Add KineticWE Layouts plugin (#252)

kineticwe-layouts/service.luau

@@ -0,0 +1,149 @@
+--!nonstrict
+-- KineticWE layout bridge service.
+--
+-- Watches the compositor's /Tiling DBus interface (plus virtual-desktop
+-- switches, which implicitly change the "current" layout) and publishes a
+-- single plain-data table on noctalia.state key "layout" for the widget and
+-- panel entries:
+--
+--   { ok = true,  current = "Columns", enabled = { "MasterStack", ... },
+--     qdbus = "qdbus-qt6" }
+--   { ok = false, reason = "missing-qdbus" | "missing-monitor" | "missing-interface" }
+--
+-- "current" is the kind string for the active output's current desktop, or
+-- "" when native tiling is disabled.
+
+local KINDS = {
+  MasterStack = true,
+  Stacked = true,
+  CenterTile = true,
+  Monocle = true,
+  AutoGrid = true,
+  Columns = true,
+}
+
+local QDBUS = nil
+local refreshing = false
+local refreshQueued = false
+local lastPublished = nil
+
+local function findQdbus()
+  for _, name in ipairs({ "qdbus-qt6", "qdbus6", "qdbus" }) do
+    if noctalia.commandExists(name) then
+      return name
+    end
+  end
+  return nil
+end
+
+local function publish(state)
+  noctalia.state.set("layout", state)
+  lastPublished = state
+end
+
+-- qdbus prints a QStringList reply as { "MasterStack", "Stacked", ... }.
+-- Some builds print bare words instead, so fall back to word splitting and
+-- keep only tokens that are real layout kinds.
+local function parseKindList(out)
+  local items, seen = {}, {}
+  local function add(s)
+    if KINDS[s] and not seen[s] then
+      seen[s] = true
+      table.insert(items, s)
+    end
+  end
+  for s in string.gmatch(out, '"([^"]+)"') do
+    add(s)
+  end
+  if #items == 0 then
+    for s in string.gmatch(out, "[%a]+") do
+      add(s)
+    end
+  end
+  return items
+end
+
+local function finishRefresh()
+  refreshing = false
+  if refreshQueued then
+    refreshQueued = false
+    refresh()
+  end
+end
+
+function refresh()
+  if refreshing then
+    -- Coalesce signal bursts (e.g. one per desktop on a reconcile pass)
+    -- into a single follow-up query.
+    refreshQueued = true
+    return
+  end
+  refreshing = true
+
+  if QDBUS == nil then
+    QDBUS = findQdbus()
+    if QDBUS == nil then
+      publish({ ok = false, reason = "missing-qdbus" })
+      finishRefresh()
+      return
+    end
+  end
+
+  noctalia.runAsync(QDBUS .. " org.kde.KWin /Tiling org.kde.KWin.Tiling.currentLayout", function(res)
+    if res.exitCode ~= 0 then
+      publish({ ok = false, reason = "missing-interface" })
+      finishRefresh()
+      return
+    end
+    local current = noctalia.string.trim(res.stdout)
+    noctalia.runAsync(QDBUS .. " org.kde.KWin /Tiling org.kde.KWin.Tiling.enabledLayouts", function(res2)
+      if res2.exitCode ~= 0 then
+        publish({ ok = false, reason = "missing-interface" })
+        finishRefresh()
+        return
+      end
+      local enabled = parseKindList(res2.stdout)
+      local unchanged = lastPublished
+        and lastPublished.ok
+        and lastPublished.current == current
+        and table.concat(lastPublished.enabled, ",") == table.concat(enabled, ",")
+      if not unchanged then
+        publish({ ok = true, current = current, enabled = enabled, qdbus = QDBUS })
+      end
+      finishRefresh()
+    end)
+  end)
+end
+
+local function onMonitorLine(line)
+  -- Any of: member=layoutChanged, member=enabledLayoutsChanged,
+  -- member=currentChanged (desktop switch). Re-query rather than parse
+  -- arguments: it is cheap and always yields a consistent snapshot.
+  if string.find(line, "member=") then
+    refresh()
+  end
+end
+
+local function startMonitor()
+  if not noctalia.commandExists("dbus-monitor") then
+    noctalia.log("dbus-monitor not found; falling back to polling only")
+    return
+  end
+  noctalia.runStream(
+    "dbus-monitor --session"
+      .. " \"type='signal',interface='org.kde.KWin.Tiling'\""
+      .. " \"type='signal',interface='org.kde.KWin.VirtualDesktopManager',member='currentChanged'\"",
+    onMonitorLine
+  )
+end
+
+-- Startup: query immediately, then keep a slow poll as a self-healing net
+-- (recovers when the monitor dies or the compositor gains /Tiling after a
+-- rebuild). Signal-driven refreshes make updates feel instant.
+refresh()
+startMonitor()
+noctalia.setUpdateInterval(5000)
+
+function update()
+  refresh()
+end