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1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 | <html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>Appendix A. Wayland Protocol Specification</title><link rel="stylesheet" type="text/css" href="css/default.css"><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="Wayland"><link rel="up" href="index.html" title="Wayland"><link rel="prev" href="ch04.html" title="Chapter 4. Wayland Protocol and Model of Operation"><link rel="next" href="apb.html" title="Appendix B. Client API"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Appendix A. Wayland Protocol Specification</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch04.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="apb.html">Next</a></td></tr></table><hr></div><div class="appendix"><div class="titlepage"><div><div><h1 class="title"><a name="appe-Wayland-Protocol"></a>Appendix A. Wayland Protocol Specification</h1></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl class="toc"><dt><span class="section"><a href="apa.html#protocol-spec-wl_display">wl_display
- core global object</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_registry">wl_registry
- global registry object</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_callback">wl_callback
- callback object</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_compositor">wl_compositor
- the compositor singleton</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_shm_pool">wl_shm_pool
- a shared memory pool</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_shm">wl_shm
- shared memory support</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_buffer">wl_buffer
- content for a wl_surface</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_data_offer">wl_data_offer
- offer to transfer data</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_data_source">wl_data_source
- offer to transfer data</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_data_device">wl_data_device
- data transfer device</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_data_device_manager">wl_data_device_manager
- data transfer interface</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_shell">wl_shell
- create desktop-style surfaces</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_shell_surface">wl_shell_surface
- desktop-style metadata interface</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_surface">wl_surface
- an onscreen surface</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_seat">wl_seat
- group of input devices</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_pointer">wl_pointer
- pointer input device</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_keyboard">wl_keyboard
- keyboard input device</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_touch">wl_touch
- touchscreen input device</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_output">wl_output
- compositor output region</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_region">wl_region
- region interface</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_subcompositor">wl_subcompositor
- sub-surface compositing</a></span></dt><dt><span class="section"><a href="apa.html#protocol-spec-wl_subsurface">wl_subsurface
- sub-surface interface to a wl_surface</a></span></dt></dl></div><p>
</p><div class="literallayout"><p><br>
    Copyright © 2008-2011 Kristian Høgsberg<br>
    Copyright © 2010-2011 Intel Corporation<br>
    Copyright © 2012-2013 Collabora, Ltd.<br>
<br>
    Permission is hereby granted, free of charge, to any person<br>
    obtaining a copy of this software and associated documentation files<br>
    (the "Software"), to deal in the Software without restriction,<br>
    including without limitation the rights to use, copy, modify, merge,<br>
    publish, distribute, sublicense, and/or sell copies of the Software,<br>
    and to permit persons to whom the Software is furnished to do so,<br>
    subject to the following conditions:<br>
<br>
    The above copyright notice and this permission notice (including the<br>
    next paragraph) shall be included in all copies or substantial<br>
    portions of the Software.<br>
<br>
    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,<br>
    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF<br>
    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND<br>
    NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS<br>
    BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN<br>
    ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN<br>
    CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE<br>
    SOFTWARE.<br>
  </p></div><p>
</p><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_display"></a>wl_display
- core global object</h2></div></div></div><p>
The core global object. This is a special singleton object. It
is used for internal Wayland protocol features.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp63403104"></a>Requests provided by wl_display</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_display-request-sync"></a>wl_display::sync
- asynchronous roundtrip</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">callback</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_callback" title="wl_callback - callback object">wl_callback</a></dd></dl></div><p>
</p><p>
The sync request asks the server to emit the 'done' event
on the returned wl_callback object. Since requests are
handled in-order and events are delivered in-order, this can
be used as a barrier to ensure all previous requests and the
resulting events have been handled.</p><p> The object returned by this request will be destroyed by the
compositor after the callback is fired and as such the client must not
attempt to use it after that point.</p><p> The callback_data passed in the callback is the event serial.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_display-request-get_registry"></a>wl_display::get_registry
- get global registry object</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">registry</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_registry" title="wl_registry - global registry object">wl_registry</a></dd></dl></div><p>
</p><p>
This request creates a registry object that allows the client
to list and bind the global objects available from the
compositor.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp63813552"></a>Events provided by wl_display</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_display-event-error"></a>wl_display::error
- fatal error event</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">object_id</span></dt><dd>object</dd><dt><span class="term">code</span></dt><dd>uint</dd><dt><span class="term">message</span></dt><dd>string</dd></dl></div><p>
</p><p>
The error event is sent out when a fatal (non-recoverable)
error has occurred. The object_id argument is the object
where the error occurred, most often in response to a request
to that object. The code identifies the error and is defined
by the object interface. As such, each interface defines its
own set of error codes. The message is an brief description
of the error, for (debugging) convenience.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_display-event-delete_id"></a>wl_display::delete_id
- acknowledge object ID deletion</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">id</span></dt><dd>uint</dd></dl></div><p>
</p><p>
This event is used internally by the object ID management
logic. When a client deletes an object, the server will send
this event to acknowledge that it has seen the delete request.
When the client receive this event, it will know that it can
safely reuse the object ID.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp62015920"></a>Enums provided by wl_display</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_display-enum-error"></a>wl_display::error
- global error values</h4></div></div></div><p>
These errors are global and can be emitted in response to any
server request.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">invalid_object</span></dt><dd>0
- server couldn't find object</dd><dt><span class="term">invalid_method</span></dt><dd>1
- method doesn't exist on the specified interface</dd><dt><span class="term">no_memory</span></dt><dd>2
- server is out of memory</dd></dl></div></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_registry"></a>wl_registry
- global registry object</h2></div></div></div><p>
The global registry object. The server has a number of global
objects that are available to all clients. These objects
typically represent an actual object in the server (for example,
an input device) or they are singleton objects that provide
extension functionality.</p><p> When a client creates a registry object, the registry object
will emit a global event for each global currently in the
registry. Globals come and go as a result of device or
monitor hotplugs, reconfiguration or other events, and the
registry will send out global and global_remove events to
keep the client up to date with the changes. To mark the end
of the initial burst of events, the client can use the
wl_display.sync request immediately after calling
wl_display.get_registry.</p><p> A client can bind to a global object by using the bind
request. This creates a client-side handle that lets the object
emit events to the client and lets the client invoke requests on
the object.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp59377632"></a>Requests provided by wl_registry</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_registry-request-bind"></a>wl_registry::bind
- bind an object to the display</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">name</span></dt><dd>uint
- unique name for the object</dd><dt><span class="term">id</span></dt><dd>new_id</dd></dl></div><p>
</p><p>
Binds a new, client-created object to the server using the
specified name as the identifier.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp60621600"></a>Events provided by wl_registry</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_registry-event-global"></a>wl_registry::global
- announce global object</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">name</span></dt><dd>uint</dd><dt><span class="term">interface</span></dt><dd>string</dd><dt><span class="term">version</span></dt><dd>uint</dd></dl></div><p>
</p><p>
Notify the client of global objects.</p><p> The event notifies the client that a global object with
the given name is now available, and it implements the
given version of the given interface.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_registry-event-global_remove"></a>wl_registry::global_remove
- announce removal of global object</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">name</span></dt><dd>uint</dd></dl></div><p>
</p><p>
Notify the client of removed global objects.</p><p> This event notifies the client that the global identified
by name is no longer available. If the client bound to
the global using the bind request, the client should now
destroy that object.</p><p> The object remains valid and requests to the object will be
ignored until the client destroys it, to avoid races between
the global going away and a client sending a request to it.
</p></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_callback"></a>wl_callback
- callback object</h2></div></div></div><p>
Clients can handle the 'done' event to get notified when
the related request is done.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp53639408"></a>Events provided by wl_callback</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_callback-event-done"></a>wl_callback::done
- done event</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">callback_data</span></dt><dd>uint
- request-specific data for the wl_callback</dd></dl></div><p>
</p><p>
Notify the client when the related request is done.
</p></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_compositor"></a>wl_compositor
- the compositor singleton</h2></div></div></div><p>
A compositor. This object is a singleton global. The
compositor is in charge of combining the contents of multiple
surfaces into one displayable output.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp53646496"></a>Requests provided by wl_compositor</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_compositor-request-create_surface"></a>wl_compositor::create_surface
- create new surface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">id</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a></dd></dl></div><p>
</p><p>
Ask the compositor to create a new surface.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_compositor-request-create_region"></a>wl_compositor::create_region
- create new region</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">id</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_region" title="wl_region - region interface">wl_region</a></dd></dl></div><p>
</p><p>
Ask the compositor to create a new region.
</p></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_shm_pool"></a>wl_shm_pool
- a shared memory pool</h2></div></div></div><p>
The wl_shm_pool object encapsulates a piece of memory shared
between the compositor and client. Through the wl_shm_pool
object, the client can allocate shared memory wl_buffer objects.
All objects created through the same pool share the same
underlying mapped memory. Reusing the mapped memory avoids the
setup/teardown overhead and is useful when interactively resizing
a surface or for many small buffers.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp69037248"></a>Requests provided by wl_shm_pool</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shm_pool-request-create_buffer"></a>wl_shm_pool::create_buffer
- create a buffer from the pool</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">id</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_buffer" title="wl_buffer - content for a wl_surface">wl_buffer</a></dd><dt><span class="term">offset</span></dt><dd>int</dd><dt><span class="term">width</span></dt><dd>int</dd><dt><span class="term">height</span></dt><dd>int</dd><dt><span class="term">stride</span></dt><dd>int</dd><dt><span class="term">format</span></dt><dd>uint</dd></dl></div><p>
</p><p>
Create a wl_buffer object from the pool.</p><p> The buffer is created offset bytes into the pool and has
width and height as specified. The stride arguments specifies
the number of bytes from beginning of one row to the beginning
of the next. The format is the pixel format of the buffer and
must be one of those advertised through the wl_shm.format event.</p><p> A buffer will keep a reference to the pool it was created from
so it is valid to destroy the pool immediately after creating
a buffer from it.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shm_pool-request-destroy"></a>wl_shm_pool::destroy
- destroy the pool</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Destroy the shared memory pool.</p><p> The mmapped memory will be released when all
buffers that have been created from this pool
are gone.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shm_pool-request-resize"></a>wl_shm_pool::resize
- change the size of the pool mapping</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">size</span></dt><dd>int</dd></dl></div><p>
</p><p>
This request will cause the server to remap the backing memory
for the pool from the file descriptor passed when the pool was
created, but using the new size. This request can only be
used to make the pool bigger.
