idle: implement screensaver interface

- Mainly used to create the idle inhibitor when an app requests
  screensaver inhibit

core/internal/server/freedesktop/constants.go

@@ -11,4 +11,9 @@ const (
 	dbusPortalSettingsInterface = "org.freedesktop.portal.Settings"
 
 	dbusPropsInterface = "org.freedesktop.DBus.Properties"
+
+	dbusScreensaverName      = "org.freedesktop.ScreenSaver"
+	dbusScreensaverPath      = "/ScreenSaver"
+	dbusScreensaverPath2     = "/org/freedesktop/ScreenSaver"
+	dbusScreensaverInterface = "org.freedesktop.ScreenSaver"
 )

core/internal/server/freedesktop/manager.go

@@ -22,8 +22,9 @@ func NewManager() (*Manager, error) {
 
 	m := &Manager{
 		state: &FreedeskState{
-			Accounts: AccountsState{},
-			Settings: SettingsState{},
+			Accounts:    AccountsState{},
+			Settings:    SettingsState{},
+			Screensaver: ScreensaverState{},
 		},
 		stateMutex:  sync.RWMutex{},
 		systemConn:  systemConn,
@@ -33,6 +34,7 @@ func NewManager() (*Manager, error) {
 
 	m.initializeAccounts()
 	m.initializeSettings()
+	m.initializeScreensaver()
 
