Add wakelock button for later gamepad testing.

Currently nonfunctional on desktop platforms due to engine limitation.

main.tscn

@@ -245,3 +245,14 @@ text = "Vsync"
 __meta__ = {
 "_edit_use_anchors_": false
 }
+
+[node name="WakelockButton" type="CheckButton" parent="InputHandler"]
+margin_left = 4.0
+margin_top = 240.0
+margin_right = 121.0
+margin_bottom = 130.0
+pressed = true
+text = "Wakelock"
+__meta__ = {
+"_edit_use_anchors_": false
+}

scripts/InputHandler.gd

@@ -36,12 +36,16 @@ func _ready():
 #	connect("button_pressed", self, "print_pressed")
 	$"/root".connect("size_changed", self, "resize")
 	$VsyncButton.connect("toggled", self, "update_vsync")
+	$WakelockButton.connect("toggled", self, "update_wakelock")
 	$FilterSlider.connect("value_changed", self, "update_filter")
 	resize()
 
 func update_vsync(setting: bool):
 	OS.vsync_enabled = setting
 
+func update_wakelock(setting: bool):
+	OS.keep_screen_on = setting  # This is waiting on godotengine/godot#35536 to be merged to do anything in Linux :(
+
 func update_filter(alpha: float):
 	GameTheme.screen_filter_min_alpha = alpha