chromium.org/unstable/text-input/text-input-extension-unstable-v1.xml

<?xml version="1.0" encoding="UTF-8"?>
<protocol name="text_input_extension_unstable_v1">

  <copyright>
    Copyright 2021 The Chromium Authors.

    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>

  <interface name="zcr_text_input_extension_v1" version="1">
    <description summary="extends text_input to support richer operations">
      Allows a text_input to sends more variation of operations to support
      richer features, such as set_preedit_region.

      Warning! The protocol described in this file is experimental and
      backward incompatible changes may be made. Backward compatible changes
      may be added together with the corresponding uinterface version bump.
      Backward incompatible changes are done by bumping the version number in
      the protocol and interface names and resetting the interface version.
      Once the protocol is to be declared stable, the 'z' prefix and the
      version number in the protocol and interface names are removed and the
      interface version number is reset.
    </description>

    <enum name="error">
      <entry name="extended_text_input_exists" value="0"
             summary="the text_input already has an extended_text_input object associated"/>
    </enum>

    <request name="get_extended_text_input">
      <description summary="get extended_text_input for a text_input">
        Create extended_text_input object.
        See zcr_extended_text_input interface for details.
        If the given text_input object already has a extended_text_input object
        associated, the extended_text_input_exists protocol error is raised.
      </description>
      <arg name="id" type="new_id" interface="zcr_extended_text_input_v1"/>
      <arg name="text_input" type="object" interface="zwp_text_input_v1"/>
    </request>
  </interface>

  <interface name="zcr_extended_text_input_v1" version="1">
    <description summary="extension of text_input protocol">
      The zcr_extended_text_input_v1 interface extends the text_input interface
      to support more rich operations on text_input.
    </description>

    <request name="destroy" type="destructor">
      <description summary="destroy extended_text_input object"/>
    </request>

    <event name="set_preedit_region">
      <description summary="set preedit from the surrounding text">
        IME requests to update text_input client to set the preedit
        from the surrounding text.

        index is the starting point of the preedit, relative to the current
        cursor position in utf-8 byte-offset.
        length is the length of the preedit region in utf-8 byte length.

        Following the convention we have in text_input::preedit_string,
        text_input::preedit_styling sent just before this will be applied.
      </description>
      <arg name="index" type="int" />
      <arg name="length" type="uint" />
    </event>

  </interface>
</protocol>