 	return m, nil
 }

core/internal/server/freedesktop/screensaver.go

@@ -0,0 +1,250 @@
+package freedesktop
+
+import (
+	"path/filepath"
+	"strings"
+	"sync/atomic"
+	"time"
+
+	"github.com/AvengeMedia/DankMaterialShell/core/internal/log"
+	"github.com/godbus/dbus/v5"
+	"github.com/godbus/dbus/v5/introspect"
+)
+
+type screensaverHandler struct {
+	manager *Manager
+}
+
+func (m *Manager) initializeScreensaver() error {
+	if m.sessionConn == nil {
+		m.stateMutex.Lock()
+		m.state.Screensaver.Available = false
+		m.stateMutex.Unlock()
+		return nil
+	}
+
+	reply, err := m.sessionConn.RequestName(dbusScreensaverName, dbus.NameFlagDoNotQueue)
+	if err != nil {
+		log.Warnf("Failed to request screensaver name: %v", err)
+		m.stateMutex.Lock()
+		m.state.Screensaver.Available = false
+		m.stateMutex.Unlock()
+		return nil
+	}
+
+	if reply != dbus.RequestNameReplyPrimaryOwner {
+		log.Warnf("Screensaver name already owned by another process")
+		m.stateMutex.Lock()
+		m.state.Screensaver.Available = false
+		m.stateMutex.Unlock()
+		return nil
+	}
+
+	handler := &screensaverHandler{manager: m}
+
+	if err := m.sessionConn.Export(handler, dbusScreensaverPath, dbusScreensaverInterface); err != nil {
+		log.Warnf("Failed to export screensaver on %s: %v", dbusScreensaverPath, err)
+		return nil
+	}
+
+	if err := m.sessionConn.Export(handler, dbusScreensaverPath2, dbusScreensaverInterface); err != nil {
+		log.Warnf("Failed to export screensaver on %s: %v", dbusScreensaverPath2, err)
+		return nil
+	}
+
+	introNode := &introspect.Node{
+		Name: dbusScreensaverPath,
+		Interfaces: []introspect.Interface{
+			introspect.IntrospectData,
+			{Name: dbusScreensaverInterface},
+		},
+	}
+	if err := m.sessionConn.Export(introspect.NewIntrospectable(introNode), dbusScreensaverPath, "org.freedesktop.DBus.Introspectable"); err != nil {
+		log.Warnf("Failed to export introspectable on %s: %v", dbusScreensaverPath, err)
+	}
+
+	introNode2 := &introspect.Node{
+		Name: dbusScreensaverPath2,
+		Interfaces: []introspect.Interface{
+			introspect.IntrospectData,
+			{Name: dbusScreensaverInterface},
+		},
+	}
+	if err := m.sessionConn.Export(introspect.NewIntrospectable(introNode2), dbusScreensaverPath2, "org.freedesktop.DBus.Introspectable"); err != nil {
+		log.Warnf("Failed to export introspectable on %s: %v", dbusScreensaverPath2, err)
+	}
+
+	go m.watchPeerDisconnects()
+
+	m.stateMutex.Lock()
+	m.state.Screensaver.Available = true
+	m.state.Screensaver.Inhibited = false
+	m.state.Screensaver.Inhibitors = []ScreensaverInhibitor{}
+	m.stateMutex.Unlock()
+
+	log.Info("Screensaver inhibit listener initialized")
+	return nil
+}
+
+func (h *screensaverHandler) Inhibit(sender dbus.Sender, appName, reason string) (uint32, *dbus.Error) {
+	if appName == "" {
+		return 0, dbus.NewError("org.freedesktop.DBus.Error.InvalidArgs", []any{"application name required"})
+	}
+
+	if reason == "" {
+		return 0, dbus.NewError("org.freedesktop.DBus.Error.InvalidArgs", []any{"reason required"})
+	}
+
+	if strings.Contains(strings.ToLower(reason), "audio") && !strings.Contains(strings.ToLower(reason), "video") {
+		log.Debugf("Ignoring audio-only inhibit from %s: %s", appName, reason)
+		return 0, nil
+	}
+
+	if idx := strings.LastIndex(appName, "/"); idx != -1 && idx < len(appName)-1 {
+		appName = appName[idx+1:]
+	}
+	appName = filepath.Base(appName)
+
+	cookie := atomic.AddUint32(&h.manager.screensaverCookieCounter, 1)
+
+	inhibitor := ScreensaverInhibitor{
+		Cookie:    cookie,
+		AppName:   appName,
+		Reason:    reason,
+		Peer:      string(sender),
+		StartTime: time.Now().Unix(),
+	}
+
+	h.manager.stateMutex.Lock()
+	h.manager.state.Screensaver.Inhibitors = append(h.manager.state.Screensaver.Inhibitors, inhibitor)
+	h.manager.state.Screensaver.Inhibited = len(h.manager.state.Screensaver.Inhibitors) > 0
+	h.manager.stateMutex.Unlock()
+
+	log.Infof("Screensaver inhibited by %s (%s): %s -> cookie %08X", appName, sender, reason, cookie)
+
+	h.manager.NotifyScreensaverSubscribers()
+
+	return cookie, nil
+}
+
+func (h *screensaverHandler) UnInhibit(sender dbus.Sender, cookie uint32) *dbus.Error {
+	h.manager.stateMutex.Lock()
+	defer h.manager.stateMutex.Unlock()
+
+	found := false
+	inhibitors := h.manager.state.Screensaver.Inhibitors
+	for i, inh := range inhibitors {
+		if inh.Cookie != cookie {
+			continue
+		}
+		log.Infof("Screensaver uninhibited by %s (%s) cookie %08X", inh.AppName, sender, cookie)
+		h.manager.state.Screensaver.Inhibitors = append(inhibitors[:i], inhibitors[i+1:]...)
+		found = true
+		break
+	}
+
+	if !found {
+		log.Debugf("UnInhibit: no match for cookie %08X", cookie)
+		return nil
+	}
+
+	h.manager.state.Screensaver.Inhibited = len(h.manager.state.Screensaver.Inhibitors) > 0
+
+	go h.manager.NotifyScreensaverSubscribers()
+
+	return nil
+}
+
+func (m *Manager) watchPeerDisconnects() {
+	if m.sessionConn == nil {
+		return
+	}
+
+	if err := m.sessionConn.AddMatchSignal(
+		dbus.WithMatchInterface("org.freedesktop.DBus"),
+		dbus.WithMatchMember("NameOwnerChanged"),
+	); err != nil {
+		log.Warnf("Failed to watch peer disconnects: %v", err)
+		return
+	}
+
+	signals := make(chan *dbus.Signal, 64)
+	m.sessionConn.Signal(signals)
+
+	for sig := range signals {
+		if sig.Name != "org.freedesktop.DBus.NameOwnerChanged" {
+			continue
+		}
+		if len(sig.Body) < 3 {
+			continue
+		}
+
+		name, ok1 := sig.Body[0].(string)
+		newOwner, ok2 := sig.Body[2].(string)
+		if !ok1 || !ok2 {
+			continue
+		}
+		if newOwner != "" {
+			continue
+		}
+
+		m.removeInhibitorsByPeer(name)
+	}
+}
+
+func (m *Manager) removeInhibitorsByPeer(peer string) {
+	m.stateMutex.Lock()
+	defer m.stateMutex.Unlock()
+
+	var remaining []ScreensaverInhibitor
+	var removed []ScreensaverInhibitor
+	for _, inh := range m.state.Screensaver.Inhibitors {
+		if inh.Peer == peer {
+			removed = append(removed, inh)
+			continue
+		}
+		remaining = append(remaining, inh)
+	}
+
+	if len(removed) == 0 {
+		return
+	}
+
+	for _, inh := range removed {
+		log.Infof("Screensaver: peer %s died, removing inhibitor from %s (cookie %08X)", peer, inh.AppName, inh.Cookie)
+	}
+
+	m.state.Screensaver.Inhibitors = remaining
+	m.state.Screensaver.Inhibited = len(remaining) > 0
+
+	go m.NotifyScreensaverSubscribers()
+}
+
+func (m *Manager) GetScreensaverState() ScreensaverState {
+	m.stateMutex.RLock()
+	defer m.stateMutex.RUnlock()
+	return m.state.Screensaver
+}
+
+func (m *Manager) SubscribeScreensaver(id string) chan ScreensaverState {
+	ch := make(chan ScreensaverState, 64)
+	m.screensaverSubscribers.Store(id, ch)
+	return ch
+}
+
+func (m *Manager) UnsubscribeScreensaver(id string) {
+	if val, ok := m.screensaverSubscribers.LoadAndDelete(id); ok {
+		close(val)
+	}
+}
+
+func (m *Manager) NotifyScreensaverSubscribers() {
+	state := m.GetScreensaverState()
+	m.screensaverSubscribers.Range(func(key string, ch chan ScreensaverState) bool {
+		select {
+		case ch <- state:
+		default:
+		}
+		return true
+	})
+}

