IdleService: restore monitors when resuming from idle screen-off (fixes #2010)

Services/Compositor/CompositorService.qml

@@ -507,6 +507,15 @@ Singleton {
     }
   }
 
+  function turnOnMonitors() {
+    Logger.i("Compositor", "Turn on monitors requested");
+    if (backend && backend.turnOnMonitors) {
+      backend.turnOnMonitors();
+    } else {
+      Logger.w("Compositor", "No backend available for turnOnMonitors");
+    }
+  }
+
   function suspend() {
     Logger.i("Compositor", "Suspend requested");
     if (executeSessionAction("suspend"))

Services/Compositor/HyprlandService.qml

@@ -490,6 +490,14 @@ Item {
     }
   }
 
+  function turnOnMonitors() {
+    try {
+      Quickshell.execDetached(["hyprctl", "dispatch", "dpms", "on"]);
+    } catch (e) {
+      Logger.e("HyprlandService", "Failed to turn on monitors:", e);
+    }
+  }
+
   function logout() {
     try {
       Quickshell.execDetached(["hyprctl", "dispatch", "exit"]);

Services/Compositor/LabwcService.qml

@@ -276,6 +276,14 @@ Item {
     }
   }
 
+  function turnOnMonitors() {
+    try {
+      Quickshell.execDetached(["wlr-randr", "--on"]);
+    } catch (e) {
+      Logger.e("LabwcService", "Failed to turn on monitors:", e);
+    }
+  }
+
   function logout() {
     stopWorkspaceHelper();
     try {

Services/Compositor/MangoService.qml

@@ -678,6 +678,14 @@ Item {
     }
   }
 
+  function turnOnMonitors() {
+    try {
+      Quickshell.execDetached(["wlr-randr", "--on"]);
+    } catch (e) {
+      Logger.e("MangoService", "Failed to turn on monitors:", e);
+    }
+  }
+
   function logout() {
     Quickshell.execDetached(["mmsg", "-s", "-q"]);
   }

Services/Compositor/NiriService.qml

@@ -480,6 +480,14 @@ Item {
     }
   }
 
+  function turnOnMonitors() {
+    try {
+      Quickshell.execDetached(["niri", "msg", "action", "power-on-monitors"]);
+    } catch (e) {
+      Logger.e("NiriService", "Failed to turn on monitors:", e);
+    }
+  }
+
   function logout() {
     try {
       Quickshell.execDetached(["niri", "msg", "action", "quit", "--skip-confirmation"]);

Services/Compositor/SwayService.qml

@@ -561,6 +561,14 @@ Item {
     }
   }
 
+  function turnOnMonitors() {
+    try {
+      Quickshell.execDetached([msgCommand, "output", "*", "dpms", "on"]);
+    } catch (e) {
+      Logger.e("SwayService", "Failed to turn on monitors:", e);
+    }
+  }
+
   function logout() {
     try {
       Quickshell.execDetached([msgCommand, "exit"]);

Services/Power/IdleService.qml

@@ -42,6 +42,7 @@ Singleton {
   property var _heartbeatMonitor: null
   property var _customMonitors: ({})
   property real _suppressUntil: 0
+  property bool _screenOffActive: false
 
   // Signals for external listeners (plugins, modules)
   signal screenOffRequested
@@ -83,12 +84,23 @@ Singleton {
 
   // -------------------------------------------------------
   function cancelFade() {
-    if (fadePending === "")
+    if (fadePending === "") {
+      _restoreMonitors();
       return;
+    }
     Logger.i("IdleService", "Fade cancelled for:", fadePending);
     fadePending = "";
     graceTimer.stop();
     overlayCleanupTimer.stop();
+    _restoreMonitors();
+  }
+
+  function _restoreMonitors() {
+    if (!_screenOffActive)
+      return;
+    _screenOffActive = false;
+    Logger.i("IdleService", "Restoring monitors (DPMS on)");
+    CompositorService.turnOnMonitors();
   }
 
   function _onIdle(stage) {
@@ -106,6 +118,7 @@ Singleton {
     if (stage === "screenOff") {
       root._suppressUntil = Date.now() + (Settings.data.idle.screenOffTimeout * 1000);
       CompositorService.turnOffMonitors();
+      root._screenOffActive = true;
       root.screenOffRequested();
     } else if (stage === "lock") {
       if (PanelService.lockScreen && !PanelService.lockScreen.active) {