efl

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<?xml version="1.0" encoding="UTF-8"?>
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<protocol name="subsurface">
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  <copyright>
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    Copyright © 2012-2013 Collabora, Ltd.
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    Permission to use, copy, modify, distribute, and sell this
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    software and its documentation for any purpose is hereby granted
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    without fee, provided that the above copyright notice appear in
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    all copies and that both that copyright notice and this permission
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    notice appear in supporting documentation, and that the name of
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    the copyright holders not be used in advertising or publicity
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    pertaining to distribution of the software without specific,
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    written prior permission.  The copyright holders make no
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    representations about the suitability of this software for any
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    purpose.  It is provided "as is" without express or implied
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    warranty.
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    THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
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    SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
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    FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
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    SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
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    AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
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    ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
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    THIS SOFTWARE.
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  </copyright>
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  <interface name="wl_subcompositor" version="1">
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    <description summary="sub-surface compositing">
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      The global interface exposing sub-surface compositing capabilities.
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      A wl_surface, that has sub-surfaces associated, is called the
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      parent surface. Sub-surfaces can be arbitrarily nested and create
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      a tree of sub-surfaces.
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      The root surface in a tree of sub-surfaces is the main
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      surface. The main surface cannot be a sub-surface, because
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      sub-surfaces must always have a parent.
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      A main surface with its sub-surfaces forms a (compound) window.
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      For window management purposes, this set of wl_surface objects is
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      to be considered as a single window, and it should also behave as
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      such.
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      The aim of sub-surfaces is to offload some of the compositing work
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      within a window from clients to the compositor. A prime example is
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      a video player with decorations and video in separate wl_surface
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      objects. This should allow the compositor to pass YUV video buffer
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      processing to dedicated overlay hardware when possible.
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    </description>
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    <request name="destroy" type="destructor">
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      <description summary="unbind from the subcompositor interface">
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	Informs the server that the client will not be using this
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	protocol object anymore. This does not affect any other
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	objects, wl_subsurface objects included.
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      </description>
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    </request>
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    <enum name="error">
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      <entry name="bad_surface" value="0"
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             summary="the to-be sub-surface is invalid"/>
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    </enum>
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    <request name="get_subsurface">
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      <description summary="give a surface the role sub-surface">
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	Create a sub-surface interface for the given surface, and
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	associate it with the given parent surface. This turns a
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	plain wl_surface into a sub-surface.
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	The to-be sub-surface must not already have a dedicated
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	purpose, like any shell surface type, cursor image, drag icon,
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	or sub-surface. Otherwise a protocol error is raised.
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      </description>
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      <arg name="id" type="new_id" interface="wl_subsurface"
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           summary="the new subsurface object id"/>
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      <arg name="surface" type="object" interface="wl_surface"
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           summary="the surface to be turned into a sub-surface"/>
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      <arg name="parent" type="object" interface="wl_surface"
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           summary="the parent surface"/>
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    </request>
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  </interface>
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  <interface name="wl_subsurface" version="1">
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    <description summary="sub-surface interface to a wl_surface">
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      An additional interface to a wl_surface object, which has been
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      made a sub-surface. A sub-surface has one parent surface. A
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      sub-surface's size and position are not limited to that of the parent.
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      Particularly, a sub-surface is not automatically clipped to its
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      parent's area.
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      A sub-surface becomes mapped, when a non-NULL wl_buffer is applied
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      and the parent surface is mapped. The order of which one happens
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      first is irrelevant. A sub-surface is hidden if the parent becomes
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      hidden, or if a NULL wl_buffer is applied. These rules apply
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      recursively through the tree of surfaces.
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      The behaviour of wl_surface.commit request on a sub-surface
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      depends on the sub-surface's mode. The possible modes are
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      synchronized and desynchronized, see methods
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      wl_subsurface.set_sync and wl_subsurface.set_desync. Synchronized
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      mode caches the wl_surface state to be applied when the parent's
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      state gets applied, and desynchronized mode applies the pending
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      wl_surface state directly. A sub-surface is initially in the
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      synchronized mode.
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      Sub-surfaces have also other kind of state, which is managed by
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      wl_subsurface requests, as opposed to wl_surface requests. This
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      state includes the sub-surface position relative to the parent
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      surface (wl_subsurface.set_position), and the stacking order of
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      the parent and its sub-surfaces (wl_subsurface.place_above and
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      .place_below). This state is applied when the parent surface's
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      wl_surface state is applied, regardless of the sub-surface's mode.
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      As the exception, set_sync and set_desync are effective immediately.
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      The main surface can be thought to be always in desynchronized mode,
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      since it does not have a parent in the sub-surfaces sense.