core/internal/server/freedesktop/types.go

@@ -29,18 +29,35 @@ type SettingsState struct {
 	ColorScheme uint32 `json:"colorScheme"`
 }
 
+type ScreensaverInhibitor struct {
+	Cookie    uint32 `json:"cookie"`
+	AppName   string `json:"appName"`
+	Reason    string `json:"reason"`
+	Peer      string `json:"peer"`
+	StartTime int64  `json:"startTime"`
+}
+
+type ScreensaverState struct {
+	Available  bool                   `json:"available"`
+	Inhibited  bool                   `json:"inhibited"`
+	Inhibitors []ScreensaverInhibitor `json:"inhibitors"`
+}
+
 type FreedeskState struct {
-	Accounts AccountsState `json:"accounts"`
-	Settings SettingsState `json:"settings"`
+	Accounts    AccountsState    `json:"accounts"`
+	Settings    SettingsState    `json:"settings"`
+	Screensaver ScreensaverState `json:"screensaver"`
 }
 
 type Manager struct {
-	state       *FreedeskState
-	stateMutex  sync.RWMutex
-	systemConn  *dbus.Conn
-	sessionConn *dbus.Conn
-	accountsObj dbus.BusObject
-	settingsObj dbus.BusObject
-	currentUID  uint64
-	subscribers syncmap.Map[string, chan FreedeskState]
+	state                    *FreedeskState
+	stateMutex               sync.RWMutex
+	systemConn               *dbus.Conn
+	sessionConn              *dbus.Conn
+	accountsObj              dbus.BusObject
+	settingsObj              dbus.BusObject
+	currentUID               uint64
+	subscribers              syncmap.Map[string, chan FreedeskState]
+	screensaverSubscribers   syncmap.Map[string, chan ScreensaverState]
+	screensaverCookieCounter uint32
 }

core/internal/server/server.go

@@ -33,7 +33,7 @@ import (
 	"github.com/AvengeMedia/DankMaterialShell/core/pkg/syncmap"
 )
 
-const APIVersion = 23
+const APIVersion = 24
 
 var CLIVersion = "dev"
 
@@ -702,6 +702,38 @@ func handleSubscribe(conn net.Conn, req models.Request) {
 		}()
 	}
 
+	if shouldSubscribe("freedesktop.screensaver") && freedesktopManager != nil {
+		wg.Add(1)
+		screensaverChan := freedesktopManager.SubscribeScreensaver(clientID + "-screensaver")
+		go func() {
+			defer wg.Done()
+			defer freedesktopManager.UnsubscribeScreensaver(clientID + "-screensaver")
+
+			initialState := freedesktopManager.GetScreensaverState()
+			select {
+			case eventChan <- ServiceEvent{Service: "freedesktop.screensaver", Data: initialState}:
+			case <-stopChan:
+				return
+			}
+
+			for {
+				select {
+				case state, ok := <-screensaverChan:
+					if !ok {
+						return
+					}
+					select {
+					case eventChan <- ServiceEvent{Service: "freedesktop.screensaver", Data: state}:
+					case <-stopChan:
+						return
+					}
+				case <-stopChan:
+					return
+				}
+			}
+		}()
+	}
+
 	if shouldSubscribe("gamma") && waylandManager != nil {
 		wg.Add(1)
 		waylandChan := waylandManager.Subscribe(clientID + "-gamma")