[PATCH wayland-protocols] unstable: add xdg-primary-selection protocol
Carlos Garnacho
carlosg at gnome.org
Thu Aug 16 17:09:00 UTC 2018
On Thu, Aug 16, 2018 at 4:46 PM, Jonas Ådahl <jadahl at gmail.com> wrote:
> 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.
Making merits for my "captain obvious" award, I'll point out the 'd'
in xdg stands for "desktop" :). If we aim 'xdg' to be a form
factor-agnostic set of standards, I would say that even window
management is a bit of a stretch... Certainly not something you
usually see in tablets or mobile.
But times surely change, so I don't say we must attain to the original
meaning, AFAIR the 'x' was already switched to 'cross' at some point.
>
> 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).
That is my line of thought, although I kind of agree this is being a
"historical artifact". This is about having heterogeneous clients have
a lingua franca. I ultimately think the prefix is least relevant for
that goal, the wayland-protocols blessing should be enough :)
>
> 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?
I guess we are less likely to regret it in 10 years time if it's wp,
but just because it's such a big bucket :). But I see some pain going
that way with the xdg rubberstamp... the amount of form factors is not
going to decrease, anything can potentially get a bad idea in
retrospective if we aim for the lowest common denominator.
Or maybe should we acknowledge form-factor variety in xdg, so eg. a VR
headset protocol could be "xdg" just as we have xdg-shell for
desktop-style window management?
Cheers,
Carlos
>
>
> 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
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