</p></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_shm"></a>wl_shm
- shared memory support</h2></div></div></div><p>
A global singleton object that provides support for shared
memory.</p><p> Clients can create wl_shm_pool objects using the create_pool
request.</p><p> At connection setup time, the wl_shm object emits one or more
format events to inform clients about the valid pixel formats
that can be used for buffers.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp69063360"></a>Requests provided by wl_shm</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shm-request-create_pool"></a>wl_shm::create_pool
- create a shm pool</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">id</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_shm_pool" title="wl_shm_pool - a shared memory pool">wl_shm_pool</a></dd><dt><span class="term">fd</span></dt><dd>fd</dd><dt><span class="term">size</span></dt><dd>int</dd></dl></div><p>
</p><p>
Create a new wl_shm_pool object.</p><p> The pool can be used to create shared memory based buffer
objects. The server will mmap size bytes of the passed file
descriptor, to use as backing memory for the pool.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp69073328"></a>Events provided by wl_shm</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shm-event-format"></a>wl_shm::format
- pixel format description</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">format</span></dt><dd>uint</dd></dl></div><p>
</p><p>
Informs the client about a valid pixel format that
can be used for buffers. Known formats include
argb8888 and xrgb8888.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp69078736"></a>Enums provided by wl_shm</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shm-enum-error"></a>wl_shm::error
- wl_shm error values</h4></div></div></div><p>
These errors can be emitted in response to wl_shm requests.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">invalid_format</span></dt><dd>0
- buffer format is not known</dd><dt><span class="term">invalid_stride</span></dt><dd>1
- invalid size or stride during pool or buffer creation</dd><dt><span class="term">invalid_fd</span></dt><dd>2
- mmapping the file descriptor failed</dd></dl></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shm-enum-format"></a>wl_shm::format
- pixel formats</h4></div></div></div><p>
This describes the memory layout of an individual pixel.</p><p> All renderers should support argb8888 and xrgb8888 but any other
formats are optional and may not be supported by the particular
renderer in use.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">argb8888</span></dt><dd>0
- 32-bit ARGB format</dd><dt><span class="term">xrgb8888</span></dt><dd>1
- 32-bit RGB format</dd><dt><span class="term">c8</span></dt><dd>0x20203843</dd><dt><span class="term">rgb332</span></dt><dd>0x38424752</dd><dt><span class="term">bgr233</span></dt><dd>0x38524742</dd><dt><span class="term">xrgb4444</span></dt><dd>0x32315258</dd><dt><span class="term">xbgr4444</span></dt><dd>0x32314258</dd><dt><span class="term">rgbx4444</span></dt><dd>0x32315852</dd><dt><span class="term">bgrx4444</span></dt><dd>0x32315842</dd><dt><span class="term">argb4444</span></dt><dd>0x32315241</dd><dt><span class="term">abgr4444</span></dt><dd>0x32314241</dd><dt><span class="term">rgba4444</span></dt><dd>0x32314152</dd><dt><span class="term">bgra4444</span></dt><dd>0x32314142</dd><dt><span class="term">xrgb1555</span></dt><dd>0x35315258</dd><dt><span class="term">xbgr1555</span></dt><dd>0x35314258</dd><dt><span class="term">rgbx5551</span></dt><dd>0x35315852</dd><dt><span class="term">bgrx5551</span></dt><dd>0x35315842</dd><dt><span class="term">argb1555</span></dt><dd>0x35315241</dd><dt><span class="term">abgr1555</span></dt><dd>0x35314241</dd><dt><span class="term">rgba5551</span></dt><dd>0x35314152</dd><dt><span class="term">bgra5551</span></dt><dd>0x35314142</dd><dt><span class="term">rgb565</span></dt><dd>0x36314752</dd><dt><span class="term">bgr565</span></dt><dd>0x36314742</dd><dt><span class="term">rgb888</span></dt><dd>0x34324752</dd><dt><span class="term">bgr888</span></dt><dd>0x34324742</dd><dt><span class="term">xbgr8888</span></dt><dd>0x34324258</dd><dt><span class="term">rgbx8888</span></dt><dd>0x34325852</dd><dt><span class="term">bgrx8888</span></dt><dd>0x34325842</dd><dt><span class="term">abgr8888</span></dt><dd>0x34324241</dd><dt><span class="term">rgba8888</span></dt><dd>0x34324152</dd><dt><span class="term">bgra8888</span></dt><dd>0x34324142</dd><dt><span class="term">xrgb2101010</span></dt><dd>0x30335258</dd><dt><span class="term">xbgr2101010</span></dt><dd>0x30334258</dd><dt><span class="term">rgbx1010102</span></dt><dd>0x30335852</dd><dt><span class="term">bgrx1010102</span></dt><dd>0x30335842</dd><dt><span class="term">argb2101010</span></dt><dd>0x30335241</dd><dt><span class="term">abgr2101010</span></dt><dd>0x30334241</dd><dt><span class="term">rgba1010102</span></dt><dd>0x30334152</dd><dt><span class="term">bgra1010102</span></dt><dd>0x30334142</dd><dt><span class="term">yuyv</span></dt><dd>0x56595559</dd><dt><span class="term">yvyu</span></dt><dd>0x55595659</dd><dt><span class="term">uyvy</span></dt><dd>0x59565955</dd><dt><span class="term">vyuy</span></dt><dd>0x59555956</dd><dt><span class="term">ayuv</span></dt><dd>0x56555941</dd><dt><span class="term">nv12</span></dt><dd>0x3231564e</dd><dt><span class="term">nv21</span></dt><dd>0x3132564e</dd><dt><span class="term">nv16</span></dt><dd>0x3631564e</dd><dt><span class="term">nv61</span></dt><dd>0x3136564e</dd><dt><span class="term">yuv410</span></dt><dd>0x39565559</dd><dt><span class="term">yvu410</span></dt><dd>0x39555659</dd><dt><span class="term">yuv411</span></dt><dd>0x31315559</dd><dt><span class="term">yvu411</span></dt><dd>0x31315659</dd><dt><span class="term">yuv420</span></dt><dd>0x32315559</dd><dt><span class="term">yvu420</span></dt><dd>0x32315659</dd><dt><span class="term">yuv422</span></dt><dd>0x36315559</dd><dt><span class="term">yvu422</span></dt><dd>0x36315659</dd><dt><span class="term">yuv444</span></dt><dd>0x34325559</dd><dt><span class="term">yvu444</span></dt><dd>0x34325659</dd></dl></div></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_buffer"></a>wl_buffer
- content for a wl_surface</h2></div></div></div><p>
A buffer provides the content for a wl_surface. Buffers are
created through factory interfaces such as wl_drm, wl_shm or
similar. It has a width and a height and can be attached to a
wl_surface, but the mechanism by which a client provides and
updates the contents is defined by the buffer factory interface.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67897792"></a>Requests provided by wl_buffer</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_buffer-request-destroy"></a>wl_buffer::destroy
- destroy a buffer</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Destroy a buffer. If and how you need to release the backing
storage is defined by the buffer factory interface.</p><p> For possible side-effects to a surface, see wl_surface.attach.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67901728"></a>Events provided by wl_buffer</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_buffer-event-release"></a>wl_buffer::release
- compositor releases buffer</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Sent when this wl_buffer is no longer used by the compositor.
The client is now free to re-use or destroy this buffer and its
backing storage.</p><p> If a client receives a release event before the frame callback
requested in the same wl_surface.commit that attaches this
wl_buffer to a surface, then the client is immediately free to
re-use the buffer and its backing storage, and does not need a
second buffer for the next surface content update. Typically
this is possible, when the compositor maintains a copy of the
wl_surface contents, e.g. as a GL texture. This is an important
optimization for GL(ES) compositors with wl_shm clients.
</p></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_data_offer"></a>wl_data_offer
- offer to transfer data</h2></div></div></div><p>
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.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67908096"></a>Requests provided by wl_data_offer</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_offer-request-accept"></a>wl_data_offer::accept
- accept one of the offered mime types</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">serial</span></dt><dd>uint</dd><dt><span class="term">mime_type</span></dt><dd>string</dd></dl></div><p>
</p><p>
Indicate that the client can accept the given mime type, or
NULL for not accepted.</p><p> Used for feedback during drag-and-drop.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_offer-request-receive"></a>wl_data_offer::receive
- request that the data is transferred</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">mime_type</span></dt><dd>string</dd><dt><span class="term">fd</span></dt><dd>fd</dd></dl></div><p>
</p><p>
To transfer the offered data, the client issues this request
and indicates the mime type 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.</p><p> The receiving client reads from the read end of the pipe until
EOF and then closes its end, at which point the transfer is
complete.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_offer-request-destroy"></a>wl_data_offer::destroy
- destroy data offer</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Destroy the data offer.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67924816"></a>Events provided by wl_data_offer</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_offer-event-offer"></a>wl_data_offer::offer
- advertise offered mime type</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">mime_type</span></dt><dd>string</dd></dl></div><p>
</p><p>
Sent immediately after creating the wl_data_offer object. One
event per offered mime type.
</p></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_data_source"></a>wl_data_source
- offer to transfer data</h2></div></div></div><p>
The wl_data_source object is the source side of a wl_data_offer.
It is created by the source client in a data transfer and
provides a way to describe the offered data and a way to respond
to requests to transfer the data.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67932160"></a>Requests provided by wl_data_source</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_source-request-offer"></a>wl_data_source::offer
- add an offered mime type</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">mime_type</span></dt><dd>string</dd></dl></div><p>
</p><p>
This request adds a mime type to the set of mime types
advertised to targets. Can be called several times to offer
multiple types.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_source-request-destroy"></a>wl_data_source::destroy
- destroy the data source</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Destroy the data source.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67939856"></a>Events provided by wl_data_source</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_source-event-target"></a>wl_data_source::target
- a target accepts an offered mime type</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">mime_type</span></dt><dd>string</dd></dl></div><p>
</p><p>
Sent when a target accepts pointer_focus or motion events. If
a target does not accept any of the offered types, type is NULL.</p><p> Used for feedback during drag-and-drop.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_source-event-send"></a>wl_data_source::send
- send the data</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">mime_type</span></dt><dd>string</dd><dt><span class="term">fd</span></dt><dd>fd</dd></dl></div><p>
</p><p>
Request for data from the client. Send the data as the
specified mime type over the passed file descriptor, then
close it.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_source-event-cancelled"></a>wl_data_source::cancelled
- selection was cancelled</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
This data source has been replaced by another data source.
