scripts: tidy-up linking related settings

* prefix all settings with just "linking."
* rename settings to make more sense
* fix the handling of the "follow" setting
* move the "move" handler to the rescan.lua script, as it's just a rescan hook

src/config/wireplumber.conf

@@ -512,10 +512,6 @@ wireplumber.components = [
     name = linking/rescan.lua, type = script/lua
     provides = hooks.linking.rescan
   }
-  {
-    name = linking/move-follow.lua, type = script/lua
-    provides = hooks.linking.move-follow
-  }
   {
     name = linking/find-defined-target.lua, type = script/lua
     provides = hooks.linking.target.find-defined
@@ -554,8 +550,7 @@ wireplumber.components = [
     requires = [ hooks.linking.rescan,
                  hooks.linking.target.prepare-link,
                  hooks.linking.target.link ]
-    wants = [ hooks.linking.move-follow,
-              hooks.linking.target.find-defined,
+    wants = [ hooks.linking.target.find-defined,
               hooks.linking.target.find-filter,
               hooks.linking.target.find-default,
               hooks.linking.target.find-best,

src/config/wireplumber.conf.d.examples/linking.conf

@@ -3,22 +3,13 @@
 wireplumber.settings = {
   ## Moves session items when metadata ``target.object`` changes. Also responds to
   ##`target.node` key. But `target.object` is the canonical key.
-  # linking.default.move = true
+  # linking.allow-moving-streams = true
 
   ## Moves session items to the default device when it has changed
-  # linking.default.follow = true
+  # linking.follow-default-target = true
 
   ## Whether to forward the ports format of filter stream nodes to their
   ## associated filter device nodes. This is needed for application to stream
   ## surround audio if echo-cancel is enabled.
-  # linking.default.filter-forward-format = false
-
-  ## Set to 'true' to disable channel splitting & merging on nodes and enable
-  ## passthrough of audio in the same format as the format of the device.
-  ## Note that this breaks JACK support; it is generally not recommended
-  # linking.default.audio-no-dsp = false
-
-  ## How much to lower the volume of lower priority streams when ducking
-  ## note that this is a linear volume modifier (not cubic as in pulseaudio)
-  # linking.default.duck-level = 0.3
+  # linking.filter-forward-format = false
 }

src/scripts/lib/linking-utils.lua

@@ -60,7 +60,7 @@ function putils.canPassthrough (si, si_target)
   return false
 end
 
-function putils.checkFollowDefault (si, si_target, has_node_defined_target)
+function putils.checkFollowDefault (si, si_target)
   -- If it got linked to the default target that is defined by node
   -- props but not metadata, start ignoring the node prop from now on.
   -- This is what Pulseaudio does.
@@ -68,15 +68,12 @@ function putils.checkFollowDefault (si, si_target, has_node_defined_target)
   -- Pulseaudio skips here filter streams (i->origin_sink and
   -- o->destination_source set in PA). Pipewire does not have a flag
   -- explicitly for this, but we can use presence of node.link-group.
-  if not has_node_defined_target then
-    return
-  end
   local si_props = si.properties
   local target_props = si_target.properties
   local reconnect = not cutils.parseBool (si_props ["node.dont-reconnect"])
   local is_filter = (si_props ["node.link-group"] ~= nil)
 
-  if follow and default_nodes ~= nil and reconnect and not is_filter then
+  if reconnect and not is_filter then
     local def_id = cutils.getDefaultNode (si_props,
       cutils.getTargetDirection (si_props))
 

src/scripts/lib/settings-linking.lua

@@ -9,11 +9,9 @@
 local settings_manager = require ("settings-manager")
 
 local defaults = {
-  ["move"] = true,
-  ["follow"] = true,
+  ["allow-moving-streams"] = true,
+  ["follow-default-target"] = true,
   ["filter-forward-format"] = false,
-  ["duck-level"] = 0.3,
 }
 
