Update

pipewire/.config/wireplumber/scripts/default-nodes/apply-default-node.lua

@@ -0,0 +1,39 @@
+-- WirePlumber
+--
+-- Copyright © 2022 Collabora Ltd.
+--
+-- SPDX-License-Identifier: MIT
+
+log = Log.open_topic ("s-default-nodes")
+
+SimpleEventHook {
+  name = "default-nodes/apply-default-node",
+  after = { "default-nodes/find-best-default-node",
+            "default-nodes/find-selected-default-node",
+            "default-nodes/find-stored-default-node" },
+  interests = {
+    EventInterest {
+      Constraint { "event.type", "=", "select-default-node" },
+    },
+  },
+  execute = function (event)
+    local source = event:get_source ()
+    local props = event:get_properties ()
+    local def_node_type = props ["default-node.type"]
+    local selected_node = event:get_data ("selected-node")
+
+    local om = source:call ("get-object-manager", "metadata")
+    local metadata = om:lookup { Constraint { "metadata.name", "=", "default" } }
+
+    if selected_node then
+      local key = "default." .. def_node_type
+
+      log:info ("set default node for " .. key .. " " .. selected_node)
+
+      metadata:set (0, key, "Spa:String:JSON",
+          Json.Object { ["name"] = selected_node }:to_string ())
+    else
+      metadata:set (0, "default." .. def_node_type, nil, nil)
+    end
+  end
+}:register ()