The client should clean up and destroy this data source.
</p></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_data_device"></a>wl_data_device
- data transfer device</h2></div></div></div><p>
There is one wl_data_device per seat which can be obtained
from the global wl_data_device_manager singleton.</p><p> A wl_data_device provides access to inter-client data transfer
mechanisms such as copy-and-paste and drag-and-drop.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67956704"></a>Requests provided by wl_data_device</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_device-request-start_drag"></a>wl_data_device::start_drag
- start drag-and-drop operation</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">source</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_data_source" title="wl_data_source - offer to transfer data">wl_data_source</a>
</dd><dt><span class="term">origin</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
</dd><dt><span class="term">icon</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
</dd><dt><span class="term">serial</span></dt><dd>uint
- serial of the implicit grab on the origin</dd></dl></div><p>
</p><p>
This request asks the compositor to start a drag-and-drop
operation on behalf of the client.</p><p> The source argument is the data source that provides the data
for the eventual data transfer. If source is NULL, enter, leave
and motion events are sent only to the client that initiated the
drag and the client is expected to handle the data passing
internally.</p><p> The origin surface is the surface where the drag originates and
the client must have an active implicit grab that matches the
serial.</p><p> The icon surface is an optional (can be NULL) surface that
provides an icon to be moved around with the cursor. Initially,
the top-left corner of the icon surface is placed at the cursor
hotspot, but subsequent wl_surface.attach request can move the
relative position. Attach requests must be confirmed with
wl_surface.commit as usual. The icon surface is given the role of
a drag-and-drop icon. If the icon surface already has another role,
it raises a protocol error.</p><p> The current and pending input regions of the icon wl_surface are
cleared, and wl_surface.set_input_region is ignored until the
wl_surface is no longer used as the icon surface. When the use
as an icon ends, the current and pending input regions become
undefined, and the wl_surface is unmapped.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_device-request-set_selection"></a>wl_data_device::set_selection
- copy data to the selection</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">source</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_data_source" title="wl_data_source - offer to transfer data">wl_data_source</a>
</dd><dt><span class="term">serial</span></dt><dd>uint
- serial of the event that triggered this request</dd></dl></div><p>
</p><p>
This request asks the compositor to set the selection
to the data from the source on behalf of the client.</p><p> To unset the selection, set the source to NULL.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_device-request-release"></a>wl_data_device::release
- destroy data device</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
This request destroys the data device.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67982240"></a>Events provided by wl_data_device</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_device-event-data_offer"></a>wl_data_device::data_offer
- introduce a new wl_data_offer</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">id</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_data_offer" title="wl_data_offer - offer to transfer data">wl_data_offer</a></dd></dl></div><p>
</p><p>
The data_offer event introduces a new wl_data_offer object,
which will subsequently be used in either the
data_device.enter event (for drag-and-drop) or the
data_device.selection event (for selections). Immediately
following the data_device_data_offer event, the new data_offer
object will send out data_offer.offer events to describe the
mime types it offers.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_device-event-enter"></a>wl_data_device::enter
- initiate drag-and-drop session</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">serial</span></dt><dd>uint</dd><dt><span class="term">surface</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
</dd><dt><span class="term">x</span></dt><dd>fixed</dd><dt><span class="term">y</span></dt><dd>fixed</dd><dt><span class="term">id</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_data_offer" title="wl_data_offer - offer to transfer data">wl_data_offer</a>
</dd></dl></div><p>
</p><p>
This event is sent when an active drag-and-drop pointer enters
a surface owned by the client. The position of the pointer at
enter time is provided by the x and y arguments, in surface
local coordinates.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_device-event-leave"></a>wl_data_device::leave
- end drag-and-drop session</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
This event is sent when the drag-and-drop pointer leaves the
surface and the session ends. The client must destroy the
wl_data_offer introduced at enter time at this point.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_device-event-motion"></a>wl_data_device::motion
- drag-and-drop session motion</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">time</span></dt><dd>uint
- timestamp with millisecond granularity</dd><dt><span class="term">x</span></dt><dd>fixed</dd><dt><span class="term">y</span></dt><dd>fixed</dd></dl></div><p>
</p><p>
This event is sent when the drag-and-drop pointer moves within
the currently focused surface. The new position of the pointer
is provided by the x and y arguments, in surface local
coordinates.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_device-event-drop"></a>wl_data_device::drop
- end drag-and-drag session successfully</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
The event is sent when a drag-and-drop operation is ended
because the implicit grab is removed.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_device-event-selection"></a>wl_data_device::selection
- advertise new selection</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">id</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_data_offer" title="wl_data_offer - offer to transfer data">wl_data_offer</a>
</dd></dl></div><p>
</p><p>
The selection event is sent out to notify the client of a new
wl_data_offer for the selection for this device. The
data_device.data_offer and the data_offer.offer events are
sent out immediately before this event to introduce the data
offer object. The selection event is sent to a client
immediately before receiving keyboard focus and when a new
selection is set while the client has keyboard focus. The
data_offer is valid until a new data_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.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp68020512"></a>Enums provided by wl_data_device</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_device-enum-error"></a>wl_data_device::error</h4></div></div></div><p></p><div class="variablelist"><dl class="variablelist"><dt><span class="term">role</span></dt><dd>0
- given wl_surface has another role</dd></dl></div></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_data_device_manager"></a>wl_data_device_manager
- data transfer interface</h2></div></div></div><p>
The wl_data_device_manager is a singleton global object that
provides access to inter-client data transfer mechanisms such as
copy-and-paste and drag-and-drop. These mechanisms are tied to
a wl_seat and this interface lets a client get a wl_data_device
corresponding to a wl_seat.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp68027152"></a>Requests provided by wl_data_device_manager</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_device_manager-request-create_data_source"></a>wl_data_device_manager::create_data_source
- create a new data source</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">id</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_data_source" title="wl_data_source - offer to transfer data">wl_data_source</a></dd></dl></div><p>
</p><p>
Create a new data source.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_data_device_manager-request-get_data_device"></a>wl_data_device_manager::get_data_device
- create a new data device</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">id</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_data_device" title="wl_data_device - data transfer device">wl_data_device</a></dd><dt><span class="term">seat</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_seat" title="wl_seat - group of input devices">wl_seat</a>
</dd></dl></div><p>
</p><p>
Create a new data device for a given seat.
</p></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_shell"></a>wl_shell
- create desktop-style surfaces</h2></div></div></div><p>
This interface is implemented by servers that provide
desktop-style user interfaces.</p><p> It allows clients to associate a wl_shell_surface with
a basic surface.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp68042704"></a>Requests provided by wl_shell</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell-request-get_shell_surface"></a>wl_shell::get_shell_surface
- create a shell surface from a surface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">id</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_shell_surface" title="wl_shell_surface - desktop-style metadata interface">wl_shell_surface</a></dd><dt><span class="term">surface</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
</dd></dl></div><p>
</p><p>
Create a shell surface for an existing surface. This gives
the wl_surface the role of a shell surface. If the wl_surface
already has another role, it raises a protocol error.</p><p> Only one shell surface can be associated with a given surface.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp68051632"></a>Enums provided by wl_shell</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell-enum-error"></a>wl_shell::error</h4></div></div></div><p></p><div class="variablelist"><dl class="variablelist"><dt><span class="term">role</span></dt><dd>0
- given wl_surface has another role</dd></dl></div></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_shell_surface"></a>wl_shell_surface
- desktop-style metadata interface</h2></div></div></div><p>
An interface that may be implemented by a wl_surface, for
implementations that provide a desktop-style user interface.</p><p> It provides requests to treat surfaces like toplevel, fullscreen
or popup windows, move, resize or maximize them, associate
metadata like title and class, etc.</p><p> On the server side the object is automatically destroyed when
the related wl_surface is destroyed. On client side,
wl_shell_surface_destroy() must be called before destroying
the wl_surface object.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp68059344"></a>Requests provided by wl_shell_surface</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-request-pong"></a>wl_shell_surface::pong
- respond to a ping event</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">serial</span></dt><dd>uint
- serial of the ping event</dd></dl></div><p>
</p><p>
A client must respond to a ping event with a pong request or
the client may be deemed unresponsive.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-request-move"></a>wl_shell_surface::move
- start an interactive move</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">seat</span></dt><dd><a class="link" href="apa.html#protocol-spec-wl_seat" title="wl_seat - group of input devices">wl_seat</a>
- the wl_seat whose pointer is used</dd><dt><span class="term">serial</span></dt><dd>uint
- serial of the implicit grab on the pointer</dd></dl></div><p>
</p><p>
Start a pointer-driven move of the surface.</p><p> This request must be used in response to a button press event.
The server may ignore move requests depending on the state of
the surface (e.g. fullscreen or maximized).
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-request-resize"></a>wl_shell_surface::resize
- start an interactive resize</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">seat</span></dt><dd><a class="link" href="apa.html#protocol-spec-wl_seat" title="wl_seat - group of input devices">wl_seat</a>
- the wl_seat whose pointer is used</dd><dt><span class="term">serial</span></dt><dd>uint
- serial of the implicit grab on the pointer</dd><dt><span class="term">edges</span></dt><dd>uint
- which edge or corner is being dragged</dd></dl></div><p>
</p><p>
Start a pointer-driven resizing of the surface.</p><p> This request must be used in response to a button press event.
The server may ignore resize requests depending on the state of
the surface (e.g. fullscreen or maximized).
