fix(Power Saver): check Gamescope input counter for mouse/keyboard inactivity

Author: ShadowApex

core/systems/power/power_saver.gd

@@ -7,6 +7,7 @@ class_name PowerSaver
 var display := load("res://core/global/display_manager.tres") as DisplayManager
 var settings := load("res://core/global/settings_manager.tres") as SettingsManager
 var power_manager := load("res://core/systems/power/power_manager.tres") as UPowerInstance
+var gamescope := load("res://core/systems/gamescope/gamescope.tres") as GamescopeInstance
 
 const MINUTE := 60
 
@@ -22,16 +23,19 @@ const MINUTE := 60
 
 @onready var dim_timer := $%DimTimer as Timer
 @onready var suspend_timer := $%SuspendTimer as Timer
+@onready var gamescope_timer := $%GamescopeCheckTimer as Timer
 
 var dimmed := false
 var prev_brightness := {}
 var supports_brightness := display.supports_brightness()
 var has_battery := false
 var display_device := power_manager.get_display_device()
+var gamescope_input_counters: Dictionary[int, int] = {}
 var logger := Log.get_logger("PowerSaver")
 
 
 func _ready() -> void:
+	gamescope_timer.timeout.connect(_on_gamescope_check_timeout)
 	if display_device:
 		has_battery = display_device.is_present
 
@@ -98,3 +102,50 @@ func _input(event: InputEvent) -> void:
 		dim_timer.start(dim_after_inactivity_mins * MINUTE)
 	if auto_suspend_enabled:
 		suspend_timer.start(suspend_after_inactivity_mins * MINUTE)
+
+
+## Called at a regular interval to check if gamescope input counters have changed.
+## Gamepad inputs will be routed to all running applications (including OpenGamepadUI)
+## which can be used to check for inactivity, but keyboard/mouse inputs will not.
+## To work around this, this method will check the input counter atom in gamescope
+## which will change whenever keyboard/mouse input is detected.
+func _on_gamescope_check_timeout() -> void:
+	# Loop through each xwayland instance to see if any have received mouse or
+	# keyboard inputs since the last check
+	var detected_input := false
+	for xwayland_type in [gamescope.XWAYLAND_TYPE_PRIMARY, gamescope.XWAYLAND_TYPE_OGUI]:
+		if not _has_gamescope_input_counter_changed(xwayland_type):
+			continue
+		detected_input = true
+		var xwayland := gamescope.get_xwayland(xwayland_type)
+		if not xwayland:
+			continue
+		self.gamescope_input_counters[xwayland_type] = xwayland.get_input_counter()
+
+	if not detected_input:
+		return
+
+	if dim_screen_enabled and supports_brightness:
+		dim_timer.start(dim_after_inactivity_mins * MINUTE)
+	if auto_suspend_enabled:
+		suspend_timer.start(suspend_after_inactivity_mins * MINUTE)
+
+
+## Returns true if input counter for the given gamescope type is different
+## than the one recorded in `self.gamescope_input_counters`
+func _has_gamescope_input_counter_changed(xwayland_type: int) -> bool:
+	var xwayland := gamescope.get_xwayland(xwayland_type)
+	if not xwayland:
+		return false
+	var last := _get_last_input_counter_for(xwayland_type)
+	var current := xwayland.get_input_counter()
+
+	return last != current
+
+
+## Returns the last set input counter for the given XWayland type.
+func _get_last_input_counter_for(xwayland_type: int) -> int:
+	var counter := 0
+	if xwayland_type in self.gamescope_input_counters:
+		counter = self.gamescope_input_counters[xwayland_type]
+	return counter

core/systems/power/power_saver.tscn

@@ -12,3 +12,7 @@ one_shot = true
 [node name="SuspendTimer" type="Timer" parent="."]
 unique_name_in_owner = true
 one_shot = true
+
+[node name="GamescopeCheckTimer" type="Timer" parent="."]
+unique_name_in_owner = true
+autostart = true

extensions/core/src/gamescope/x11_client.rs

@@ -232,6 +232,25 @@ impl GamescopeXWayland {
         }
     }
 
+    /// Returns the value of the Gamescope input counter. This is useful to detect
+    /// whether or not Gamescope has been receiving mouse or keyboard inputs.
+    #[func]
+    pub fn get_input_counter(&self) -> u32 {
+        let Ok(root_id) = self.xwayland.get_root_window_id() else {
+            return 0;
+        };
+        let result = self
+            .xwayland
+            .get_one_xprop(root_id, GamescopeAtom::InputCounter);
+        match result {
+            Ok(counter) => counter.unwrap_or_default(),
+            Err(e) => {
+                log::trace!("No input counter found: {e}");
+                0
+            }
+        }
+    }
+
     /// Returns the list of currently watched windows.
     #[func]
     pub fn get_watched_windows(&self) -> PackedInt64Array {