-return settings_manager.new ("linking.default.", defaults)
-
+return settings_manager.new ("linking.", defaults)

src/scripts/linking/find-defined-target.lua

@@ -34,7 +34,7 @@ SimpleEventHook {
     log:info (si, string.format ("handling item: %s (%s)",
         tostring (si_props ["node.name"]), tostring (si_props ["node.id"])))
 
-    local metadata = settings.move and cutils.get_default_metadata_object ()
+    local metadata = settings.allow_moving_streams and cutils.get_default_metadata_object ()
     local dont_fallback = cutils.parseBool (si_props ["target.dont-fallback"])
     local dont_move = cutils.parseBool (si_props ["target.dont-move"])
     local target_key

src/scripts/linking/move-follow.lua

@@ -1,38 +0,0 @@
--- WirePlumber
---
--- Copyright © 2022 Collabora Ltd.
---
--- SPDX-License-Identifier: MIT
---
--- Move & follow settings handlers. If the relevant settings are enabled,
--- install hooks that will schedule a rescan of the graph when needed
-
-log = Log.open_topic ("s-linking")
-settings = require ("settings-linking")
-handles = {}
-
-function handleMoveSetting (enable)
-  if (not handles.move_hook) and (enable == true) then
-    handles.move_hook = SimpleEventHook {
-      name = "linking/move",
-      interests = {
-        EventInterest {
-          Constraint { "event.type", "=", "metadata-changed" },
-          Constraint { "metadata.name", "=", "default" },
-          Constraint { "event.subject.key", "c", "target.node", "target.object" },
-        },
-      },
-      execute = function (event)
-        local source = event:get_source ()
-        source:call ("schedule-rescan", "linking")
-      end
-    }
-    handles.move_hook:register()
-  elseif (handles.move_hook) and (enable == false) then
-    handles.move_hook:remove ()
-    handles.move_hook = nil
-  end
-end
-
-settings:subscribe ("move", handleMoveSetting)
-handleMoveSetting (settings.move)

src/scripts/linking/prepare-link.lua

@@ -10,6 +10,7 @@
 
 putils = require ("linking-utils")
 cutils = require ("common-utils")
+settings = require ("settings-linking")
 log = Log.open_topic ("s-linking")
 
 SimpleEventHook {
@@ -36,9 +37,12 @@ SimpleEventHook {
     if si_flags.peer_id then
       if target and si_flags.peer_id == target.id then
         log:debug (si, "... already linked to proper target")
+
         -- Check this also here, in case in default targets changed
-        putils.checkFollowDefault (si, target,
-            si_flags.has_node_defined_target)
+        if settings.follow_default_target and si_flags.has_node_defined_target then
+          putils.checkFollowDefault (si, target)
+        end
+
         target = nil
         goto done
       end

src/scripts/linking/rescan.lua

@@ -13,7 +13,9 @@
 putils = require ("linking-utils")
 cutils = require ("common-utils")
 futils = require ("filter-utils")
+settings = require ("settings-linking")
 log = Log.open_topic ("s-linking")
+handles = {}
 
 function checkFilter (si, om, handle_nonstreams)
   -- always handle filters if handle_nonstreams is true, even if it is disabled
@@ -206,3 +208,29 @@ SimpleEventHook {
     source:call ("schedule-rescan", "linking")
   end
 }:register ()
+
+function handleMoveSetting (enable)
+  if (not handles.move_hook) and (enable == true) then
+    handles.move_hook = SimpleEventHook {
+      name = "linking/rescan-trigger-on-target-metadata-changed",
+      interests = {
+        EventInterest {
+          Constraint { "event.type", "=", "metadata-changed" },
+          Constraint { "metadata.name", "=", "default" },
+          Constraint { "event.subject.key", "c", "target.object", "target.node" },
+        },
+      },
+      execute = function (event)
+        local source = event:get_source ()
+        source:call ("schedule-rescan", "linking")
+      end
+    }
+    handles.move_hook:register()
+  elseif (handles.move_hook) and (enable == false) then
+    handles.move_hook:remove ()
+    handles.move_hook = nil
+  end
+end
+
+settings:subscribe ("allow-moving-streams", handleMoveSetting)
+handleMoveSetting (settings.allow_moving_streams)