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-request-set_toplevel"></a>wl_shell_surface::set_toplevel
- make the surface a toplevel surface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Map the surface as a toplevel surface.</p><p> A toplevel surface is not fullscreen, maximized or transient.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-request-set_transient"></a>wl_shell_surface::set_transient
- make the surface a transient surface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">parent</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
</dd><dt><span class="term">x</span></dt><dd>int</dd><dt><span class="term">y</span></dt><dd>int</dd><dt><span class="term">flags</span></dt><dd>uint</dd></dl></div><p>
</p><p>
Map the surface relative to an existing surface.</p><p> The x and y arguments specify the locations of the upper left
corner of the surface relative to the upper left corner of the
parent surface, in surface local coordinates.</p><p> The flags argument controls details of the transient behaviour.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-request-set_fullscreen"></a>wl_shell_surface::set_fullscreen
- make the surface a fullscreen surface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">method</span></dt><dd>uint</dd><dt><span class="term">framerate</span></dt><dd>uint</dd><dt><span class="term">output</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_output" title="wl_output - compositor output region">wl_output</a>
</dd></dl></div><p>
</p><p>
Map the surface as a fullscreen surface.</p><p> If an output parameter is given then the surface will be made
fullscreen on that output. If the client does not specify the
output then the compositor will apply its policy - usually
choosing the output on which the surface has the biggest surface
area.</p><p> The client may specify a method to resolve a size conflict
between the output size and the surface size - this is provided
through the method parameter.</p><p> The framerate parameter is used only when the method is set
to "driver", to indicate the preferred framerate. A value of 0
indicates that the app does not care about framerate. The
framerate is specified in mHz, that is framerate of 60000 is 60Hz.</p><p> A method of "scale" or "driver" implies a scaling operation of
the surface, either via a direct scaling operation or a change of
the output mode. This will override any kind of output scaling, so
that mapping a surface with a buffer size equal to the mode can
fill the screen independent of buffer_scale.</p><p> A method of "fill" means we don't scale up the buffer, however
any output scale is applied. This means that you may run into
an edge case where the application maps a buffer with the same
size of the output mode but buffer_scale 1 (thus making a
surface larger than the output). In this case it is allowed to
downscale the results to fit the screen.</p><p> The compositor must reply to this request with a configure event
with the dimensions for the output on which the surface will
be made fullscreen.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-request-set_popup"></a>wl_shell_surface::set_popup
- make the surface a popup surface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">seat</span></dt><dd><a class="link" href="apa.html#protocol-spec-wl_seat" title="wl_seat - group of input devices">wl_seat</a>
- the wl_seat whose pointer is used</dd><dt><span class="term">serial</span></dt><dd>uint
- serial of the implicit grab on the pointer</dd><dt><span class="term">parent</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
</dd><dt><span class="term">x</span></dt><dd>int</dd><dt><span class="term">y</span></dt><dd>int</dd><dt><span class="term">flags</span></dt><dd>uint</dd></dl></div><p>
</p><p>
Map the surface as a popup.</p><p> A popup surface is a transient surface with an added pointer
grab.</p><p> An existing implicit grab will be changed to owner-events mode,
and the popup grab will continue after the implicit grab ends
(i.e. releasing the mouse button does not cause the popup to
be unmapped).</p><p> The popup grab continues until the window is destroyed or a
mouse button is pressed in any other clients window. A click
in any of the clients surfaces is reported as normal, however,
clicks in other clients surfaces will be discarded and trigger
the callback.</p><p> The x and y arguments specify the locations of the upper left
corner of the surface relative to the upper left corner of the
parent surface, in surface local coordinates.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-request-set_maximized"></a>wl_shell_surface::set_maximized
- make the surface a maximized surface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">output</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_output" title="wl_output - compositor output region">wl_output</a>
</dd></dl></div><p>
</p><p>
Map the surface as a maximized surface.</p><p> If an output parameter is given then the surface will be
maximized on that output. If the client does not specify the
output then the compositor will apply its policy - usually
choosing the output on which the surface has the biggest surface
area.</p><p> The compositor will reply with a configure event telling
the expected new surface size. The operation is completed
on the next buffer attach to this surface.</p><p> A maximized surface typically fills the entire output it is
bound to, except for desktop element such as panels. This is
the main difference between a maximized shell surface and a
fullscreen shell surface.</p><p> The details depend on the compositor implementation.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-request-set_title"></a>wl_shell_surface::set_title
- set surface title</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">title</span></dt><dd>string</dd></dl></div><p>
</p><p>
Set a short title for the surface.</p><p> This string may be used to identify the surface in a task bar,
window list, or other user interface elements provided by the
compositor.</p><p> The string must be encoded in UTF-8.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-request-set_class"></a>wl_shell_surface::set_class
- set surface class</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">class_</span></dt><dd>string</dd></dl></div><p>
</p><p>
Set a class for the surface.</p><p> The surface class identifies the general class of applications
to which the surface belongs. A common convention is to use the
file name (or the full path if it is a non-standard location) of
the application's .desktop file as the class.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp64733264"></a>Events provided by wl_shell_surface</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-event-ping"></a>wl_shell_surface::ping
- ping client</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">serial</span></dt><dd>uint</dd></dl></div><p>
</p><p>
Ping a client to check if it is receiving events and sending
requests. A client is expected to reply with a pong request.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-event-configure"></a>wl_shell_surface::configure
- suggest resize</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">edges</span></dt><dd>uint</dd><dt><span class="term">width</span></dt><dd>int</dd><dt><span class="term">height</span></dt><dd>int</dd></dl></div><p>
</p><p>
The configure event asks the client to resize its surface.</p><p> The size is a hint, in the sense that the client is free to
ignore it if it doesn't resize, pick a smaller size (to
satisfy aspect ratio or resize in steps of NxM pixels).</p><p> The edges parameter provides a hint about how the surface
was resized. The client may use this information to decide
how to adjust its content to the new size (e.g. a scrolling
area might adjust its content position to leave the viewable
content unmoved).</p><p> The client is free to dismiss all but the last configure
event it received.</p><p> The width and height arguments specify the size of the window
in surface local coordinates.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-event-popup_done"></a>wl_shell_surface::popup_done
- popup interaction is done</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
The popup_done event is sent out when a popup grab is broken,
that is, when the user clicks a surface that doesn't belong
to the client owning the popup surface.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp64751168"></a>Enums provided by wl_shell_surface</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-enum-resize"></a>wl_shell_surface::resize
- edge values for resizing</h4></div></div></div><p>
These values are used to indicate which edge of a surface
is being dragged in a resize operation. The server may
use this information to adapt its behavior, e.g. choose
an appropriate cursor image.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">none</span></dt><dd>0</dd><dt><span class="term">top</span></dt><dd>1</dd><dt><span class="term">bottom</span></dt><dd>2</dd><dt><span class="term">left</span></dt><dd>4</dd><dt><span class="term">top_left</span></dt><dd>5</dd><dt><span class="term">bottom_left</span></dt><dd>6</dd><dt><span class="term">right</span></dt><dd>8</dd><dt><span class="term">top_right</span></dt><dd>9</dd><dt><span class="term">bottom_right</span></dt><dd>10</dd></dl></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-enum-transient"></a>wl_shell_surface::transient
- details of transient behaviour</h4></div></div></div><p>
These flags specify details of the expected behaviour
of transient surfaces. Used in the set_transient request.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">inactive</span></dt><dd>0x1
- do not set keyboard focus</dd></dl></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_shell_surface-enum-fullscreen_method"></a>wl_shell_surface::fullscreen_method
- different method to set the surface fullscreen</h4></div></div></div><p>
Hints to indicate to the compositor how to deal with a conflict
between the dimensions of the surface and the dimensions of the
output. The compositor is free to ignore this parameter.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">default</span></dt><dd>0
- no preference, apply default policy</dd><dt><span class="term">scale</span></dt><dd>1
- scale, preserve the surface's aspect ratio and center on output</dd><dt><span class="term">driver</span></dt><dd>2
- switch output mode to the smallest mode that can fit the surface, add black borders to compensate size mismatch</dd><dt><span class="term">fill</span></dt><dd>3
- no upscaling, center on output and add black borders to compensate size mismatch</dd></dl></div></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_surface"></a>wl_surface
- an onscreen surface</h2></div></div></div><p>
A surface is a rectangular area that is displayed on the screen.
It has a location, size and pixel contents.</p><p> The size of a surface (and relative positions on it) is described
in surface local coordinates, which may differ from the buffer
local coordinates of the pixel content, in case a buffer_transform
or a buffer_scale is used.</p><p> A surface without a "role" is fairly useless, a compositor does
not know where, when or how to present it. The role is the
purpose of a wl_surface. Examples of roles are a cursor for a
pointer (as set by wl_pointer.set_cursor), a drag icon
(wl_data_device.start_drag), a sub-surface
(wl_subcompositor.get_subsurface), and a window as defined by a
shell protocol (e.g. wl_shell.get_shell_surface).</p><p> A surface can have only one role at a time. Initially a
wl_surface does not have a role. Once a wl_surface is given a
role, it is set permanently for the whole lifetime of the
wl_surface object. Giving the current role again is allowed,
unless explicitly forbidden by the relevant interface
specification.</p><p> Surface roles are given by requests in other interfaces such as
wl_pointer.set_cursor. The request should explicitly mention
that this request gives a role to a wl_surface. Often, this
request also creates a new protocol object that represents the
role and adds additional functionality to wl_surface. When a
client wants to destroy a wl_surface, they must destroy this 'role
object' before the wl_surface.</p><p> Destroying the role object does not remove the role from the
wl_surface, but it may stop the wl_surface from "playing the role".
For instance, if a wl_subsurface object is destroyed, the wl_surface
it was created for will be unmapped and forget its position and
z-order. It is allowed to create a wl_subsurface for the same
wl_surface again, but it is not allowed to use the wl_surface as
a cursor (cursor is a different role than sub-surface, and role
switching is not allowed).
