Update

pipewire/.config/wireplumber/scripts/linking/find-default-target.lua

@@ -0,0 +1,58 @@
+-- WirePlumber
+--
+-- Copyright © 2022 Collabora Ltd.
+--
+-- SPDX-License-Identifier: MIT
+--
+-- Check if default nodes can be picked up as target node.
+
+lutils = require ("linking-utils")
+log = Log.open_topic ("s-linking")
+
+SimpleEventHook {
+  name = "linking/find-default-target",
+  after = { "linking/find-defined-target",
+            "linking/find-filter-target",
+            "linking/find-media-role-target" },
+  before = "linking/prepare-link",
+  interests = {
+    EventInterest {
+      Constraint { "event.type", "=", "select-target" },
+    },
+  },
+  execute = function (event)
+    local source, om, si, si_props, si_flags, target =
+        lutils:unwrap_select_target_event (event)
+
+    -- bypass the hook if the target is already picked up
+    if target then
+      return
+    end
+
+    local target_picked = false
+
+    log:info (si, string.format ("handling item: %s (%s)",
+        tostring (si_props ["node.name"]), tostring (si_props ["node.id"])))
+
+    target = lutils.findDefaultLinkable (si)
+
+    local can_passthrough, passthrough_compatible
+    if target then
+      passthrough_compatible, can_passthrough =
+      lutils.checkPassthroughCompatibility (si, target)
+      if lutils.canLink (si_props, target) and passthrough_compatible then
+        target_picked = true;
+      end
+    end
+
+    if target_picked then
+      log:info (si,
+        string.format ("... default target picked: %s (%s), can_passthrough:%s",
+          tostring (target.properties ["node.name"]),
+          tostring (target.properties ["node.id"]),
+          tostring (can_passthrough)))
+      si_flags.can_passthrough = can_passthrough
+      event:set_data ("target", target)
+    end
+  end
+}:register ()