From 1509a2a111cbb00c3d5d569dfd80cf703ad620fa Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Fri, 14 Feb 2020 12:22:03 +0100
Subject: [PATCH] xdg-decoration: allow get_toplevel_decoration with a mapped
 toplevel

When clients create an xdg_toplevel_decoration object, they opt-in for
being self-decorated by the compositor if it decides to. Clients have no
way to prevent the compositor from potentially decorating them, if they
don't want any decorations they should destroy the
xdg_toplevel_decoration object.

Some toolkits allow toggling toplevel decorations at runtime. In this
case they need a way to transition from having no decorations at all to
a state where they can be decorated.

Allow creating an xdg_toplevel_decoration object on an already-mapped
toplevel to accomodate for this use-case.

Signed-off-by: Simon Ser <contact@emersion.fr>
Closes: https://gitlab.freedesktop.org/wayland/wayland-protocols/issues/9
---
 .../xdg-decoration-unstable-v1.xml            | 32 ++++++++++++++-----
 1 file changed, 24 insertions(+), 8 deletions(-)

diff --git a/unstable/xdg-decoration/xdg-decoration-unstable-v1.xml b/unstable/xdg-decoration/xdg-decoration-unstable-v1.xml
index 378e8ff..ce83439 100644
--- a/unstable/xdg-decoration/xdg-decoration-unstable-v1.xml
+++ b/unstable/xdg-decoration/xdg-decoration-unstable-v1.xml
@@ -23,7 +23,7 @@
     DEALINGS IN THE SOFTWARE.
   </copyright>
 
-  <interface name="zxdg_decoration_manager_v1" version="1">
+  <interface name="zxdg_decoration_manager_v1" version="2">
     <description summary="window decoration manager">
       This interface allows a compositor to announce support for server-side
       decorations.
@@ -60,18 +60,33 @@
       <description summary="create a new toplevel decoration object">
         Create a new decoration object associated with the given toplevel.
 
-        Creating an xdg_toplevel_decoration from an xdg_toplevel which has a
-        buffer attached or committed is a client error, and any attempts by a
-        client to attach or manipulate a buffer prior to the first
-        xdg_toplevel_decoration.configure event must also be treated as
-        errors.
+        For objects of version 1, creating an xdg_toplevel_decoration from an
+        xdg_toplevel which has a buffer attached or committed is a client
+        error, and any attempts by a client to attach or manipulate a buffer
+        prior to the first xdg_toplevel_decoration.configure event must also be
+        treated as errors.
+
+        For objects of version 2 or newer, creating an xdg_toplevel_decoration
+        from an xdg_toplevel which has a buffer attached or committed is
+        allowed. The initial decoration mode of the surface if a buffer is
+        already attached depends on whether a xdg_toplevel_decoration object
+        has been associated with the surface or not prior to this request.
+
+        If an xdg_toplevel_decoration was associated with the surface, then
+        destroyed without a surface commit, the previous decoration mode is
+        retained.
+
+        If no xdg_toplevel_decoration was associated with the surface prior to
+        this request, or if a surface commit has been perfomed after a previous
+        xdg_toplevel_decoration object associated with the surface was
+        destroyed, the decoration mode is assumed to be client-side.
       </description>
       <arg name="id" type="new_id" interface="zxdg_toplevel_decoration_v1"/>
       <arg name="toplevel" type="object" interface="xdg_toplevel"/>
     </request>
   </interface>
 
-  <interface name="zxdg_toplevel_decoration_v1" version="1">
+  <interface name="zxdg_toplevel_decoration_v1" version="2">
     <description summary="decoration object for a toplevel surface">
       The decoration object allows the compositor to toggle server-side window
       decorations for a toplevel surface. The client can request to switch to
@@ -93,7 +108,8 @@
     <request name="destroy" type="destructor">
       <description summary="destroy the decoration object">
         Switch back to a mode without any server-side decorations at the next
-        commit.
+        commit, unless a new xdg_toplevel_decoration is created for the surface
+        first.
       </description>
     </request>