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp64789968"></a>Requests provided by wl_surface</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_surface-request-destroy"></a>wl_surface::destroy
- delete surface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Deletes the surface and invalidates its object ID.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_surface-request-attach"></a>wl_surface::attach
- set the surface contents</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">buffer</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_buffer" title="wl_buffer - content for a wl_surface">wl_buffer</a>
</dd><dt><span class="term">x</span></dt><dd>int</dd><dt><span class="term">y</span></dt><dd>int</dd></dl></div><p>
</p><p>
Set a buffer as the content of this surface.</p><p> The new size of the surface is calculated based on the buffer
size transformed by the inverse buffer_transform and the
inverse buffer_scale. This means that the supplied buffer
must be an integer multiple of the buffer_scale.</p><p> The x and y arguments specify the location of the new pending
buffer's upper left corner, relative to the current buffer's upper
left corner, in surface local coordinates. In other words, the
x and y, combined with the new surface size define in which
directions the surface's size changes.</p><p> Surface contents are double-buffered state, see wl_surface.commit.</p><p> The initial surface contents are void; there is no content.
wl_surface.attach assigns the given wl_buffer as the pending
wl_buffer. wl_surface.commit makes the pending wl_buffer the new
surface contents, and the size of the surface becomes the size
calculated from the wl_buffer, as described above. After commit,
there is no pending buffer until the next attach.</p><p> Committing a pending wl_buffer allows the compositor to read the
pixels in the wl_buffer. The compositor may access the pixels at
any time after the wl_surface.commit request. When the compositor
will not access the pixels anymore, it will send the
wl_buffer.release event. Only after receiving wl_buffer.release,
the client may re-use the wl_buffer. A wl_buffer that has been
attached and then replaced by another attach instead of committed
will not receive a release event, and is not used by the
compositor.</p><p> Destroying the wl_buffer after wl_buffer.release does not change
the surface contents. However, if the client destroys the
wl_buffer before receiving the wl_buffer.release event, the surface
contents become undefined immediately.</p><p> If wl_surface.attach is sent with a NULL wl_buffer, the
following wl_surface.commit will remove the surface content.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_surface-request-damage"></a>wl_surface::damage
- mark part of the surface damaged</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">x</span></dt><dd>int</dd><dt><span class="term">y</span></dt><dd>int</dd><dt><span class="term">width</span></dt><dd>int</dd><dt><span class="term">height</span></dt><dd>int</dd></dl></div><p>
</p><p>
This request is used to describe the regions where the pending
buffer is different from the current surface contents, and where
the surface therefore needs to be repainted. The pending buffer
must be set by wl_surface.attach before sending damage. The
compositor ignores the parts of the damage that fall outside of
the surface.</p><p> Damage is double-buffered state, see wl_surface.commit.</p><p> The damage rectangle is specified in surface local coordinates.</p><p> The initial value for pending damage is empty: no damage.
wl_surface.damage adds pending damage: the new pending damage
is the union of old pending damage and the given rectangle.</p><p> wl_surface.commit assigns pending damage as the current damage,
and clears pending damage. The server will clear the current
damage as it repaints the surface.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_surface-request-frame"></a>wl_surface::frame
- request a frame throttling hint</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">callback</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_callback" title="wl_callback - callback object">wl_callback</a></dd></dl></div><p>
</p><p>
Request a notification when it is a good time start drawing a new
frame, by creating a frame callback. This is useful for throttling
redrawing operations, and driving animations.</p><p> When a client is animating on a wl_surface, it can use the 'frame'
request to get notified when it is a good time to draw and commit the
next frame of animation. If the client commits an update earlier than
that, it is likely that some updates will not make it to the display,
and the client is wasting resources by drawing too often.</p><p> The frame request will take effect on the next wl_surface.commit.
The notification will only be posted for one frame unless
requested again. For a wl_surface, the notifications are posted in
the order the frame requests were committed.</p><p> The server must send the notifications so that a client
will not send excessive updates, while still allowing
the highest possible update rate for clients that wait for the reply
before drawing again. The server should give some time for the client
to draw and commit after sending the frame callback events to let them
hit the next output refresh.</p><p> A server should avoid signalling the frame callbacks if the
surface is not visible in any way, e.g. the surface is off-screen,
or completely obscured by other opaque surfaces.</p><p> The object returned by this request will be destroyed by the
compositor after the callback is fired and as such the client must not
attempt to use it after that point.</p><p> The callback_data passed in the callback is the current time, in
milliseconds, with an undefined base.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_surface-request-set_opaque_region"></a>wl_surface::set_opaque_region
- set opaque region</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">region</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_region" title="wl_region - region interface">wl_region</a>
</dd></dl></div><p>
</p><p>
This request sets the region of the surface that contains
opaque content.</p><p> The opaque region is an optimization hint for the compositor
that lets it optimize out redrawing of content behind opaque
regions. Setting an opaque region is not required for correct
behaviour, but marking transparent content as opaque will result
in repaint artifacts.</p><p> The opaque region is specified in surface local coordinates.</p><p> The compositor ignores the parts of the opaque region that fall
outside of the surface.</p><p> Opaque region is double-buffered state, see wl_surface.commit.</p><p> wl_surface.set_opaque_region changes the pending opaque region.
wl_surface.commit copies the pending region to the current region.
Otherwise, the pending and current regions are never changed.</p><p> The initial value for opaque region is empty. Setting the pending
opaque region has copy semantics, and the wl_region object can be
destroyed immediately. A NULL wl_region causes the pending opaque
region to be set to empty.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_surface-request-set_input_region"></a>wl_surface::set_input_region
- set input region</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">region</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_region" title="wl_region - region interface">wl_region</a>
</dd></dl></div><p>
</p><p>
This request sets the region of the surface that can receive
pointer and touch events.</p><p> Input events happening outside of this region will try the next
surface in the server surface stack. The compositor ignores the
parts of the input region that fall outside of the surface.</p><p> The input region is specified in surface local coordinates.</p><p> Input region is double-buffered state, see wl_surface.commit.</p><p> wl_surface.set_input_region changes the pending input region.
wl_surface.commit copies the pending region to the current region.
Otherwise the pending and current regions are never changed,
except cursor and icon surfaces are special cases, see
wl_pointer.set_cursor and wl_data_device.start_drag.</p><p> The initial value for input region is infinite. That means the
whole surface will accept input. Setting the pending input region
has copy semantics, and the wl_region object can be destroyed
immediately. A NULL wl_region causes the input region to be set
to infinite.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_surface-request-commit"></a>wl_surface::commit
- commit pending surface state</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Surface state (input, opaque, and damage regions, attached buffers,
etc.) is double-buffered. Protocol requests modify the pending
state, as opposed to current state in use by the compositor. Commit
request atomically applies all pending state, replacing the current
state. After commit, the new pending state is as documented for each
related request.</p><p> On commit, a pending wl_buffer is applied first, all other state
second. This means that all coordinates in double-buffered state are
relative to the new wl_buffer coming into use, except for
wl_surface.attach itself. If there is no pending wl_buffer, the
coordinates are relative to the current surface contents.</p><p> All requests that need a commit to become effective are documented
to affect double-buffered state.</p><p> Other interfaces may add further double-buffered surface state.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_surface-request-set_buffer_transform"></a>wl_surface::set_buffer_transform
- sets the buffer transformation</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">transform</span></dt><dd>int</dd></dl></div><p>
</p><p>
This request sets an optional transformation on how the compositor
interprets the contents of the buffer attached to the surface. The
accepted values for the transform parameter are the values for
wl_output.transform.</p><p> Buffer transform is double-buffered state, see wl_surface.commit.</p><p> A newly created surface has its buffer transformation set to normal.</p><p> wl_surface.set_buffer_transform changes the pending buffer
transformation. wl_surface.commit copies the pending buffer
transformation to the current one. Otherwise, the pending and current
values are never changed.</p><p> The purpose of this request is to allow clients to render content
according to the output transform, thus permiting the compositor to
use certain optimizations even if the display is rotated. Using
hardware overlays and scanning out a client buffer for fullscreen
surfaces are examples of such optimizations. Those optimizations are
highly dependent on the compositor implementation, so the use of this
request should be considered on a case-by-case basis.</p><p> Note that if the transform value includes 90 or 270 degree rotation,
the width of the buffer will become the surface height and the height
of the buffer will become the surface width.</p><p> If transform is not one of the values from the
wl_output.transform enum the invalid_transform protocol error
is raised.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_surface-request-set_buffer_scale"></a>wl_surface::set_buffer_scale
- sets the buffer scaling factor</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">scale</span></dt><dd>int</dd></dl></div><p>
</p><p>
This request sets an optional scaling factor on how the compositor
interprets the contents of the buffer attached to the window.</p><p> Buffer scale is double-buffered state, see wl_surface.commit.</p><p> A newly created surface has its buffer scale set to 1.</p><p> wl_surface.set_buffer_scale changes the pending buffer scale.
wl_surface.commit copies the pending buffer scale to the current one.
