Add a LOCK scenegraph layer.

This will be used by the upcoming implementation of the
ext-session-lock protocol.

plugins/single_plugins/ipc-rules.cpp

@@ -66,6 +66,9 @@ static std::string layer_to_string(std::optional<wf::scene::layer> layer)
         return "unmanaged";
 
       case wf::scene::layer::OVERLAY:
+        return "overlay";
+
+      case wf::scene::layer::LOCK:
         return "lock";
 
       case wf::scene::layer::DWIDGET:

src/api/wayfire/scene.hpp

@@ -414,8 +414,9 @@ enum class layer : size_t
     TOP        = 3,
     UNMANAGED  = 4,
     OVERLAY    = 5,
+    LOCK       = 6,
     // For compatibility with workspace-manager, to be removed
-    DWIDGET    = 6,
+    DWIDGET    = 7,
     /** Not a real layer, but a placeholder for the number of layers. */
     ALL_LAYERS,
 };

src/core/scene.cpp

@@ -177,6 +177,7 @@ std::string node_t::stringify() const
             "top",
             "unmanaged",
             "overlay",
+            "lock",
             "dwidget"
         };