Add protocol for sub-surfaces, wl_subcompositor as the global interface, and wl_subsurface as the per-surface interface extension. This patch is meant to be reverted, once sub-surfaces are moved into Wayland core. Changes in v2: - Rewrite wl_subcompositor.get_subsurface description, and move mapping and commit details into wl_subsurface description. Check the wording in wl_subsurface.set_position description. - Add wl_subsurface.set_commit_mode request, and document it, with the commit_mode enum. Add bad_value error code for wl_subsurface. - Moved the protocol into Weston repository so we can land it upstream sooner for public exposure. It is to be moved into Wayland core later. - Add destroy requests to both wl_subcompositor and wl_subsurface, and document them. Experience has showed, that interfaces should always have a destructor unless there is a good and future-proof reason to not have it. Changes in v3: - Specify, that wl_subsurface will become inert, if the corresponding wl_surface is destroyed, instead of requiring a certain destruction order. - Replaced wl_subsurface.set_commit_mode with wl_subsurface.set_sync and wl_subsurface.set_desync. Parent-cached commit mode is now called synchronized, and independent mode is desynchronized. Removed commit_mode enum, and bad_value error. - Added support for nested sub-surfaces. Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>
Pekka Paalanen
12 years ago
committed by
Kristian Høgsberg
parent
3d64a3e868
commit
2396aec684
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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<entry name="bad_parent" value="1" |
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summary="the given parent is a sub-surface"/> |
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</enum> |
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|
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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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|
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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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|
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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. |
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|
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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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|
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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 wl_surface state to be applied on the next parent |
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surface's commit, 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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|
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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 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 sub-surfaces |
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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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|
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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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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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</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 dependant 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 when |
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wl_surface.commit is called on the parent surface, after the |
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parent surface's own 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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</description> |
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</request> |
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</interface> |
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</protocol> |
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