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      Even if a sub-surface is in desynchronized mode, it will behave as
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      in synchronized mode, if its parent surface behaves as in
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      synchronized mode. This rule is applied recursively throughout the
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      tree of surfaces. This means, that one can set a sub-surface into
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      synchronized mode, and then assume that all its child and grand-child
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      sub-surfaces are synchronized, too, without explicitly setting them.
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      If the wl_surface associated with the wl_subsurface is destroyed, the
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      wl_subsurface object becomes inert. Note, that destroying either object
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      takes effect immediately. If you need to synchronize the removal
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      of a sub-surface to the parent surface update, unmap the sub-surface
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      first by attaching a NULL wl_buffer, update parent, and then destroy
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      the sub-surface.
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      If the parent wl_surface object is destroyed, the sub-surface is
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      unmapped.
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    </description>
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    <request name="destroy" type="destructor">
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      <description summary="remove sub-surface interface">
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	The sub-surface interface is removed from the wl_surface object
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	that was turned into a sub-surface with
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	wl_subcompositor.get_subsurface request. The wl_surface's association
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	to the parent is deleted, and the wl_surface loses its role as
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	a sub-surface. The wl_surface is unmapped.
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      </description>
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    </request>
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    <enum name="error">
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      <entry name="bad_surface" value="0"
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             summary="wl_surface is not a sibling or the parent"/>
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    </enum>
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    <request name="set_position">
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      <description summary="reposition the sub-surface">
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	This schedules a sub-surface position change.
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	The sub-surface will be moved so, that its origin (top-left
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	corner pixel) will be at the location x, y of the parent surface
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	coordinate system. The coordinates are not restricted to the parent
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	surface area. Negative values are allowed.
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	The next wl_surface.commit on the parent surface will reset
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	the sub-surface's position to the scheduled coordinates.
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	The initial position is 0, 0.
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      </description>
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      <arg name="x" type="int" summary="coordinate in the parent surface"/>
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      <arg name="y" type="int" summary="coordinate in the parent surface"/>
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    </request>
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    <request name="place_above">
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      <description summary="restack the sub-surface">
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	This sub-surface is taken from the stack, and put back just
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	above the reference surface, changing the z-order of the sub-surfaces.
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	The reference surface must be one of the sibling surfaces, or the
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	parent surface. Using any other surface, including this sub-surface,
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	will cause a protocol error.
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	The z-order is double-buffered state, and will be applied on the
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	next commit of the parent surface.
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	See wl_surface.commit and wl_subcompositor.get_subsurface.
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	A new sub-surface is initially added as the top-most in the stack
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	of its siblings and parent.
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      </description>
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      <arg name="sibling" type="object" interface="wl_surface"
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           summary="the reference surface"/>
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    </request>
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    <request name="place_below">
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      <description summary="restack the sub-surface">
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	The sub-surface is placed just below of the reference surface.
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	See wl_subsurface.place_above.
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      </description>
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      <arg name="sibling" type="object" interface="wl_surface"
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           summary="the reference surface"/>
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    </request>
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    <request name="set_sync">
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      <description summary="set sub-surface to synchronized mode">
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	Change the commit behaviour of the sub-surface to synchronized
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	mode, also described as the parent dependent mode.
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	In synchronized mode, wl_surface.commit on a sub-surface will
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	accumulate the committed state in a cache, but the state will
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	not be applied and hence will not change the compositor output.
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	The cached state is applied to the sub-surface immediately after
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	the parent surface's state is applied. This ensures atomic
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	updates of the parent and all its synchronized sub-surfaces.
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	Applying the cached state will invalidate the cache, so further
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	parent surface commits do not (re-)apply old state.
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	See wl_subsurface for the recursive effect of this mode.
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      </description>
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    </request>
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    <request name="set_desync">
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      <description summary="set sub-surface to desynchronized mode">
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	Change the commit behaviour of the sub-surface to desynchronized
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	mode, also described as independent or freely running mode.
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	In desynchronized mode, wl_surface.commit on a sub-surface will
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	apply the pending state directly, without caching, as happens
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	normally with a wl_surface. Calling wl_surface.commit on the
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	parent surface has no effect on the sub-surface's wl_surface
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	state. This mode allows a sub-surface to be updated on its own.
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	If cached state exists when wl_surface.commit is called in
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	desynchronized mode, the pending state is added to the cached
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	state, and applied as whole. This invalidates the cache.
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	Note: even if a sub-surface is set to desynchronized, a parent
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	sub-surface may override it to behave as synchronized. For details,
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	see wl_subsurface.
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	If a surface's parent surface behaves as desynchronized, then
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	the cached state is applied on set_desync.
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      </description>
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    </request>
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  </interface>
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</protocol>
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