Otherwise, the pending and current values are never changed.</p><p> The purpose of this request is to allow clients to supply higher
resolution buffer data for use on high resolution outputs. Its
intended that you pick the same buffer scale as the scale of the
output that the surface is displayed on.This means the compositor
can avoid scaling when rendering the surface on that output.</p><p> Note that if the scale is larger than 1, then you have to attach
a buffer that is larger (by a factor of scale in each dimension)
than the desired surface size.</p><p> If scale is not positive the invalid_scale protocol error is
raised.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp64865408"></a>Events provided by wl_surface</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_surface-event-enter"></a>wl_surface::enter
- surface enters an output</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">output</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_output" title="wl_output - compositor output region">wl_output</a>
</dd></dl></div><p>
</p><p>
This is emitted whenever a surface's creation, movement, or resizing
results in some part of it being within the scanout region of an
output.</p><p> Note that a surface may be overlapping with zero or more outputs.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_surface-event-leave"></a>wl_surface::leave
- surface leaves an output</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">output</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_output" title="wl_output - compositor output region">wl_output</a>
</dd></dl></div><p>
</p><p>
This is emitted whenever a surface's creation, movement, or resizing
results in it no longer having any part of it within the scanout region
of an output.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp64877216"></a>Enums provided by wl_surface</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_surface-enum-error"></a>wl_surface::error
- wl_surface error values</h4></div></div></div><p>
These errors can be emitted in response to wl_surface requests.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">invalid_scale</span></dt><dd>0
- buffer scale value is invalid</dd><dt><span class="term">invalid_transform</span></dt><dd>1
- buffer transform value is invalid</dd></dl></div></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_seat"></a>wl_seat
- group of input devices</h2></div></div></div><p>
A seat is a group of keyboards, pointer and touch devices. This
object is published as a global during start up, or when such a
device is hot plugged. A seat typically has a pointer and
maintains a keyboard focus and a pointer focus.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp64885680"></a>Requests provided by wl_seat</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_seat-request-get_pointer"></a>wl_seat::get_pointer
- return pointer object</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">id</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_pointer" title="wl_pointer - pointer input device">wl_pointer</a></dd></dl></div><p>
</p><p>
The ID provided will be initialized to the wl_pointer interface
for this seat.</p><p> This request only takes effect if the seat has the pointer
capability.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_seat-request-get_keyboard"></a>wl_seat::get_keyboard
- return keyboard object</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">id</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_keyboard" title="wl_keyboard - keyboard input device">wl_keyboard</a></dd></dl></div><p>
</p><p>
The ID provided will be initialized to the wl_keyboard interface
for this seat.</p><p> This request only takes effect if the seat has the keyboard
capability.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_seat-request-get_touch"></a>wl_seat::get_touch
- return touch object</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">id</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_touch" title="wl_touch - touchscreen input device">wl_touch</a></dd></dl></div><p>
</p><p>
The ID provided will be initialized to the wl_touch interface
for this seat.</p><p> This request only takes effect if the seat has the touch
capability.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp64902976"></a>Events provided by wl_seat</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_seat-event-capabilities"></a>wl_seat::capabilities
- seat capabilities changed</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">capabilities</span></dt><dd>uint</dd></dl></div><p>
</p><p>
This is emitted whenever a seat gains or loses the pointer,
keyboard or touch capabilities. The argument is a capability
enum containing the complete set of capabilities this seat has.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_seat-event-name"></a>wl_seat::name
- unique identifier for this seat</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">name</span></dt><dd>string</dd></dl></div><p>
</p><p>
In a multiseat configuration this can be used by the client to help
identify which physical devices the seat represents. Based on
the seat configuration used by the compositor.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp64912960"></a>Enums provided by wl_seat</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_seat-enum-capability"></a>wl_seat::capability
- seat capability bitmask</h4></div></div></div><p>
This is a bitmask of capabilities this seat has; if a member is
set, then it is present on the seat.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">pointer</span></dt><dd>1
- The seat has pointer devices</dd><dt><span class="term">keyboard</span></dt><dd>2
- The seat has one or more keyboards</dd><dt><span class="term">touch</span></dt><dd>4
- The seat has touch devices</dd></dl></div></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_pointer"></a>wl_pointer
- pointer input device</h2></div></div></div><p>
The wl_pointer interface represents one or more input devices,
such as mice, which control the pointer location and pointer_focus
of a seat.</p><p> The wl_pointer interface generates motion, enter and leave
events for the surfaces that the pointer is located over,
and button and axis events for button presses, button releases
and scrolling.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67499936"></a>Requests provided by wl_pointer</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_pointer-request-set_cursor"></a>wl_pointer::set_cursor
- set the pointer surface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">serial</span></dt><dd>uint
- serial of the enter event</dd><dt><span class="term">surface</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
</dd><dt><span class="term">hotspot_x</span></dt><dd>int
- x coordinate in surface-relative coordinates</dd><dt><span class="term">hotspot_y</span></dt><dd>int
- y coordinate in surface-relative coordinates</dd></dl></div><p>
</p><p>
Set the pointer surface, i.e., the surface that contains the
pointer image (cursor). This request gives the surface the role
of a cursor. If the surface already has another role, it raises
a protocol error.</p><p> The cursor actually changes only if the pointer
focus for this device is one of the requesting client's surfaces
or the surface parameter is the current pointer surface. If
there was a previous surface set with this request it is
replaced. If surface is NULL, the pointer image is hidden.</p><p> The parameters hotspot_x and hotspot_y define the position of
the pointer surface relative to the pointer location. Its
top-left corner is always at (x, y) - (hotspot_x, hotspot_y),
where (x, y) are the coordinates of the pointer location, in surface
local coordinates.</p><p> On surface.attach requests to the pointer surface, hotspot_x
and hotspot_y are decremented by the x and y parameters
passed to the request. Attach must be confirmed by
wl_surface.commit as usual.</p><p> The hotspot can also be updated by passing the currently set
pointer surface to this request with new values for hotspot_x
and hotspot_y.</p><p> The current and pending input regions of the wl_surface are
cleared, and wl_surface.set_input_region is ignored until the
wl_surface is no longer used as the cursor. When the use as a
cursor ends, the current and pending input regions become
undefined, and the wl_surface is unmapped.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_pointer-request-release"></a>wl_pointer::release
- release the pointer object</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Using this request client can tell the server that it is not going to
use the pointer object anymore.</p><p> This request destroys the pointer proxy object, so user must not call
wl_pointer_destroy() after using this request.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67517920"></a>Events provided by wl_pointer</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_pointer-event-enter"></a>wl_pointer::enter
- enter event</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">serial</span></dt><dd>uint</dd><dt><span class="term">surface</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
</dd><dt><span class="term">surface_x</span></dt><dd>fixed
- x coordinate in surface-relative coordinates</dd><dt><span class="term">surface_y</span></dt><dd>fixed
- y coordinate in surface-relative coordinates</dd></dl></div><p>
</p><p>
Notification that this seat's pointer is focused on a certain
surface.</p><p> When an seat's focus enters a surface, the pointer image
is undefined and a client should respond to this event by setting
an appropriate pointer image with the set_cursor request.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_pointer-event-leave"></a>wl_pointer::leave
- leave event</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">serial</span></dt><dd>uint</dd><dt><span class="term">surface</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
</dd></dl></div><p>
</p><p>
Notification that this seat's pointer is no longer focused on
a certain surface.</p><p> The leave notification is sent before the enter notification
for the new focus.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_pointer-event-motion"></a>wl_pointer::motion
- pointer motion event</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">time</span></dt><dd>uint
- timestamp with millisecond granularity</dd><dt><span class="term">surface_x</span></dt><dd>fixed
- x coordinate in surface-relative coordinates</dd><dt><span class="term">surface_y</span></dt><dd>fixed
- y coordinate in surface-relative coordinates</dd></dl></div><p>
</p><p>
Notification of pointer location change. The arguments
surface_x and surface_y are the location relative to the
focused surface.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_pointer-event-button"></a>wl_pointer::button
- pointer button event</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">serial</span></dt><dd>uint</dd><dt><span class="term">time</span></dt><dd>uint
- timestamp with millisecond granularity</dd><dt><span class="term">button</span></dt><dd>uint</dd><dt><span class="term">state</span></dt><dd>uint</dd></dl></div><p>
</p><p>
Mouse button click and release notifications.</p><p> The location of the click is given by the last motion or
enter event.
The time argument is a timestamp with millisecond
granularity, with an undefined base.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_pointer-event-axis"></a>wl_pointer::axis
- axis event</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">time</span></dt><dd>uint
- timestamp with millisecond granularity</dd><dt><span class="term">axis</span></dt><dd>uint</dd><dt><span class="term">value</span></dt><dd>fixed</dd></dl></div><p>
</p><p>
Scroll and other axis notifications.</p><p> For scroll events (vertical and horizontal scroll axes), the
value parameter is the length of a vector along the specified
axis in a coordinate space identical to those of motion events,
representing a relative movement along the specified axis.</p><p> For devices that support movements non-parallel to axes multiple
axis events will be emitted.</p><p> When applicable, for example for touch pads, the server can
choose to emit scroll events where the motion vector is
equivalent to a motion event vector.</p><p> When applicable, clients can transform its view relative to the
scroll distance.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67566512"></a>Enums provided by wl_pointer</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_pointer-enum-error"></a>wl_pointer::error</h4></div></div></div><p></p><div class="variablelist"><dl class="variablelist"><dt><span class="term">role</span></dt><dd>0
- given wl_surface has another role</dd></dl></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_pointer-enum-button_state"></a>wl_pointer::button_state
- physical button state</h4></div></div></div><p>
Describes the physical state of a button which provoked the button
event.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">released</span></dt><dd>0
- The button is not pressed</dd><dt><span class="term">pressed</span></dt><dd>1
- The button is pressed</dd></dl></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_pointer-enum-axis"></a>wl_pointer::axis
- axis types</h4></div></div></div><p>
Describes the axis types of scroll events.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">vertical_scroll</span></dt><dd>0</dd><dt><span class="term">horizontal_scroll</span></dt><dd>1</dd></dl></div></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_keyboard"></a>wl_keyboard
- keyboard input device</h2></div></div></div><p>
The wl_keyboard interface represents one or more keyboards
associated with a seat.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67584400"></a>Requests provided by wl_keyboard</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_keyboard-request-release"></a>wl_keyboard::release
- release the keyboard object</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p></p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67587520"></a>Events provided by wl_keyboard</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_keyboard-event-keymap"></a>wl_keyboard::keymap
- keyboard mapping</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">format</span></dt><dd>uint</dd><dt><span class="term">fd</span></dt><dd>fd</dd><dt><span class="term">size</span></dt><dd>uint</dd></dl></div><p>
</p><p>
This event provides a file descriptor to the client which can be
memory-mapped to provide a keyboard mapping description.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_keyboard-event-enter"></a>wl_keyboard::enter
- enter event</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">serial</span></dt><dd>uint</dd><dt><span class="term">surface</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
</dd><dt><span class="term">keys</span></dt><dd>array
- the currently pressed keys</dd></dl></div><p>
</p><p>
Notification that this seat's keyboard focus is on a certain
surface.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_keyboard-event-leave"></a>wl_keyboard::leave
- leave event</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">serial</span></dt><dd>uint</dd><dt><span class="term">surface</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
</dd></dl></div><p>
</p><p>
Notification that this seat's keyboard focus is no longer on
a certain surface.</p><p> The leave notification is sent before the enter notification
for the new focus.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_keyboard-event-key"></a>wl_keyboard::key
- key event</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">serial</span></dt><dd>uint</dd><dt><span class="term">time</span></dt><dd>uint
- timestamp with millisecond granularity</dd><dt><span class="term">key</span></dt><dd>uint</dd><dt><span class="term">state</span></dt><dd>uint</dd></dl></div><p>
</p><p>
A key was pressed or released.
