> > + data directly to the client.
> > + </description>
> > +
> > + <request name="receive">
> > + <description summary="request that the data is transferred">
> > + To transfer the contents of the primary selection clipboard, the client
> > + issues this request and indicates the mime type that 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
> > + closes its end, at which point the transfer is complete.
> > + </description>
> > + <arg name="mime_type" type="string"/>
> > + <arg name="fd" type="fd"/>
> > + </request>
> > +
> > + <request name="destroy" type="destructor">
> > + <description summary="destroy the primary selection offer">
> > + Destroy the primary selection offer.
> > + </description>
> > + </request>
> > +
> > + <event name="offer">
> > + <description summary="advertise offered mime type">
> > + Sent immediately after creating announcing the xdg_primary_selection_offer
> > + through xdg_primary_selection_device.data_offer. One event is sent per
> > + offered mime type.
> > + </description>
> > + <arg name="mime_type" type="string"/>
> > + </event>
> > + </interface>
> > +
> > + <interface name="zxdg_primary_selection_source_v1" version="1">
> > + <description summary="offer to replace the contents of the primary selection">
> > + The source side of a xdg_primary_selection_offer, it provides a way to
> > + describe the offered data and respond to requests to transfer the
> > + requested contents of the primary selection clipboard.
> > + </description>
> > +
> > + <request name="offer">
> > + <description summary="add an offered mime type">
> > + This request adds a mime type to the set of mime types advertised to
> > + targets. Can be called several times to offer multiple types.
> > + </description>
> > + <arg name="mime_type" type="string"/>
> > + </request>
> > +
> > + <request name="destroy" type="destructor">
> > + <description summary="destroy the primary selection source">
> > + Destroy the primary selection source.
> > + </description>
> > + </request>
> > +
> > + <event name="send">
> > + <description summary="send the primary selection contents">
> > + Request for the current primary selection contents from the client.
> > + Send the specified mime type over the passed file descriptor, then
> > + close it.
> > + </description>
> > + <arg name="mime_type" type="string"/>
> > + <arg name="fd" type="fd"/>
> > + </event>
> > +
> > + <event name="cancelled">
> > + <description summary="request for primary selection contents was canceled">
> > + This primary selection source is no longer valid. The client should
> > + clean up and destroy this primary selection source.
> > + </description>
> > + </event>
> > + </interface>
> > +</protocol>
> > --
> > 2.18.0
> >
> >
> > _______________________________________________
> > wayland-devel mailing list
> > wayland-devel at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/wayland-devel
More information about the wayland-devel
mailing list