layer_shell: set layer of existing surface

unstable/wlr-layer-shell-unstable-v1.xml

@@ -25,7 +25,7 @@
     THIS SOFTWARE.
   </copyright>
 
-  <interface name="zwlr_layer_shell_v1" version="1">
+  <interface name="zwlr_layer_shell_v1" version="2">
     <description summary="create surfaces that are layers of the desktop">
       Clients can use this interface to assign the surface_layer role to
       wl_surfaces. Such surfaces are assigned to a "layer" of the output and
@@ -84,15 +84,15 @@
     </enum>
   </interface>
 
-  <interface name="zwlr_layer_surface_v1" version="1">
+  <interface name="zwlr_layer_surface_v1" version="2">
     <description summary="layer metadata interface">
       An interface that may be implemented by a wl_surface, for surfaces that
       are designed to be rendered as a layer of a stacked desktop-like
       environment.
 
-      Layer surface state (size, anchor, exclusive zone, margin, interactivity)
-      is double-buffered, and will be applied at the time wl_surface.commit of
-      the corresponding wl_surface is called.
+      Layer surface state (layer, size, anchor, exclusive zone,
+      margin, interactivity) is double-buffered, and will be applied at the
+      time wl_surface.commit of the corresponding wl_surface is called.
     </description>
 
     <request name="set_size">
@@ -286,5 +286,16 @@
       <entry name="left" value="4" summary="the left edge of the anchor rectangle"/>
       <entry name="right" value="8" summary="the right edge of the anchor rectangle"/>
     </enum>
+
+    <!-- Version 2 additions -->
+
+    <request name="set_layer" since="2">
+      <description summary="change the layer of the surface">
+        Change the layer that the surface is rendered on.
+
+        Layer is double-buffered, see wl_surface.commit.
+      </description>
+      <arg name="layer" type="uint" enum="layer" summary="layer to move this surface to"/>
+    </request>
   </interface>
 </protocol>