The time argument is a timestamp with millisecond
granularity, with an undefined base.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_keyboard-event-modifiers"></a>wl_keyboard::modifiers
- modifier and group state</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">serial</span></dt><dd>uint</dd><dt><span class="term">mods_depressed</span></dt><dd>uint</dd><dt><span class="term">mods_latched</span></dt><dd>uint</dd><dt><span class="term">mods_locked</span></dt><dd>uint</dd><dt><span class="term">group</span></dt><dd>uint</dd></dl></div><p>
</p><p>
Notifies clients that the modifier and/or group state has
changed, and it should update its local state.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_keyboard-event-repeat_info"></a>wl_keyboard::repeat_info
- repeat rate and delay</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">rate</span></dt><dd>int
- the rate of repeating keys in characters per second</dd><dt><span class="term">delay</span></dt><dd>int
- delay in milliseconds since key down until repeating starts</dd></dl></div><p>
</p><p>
Informs the client about the keyboard's repeat rate and delay.</p><p> This event is sent as soon as the wl_keyboard object has been created,
and is guaranteed to be received by the client before any key press
event.</p><p> Negative values for either rate or delay are illegal. A rate of zero
will disable any repeating (regardless of the value of delay).</p><p> This event can be sent later on as well with a new value if necessary,
so clients should continue listening for the event past the creation
of wl_keyboard.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67642208"></a>Enums provided by wl_keyboard</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_keyboard-enum-keymap_format"></a>wl_keyboard::keymap_format
- keyboard mapping format</h4></div></div></div><p>
This specifies the format of the keymap provided to the
client with the wl_keyboard.keymap event.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">no_keymap</span></dt><dd>0
- no keymap; client must understand how to interpret the raw keycode</dd><dt><span class="term">xkb_v1</span></dt><dd>1
- libxkbcommon compatible; to determine the xkb keycode, clients must add 8 to the key event keycode</dd></dl></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_keyboard-enum-key_state"></a>wl_keyboard::key_state
- physical key state</h4></div></div></div><p>
Describes the physical state of a key which provoked the key event.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">released</span></dt><dd>0
- key is not pressed</dd><dt><span class="term">pressed</span></dt><dd>1
- key is pressed</dd></dl></div></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_touch"></a>wl_touch
- touchscreen input device</h2></div></div></div><p>
The wl_touch interface represents a touchscreen
associated with a seat.</p><p> Touch interactions can consist of one or more contacts.
For each contact, a series of events is generated, starting
with a down event, followed by zero or more motion events,
and ending with an up event. Events relating to the same
contact point can be identified by the ID of the sequence.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67657200"></a>Requests provided by wl_touch</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_touch-request-release"></a>wl_touch::release
- release the touch object</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p></p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67660384"></a>Events provided by wl_touch</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_touch-event-down"></a>wl_touch::down
- touch down event and beginning of a touch sequence</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">serial</span></dt><dd>uint</dd><dt><span class="term">time</span></dt><dd>uint
- timestamp with millisecond granularity</dd><dt><span class="term">surface</span></dt><dd>
<a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
</dd><dt><span class="term">id</span></dt><dd>int
- the unique ID of this touch point</dd><dt><span class="term">x</span></dt><dd>fixed
- x coordinate in surface-relative coordinates</dd><dt><span class="term">y</span></dt><dd>fixed
- y coordinate in surface-relative coordinates</dd></dl></div><p>
</p><p>
A new touch point has appeared on the surface. This touch point is
assigned a unique @id. Future events from this touchpoint reference
this ID. The ID ceases to be valid after a touch up event and may be
re-used in the future.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_touch-event-up"></a>wl_touch::up
- end of a touch event sequence</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">serial</span></dt><dd>uint</dd><dt><span class="term">time</span></dt><dd>uint
- timestamp with millisecond granularity</dd><dt><span class="term">id</span></dt><dd>int
- the unique ID of this touch point</dd></dl></div><p>
</p><p>
The touch point has disappeared. No further events will be sent for
this touchpoint and the touch point's ID is released and may be
re-used in a future touch down event.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_touch-event-motion"></a>wl_touch::motion
- update of touch point coordinates</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">time</span></dt><dd>uint
- timestamp with millisecond granularity</dd><dt><span class="term">id</span></dt><dd>int
- the unique ID of this touch point</dd><dt><span class="term">x</span></dt><dd>fixed
- x coordinate in surface-relative coordinates</dd><dt><span class="term">y</span></dt><dd>fixed
- y coordinate in surface-relative coordinates</dd></dl></div><p>
</p><p>
A touchpoint has changed coordinates.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_touch-event-frame"></a>wl_touch::frame
- end of touch frame event</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Indicates the end of a contact point list.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_touch-event-cancel"></a>wl_touch::cancel
- touch session cancelled</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Sent if the compositor decides the touch stream is a global
gesture. No further events are sent to the clients from that
particular gesture. Touch cancellation applies to all touch points
currently active on this client's surface. The client is
responsible for finalizing the touch points, future touch points on
this surface may re-use the touch point ID.
</p></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_output"></a>wl_output
- compositor output region</h2></div></div></div><p>
An output describes part of the compositor geometry. The
compositor works in the 'compositor coordinate system' and an
output corresponds to rectangular area in that space that is
actually visible. This typically corresponds to a monitor that
displays part of the compositor space. This object is published
as global during start up, or when a monitor is hotplugged.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67700832"></a>Events provided by wl_output</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_output-event-geometry"></a>wl_output::geometry
- properties of the output</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">x</span></dt><dd>int
- x position within the global compositor space</dd><dt><span class="term">y</span></dt><dd>int
- y position within the global compositor space</dd><dt><span class="term">physical_width</span></dt><dd>int
- width in millimeters of the output</dd><dt><span class="term">physical_height</span></dt><dd>int
- height in millimeters of the output</dd><dt><span class="term">subpixel</span></dt><dd>int
- subpixel orientation of the output</dd><dt><span class="term">make</span></dt><dd>string
- textual description of the manufacturer</dd><dt><span class="term">model</span></dt><dd>string
- textual description of the model</dd><dt><span class="term">transform</span></dt><dd>int
- transform that maps framebuffer to output</dd></dl></div><p>
</p><p>
The geometry event describes geometric properties of the output.
The event is sent when binding to the output object and whenever
any of the properties change.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_output-event-mode"></a>wl_output::mode
- advertise available modes for the output</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">flags</span></dt><dd>uint
- bitfield of mode flags</dd><dt><span class="term">width</span></dt><dd>int
- width of the mode in hardware units</dd><dt><span class="term">height</span></dt><dd>int
- height of the mode in hardware units</dd><dt><span class="term">refresh</span></dt><dd>int
- vertical refresh rate in mHz</dd></dl></div><p>
</p><p>
The mode event describes an available mode for the output.</p><p> The event is sent when binding to the output object and there
will always be one mode, the current mode. The event is sent
again if an output changes mode, for the mode that is now
current. In other words, the current mode is always the last
mode that was received with the current flag set.</p><p> The size of a mode is given in physical hardware units of
the output device. This is not necessarily the same as
the output size in the global compositor space. For instance,
the output may be scaled, as described in wl_output.scale,
or transformed , as described in wl_output.transform.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_output-event-done"></a>wl_output::done
- sent all information about output</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
This event is sent after all other properties has been
sent after binding to the output object and after any
other property changes done after that. This allows
changes to the output properties to be seen as
atomic, even if they happen via multiple events.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_output-event-scale"></a>wl_output::scale
- output scaling properties</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">factor</span></dt><dd>int
- scaling factor of output</dd></dl></div><p>
</p><p>
This event contains scaling geometry information
that is not in the geometry event. It may be sent after
binding the output object or if the output scale changes
later. If it is not sent, the client should assume a
scale of 1.</p><p> A scale larger than 1 means that the compositor will
automatically scale surface buffers by this amount
when rendering. This is used for very high resolution
displays where applications rendering at the native
resolution would be too small to be legible.</p><p> It is intended that scaling aware clients track the
current output of a surface, and if it is on a scaled
output it should use wl_surface.set_buffer_scale with
the scale of the output. That way the compositor can
avoid scaling the surface, and the client can supply
a higher detail image.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67738816"></a>Enums provided by wl_output</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_output-enum-subpixel"></a>wl_output::subpixel
- subpixel geometry information</h4></div></div></div><p>
This enumeration describes how the physical
pixels on an output are laid out.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">unknown</span></dt><dd>0</dd><dt><span class="term">none</span></dt><dd>1</dd><dt><span class="term">horizontal_rgb</span></dt><dd>2</dd><dt><span class="term">horizontal_bgr</span></dt><dd>3</dd><dt><span class="term">vertical_rgb</span></dt><dd>4</dd><dt><span class="term">vertical_bgr</span></dt><dd>5</dd></dl></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_output-enum-transform"></a>wl_output::transform
- transform from framebuffer to output</h4></div></div></div><p>
This describes the transform that a compositor will apply to a
surface to compensate for the rotation or mirroring of an
output device.</p><p> The flipped values correspond to an initial flip around a
vertical axis followed by rotation.</p><p> The purpose is mainly to allow clients render accordingly and
tell the compositor, so that for fullscreen surfaces, the
compositor will still be able to scan out directly from client
surfaces.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">normal</span></dt><dd>0</dd><dt><span class="term">90</span></dt><dd>1</dd><dt><span class="term">180</span></dt><dd>2</dd><dt><span class="term">270</span></dt><dd>3</dd><dt><span class="term">flipped</span></dt><dd>4</dd><dt><span class="term">flipped_90</span></dt><dd>5</dd><dt><span class="term">flipped_180</span></dt><dd>6</dd><dt><span class="term">flipped_270</span></dt><dd>7</dd></dl></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_output-enum-mode"></a>wl_output::mode
- mode information</h4></div></div></div><p>
These flags describe properties of an output mode.
They are used in the flags bitfield of the mode event.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">current</span></dt><dd>0x1
- indicates this is the current mode</dd><dt><span class="term">preferred</span></dt><dd>0x2
- indicates this is the preferred mode</dd></dl></div></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_region"></a>wl_region
- region interface</h2></div></div></div><p>
A region object describes an area.</p><p> Region objects are used to describe the opaque and input
regions of a surface.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67778352"></a>Requests provided by wl_region</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_region-request-destroy"></a>wl_region::destroy
- destroy region</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Destroy the region. This will invalidate the object ID.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_region-request-add"></a>wl_region::add
- add rectangle to region</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">x</span></dt><dd>int</dd><dt><span class="term">y</span></dt><dd>int</dd><dt><span class="term">width</span></dt><dd>int</dd><dt><span class="term">height</span></dt><dd>int</dd></dl></div><p>
</p><p>
Add the specified rectangle to the region.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_region-request-subtract"></a>wl_region::subtract
- subtract rectangle from region</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">x</span></dt><dd>int</dd><dt><span class="term">y</span></dt><dd>int</dd><dt><span class="term">width</span></dt><dd>int</dd><dt><span class="term">height</span></dt><dd>int</dd></dl></div><p>
</p><p>
Subtract the specified rectangle from the region.
</p></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_subcompositor"></a>wl_subcompositor
- sub-surface compositing</h2></div></div></div><p>
The global interface exposing sub-surface compositing capabilities.
A wl_surface, that has sub-surfaces associated, is called the
parent surface. Sub-surfaces can be arbitrarily nested and create
a tree of sub-surfaces.</p><p> The root surface in a tree of sub-surfaces is the main
surface. The main surface cannot be a sub-surface, because
sub-surfaces must always have a parent.</p><p> A main surface with its sub-surfaces forms a (compound) window.
For window management purposes, this set of wl_surface objects is
to be considered as a single window, and it should also behave as
such.</p><p> The aim of sub-surfaces is to offload some of the compositing work
within a window from clients to the compositor. A prime example is
a video player with decorations and video in separate wl_surface
objects. This should allow the compositor to pass YUV video buffer
processing to dedicated overlay hardware when possible.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67805088"></a>Requests provided by wl_subcompositor</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_subcompositor-request-destroy"></a>wl_subcompositor::destroy
- unbind from the subcompositor interface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Informs the server that the client will not be using this
protocol object anymore. This does not affect any other
objects, wl_subsurface objects included.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_subcompositor-request-get_subsurface"></a>wl_subcompositor::get_subsurface
- give a surface the role sub-surface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">id</span></dt><dd>
id for the new
<a class="link" href="apa.html#protocol-spec-wl_subsurface" title="wl_subsurface - sub-surface interface to a wl_surface">wl_subsurface</a>
- the new subsurface object id</dd><dt><span class="term">surface</span></dt><dd><a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
- the surface to be turned into a sub-surface</dd><dt><span class="term">parent</span></dt><dd><a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
- the parent surface</dd></dl></div><p>
</p><p>
Create a sub-surface interface for the given surface, and
associate it with the given parent surface. This turns a
plain wl_surface into a sub-surface.</p><p> The to-be sub-surface must not already have another role, and it
must not have an existing wl_subsurface object. Otherwise a protocol
error is raised.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67819072"></a>Enums provided by wl_subcompositor</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_subcompositor-enum-error"></a>wl_subcompositor::error</h4></div></div></div><p></p><div class="variablelist"><dl class="variablelist"><dt><span class="term">bad_surface</span></dt><dd>0
- the to-be sub-surface is invalid</dd></dl></div></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="protocol-spec-wl_subsurface"></a>wl_subsurface
- sub-surface interface to a wl_surface</h2></div></div></div><p>
An additional interface to a wl_surface object, which has been
made a sub-surface. A sub-surface has one parent surface. A
sub-surface's size and position are not limited to that of the parent.
Particularly, a sub-surface is not automatically clipped to its
parent's area.</p><p> A sub-surface becomes mapped, when a non-NULL wl_buffer is applied
and the parent surface is mapped. The order of which one happens
first is irrelevant. A sub-surface is hidden if the parent becomes
hidden, or if a NULL wl_buffer is applied. These rules apply
recursively through the tree of surfaces.</p><p> The behaviour of wl_surface.commit request on a sub-surface
depends on the sub-surface's mode. The possible modes are
synchronized and desynchronized, see methods
wl_subsurface.set_sync and wl_subsurface.set_desync. Synchronized
mode caches the wl_surface state to be applied when the parent's
state gets applied, and desynchronized mode applies the pending
wl_surface state directly. A sub-surface is initially in the
synchronized mode.</p><p> Sub-surfaces have also other kind of state, which is managed by
wl_subsurface requests, as opposed to wl_surface requests. This
state includes the sub-surface position relative to the parent
surface (wl_subsurface.set_position), and the stacking order of
the parent and its sub-surfaces (wl_subsurface.place_above and
.place_below). This state is applied when the parent surface's
wl_surface state is applied, regardless of the sub-surface's mode.
As the exception, set_sync and set_desync are effective immediately.</p><p> The main surface can be thought to be always in desynchronized mode,
since it does not have a parent in the sub-surfaces sense.</p><p> Even if a sub-surface is in desynchronized mode, it will behave as
in synchronized mode, if its parent surface behaves as in
synchronized mode. This rule is applied recursively throughout the
tree of surfaces. This means, that one can set a sub-surface into
synchronized mode, and then assume that all its child and grand-child
sub-surfaces are synchronized, too, without explicitly setting them.</p><p> If the wl_surface associated with the wl_subsurface is destroyed, the
wl_subsurface object becomes inert. Note, that destroying either object
takes effect immediately. If you need to synchronize the removal
of a sub-surface to the parent surface update, unmap the sub-surface
first by attaching a NULL wl_buffer, update parent, and then destroy
the sub-surface.</p><p> If the parent wl_surface object is destroyed, the sub-surface is
unmapped.
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67831072"></a>Requests provided by wl_subsurface</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_subsurface-request-destroy"></a>wl_subsurface::destroy
- remove sub-surface interface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
The sub-surface interface is removed from the wl_surface object
that was turned into a sub-surface with
wl_subcompositor.get_subsurface request. The wl_surface's association
to the parent is deleted, and the wl_surface loses its role as
a sub-surface. The wl_surface is unmapped.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_subsurface-request-set_position"></a>wl_subsurface::set_position
- reposition the sub-surface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">x</span></dt><dd>int
- coordinate in the parent surface</dd><dt><span class="term">y</span></dt><dd>int
- coordinate in the parent surface</dd></dl></div><p>
</p><p>
This schedules a sub-surface position change.
The sub-surface will be moved so, that its origin (top-left
corner pixel) will be at the location x, y of the parent surface
coordinate system. The coordinates are not restricted to the parent
surface area. Negative values are allowed.</p><p> The scheduled coordinates will take effect whenever the state of the
parent surface is applied. When this happens depends on whether the
parent surface is in synchronized mode or not. See
wl_subsurface.set_sync and wl_subsurface.set_desync for details.</p><p> If more than one set_position request is invoked by the client before
the commit of the parent surface, the position of a new request always
replaces the scheduled position from any previous request.</p><p> The initial position is 0, 0.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_subsurface-request-place_above"></a>wl_subsurface::place_above
- restack the sub-surface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">sibling</span></dt><dd><a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
- the reference surface</dd></dl></div><p>
</p><p>
This sub-surface is taken from the stack, and put back just
above the reference surface, changing the z-order of the sub-surfaces.
The reference surface must be one of the sibling surfaces, or the
parent surface. Using any other surface, including this sub-surface,
will cause a protocol error.</p><p> The z-order is double-buffered. Requests are handled in order and
applied immediately to a pending state. The final pending state is
copied to the active state the next time the state of the parent
surface is applied. When this happens depends on whether the parent
surface is in synchronized mode or not. See wl_subsurface.set_sync and
wl_subsurface.set_desync for details.</p><p> A new sub-surface is initially added as the top-most in the stack
of its siblings and parent.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_subsurface-request-place_below"></a>wl_subsurface::place_below
- restack the sub-surface</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">sibling</span></dt><dd><a class="link" href="apa.html#protocol-spec-wl_surface" title="wl_surface - an onscreen surface">wl_surface</a>
- the reference surface</dd></dl></div><p>
</p><p>
The sub-surface is placed just below of the reference surface.
See wl_subsurface.place_above.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_subsurface-request-set_sync"></a>wl_subsurface::set_sync
- set sub-surface to synchronized mode</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Change the commit behaviour of the sub-surface to synchronized
mode, also described as the parent dependent mode.</p><p> In synchronized mode, wl_surface.commit on a sub-surface will
accumulate the committed state in a cache, but the state will
not be applied and hence will not change the compositor output.
The cached state is applied to the sub-surface immediately after
the parent surface's state is applied. This ensures atomic
updates of the parent and all its synchronized sub-surfaces.
Applying the cached state will invalidate the cache, so further
parent surface commits do not (re-)apply old state.</p><p> See wl_subsurface for the recursive effect of this mode.
</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_subsurface-request-set_desync"></a>wl_subsurface::set_desync
- set sub-surface to desynchronized mode</h4></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"></dl></div><p>
</p><p>
Change the commit behaviour of the sub-surface to desynchronized
mode, also described as independent or freely running mode.</p><p> In desynchronized mode, wl_surface.commit on a sub-surface will
apply the pending state directly, without caching, as happens
normally with a wl_surface. Calling wl_surface.commit on the
parent surface has no effect on the sub-surface's wl_surface
state. This mode allows a sub-surface to be updated on its own.</p><p> If cached state exists when wl_surface.commit is called in
desynchronized mode, the pending state is added to the cached
state, and applied as whole. This invalidates the cache.</p><p> Note: even if a sub-surface is set to desynchronized, a parent
sub-surface may override it to behave as synchronized. For details,
see wl_subsurface.</p><p> If a surface's parent surface behaves as desynchronized, then
the cached state is applied on set_desync.
</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp67863104"></a>Enums provided by wl_subsurface</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="protocol-spec-wl_subsurface-enum-error"></a>wl_subsurface::error</h4></div></div></div><p></p><div class="variablelist"><dl class="variablelist"><dt><span class="term">bad_surface</span></dt><dd>0
- wl_surface is not a sibling or the parent</dd></dl></div></div></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ch04.html">Prev</a> </td><td width="20%" align="center"> </td><td width="40%" align="right"> <a accesskey="n" href="apb.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 4. Wayland Protocol and Model of Operation </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Appendix B. Client API</td></tr></table></div></body></html>
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